Luminous Landscape Forum

Equipment & Techniques => Cameras, Lenses and Shooting gear => Topic started by: ErikKaffehr on March 12, 2010, 12:58:39 am

Title: Interesting article on sample variations
Post by: ErikKaffehr on March 12, 2010, 12:58:39 am
Hi,

Everyone buying lenses should read this: http://www.lensrentals.com/news/2010.03.06...and-other-facts (http://www.lensrentals.com/news/2010.03.06/this-lens-is-soft-and-other-facts)

If you buy a lens try to test it, return to store if it's underperforming.

I had a couple of obvious lemons. The second I found out to be bad on second day of shooting and returned to the shop for prompt replacement. The other I spent to warrant repair, but they said it was within specifications and I should check the camera. I'm pretty sure that the repair shop was wrong, but I got a better lens anyway. 400 USD in the drain.


Best regards
Erik
Title: Interesting article on sample variations
Post by: Rob C on March 12, 2010, 04:48:00 am
Erik

Your thread shows the problem for what it is: unacceptable.

There is something far wrong with a system that permits manufacturers to put out material that is sub- their own standards; despite the fact that some people here seem able to return lenses time after time for replacement, I can tell you that trying to do that in most places that I have experienced would be impossible. When my 24-70 turned out to suck, the only way I got my money back was by exchanging it for another, slightly more expensive item, and I only managed this on the sympathy card: I pointed out that the dealer's catalogue did not state that the G lens would be inoperable with my F3, which I had also bought years ago from the same source ( the dealer knows I run it alongside the digi ones since he would no longer accept it as trade-in) and maybe the grey hair helped a bit too...

Anyway, all that toing and froing can't be without its financial (and reputational) costs to all the providers; surely they should just step up the factory inspections to where they used to be some decades ago? I have bought lenses over many many years and only in the last few have I ever come across or even heard of substandard Nikkors. To me, that's an avoidable disgrace to a fine reputation. Nikon, please take note!

Rob C

EDIT: the fact that film didn't lie as flat as digital is not the entire point. If it were such a factor against sharpness, then can anyone explain why I can get such crisp scanned prints from my Kodachromes?
Title: Interesting article on sample variations
Post by: stever on March 12, 2010, 11:29:38 am
i found this article extremely interesting, in many ways consistent with my experience, and i agree with Roger's conclusion that Canon and Nikon are getting near the resolution limit for FF SLRs  without changes in manufacturing and quality control and perhaps design (Canon may have already surpassed the limit on crop-frame). i don't believe that the quality of the best lenses (Leica and Zeiss) have increased substantially over the last 30 years (Leica experts correct me if i'm wrong on this) - there are some exceptions like the Nikon 12-24 and Canon 17 and 24 TS which also reflect the cost of producing high quality lenses.

i should not have been surprised that the more obvious lens problems are batch related rather than statistical - if processes are under control, statistical variation should be relatively small.  my Canon 300 f4 and original 100-400 both seemed to be okay in the bad old days of film, but showed serious issues on the 20D and unacceptable on FF cameras - for about $250 each Canon Service dramatically improved the quality of these long out of warranty lenses to be quite satisfactory with a 5D2.

the comment on the 50 f1.4 was particularly interesting as i had just received mine back from service -- VERY soft on the right had edge wider than f5.6.  it came back much improved - but not symetrical - at f4 and f2.8 with repair comments that did not appear to relate to the problem.  i should add that at f5.6 to diffraction this lens has superb resolution - a real bargain if you don't expect it to perform at large apertures.

fortunately buying multiple copies of lenses and testing them is not an issue in the US and i've resigned myself to doing so and find Imatest SFRPlus to be a worthwhile investment for quantitatively evaluating lenses across the entire field -- unfortunately the numbers are probably not much use on an absolute basis so there's a significant time investment cross checking lenses and camera bodies to develop realistic expectations

the lensrentals.com site is generally informative and Roger's annual report on lens reliability very much worth reading as well.  my experience renting their lenses has been excellent
Title: Interesting article on sample variations
Post by: ErikKaffehr on March 12, 2010, 12:42:12 pm
Hi,

I essentially agree.

Regarding returning bad lenses I guess dealers may be different. Mine has been very good. I use just two dealers in Sweden so they know who I am and that I'm serious.

Best regards
Erik


Quote from: Rob C
Erik

Your thread shows the problem for what it is: unacceptable.

There is something far wrong with a system that permits manufacturers to put out material that is sub- their own standards; despite the fact that some people here seem able to return lenses time after time for replacement, I can tell you that trying to do that in most places that I have experienced would be impossible. When my 24-70 turned out to suck, the only way I got my money back was by exchanging it for another, slightly more expensive item, and I only managed this on the sympathy card: I pointed out that the dealer's catalogue did not state that the G lens would be inoperable with my F3, which I had also bought years ago from the same source ( the dealer knows I run it alongside the digi ones since he would no longer accept it as trade-in) and maybe the grey hair helped a bit too...

Anyway, all that toing and froing can't be without its financial (and reputational) costs to all the providers; surely they should just step up the factory inspections to where they used to be some decades ago? I have bought lenses over many many years and only in the last few have I ever come across or even heard of substandard Nikkors. To me, that's an avoidable disgrace to a fine reputation. Nikon, please take note!

Rob C

EDIT: the fact that film didn't lie as flat as digital is not the entire point. If it were such a factor against sharpness, then can anyone explain why I can get such crisp scanned prints from my Kodachromes?
Title: Interesting article on sample variations
Post by: Jeremy Payne on March 12, 2010, 12:47:43 pm
Quote from: Rob C
Erik

Your thread shows the problem for what it is: unacceptable.

There is something far wrong with a system that permits manufacturers to put out material that is sub- their own standards

Markets aren't perfect ... but in this kind of situation, the market is the best solution to the problem, IMO.

I also don't agree that manufacturing has gotten "worse" since the "good old days".
Title: Interesting article on sample variations
Post by: fredjeang on March 12, 2010, 01:13:23 pm
Quote from: Jeremy Payne
Markets aren't perfect ... but in this kind of situation, the market is the best solution to the problem, IMO.

I also don't agree that manufacturing has gotten "worse" since the "good old days".
Well I tend to agree with both Jeremy and the other posts.
I do not think that the industry has gotten worse in terms of built quality. And this is probably true in many other industries. I remember the old Renault and if you compare to the nowdays generations, what we have now is far better built and finished.
Now, there are problems, some of them half-hidden. The tolerance should be higher now than in the "good old days", but many problems come when an increase demand force a brand to open fast others chains, generaly delocalized and in a very short time in order to supply the demand and prices pressure.
That is where most of the failure happen. They accept that many unities will be returned and they know it, it's part of the game. They have to sell, no matter the problems with customers. They have to sell, point.
Also, the products now are made in such a way, and it is not a mistake from companies, that their average life-time has to be short for obvious reasons.
This happen in consumer products, not in some very high-end specific ones. So there are various combinations that have to be considered.
Now, when I look and use my old pentaxes primes, I'm amazed how just perfect and smooth these mecanisms are still today...

Cheers,

Fred.
Title: Interesting article on sample variations
Post by: ErikKaffehr on March 12, 2010, 02:25:10 pm
Hi,

Both the article and the references indicate that products that are clearly below acceptable standards do reach the market and also that the problems seem to be systematic, certain batches are bad.

Less testing was done in the good old days, so we cannot say for sure, but I actually guess that we have to many issues today. Equipment today is very demanding.

An interesting issue is the 100-400/4,5-5,6 L USM IS lens which does well in tests but seems to have quite a few issues. Both Michael Reichmann and Andy Biggs indicated some issues. The lens may just be a bit to sensitive to wear.

Best regards
Erik


Quote from: Jeremy Payne
Markets aren't perfect ... but in this kind of situation, the market is the best solution to the problem, IMO.

I also don't agree that manufacturing has gotten "worse" since the "good old days".
Title: Interesting article on sample variations
Post by: fredjeang on March 12, 2010, 02:40:30 pm
Quote from: ErikKaffehr
Hi,

Both the article and the references indicate that products that are clearly below acceptable standards do reach the market and also that the problems seem to be systematic, certain batches are bad.

