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Author Topic: 40D autofocus  (Read 17263 times)

josephhigbee

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40D autofocus
« on: August 03, 2008, 06:40:19 pm »

I have a 40D I purchased when first released. The first few months I spent wondering why I was having so much problem focusing. I had previously owned 10, 20, 30 and 5D models with no large problem. Others I talked to assured me they had no problem but one person upon checking his in the field alongside me found his would also fail to lock on some subjects. I sent mine in for repair and it works well now except it does shift and it does fail to focus accurately on small objects. What I'm coming too is that I just read Galbraith's final report on the mk III's and in it he talked about the 40D and described my camera's action to a T. Are we the only two? And if not why has this not shown up on a review or  on the boards? I at least haven't found anything previous to this.

Curious,
Joe
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Ray

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40D autofocus
« Reply #1 on: August 03, 2008, 08:57:08 pm »

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Are we the only two? And if not why has this not shown up on a review or  on the boards? I at least haven't found anything previous to this.
[a href=\"index.php?act=findpost&pid=212854\"][{POST_SNAPBACK}][/a]

I sometimes have trouble with my 40D focussing in One Shot mode and single AF point on static subjects, never mind AI Servo.

As you can see from Rob Galbraith's lengthy article, it takes a lot of time and careful testing to nail the precise circumstances in which misfocussing takes place.

I recently sent two lenses to Canon for calibration, the EF-S 17-55/2.8 and the 50/1.4. Things are still not quite right and I'm not sure if I should now send the 40D body in for calibration. I need to do more testing with a variety of lenses, different AF point configurations, different lighting situations, and make comparisons with the same lenses on my 20D and 5D.

That all takes more time than I'm prepared to spend and I'm not too excited at the prospect of shooting rulers   .
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Eric Myrvaagnes

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40D autofocus
« Reply #2 on: August 03, 2008, 09:46:13 pm »

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That all takes more time than I'm prepared to spend and I'm not too excited at the prospect of shooting rulers   .
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How about rulers with dancing girls on them?  
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Ray

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40D autofocus
« Reply #3 on: August 04, 2008, 03:42:03 am »

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How about rulers with dancing girls on them?   
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Eric, that is what I would call the epitome of impracticability   .
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Rob C

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40D autofocus
« Reply #4 on: August 04, 2008, 07:24:27 am »

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Eric, that is what I would call the epitome of impracticability   .
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Absolutely, Ray, particularly when they could be dancing on the head of a pin, thereby providing you with both a tighter spacing of exotica and a pin-sharp focus locus at the same time.

Rob C

Rob C

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40D autofocus
« Reply #5 on: August 04, 2008, 07:49:56 am »

Lighter moments aside, there is something worrying about these posts concerning autofocus.  It could just be my usual old reactionary problem, of course, but I have to wonder about the current need that so many people believe that they have for autofocus in the first place. More so than the invention of digital, I feel it to have been an enornmous answer looking for a problem which perhaps existed within the world of professional sports photography, though seeing so many fantastic images over my long(ish) life that were extant prior to said development, I even doubt that. Ditto war reportage.

So what happened along the way to produce this breed of photographers that can´t use their own eyes?

This is particularly worrying when one reads these posts questioning the use of the alternative Zeiss offering within the slr world. I have lived through a full-time, life-time career in photography and have never found myself unable to operate a camera because of focussing problems - never owned an autofocus lens, even. So what´s up with the new dependants, is it too much trouble to DIY; is it perhaps lack of confidence in your own eyes? Whatever, it is bloody disappointing.

Apart from the failure of the personal input, it´s also my belief that the current problems of lens build are mainly down to the need to produce lightweight materials than can move quickly under relatively low motor power. Has nobody felt the difference in quality between the current offerings and their non-af predecessors? What a price to pay for "progress".

Rob C

Ray

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40D autofocus
« Reply #6 on: August 04, 2008, 08:03:04 am »

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Absolutely, Ray, particularly when they could be dancing on the head of a pin, thereby providing you with both a tighter spacing of exotica and a pin-sharp focus locus at the same time.

Rob C
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Indeed! That would be the quintessence of impracticability.  
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DarkPenguin

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40D autofocus
« Reply #7 on: August 04, 2008, 09:01:45 am »

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So what happened along the way to produce this breed of photographers that can´t use their own eyes?

6.5 fps.
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Rob C

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« Reply #8 on: August 04, 2008, 09:18:33 am »

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6.5 fps.
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Hi Mr P!