Less testing was done in the good old days, so we cannot say for sure, but I actually guess that we have to many issues today. Equipment today is very demanding.

An interesting issue is the 100-400/4,5-5,6 L USM IS lens which does well in tests but seems to have quite a few issues. Both Michael Reichmann and Andy Biggs indicated some issues. The lens may just be a bit to sensitive to wear.

Best regards
Erik
...fast and maximum profits, short term politics, cheap unskilled labours, marketing lies, consumers spoiled etc...
Look what just happened to the world economy...
we are all in a nice friendly world.

Fred.
Title: Interesting article on sample variations
Post by: vandevanterSH on March 12, 2010, 02:49:09 pm
Interesting article, especially since the author has the opportunity to examine a lot of "product".

"The “silent upgrade” may simply be that a subcontractor of a part was simply replaced by a different subcontractor that made a better part. Recently, for another example, Nikon’s 70-200 f2.8 VR II lens has been noted to have small metal sparkles (shavings? flakes?) which Nikon states are “air holes remaining in the metal portion of the barrel in the process of component production”.

It is interesting that the six copies of this lens that I have examined, they all have the "pitted" light baffle and metallic sparkles.  The interesting thing is that they were are different in "severity".  Nikon has address the "pitting" issue by saying it was basically caused buy inconsistencies in the casting process (makes sense) but I don't think that they have ever explained the metallic sparkles.  In their response they said they were not caused by the "pitted" metal (pretty obvious since the problems are in different parts of the lens) and that image quality isn't affected (also true, probably).  The conclusion was that since image quality wasn't affected, the lens meets Nikon standards.

I think that "meets standards...move on folks, nothing to see here, etc" is unfortunate position for Nikon to take but seems to be the big business standard.   At least with Nikon, unlike denial of problems with Cars, Drugs, food, etc....no death or injury will result.

Steve
Title: Interesting article on sample variations
Post by: JohnKoerner on March 13, 2010, 12:05:05 pm
Well, this article may seem to be "revealing," but in truth it is really just common sense. While it is easy to imagine everything made being "exactly the same," in truth nothing ever is. As Heraclitus once said, "It is impossible to step twice into the same river."

Have you ever built something? Have you ever built another of the same thing? The two results are never quite the same, in every detail, are they?

Consider this same truth as it applies to automobiles. How many auto companies (most recently Toyota) have "recalled" their products (and spent billions of dollars doing so), simply because they tried to cut corners somewhere? With automobiles, plenty never do get recalled, but when they are recalled it is ONLY because human lives are at stake and the potential for catastrophic, company-killing lawsuits are possible. With cameras, even though the principle is the same (as far as the attempt to cut corners and save money is concerned), but how a product blunder is handled is a whole different deal, because the potential for damage isn't as great. Hence the "silent upgrade" in future renditions, whilst the company will just deal with "the complaints" on the previous renditions, in a case-by-case basis, that didn't turn out so well.

As an interesting addendum, how many of you, as you read this article, harkened back to the story of "The Canon 5D Mk II and Antarctica" post made awhile back, where many of the photographers experienced a surprising "product failure" of their 5D Mk IIs ... but several did not? I would be willing to bet a million dollars to a penny that this same "product variation" was going on there too, where a certain run of the 5DMkII was simply inferior to the rest.

So, what is a person to do? Really there is nothing you can do, besides test your products when you get them, as has already been mentioned. I think this is one of the most valuable features of this forum and forums like this, which is a place for consumers to go to and share their experiences. To this end, I believe folks were already comparing serial numbers on the "Antarctica" thread, which empowers the consumer with the ability to "know where they're at" on a much broader scale than ever would be possible only knowing their own situation.

Yet still, by and large, I don't think there is a whole lot to worry about. A simple reality check will remind us that it will never be a perfect world, and some offerings of any company will simply suck. And some products will simply have "bad batches." Is this so-called revelation anything we don't already know? I think, in the end, most of the offerings produced by any (long-term successful) company will be good, and most people will be quite happy with their purchases.

Jack




.
Title: Interesting article on sample variations
Post by: Jeremy Payne on March 13, 2010, 02:41:55 pm
Quote from: ErikKaffehr
Both the article and the references indicate that products that are clearly below acceptable standards do reach the market and also that the problems seem to be systematic, certain batches are bad

I think you misunderstood me ... perhaps ...

Of course they reach the market, but if the current manufacturers are sloppy beyond what is reasonable or commercially acceptable, they will open the door to competition and new entrants.

I'm by no means a market purist, but in THIS kind of situation there is nothing that will resolve the issue like competition and transparency.

Call them out - by all means ... but when I hear people calling for a new "system" to enforce manufacturing standards like that, the hairs on the back of my neck stand up.
Title: Interesting article on sample variations
Post by: fredjeang on March 13, 2010, 03:22:08 pm
Quote from: Jeremy Payne
I think you misunderstood me ... perhaps ...

Of course they reach the market, but if the current manufacturers are sloppy beyond what is reasonable or commercially acceptable, they will open the door to competition and new entrants.

I'm by no means a market purist, but in THIS kind of situation there is nothing that will resolve the issue like competition and transparency.

Call them out - by all means ... but when I hear people calling for a new "system" to enforce manufacturing standards like that, the hairs on the back of my neck stand up.
I agree completely Jeremy.
The market will simply regulate by himself with the competition pressure ( if your products failed there are other brands ), simply when the information start to be too visible. In that sense, there is no need for a new system to reenforce manufacturing tolerance, just with the communication tools that are available and current consumer organisms, when the information is spread out then the industry will start to rectify by itself IMO.

Fred.
Title: Interesting article on sample variations
Post by: telyt on March 13, 2010, 06:50:54 pm
Quote from: JohnKoerner
Consider this same truth as it applies to automobiles. How many auto companies (most recently Toyota) have "recalled" their products (and spent billions of dollars doing so), simply because they tried to cut corners somewhere? ... So, what is a person to do?

We could stop evaluating equipment on a features per dollar basis.  Lots of features make impressive spec sheets, but it's only after the purchaser used the tool for a while the usefulness and appropriateness of the feature become apparent.  As long as camera makers see us tripping over each other to buy the next, cheaper, feature-loaded camera they'll keep cutting corners.
Title: Interesting article on sample variations
Post by: Ray on March 14, 2010, 01:08:24 am
C'mon guys! You know the solution to this problem. It's one I've been advocating for years.

We have MTF procedures. Photodo used to specialise in this, but perhaps they realised that their results were not reliable because of too many QC variations in the manufacturing process.

Each lens after manufacture needs to be tested by an independent company, preferably in some sort of relationship with the manufacturer, in order to provide reliable and detailed MTF specifications for each lens packaged for sale.

The lens would ship with a complete set of MTF charts and an imatest-type test for lens flare (veiling flare).

Of course such testing will add to the cost of the lens. (You want something for free!!)

Lenses of the same model would be graded according to quality, say A, B, C, D, E.

The cost of an A grade Canon 100-400 zoom might be double the cost of an E grade Canon 100-400 zoom, and 50% more than the current cost of an ad hoc, take-your-chances lens. The choice is yours.

Such a procedure would also provide a feed-back mechanism to manufacturers regarding price and appreciation of quality.
Title: Interesting article on sample variations
Post by: Rob C on March 14, 2010, 06:04:45 am
Ray, whilst I am not happy at the thought of paying more than I have to for anything, I have to agree that some form of qualification might help. However, how on Earth would you police it? How do you show that your A quality lens is inferior (as it sometimes still might turn out to be) to the B quality version, and get your refund?

I would rather bite the bullet and pay more on the understanding that any lens I bought from Nikon was going to be top-grade and reliable - a staggered array of standards might just become a further cop-out for the makers, though I do remember that Nikon played with that idea with its E lenses. Final inspection and quality control is the responsibility of the maker, not the buyer; why should we have to buy inconvenience along with the glass?

Attention has been drawn to competition between brands as being a sort of alternative quality control of its own - I don't think so. It seems to me that the reverse holds true: all makers are in the same boat and happy to paddle along together at the lowest possible cost to themselves. In a sense, the internet has actually helped them in a sort of perverse manner, because they know perfectly well that the forums are full of moans and groans about all of them, and few are likely to swap brands, lose a fortune in gear, simply to swap over from one company that they mistrust to another whose products are just as slated by other owners.

Come to think of it, Leica seems to be the only firm whose customers seem happy with the lenses it produces. I can't think those people are all stupid.

Rob C
Title: Interesting article on sample variations
Post by: telyt on March 14, 2010, 05:33:02 pm
Quote from: Rob C
... Final inspection and quality control is the responsibility of the maker, not the buyer; why should we have to buy inconvenience along with the glass?

It seems that many people are more willing to put up with the sample variation than with the cost of manufacturer QC.

Quote from: Rob C
Come to think of it, Leica seems to be the only firm whose customers seem happy with the lenses it produces. I can't think those people are all stupid.

I'm not sure what role stupidity plays in my choices but I'd rather pay the cost of Leica lenses that put up with the degree of sample variation often seen in other brands.
Title: Interesting article on sample variations
Post by: Ray on March 15, 2010, 01:26:55 am
Quote from: Rob C
Ray, whilst I am not happy at the thought of paying more than I have to for anything, I have to agree that some form of qualification might help. However, how on Earth would you police it? How do you show that your A quality lens is inferior (as it sometimes still might turn out to be) to the B quality version, and get your refund?

I would rather bite the bullet and pay more on the understanding that any lens I bought from Nikon was going to be top-grade and reliable - a staggered array of standards might just become a further cop-out for the makers, though I do remember that Nikon played with that idea with its E lenses. Final inspection and quality control is the responsibility of the maker, not the buyer; why should we have to buy inconvenience along with the glass?

Attention has been drawn to competition between brands as being a sort of alternative quality control of its own - I don't think so. It seems to me that the reverse holds true: all makers are in the same boat and happy to paddle along together at the lowest possible cost to themselves. In a sense, the internet has actually helped them in a sort of perverse manner, because they know perfectly well that the forums are full of moans and groans about all of them, and few are likely to swap brands, lose a fortune in gear, simply to swap over from one company that they mistrust to another whose products are just as slated by other owners.

Come to think of it, Leica seems to be the only firm whose customers seem happy with the lenses it produces. I can't think those people are all stupid.

Rob C

Rob,
Policing should not be a problem. We have the internet.  

This is also why I suggested that any company specialising in the MTF testing of lenses straight from the factory floor, should have an association with, and endorsement by, the manufacturer, otherwise it's would be too easy for a disreputable private lens-testing company, experiencing a shortage of Grade A lenses of a particular model, to substitute grade C or D lenses which were in plentiful supply, and use fake MTF charts.

The problem at present seems to be that the QC tolerance range for many popular lenses is from Grade A to Grade E. If you have the time and opportunity to spend many hours and even days testing and comparing a number of different copies of a particular model of lens from perhaps a number of different suppliers, in order to cherry pick a Grade A copy, you might consider your time and effort well spent, if you eventually succeed.

However, if you fail to find a Grade A copy after a lot of effort, how do you know when to stop? This happened to me with the Canon EF-S 10-22mm. I tested 3 different copies from 3 different suppliers. Each retailer I visited had only one copy of the lens in stock at the time; one in Australia; one in Singapore, and one in Kuala Lumpur. I took photos in each shop, comparing the quality on my laptop with identical shots from my Sigma 15-30 at 15mm.

The third lens I tested in KL appeared to be the best and the closest in sharpness to my Sigma, but still not quite as sharp as the Sigma. I was very undecided, but ended up buying it because the price was so good and the sales assistant was so helpful and so attractive.

I wish I hadn't. I rarely use the lens because it's really not up to scratch. I recently compared a few shots using the 15mp 50D with the EF-S10-22, and the 12mp D700 with the Nikkor 14-24. Despite the higher pixel count of the 50D, the D700 shots with Nikkor 14-24 were vastly superior.

With my idea of including real MTF charts specific to each lens sold, the customer would know exactly what he's buying (if he takes the trouble to inform himself) and the manufacturer would know exacly how much the customer is prepared to pay for a premium product, and might adjust their own QC practices accordingly.

We'd all benefit from such a process.

It's all very well saying, why not just buy an expensive lens like a Leica or Zeiss manufactured with more stringent QC practices. Do they have the type, the fitting, the focal length, the IS or VR that one desires? Not in my case. Two lenses I use a lot are the Canons 24-105 and 100-400 zooms. They both have IS and autofocus, and both complement each other in focal length. There are simply no other lenses available with the same features and a Canon fit.
Title: Interesting article on sample variations
Post by: telyt on March 15, 2010, 07:37:50 am
Quote from: Ray
It's all very well saying, why not just buy an expensive lens like a Leica or Zeiss manufactured with more stringent QC practices. Do they have the type, the fitting, the focal length, the IS or VR that one desires? Not in my case. Two lenses I use a lot are the Canons 24-105 and 100-400 zooms. They both have IS and autofocus, and both complement each other in focal length. There are simply no other lenses available with the same features and a Canon fit.

So what you're telling Canon is that you prefer features despite the poorer QC.  And they're listening.  Tell Canon with your purchases that you value QC over features and I suspect that's what they'll provide.  Or provide both - but be prepared to pay more.

This is sounding like an opportunity!  How many would be willing to pay for a cherry-picking service?  Suppose an enterprising individual were to buy a dozen samples of a lens, test them all, and return all but the best.  Would you be willing to pay this person to do the QC the camera makers have skimped on?
Title: Interesting article on sample variations
Post by: JohnKoerner on March 15, 2010, 09:58:37 am
Quote from: telyt
We could stop evaluating equipment on a features per dollar basis.  Lots of features make impressive spec sheets, but it's only after the purchaser used the tool for a while the usefulness and appropriateness of the feature become apparent.  As long as camera makers see us tripping over each other to buy the next, cheaper, feature-loaded camera they'll keep cutting corners.



Why would anyone want to cease evaluating equipment on a features-per-dollar basis? Only a fool would want to "spend more money to get less product," while any thinking person is going to want to "get more product for less money spent."

Nor do I see how this relates to a company's desire to forever reduce its spending, while forever trying to maximize its profits. ALL companies are forever looking for ways to achieve the same thing, for less, and will forever have "low bidders" coming to them for a try. Some of these "low bidders" will stay, after proving their worth, while others will prove inefficient and get whacked from the list of acceptable providers. For example, I publish a book via an online publisher, who itself has contracts with various printers all over the world who print and ship the books in an on-demand basis. One of those outlet printers (in Europe) has steadfastly caused me problems, where the books that it is printing are continually "lost," or printed backwards, or have pages falling out, or some other pitiful example of "quality" ... yet this never happens from any of the other outlet printers. I am sure this European outlet will be xxed from the main publisher's list of printing outlets very soon. Everyone wants to cut corners, but no one wants to do so at the expense of quality, and where the variance is found to be consistently unacceptable, a replacement vendor will always be around the corner.

Thus, in the end, I do agree with you that only after using a tool for a length of time may a person come to understand all its functions and applications, but I am not sure how this relates to the simple fact is there is variance with everything that gets manufactured ... whether you keep it a long time or not ... and that there will always be some vendors that prove to be a bargain to the main company, while others prove to be a bust.

Jack



.
Title: Interesting article on sample variations
Post by: telyt on March 15, 2010, 09:00:26 pm
Quote from: JohnKoerner
Why would anyone want to cease evaluating equipment on a features-per-dollar basis? Only a fool would want to "spend more money to get less product," while any thinking person is going to want to "get more product for less money spent."

The typical purchaser isn't a 'thinking person'.  He (usually) doesn't think to ask if these features are useable, reliable, or accurate.  More useful features for the money spent, cool.  More crap-shoot features?  Why bother.  Spec sheets don't show manufacturing tolerances, MTBF, or in most cases, meaningful environmental tolerances.  45-point AF is pointless if it's not accurate, 'weather resistance' that fails in ordinary use is likewise pointless.  Yet there are consumers who live for spec sheet 'performance' and dump perfectly good lower-spec equipment for the latest stuff.  It's very common on this forum, and most others.  It's great for me when I buy lightly-used, user-QC'd 'obsolete' equipment, great for the camera makers because these consumers don't think to ask if these features are any good, more of a crap shoot for someone who needs to use a reliable, accurate, durable camera.  More features without good QC invites Murphy's Law to play havoc with your 'features-per-dollar' equipment.
Title: Interesting article on sample variations
Post by: Ray on March 15, 2010, 09:33:51 pm
Quote from: telyt
So what you're telling Canon is that you prefer features despite the poorer QC.  And they're listening.  Tell Canon with your purchases that you value QC over features and I suspect that's what they'll provide.  Or provide both - but be prepared to pay more.