Could have done with that speed of response yesterday when I had to do my Mr Pres at the local community of owners AGM; I hate these meetings, where the only thing that matters is how cheaply something can be done. We even had an ex-pres saying that the gardens had never looked better, but could we get the gardener to work for less!

Somebody from the floor said that they had been thinking of proposing that we offer the gardener an increase in his pay, but that should have been coming form me, and had I not been too slow, so it would have been. There is no advantage in age...

But I still don´t require autofocus.

Rob C

Ray

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40D autofocus
« Reply #9 on: August 04, 2008, 09:34:50 am »

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This is particularly worrying when one reads these posts questioning the use of the alternative Zeiss offering within the slr world. I have lived through a full-time, life-time career in photography and have never found myself unable to operate a camera because of focussing problems - never owned an autofocus lens, even. [a href=\"index.php?act=findpost&pid=212940\"][{POST_SNAPBACK}][/a]

That says it all, Rob. I remember well my experiences with the first autofocus film SLR that appeared on the market, the Minolta 7000. It won 'Camera of the year' award in (my memory perhaps fails me) 1985?

It was the camera that got me back into amateur photography after a number of years slogging it out in the Australian public Service performing rather sterile and uncreative chores.

I've still got some slides of my trip to China in 1986, which I occasionally scan in search of something I can make interesting. The autofocus was very slow by today's standards.. A very old lady with an interestingly craggy face might appear in a door way but, before the camera could autofocus, the lady would withdraw and I would miss the shot. If I'd had to manually focus, I woulld also have missed the shot.

Autofocus is all about increasing the options and possibilities. I can only presume that Rob Galbraith's criticism of the 1D3 autofocus capability is justified because current Nikon cameras perform better. It's an assumption. Is it true? I don't know.
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Eric Myrvaagnes

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« Reply #10 on: August 04, 2008, 09:42:03 am »

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But I still don´t require autofocus.

Rob C
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I envy you, Rob. My old eyes don't focus as well as they used to (perhaps Canon has been diddling with my firmware).

My last non-autofocus camera was a film Pentax before I went over to the Dark Side (i.e., digital). A few horribly out-of-focus shots in somewhat dim light finally got me to listen to my older brother, who had been urging me for some time to get an auto-focus camera.

My Canon 5D auto-focusing may not be perfect, but it's consistently better than my own tired, old eyes.

But for you youngsters, I agree it's a different story.    

Eric
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ejmartin

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40D autofocus
« Reply #11 on: August 04, 2008, 10:02:42 am »

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So what happened along the way to produce this breed of photographers that can´t use their own eyes?

Rob C
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I can bloody well use my own eyes when my subject sits still long enough for me to do so, but I rarely find warblers at 700mm to be so cooperative.  

Even then the focus control is so coarse that the slightest twitch of the focus ring sends the lens right through the cm or two depth of field; this is likely because the focus ring is meant for coarse focussing, to get the lens close to the right plane of focus, with the AF there to pinpoint the subject.  That's certainly the way I use the lens.
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emil

josephhigbee

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40D autofocus
« Reply #12 on: August 04, 2008, 11:01:53 am »

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I can bloody well use my own eyes when my subject sits still long enough for me to do so, but I rarely find warblers at 700mm to be so cooperative.   

Even then the focus control is so coarse that the slightest twitch of the focus ring sends the lens right through the cm or two depth of field; this is likely because the focus ring is meant for coarse focussing, to get the lens close to the right plane of focus, with the AF there to pinpoint the subject.  That's certainly the way I use the lens.
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Thanks ejmartin
I was about to make the same point. If autofocus is on, it overrides any manual adjustment. If it is off you miss the warbler, which is often my subject.
Also, please note; my point isn't whether one camera is better or worse but rather that a current offering is notably worse than it's predecessor and yet few seem to notice or care.
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Rob C

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« Reply #13 on: August 04, 2008, 12:30:37 pm »

Quote from: ejmartin,Aug 4 2008, 02:02 PM
 

Even then the focus control is so coarse that the slightest twitch of the focus ring sends the lens right through the cm or two depth of field; this is likely because the focus ring is meant for coarse focussing,


That´s an interesting take: I used to have one of those poor-man´s versions of the Nikkor 300 - the 4.5IF-ED, and the problem there was with an over light focussing movement, not a coarse one: letting go of the barrel provoked movement of the ring...

However, the cure would have been to return it to Nikon for service, which they did suggest, but living in one country and buying in another and running the business elsewhere has its problems, or did at the time. Also, if I´d thought it worth the investment I would have gone for a 2.8 version where the shallow depth of field which seems to  bother you would, for me, have been an advantage. But then, as I say, we are all different animals and it wasn´t finding focus that was a problem, it was having the particular lens retain it.