This is sounding like an opportunity!  How many would be willing to pay for a cherry-picking service?  Suppose an enterprising individual were to buy a dozen samples of a lens, test them all, and return all but the best.  Would you be willing to pay this person to do the QC the camera makers have skimped on?


Exactly! A lower quality lens with the right features is often preferrable to a first class lens without the features or with the wrong features.

A medium quality 150mm lens in a zoom will likely provide more satisfying results than the best 100mm prime ever made, if the FoV of the composition is that of a 150mm lens, making it necessary to crop the 100mm shot.

Likewise, a hand-held shot at the long end of a 100-400 medium quality zoom with the feature of IS, using say 1/200th sec exposure at ISO 200, will likely provide better results than a Zeiss 400mm prime without IS, at the same shutter speed and ISO.

Features can be important, particularly IS and accurate autofocus. I think Canon have demonstrated they are capable of manufacturing a lens with the IS feature without compromising the optical MTF response. For example, the 70-200/F4 IS is at least as good, and slightly better I believe, than the highly acclaimed previous non-IS version. Also, the recent 100/2.8 IS seems to be optically as excellent as the previous non-IS version, if not better.

I don't think an ad hoc cherry-picking service as a business would be allowed. There would be legal ramifications. What would happen to the returned lenses? It would be fraudulent to sell them without mentioning they are the rejects of cherry-picking.

Of course, in an informal manner, this is effectively what has been occurring for years. I once went to a lot of trouble comparing the Canon 400/5.6 prime with my 100-400 IS zoom which is noticeably soft at F5.6. I understood the 400 prime was supposed to be at least as good at F5.6 as the 100-400 at F8, its sharpest aperture.

Although the prime lacked IS, being sharp at full aperture would give it an advantage in certain circumstances when the subject is moving and a fast shutter speed is required irrespective of an IS feature.

I was surprised to find that the copy of the 400 prime I'd bought was not even as good as my 100-400 zoom. It was the last one in the warehouse, apparently. After my testing, it was returned to the Canon agent (by the retailer) for adjustment and tweaking, and I then repeated the whole series of tests on the same lens. I detected a very marginal improvement as a result of the adjustments, but not enough to make it sharper than the zoom. I got a refund.

This seems clearly a case of a Grade C zoom being compared with a Grade E prime. Whoever subsequently bought and accepted that lens that I'd rejected, would probably not be aware it was a Grade E within the QC manufacturing parameters for that particular model.

I'm advocating a system of honesty and transparency whereby the entire output of lenses is subjected to a rigorous MTF testing procedure along the lines of the old Photodo tests.

The additional cost might be 10% of the wholesale price of each lens. Such additional cost would be borne by the purchasers of Grade A and Grade B lenses plus a small discount that rightfully should be applied to the Grade D and Grade E lenses. Grade C lenses would cost the same as usual.


Title: Interesting article on sample variations
Post by: telyt on March 15, 2010, 11:30:34 pm
Quote from: Ray
Exactly! A lower quality lens with the right features is often preferrable to a first class lens without the features or with the wrong features.

Perhaps but not if they're not working well- the AF needs micro-adjustment, the lens's performance is uneven in the corners, has to be stopped down for good performance, is weak at some focal lengths & sucks dust inside, the camera body's AF system is erratic and calibrated for no better than +- 1 DOF, the mirror box isn't aligned accurately, the IS goes fubar.  Without QC these features make the equipment more difficult to use.

Where did you get the 10% added cost figure for the QC'd lenses?
Title: Interesting article on sample variations
Post by: Ray on March 16, 2010, 07:57:15 pm
Quote from: telyt
Perhaps but not if they're not working well- the AF needs micro-adjustment, the lens's performance is uneven in the corners, has to be stopped down for good performance, is weak at some focal lengths & sucks dust inside, the camera body's AF system is erratic and calibrated for no better than +- 1 DOF, the mirror box isn't aligned accurately, the IS goes fubar.  Without QC these features make the equipment more difficult to use.

Where did you get the 10% added cost figure for the QC'd lenses?

I'm addressing only lens variability here. The new features of AF micro-adjustment, and LiveView for extremely accurate manual focussing on the latest Canon DSLRs, are very welcome features.

The 10% figure is a guess based upon the use of properly designed, automated MTF testing eqipment and the use of low-cost Chinese labour. Such testing might be possible at an additional cost of less than 10%.

Here's an example of the sort of equipment I have in mind, although this equipment and software is designed to test P&S camera systems with fixed lenses.

http://kreysite.com/papers/SPIE2003.pdf (http://kreysite.com/papers/SPIE2003.pdf)

The chief point here is that a range of MTF measurements can be taken in just 6 seconds. To quote:

Quote
The draw back of MTF testing is that the proper measurement of the lens MTF is quite cumbersome and time consuming.

In the current investigation we designed, produced and tested a new semi-automated MTF set up that is able to measure the polychromatic lens system MTF at 6 or more field points at best focus in less than 6 seconds.

The computed MTF is a real diffraction MTF derived from a line spread function (not merely a contrast measurement). This enables lens manufactures to perform 100% MTF testing even in high volume applications.

Title: Interesting article on sample variations
Post by: Ray on March 16, 2010, 08:47:44 pm
Quote from: telyt
.... the lens's performance is uneven in the corners, has to be stopped down for good performance, is weak at some focal lengths & sucks dust inside ......

Doug,
Are you referring to the Canon 100-400/5.6 IS ?  

I've looked at your site. You don't need further praise from me, but I sense you must be very concerned about lens performance and must appreciate the benefits of IS or VR. Animals and birds can frequently sit very still for their portrait, but not always for a sufficiently long time to enable one to set up tripod. In such circumstances, with a long telephoto, one wants to use the lowest ISO possible, consistent with a sufficiently fast shutter speed to freeze camera shake.

Most good lenses are sharpest at F5.6. The Canon 100-400 does not appear to be. My copy is sharpest at F8 and virtually as sharp at F11 as at F8. A 100-400 which is sharpest at F5.6, would be worth paying more for. Do they exist? Maybe they do.

A set of MTF charts would be the most certain way of informing the buyer.
 
Title: Interesting article on sample variations
Post by: telyt on March 17, 2010, 08:02:17 am
Quote from: Ray
The new features of AF micro-adjustment... are very welcome features.
Micro-adjustment is an admission of variability and poor QC.  Camera makers have convinced consumers that this is a 'feature' not a kludge.  The Leica S2 doesn't have this 'feature' because the QC work is done at the factory instead of shifting the cost to the purchaser.  The S2 is expensive - part of the high cost is QC.

You want lots of convenience features at low out-of-pocket cost?  Who wouldn't - but the purchaser is going to do the QC.  How much is your time worth?  I'm not trying to say this is right or wrong, good or bad... just please recognize that user QC is one of the drawbacks of low initial cost.

Quote from: Ray
... I sense you must be very concerned about lens performance and must appreciate the benefits of IS or VR. Animals and birds can frequently sit very still for their portrait, but not always for a sufficiently long time to enable one to set up tripod.
I don't use a tripod.  I use a shoulder stock with monopod.  The weight is out of my hands, the stability is good enough that subject motion limits usably slow shutter speeds, mobility is nearly as good as a hand-held camera, and I avoid the flare and color quality loss of the added IS or VR glass.

Quote from: Ray
Most good lenses are sharpest at F5.6.
That's why I avoid most lenses.  I want lenses that are sharp at full aperture.  In my experience with the Leica 280mm f/4 APO the aperture is used for DOF only, not to make the lens perform well.  Same applies with the Leica 1.4x APO-Extender on the 280.
Title: Interesting article on sample variations
Post by: vandevanterSH on March 17, 2010, 11:18:31 am
I don't use a tripod. I use a shoulder stock with monopod.
**********
I stumbled on that combination by trial and error...A nice combination of stability with ease of use and mobility.

Steve
Title: Interesting article on sample variations
Post by: JohnKoerner on March 17, 2010, 11:21:44 am
Quote from: telyt
The typical purchaser isn't a 'thinking person'.  He (usually) doesn't think to ask if these features are useable, reliable, or accurate.  More useful features for the money spent, cool.  More crap-shoot features?  Why bother.

This may be true, but I would say that most people looking to buy mid-level to very nice equipment "think" enough to know the difference between what they need versus what they "want" but don't really need. I can't speak for others, but I myself do want (and look for) are the most useable features that I actually need, for the lowest price. I look first through competing companies, and then for lowest price/best rep amongst vendors. But, here again, I am not sure what this has to do with the subject, namely quality control in companies as well as the reality of manufacture-variance within product lines.




Quote from: telyt
Spec sheets don't show manufacturing tolerances, MTBF, or in most cases, meaningful environmental tolerances.  45-point AF is pointless if it's not accurate, 'weather resistance' that fails in ordinary use is likewise pointless.  Yet there are consumers who live for spec sheet 'performance' and dump perfectly good lower-spec equipment for the latest stuff.  It's very common on this forum, and most others.

I personally do not go on just company-generated spec sheets, but wait until I read a few hundred examples of actual buyer feedback, as well as several examples of "web review" feedback and testing from qualified individuals. For example, I have been watching and waiting for several examples of feed back on both the 7D as well as the 100mm "L" macro lens before purchasing. I did not just run right out and get these products, and I still have not, even though I am very interested. After checking and re-checking the buyer/user feedback, the almost universal consensus is there are both truly superior upgrades, and not "the same thing with a new label."




Quote from: telyt
It's great for me when I buy lightly-used, user-QC'd 'obsolete' equipment, great for the camera makers because these consumers don't think to ask if these features are any good, more of a crap shoot for someone who needs to use a reliable, accurate, durable camera.  More features without good QC invites Murphy's Law to play havoc with your 'features-per-dollar' equipment.

I agree 100% that this is a sensible way to upgrade, and as a matter of fact this is how I am considering upgrading into the aforementioned two relatively new Canon products, by obtaining them either used or after they have gathered a little bit of dust and are no longer a novelty. Already the 7D is down to $1599 and the 100mm L is down to $849, and I am sure they will be even less in another year. And I also agree that buying a used camera, tested and true from an honest person is, without question, the best way to get a proven-good product inexpensively.

Jack




.
Title: Interesting article on sample variations
Post by: Ray on March 18, 2010, 07:20:02 am
Quote from: telyt
Micro-adjustment is an admission of variability and poor QC.  Camera makers have convinced consumers that this is a 'feature' not a kludge.


Good! I'm all in favour of honesty. An honest admission and a brilliant, cost-effective solution. What more do you want! Furthermore, the micro-adjustment is not just a feature which allows a degree of user quality control as a kludge for camera body misalignment, but also compensates for lens misalignment.

If it works, it works. No point in despising it because it's cheap. This is progress.

Quote
....but the purchaser is going to do the QC.  How much is your time worth?

It's worth enough to favour an efficient MTF testing procedure to grade mass-produced lenses so I get a choice of paying in accordance with a well-defined quality instead of buying a lottery ticket.
Title: Interesting article on sample variations
Post by: telyt on March 18, 2010, 07:43:17 am
Quote from: Ray
Good! I'm all in favour of honesty. An honest admission and a brilliant, cost-effective solution. What more do you want! Furthermore, the micro-adjustment is not just a feature which allows a degree of user quality control as a kludge for camera body misalignment, but also compensates for lens misalignment.

If it works, it works. No point in despising it because it's cheap. This is progress.

Sorry, it's still a dumb kludge.  The real problem is that CaNikon have conditioned us to expect this shoddy level of QC.
Title: Interesting article on sample variations
Post by: vandevanterSH on March 18, 2010, 09:52:30 am
The real problem is that CaNikon have conditioned us to expect this shoddy level of QC.
*********
As demonstrated by the general end user acceptance of the "problems" associated with the Nikkor 70-200 VR II.  "Pitted metal casting and silver particulates inside of the lens, doesn't affect function or image quality, why are you complaining???"  One good response, basically " it's your fault for looking inside the lens".  

Steve
Title: Interesting article on sample variations
Post by: Playdo on March 18, 2010, 12:06:36 pm
Very nice thread. I'm adamant that companies such as Canon would use this lack of QC to profit from lens calibration/repair, thus the low warranty. It amazes me how many posts I read where people send their equipment in at a high cost for calibration, yet it seems they find it perfectly acceptable. As long as there is financial gain from it, or preventative laws, nothing will change.

Quote from: JohnKoerner
I believe folks were already comparing serial numbers on the "Antarctica" thread, which empowers the consumer with the ability to "know where they're at" on a much broader scale than ever would be possible only knowing their own situation.

Yes, I'd have thought that most returned goods would end up back on the shelf.  I was thinking a while back of having a site where anyone who has returned equipment could place the serial number and a description of the problem. Users could easily locate and check an item before or immediately after buying. Any thoughts?
Title: Interesting article on sample variations
Post by: vandevanterSH on March 18, 2010, 12:33:35 pm
Yes, I'd have thought that most returned goods would end up back on the shelf.
**********
I am sure that my returned 70-200 was resold for full price.  Nikon said that pitted metal and silver particulates didn't affect image quality and thus met standards for that lens.

Steve
Title: Interesting article on sample variations
Post by: Ray on March 18, 2010, 08:25:02 pm
Quote from: telyt
Sorry, it's still a dumb kludge.  The real problem is that CaNikon have conditioned us to expect this shoddy level of QC.

Can you elaborate on that? What do you mean by a dumb kludge? Have you had a bad experience trying to use the micro-adjustment with lenses that don't autofocus accurately? Have you found this feature to be unsatisfactory?

If you want military grade products then you have to pay more than military grade prices due to the low demand and low quantities produced, much like MFDB systems. At least there's a large, well-defined market for military products, which tends to keep the price lower than it otherwise might be.

Perhaps you mean a kludge in the sense that some folks think that using a monopod is a kludge compared with a full tripod.

Your ideas would seem to lead to a situation whereby lots of consumers would not be able to afford cameras because the manufacturers insist on producing nothing which is not of military grade quality.
Title: Interesting article on sample variations
Post by: stever on March 18, 2010, 10:51:07 pm
i think the micro-adjust is a kludge, but not dumb.  it's a reasonable solution to make legacy lenses work with high-resolution SLRs -- and it works.

but Canon (and i believe Nikon) provide no help in it's practical application and left this to 3rd parties - fortunately we have Lensalign - but the camera manufacturers should provide the tools to make the bodies work with the lenses (and i'd much rather have them do that than provide worthless software disks with the cameras)

going forward, however, i don't see why bodies shouldn't be tested and firmwared with focus adjust parameters and likewise lenses - at least the Canon L lenses

i have no objection to software solutions to mechanical tolerance issues that are impossible or uneconomic to solve otherwise, they just need to be implemented effectively


this, however, is aside from the need to keep manufacturing under control, and i don't see any good excuses for Japanese companies who were early adopters of modern quality control practices and maintain manufacturing in Japan for reasons of product control  - i would not be surprised by statistical differences in lenses to be cherry picked, but the batch problems are not excusible
Title: Interesting article on sample variations
Post by: telyt on March 18, 2010, 11:13:25 pm
Quote from: Ray
Can you elaborate on that? What do you mean by a dumb kludge? Have you had a bad experience trying to use the micro-adjustment with lenses that don't autofocus accurately? Have you found this feature to be unsatisfactory?

If you want military grade products then you have to pay more than military grade prices due to the low demand and low quantities produced, much like MFDB systems. At least there's a large, well-defined market for military products, which tends to keep the price lower than it otherwise might be.

Perhaps you mean a kludge in the sense that some folks think that using a monopod is a kludge compared with a full tripod.

Your ideas would seem to lead to a situation whereby lots of consumers would not be able to afford cameras because the manufacturers insist on producing nothing which is not of military grade quality.

You seem quite defensive of this technology.  With automated procedures and proper tools, do you think that correctly adjusting a lens at the factory to focus accurately would raise the retail cost to military-grade levels?  How did you arrive at this estimate?
Title: Interesting article on sample variations
Post by: Ray on March 19, 2010, 01:46:07 am
Quote from: telyt
You seem quite defensive of this technology.  With automated procedures and proper tools, do you think that correctly adjusting a lens at the factory to focus accurately would raise the retail cost to military-grade levels?  How did you arrive at this estimate?


Correctly adjusting a lens after fabrication to make it autofocus accurately may not always be possible. The lens may have to be junked, thus increasing manufacturing costs. The micro-adjustment feature is not simply a solution to compensate for a kludge of a camera body, but also a kludge of a lens which might otherwise never autofocus properly.

I confess I don't know this for certain, but I have experienced two situations of a lens that didn't auto-focus accurately on camera bodies that were quite satisfactory with all my other lenses.

I also once sent off a lens, still under warranty, to Canon for adjustment because it didn't autofocus properly. It still didn't autofocus accurately after adjustment, hence my purchase of the 50D with micro-adjustment.

By definition, military grade components are of the highest standard. Each component is manufactured using the highest QC procedures available.

Everything is a kludge in relation to the highest standards. Remember the Einstein quote about the Heisenberg theory of Quantum Mechanics? 'God does not play dice.' He was wrong on this point, wasn't he?  
Title: Interesting article on sample variations
Post by: ErikKaffehr on March 19, 2010, 02:03:23 am
Hi,

I would recommend these two articles

http://www.josephholmes.com/news-sharpmediumformat.html (http://www.josephholmes.com/news-sharpmediumformat.html)

http://www.josephholmes.com/news-medformatprecision.html (http://www.josephholmes.com/news-medformatprecision.html)

It's obvious that modern photographic equipment can be very demanding. We perhaps need like 10 my (microns) tolerance between AF-sensor and sensor. The optical path involves two moving mirrors. There is also wear, thermal expansion and handling related issues. From the articles above it is quite obvious that it cannot be taken for granted that expensive pro equipment is properly in adjustment and it's also obvious that lens variations are large. The author also indicates that he has not observed similar problems with his Canons.

I'm a strong believer in mirror less designs, using live view and contrast detecting auto focus. The technology is not here yet. Contrast based AF is still slow, AFAIK, and I don't see live view working in darkness.

The mirror less design eliminates AF-problems, as the sensor itself is used to focus. The sensor lens still need to be aligned as the image plane and the sensor needs to be within a few microns.

Check also:
http://www.diglloyd.com/articles/Focus/focus-accuracy.html (http://www.diglloyd.com/articles/Focus/focus-accuracy.html)
http://diglloyd.com/articles/LensAndCamera...andNewBlur.html (http://diglloyd.com/articles/LensAndCameraIssues/BrandNewBlur.html)

My view is that pixel peeping with digital technology is easy and sensor resolution is going up, increasing the demands on the lenses and the focusing system.

Best regards
Erik

Quote from: Ray
Can you elaborate on that? What do you mean by a dumb kludge? Have you had a bad experience trying to use the micro-adjustment with lenses that don't autofocus accurately? Have you found this feature to be unsatisfactory?

If you want military grade products then you have to pay more than military grade prices due to the low demand and low quantities produced, much like MFDB systems. At least there's a large, well-defined market for military products, which tends to keep the price lower than it otherwise might be.

Perhaps you mean a kludge in the sense that some folks think that using a monopod is a kludge compared with a full tripod.

Your ideas would seem to lead to a situation whereby lots of consumers would not be able to afford cameras because the manufacturers insist on producing nothing which is not of military grade quality.
Title: Interesting article on sample variations
Post by: telyt on March 20, 2010, 02:29:40 pm
Quote from: Ray
Correctly adjusting a lens after fabrication to make it autofocus accurately may not always be possible.

Given the sorry state of most AF cameras' viewfinders for manual focus, how much would you be willing to pay for a lens that can't AF accurately?
Title: Interesting article on sample variations
Post by: Ray on March 20, 2010, 11:24:04 pm
Quote from: telyt
Given the sorry state of most AF cameras' viewfinders for manual focus, how much would you be willing to pay for a lens that can't AF accurately?


Doug,
Canon have already addressed this difficulty you refer to. My 50D has a 920,000 pixel LiveView screen. My 40D also has a Liveview screen, but only 230,000 pixels.

When recently comparing resolution from the 40D and 50D (using the same lens), photographing a mounted banknote from a distance of a couple of metres, I was surprised to find that the higher resolution LCD screen of the 50D did allow for more accurate manual focussing. With the 40D, I was never quite sure if focussing was really spot on. Good enough for most practical applications, but not necessarily good enough for critical comparisons at the extreme pixel-peeping level.

So I resorted to the trick of using the appearance of moire effects on the LCD screen as an indication of absolutely accurate focus. Even when looking through an optical viewfinder, one can notice moire (or chromatic aberration, or aliasing) whenever a lens is perfectly focussed on a line chart (such as a Norman Koren Resolution Test Chart) at a particular distance from the chart and at a particular line spacing.

The fact is, autofocussing is never perfectly accurate (except perhaps by accident), no matter how expensive the lens. It's always a matter of the degree of accuracy that is acceptable for the application and/or the standards required. The more expensive lens (one would hope) has more accurate autofocussing.

As a person who is a bit obsessed with issues of resolution, I would not be interested in buying a lens which could not autofocus properly, according to my own standards. But many 'more normal' people might be quite satisfied with a lens that I would reject.

It's interesting that the P&S world is leading the way in this regard. There are a few P&S cameras, Ricoh in particular, that do autofocussing bracketing. My initial interest was perhaps that such bracketed images could be used to extend DoF using a program like Helicon Focus. However, it seems that the autofocus bracketing in such cameras is not designed for this purpose. The differences in focal plane are not great enough. It's purpose is to provide a choice from small differences in focal points in macro shots where DoF is extremely shallow, even with a P&S. Even in 'wide' mode, the focal points will not range from the insect's tail to the insect's head, but rather from the insect's nose to it's eye.

I would hope that autofussing bracketing will become a feature in future DSLRs.
Title: Interesting article on sample variations
Post by: Rob C on March 21, 2010, 04:39:47 pm
Quote from: Ray
I would hope that autofussing bracketing will become a feature in future DSLRs.






I despair of me Ray; if such did become the norm it would be but one more device I would have to learn to override in my attempts at getting back to a digital F3.

Rob C
Title: Interesting article on sample variations
Post by: Ray on March 21, 2010, 07:30:43 pm
Quote from: Rob C
I despair of me Ray; if such did become the norm it would be but one more device I would have to learn to override in my attempts at getting back to a digital F3.

Rob C

Rob,
Surely by now you have worked out all the functions of those 32 buttons and dials on the D700, and found that their use has become second nature to you!  

Autofocus bracketing seems a great idea to me, not only to ensure that one of your 5 or 7 or 9 shots is precisely focussed on the feathered bird's left pupil, but also in order to extend the DoF range (by merging the 9 shots using a program like Helicon Focus) to get the effect of a razor sharp pin-hole camera.

This is progress, no?
Title: Interesting article on sample variations
Post by: Rob C on March 22, 2010, 05:50:35 am
Quote from: Ray
Rob,
Surely by now you have worked out all the functions of those 32 buttons and dials on the D700, and found that their use has become second nature to you!  

Autofocus bracketing seems a great idea to me, not only to ensure that one of your 5 or 7 or 9 shots is precisely focussed on the feathered bird's left pupil, but also in order to extend the DoF range (by merging the 9 shots using a program like Helicon Focus) to get the effect of a razor sharp pin-hole camera.

This is progress, no?




But Ray, why would I do that when I don't need to? Why would I seek to complicate the otherwise very simple process of making a piccy? Can anyone really say that shooting a film camera was difficult, more complex than working a digital one? The very fact that it is - so far - possible to cut out all the bells, whistles and fantasy buttons is a veritable blessing I would hate to see vanish forever under the mists of psuedo-technological advances. The one and only benefit I see to the digital camera is this: the histogram. In fact, even that is somewhat doubtful because prior to digital image making, all you needed was a Weston that you could buy for peanuts and never was the need for the then non-existent histogram even imagined or felt.

We have thrown the poor old baby out with the suds and substituted a very simple process by one far more complex if you wanna get it right!

This is progress, no? No. It is the enforced swapping of a perfectly good, perfected system for a new one that came as much of a culture and business shock to the established camera makers as to Kodak who played Dr Frankenstein, in the process effing up huge numbers of established photographic businesses. Some people on this site keep saying how digital has lowered the cost of entry into the business of photography. Nonsense! You have to include all of the associated digital costs when you make claims like that, not just draw a line at the cameras. I certainly never had a computer when I was working, never needed one, never imagined I'd even be interested in one which, to be honest, I still am not. It is simply a necessary evil without which I couldn't communicate in this contemporary world since nobody remembers how to use the telephone, and writing is simply unheard of apart from the card at Christmas. No wonder the number of illiterates is forever growing, punctuation has become a mystery and eloquence suspect, the butt of accusations of elitism which also, by the way, is a word utterly misunderstood.

So all in all, the fewer 'functions' the better for me!

Rob C
Title: Interesting article on sample variations
Post by: Ray on March 22, 2010, 07:40:06 am
Quote from: Rob C
But Ray, why would I do that when I don't need to? Why would I seek to complicate the otherwise very simple process of making a piccy? Can anyone really say that shooting a film camera was difficult, more complex than working a digital one?

Rob C


Absolutely yes! I see that you freed yourself of the complexity and mess of wet darkroom processing when you were once earning a crust as a professional photographer. Some of us, amateurs, struggle with the entire processing chain from pressing the shutter to making the print, and we work to our own standards. We are our own most difficult and exacting client.

Quote
The very fact that it is - so far - possible to cut out all the bells, whistles and fantasy buttons is a veritable blessing I would hate to see vanish forever under the mists of psuedo-technological advances. The one and only benefit I see to the digital camera is this: the histogram. In fact, even that is somewhat doubtful because prior to digital image making, all you needed was a Weston that you could buy for peanuts and never was the need for the then non-existent histogram even imagined or felt.

If you don't need a feature, don't select it or activate it. No need to cut it out. I always preferred 'through-the-lens' metering to an external light meter, even 40 years ago. The only problem I find, sometimes with the myriad of buttons and options, is how to activate a feature I want.


Quote
This is progress, no? No. It is the enforced swapping of a perfectly good, perfected system for a new one that came as much of a culture and business shock to the established camera makers as to Kodak who played Dr Frankenstein, in the process effing up huge numbers of established photographic businesses. Some people on this site keep saying how digital has lowered the cost of entry into the business of photography. Nonsense! You have to include all of the associated digital costs when you make claims like that, not just draw a line at the cameras. I certainly never had a computer when I was working, never needed one, never imagined I'd even be interested in one which, to be honest, I still am not. It is simply a necessary evil without which I couldn't communicate in this contemporary world since nobody remembers how to use the telephone, and writing is simply unheard of apart from the card at Christmas. No wonder the number of illiterates is forever growing, punctuation has become a mystery and eloquence suspect, the butt of accusations of elitism which also, by the way, is a word utterly misunderstood.

Rob, you're beginning to sound like the quintessential Luddite of photography   .
Title: Interesting article on sample variations
Post by: Rob C on March 22, 2010, 11:15:57 am
[quote name='Ray' date='Mar 22 2010, 12:40 PM' post='354854']
1.   Absolutely yes! I see that you freed yourself of the complexity and mess of wet darkroom processing when you were once earning a crust as a professional photographer. Some of us, amateurs, struggle with the entire processing chain from pressing the shutter to making the print, and we work to our own standards. We are our own most difficult and exacting client.

Reply 1.   Freed no; living in an apartment in a water-challenged country I couldn't keep it going in all good faith. I had air-con installed in the office/darkroom, and then I had a heart attack installed and I could no longer risk pouring 20x16 dishes of chemicals back into winchesters when all that lay as security between my new, weaker self and the fitted carpets was a towel! I have never found anything to match a WSG 2D print well glazed! (Something St Ansel also discovered when he gave up textures.) A Hahne matt print inside a crystal archival envelope comes close, but remove the thing from the envelope and it is dull and flat again. All a bitter irony when I realise that I ended up being the guy running the colour lab in the industrial photo unit I started in as a trainee six years earlier. Oh well, the commercial world did beckon after that...

2.   If you don't need a feature, don't select it or activate it. No need to cut it out. I always preferred 'through-the-lens' metering to an external light meter, even 40 years ago. The only problem I find, sometimes with the myriad of buttons and options, is how to activate a feature I want.

Reply 2.   Never did like ttl metering, even though my F2 was a Photomic; never used that feature and relied on the Weston with Invercone.

3.   Rob, you're beginning to sound like the quintessential Luddite of photography.

Reply 3.   For Luddite, substitute practical realist.

But to each his own!

;- )

Rob C  
Title: Interesting article on sample variations
Post by: telyt on March 22, 2010, 09:20:19 pm
Quote from: Ray
If you don't need a feature, don't select it or activate it.

Every feature even when deactivated has a cost: poorer ergonomic design, compromised de-activated function (I'm thinking particularly of the dismal viewfinders of AF cameras) and each feature is is an opportunity for Murphy's Law to rear it's famous head.

Quote from: Ray
Doug,
Canon have already addressed this difficulty you refer to. My 50D has a 920,000 pixel LiveView screen. My 40D also has a Liveview screen, but only 230,000 pixels.

Have you ever tried focussing using live view with an active subject?

Quote from: Ray
The fact is, autofocussing is never perfectly accurate (except perhaps by accident), no matter how expensive the lens.

Which is exactly why I favor a good optical viewfinder over AF or live view.

Quote from: Ray
As a person who is a bit obsessed with issues of resolution, I would not be interested in buying a lens which could not autofocus properly, according to my own standards. But many 'more normal' people might be quite satisfied with a lens that I would reject.

If you're obsessed with resolution you might be better off eschewing AF altogether.

Quote from: Ray
I would hope that autofussing bracketing will become a feature in future DSLRs.

It would be absolutely useless to me.  For the 1/10 of a second a bird's posture is what I want, I want accurate focus.  Not accurate focus on the exposure before or the exposure after.  Accuracy beats spray & pray.
Title: Interesting article on sample variations
Post by: Ray on March 22, 2010, 11:54:56 pm
Quote from: telyt
Every feature even when deactivated has a cost: poorer ergonomic design, compromised de-activated function (I'm thinking particularly of the dismal viewfinders of AF cameras) and each feature is is an opportunity for Murphy's Law to rear it's famous head.

This is a fallacy. The way it works according to economic reality is: the more features, the more attractive the item becomes to the public at large, and the more units are sold. As a consequence, the cost becomes lower or the quality becomes higher at the same cost. Just because you personally may have no use for a particular feature, does not mean that no-one else does. For example, I never shoot in jpeg mode with a DSLR. However, I don't find the option to shoot jpeg a disadvantage in any way, nor do I think such an option could contribute towards camera mal-function.

However, this is not always the case. A particular feature which puts more stress on a mechanical component in the camera may contribute towards its mal-function. For example, after about 100,000 shots with my Canon 5D, the mirror fell off. I don't believe this was due to the actual quantity of shutter actuations but due to my frequent use the 'autobracketing-of-exposure' feature which causes the mirror to flip up and down rapidly 3 times at each press of the shutter button.

If you had no use for such a feature, preferring an accurate exposure reading from a hand-held Weston, as Rob does, then your mirror is not likely to fall off as a result of not using the autobracket feature.

Quote
Have you ever tried focussing using live view with an active subject?

Any type of accurate manual focussing with an active subject is difficult. Autofocussing is a relatively modern feature in cameras. I renewed my interest in Photography about 25 years ago with the purchase of the first autofocus SLR, the Minolta Maxxum 7000. I later switched to Canon because of another great feature, Image Stabilisation.

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Which is exactly why I favor a good optical viewfinder over AF or live view.

Please enlighten me. I've never heard of any optical viewfinder that is a patch on the Canon LiveView system, provided you are able to use a tripod. (A monopod might be too much of a compromise).

The image on my 50D LiveView screen can be magnified 10x for the most accurate of manual focussing. That means, in effect, when you are using a 400mm lens that fills the screen with, say, the body of a bird, you can magnify the scene 10x which is equivalent to looking at the bird with a 4,000mm lens. It's eyeball fills the screen. Whether or not the bird will sit still long enough for you to accurately focus on its 3rd eyelash to the right of its left eye, is another matter. (Okay! Birds may not have eyelashes. Could we say they have eye bristles?   ).

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If you're obsessed with resolution you might be better off eschewing AF altogether.

If I were very obsessed I probably would, but I'm only a bit obsessed.  

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It would be absolutely useless to me. For the 1/10 of a second a bird's posture is what I want, I want accurate focus. Not accurate focus on the exposure before or the exposure after. Accuracy beats spray & pray.

Now! now! Doug, I can't believe that. First, there's no exposure before, only exposures after. The shot which is a fraction of a second immediately after the one envisaged (or the second or third or 4th or 5th one after) might not only be the perfectly focussed shot, but the preferred posture and composition. Some of the greatest shots in the history of photography have been fortuitous accidents

Nevertheless, irrespective of whether or not one's camera has the feature of autofocus bracketing, one would like the camera to have as accurate a focus as possible on that first shot. As far as I know, absolute auto-focussing accuracy does not exist, but manual focussing of a 10x enlarged image on a high resolution LiveView screen is the next best thing.


Title: Interesting article on sample variations
Post by: ErikKaffehr on March 23, 2010, 02:02:45 am
Hi,

Just a few comments.

I wouldn't agree that current viewfinders are bad in general. APS-C cameras are often pentamirror designs but top class cameras use pentaprisms. Another issue is that modern focusing screen assemblies are not really intended for focusing but more to be bright. The focusing screens are often user changable.

The focusing system includes the mirror and the focusing screen, in AF systems we have an additional mirror casting an image on the AF-sensor, both mirrors are moving.

To get correct focus all parts, moving or not, must be aligned within say 10 microns, not a small feat. There is also thermal expansion which may effect the focusing mechanism. Replacing a finder screen may reduce accuracy.

The eyefinder magnification is not really good enough for critical focusing. Microprisms/Split image may help. Exact focusing is probably best achieved by finding near and far limits of focus and positioning the focusing ring midway between.

Live view removes all uncertainty. Focusing is done on actual pixels coming from the sensor, so axial alignment errors are compensated for. Would the sensor not be perpendicular to the optical axis of the lens critical focus could still be achieved at the point used for focusing.

Live view does not add complexity to the system, but at the present state of art it's quite slow, because the shutter needs to be closed and re-cocked before exposure.

I recommend this reading:

http://theonlinephotographer.typepad.com/t...ng-follies.html (http://theonlinephotographer.typepad.com/the_online_photographer/2010/01/focusing-follies.html)

http://www.josephholmes.com/news-medformatprecision.html (http://www.josephholmes.com/news-medformatprecision.html)

Best regards
Erik


Quote from: telyt
Every feature even when deactivated has a cost: poorer ergonomic design, compromised de-activated function (I'm thinking particularly of the dismal viewfinders of AF cameras) and each feature is is an opportunity for Murphy's Law to rear it's famous head.



Have you ever tried focussing using live view with an active subject?



Which is exactly why I favor a good optical viewfinder over AF or live view.



If you're obsessed with resolution you might be better off eschewing AF altogether.



It would be absolutely useless to me.  For the 1/10 of a second a bird's posture is what I want, I want accurate focus.  Not accurate focus on the exposure before or the exposure after.  Accuracy beats spray & pray.
Title: Interesting article on sample variations
Post by: telyt on March 23, 2010, 06:19:40 am
Quote from: ErikKaffehr
I wouldn't agree that current viewfinders are bad in general.
Have you compared them with a good manual-focus SLR viewfinder?  A Nikon F with E viewscreen or a Leicaflex SL viewfinder exposes the top-of-the-line AF camera's viewfinder as the compromised tools they are.  I don't know what's more unfortunate, that one of the photographers most important tools, the viewfinder, has been compromised in order to include a convenience feature of dubious accuracy, or that people accept this as state-of-the-art.

[!--quoteo(post=0:date=:name=ErikKaffehr)--][div class=\'quotetop\']QUOTE (ErikKaffehr)[div class=\'quotemain\'][!--quotec--]Live view removes all uncertainty.[/quote]
I agree, but try using live view on an active subject.  These photos were made using a manual-focus optical viewfinder:

(http://www.wildlightphoto.com/birds/threskiornithidae/wfib01.jpg)

(http://wildlightphoto.com/birds/anatidae/cago01.jpg)

(http://wildlightphoto.com/birds/anatidae/mall04.jpg)
Title: Interesting article on sample variations
Post by: Ray on March 23, 2010, 07:16:34 am
Quote from: telyt
Have you compared them with a good manual-focus SLR viewfinder?  A Nikon F with E viewscreen or a Leicaflex SL viewfinder exposes the top-of-the-line AF camera's viewfinder as the compromised tools they are.  I don't know what's more unfortunate, that one of the photographers most important tools, the viewfinder, has been compromised in order to include a convenience feature of dubious accuracy, or that people accept this as state-of-the-art.


I agree, but try using live view on an active subject.  These photos were made using a manual-focus optical viewfinder:

 
Title: Interesting article on sample variations
Post by: Rob C on March 23, 2010, 05:44:10 pm
Quote from: telyt
Have you compared them with a good manual-focus SLR viewfinder?  A Nikon F with E viewscreen or a Leicaflex SL viewfinder exposes the top-of-the-line AF camera's viewfinder as the compromised tools they are.  I don't know what's more unfortunate, that one of the photographers most important tools, the viewfinder, has been compromised in order to include a convenience feature of dubious accuracy, or that people accept this as state-of-the-art.





That's something I can sympathise and agree with, but I would still go with the standard split-image one that came with the body unless the horizon line of the sea was included in the shot; I always found that getting it right, hand-held, in vertical shots especially, was always a dodgy hope at best! That was why I bought the checkered screen for those occassions, though even then, it was better doing it on a tripod.

Your last bit, about people now accepting the compromised solutions they get as okay, really burns me up, as I have stated several times over with the growing sense of crying to myself in the wilderness. For those who remember nothing better, great; for those who know better, it is a gross betrayal by the marques we trusted and supported over a lifetime.

I wish there were more with your thoughts.

Rob C
Title: Interesting article on sample variations
Post by: Ray on March 23, 2010, 07:10:33 pm
Quote from: Rob C
That's something I can sympathise and agree with, but I would still go with the standard split-image one that came with the body unless the horizon line of the sea was included in the shot; I always found that getting it right, hand-held, in vertical shots especially, was always a dodgy hope at best! That was why I bought the checkered screen for those occassions, though even then, it was better doing it on a tripod.

Your last bit, about people now accepting the compromised solutions they get as okay, really burns me up, as I have stated several times over with the growing sense of crying to myself in the wilderness.

Rob,
Whilst I agree that the old 'split image' method for manual focussing is vastly easier and more accurate than trying to assess sharpness through a plain viewfinder, I don't agree that everyone accepts compromised solutions as okay. Everytime Canon produces a new model with an autofocus tracking problem, there's a great hullabaloo. (Was it the 1D3 that had  such a problem investigated by Rob Galbraith?)

One of the great things about the Canon LiveView system is that the mirror remains up when you take the shot, so you not only get the benefit of perfectly accurate manual focussing, (even more accurate than the 'split image' method when conditions are stable), but the benefit of MLU for that ultimate, vibration-free, tack-sharp image.

If you really want the old-fashioned split-image focussing screen, I believe there are third party suppliers catering to your needs. Here's one for the Canon 5D and 5D2.    http://haodascreen.com/Canon5D.aspx (http://haodascreen.com/Canon5D.aspx)
Title: Interesting article on sample variations
Post by: telyt on March 23, 2010, 09:58:17 pm
Quote from: Ray
Excellent and well-focussed shots, Doug. Are all your shots like that, or do you get a few out-of-focus sometimes?  

These are from single exposures, not the pick of a sequence.  I did not 'spray & pray'.