Rob C

Rob C

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40D autofocus
« Reply #14 on: August 04, 2008, 12:39:37 pm »

Quote from: Ray,Aug 4 2008, 01:34 PM
That says it all, Rob.


Hi Ray

From the bold type I assume that you are saying that my failure to own an autofocus lens should preclude me from voicing an opinion. I fail again here, then, because I cannot see that not experiencing a need makes me somehow wrong in my asumption of my not having said need.

Further, the lack of a/f didn´t deprive us of the proud history of early street images from the school of HC-B, Doisneau, Ronis etc. etc.

On the other hand, it might be that I have totally misunderstood what you have written. Cést la vie - it happens.

Rob C

Rob C

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« Reply #15 on: August 04, 2008, 01:37:09 pm »

Quote from: EricM,Aug 4 2008, 01:42 PM
I envy you, Rob. My old eyes don't focus as well as they used to (perhaps Canon has been diddling with my firmware).



Hi Eric

My own peepers are not that hot c/u but I can still see distant things that others do not.

But regarding focus and how it applies within the remit of the camera screen, my personal choice has always been for the split-image which never failed me other than in one constant way: working on beaches, I could not get the horizon level enough to suit my needs, which were mainly for fairly large blow-ups which didn´t provide a lot of room for cropping.

The perfect answer was the grid screen with split-image, which Nikon did make, but only for use with slow lenses. Why? They wouldn´t tell me. I ended up using the grid which has no split-image facility. So I don´t see that a/f would have helped in that respect, because the focus of the mind and the camera was always on the model anyway, the problem being the background.

In that context, models, I would try to hand-hold (the camera) as much as I could because the tripod was a mental cart of bricks, to borrow James´s phrase, which I could well do without. However, on long lenses there was no choice. But even there, with the horizon leveled with the grid, a/f wouldn´t have helped because people do move about more than (note, egmartin) birds on a twig. Once on the twig, there´s not a lot of places for it to go. Other than away, which you´d miss anyhow. But a model, even one tring to stand still, does tend to sway a bit in the breeze and requires the sort of constant focus correction that even a/f is reputed to require in such situations.

One huge improvement with viewfinders was the replacement of fixed diopter correction lenses with the later system which allowed one to turn a wheel until the screen lines were at their crispest and thus settle the correction at a personal optimum point. Just as with my little D200, in fact. Great stuff.

However, using an olde Hass with its 80mm or 150mm under studio flash  modelling lights was never easy - my trick was for the girl to hold her hand on the spot where I wanted maximum focus and then use the highlights on her rings as an aid to getting something bright on which to focus. Usually worked.

But then, let´s not get into a fight about any of this; I will never appreciate how wrong I am because I can´t understand where I have made the mistake which I can´t see...

Rob C

woof75

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40D autofocus
« Reply #16 on: August 04, 2008, 01:46:55 pm »

Why should we spend precious mental energy doing something as rudimentary as focusing when it can be done automatically?
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Rob C

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« Reply #17 on: August 04, 2008, 03:48:22 pm »

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Why should we spend precious mental energy doing something as rudimentary as focusing when it can be done automatically?
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Focussing, at least for me, is one of the least rudimentary aspects of photography.

Unless you have enjoyed the almost tangible experience of focusing a fairly long lens through foreground foliage, for example, to your model beyond; experienced the utter joy of those different colours swimming in and out of focus, you have denied yourself the most wonderful part of the making of a photograph - the excitement of getting to the image. It also means that you are missing seeing the world around you in anything other than the final, flat cut to which your automation (or even your eyesight) will get you. A/f robs you of that, if of nothing else. But then, perhaps photography means something quite else to you than it does to me.

Rob C

woof75

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« Reply #18 on: August 04, 2008, 03:57:14 pm »

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Focussing, at least for me, is one of the least rudimentary aspects of photography.

Unless you have enjoyed the almost tangible experience of focusing a fairly long lens through foreground foliage, for example, to your model beyond; experienced the utter joy of those different colours swimming in and out of focus, you have denied yourself the most wonderful part of the making of a photograph - the excitement of getting to the image. It also means that you are missing seeing the world around you in anything other than the final, flat cut to which your automation (or even your eyesight) will get you. A/f robs you of that, if of nothing else. But then, perhaps photography means something quite else to you than it does to me.

Rob C
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I guess whatever floats your boat.
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Ray

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« Reply #19 on: August 04, 2008, 07:04:09 pm »

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From the bold type I assume that you are saying that my failure to own an autofocus lens should preclude me from voicing an opinion. [a href=\"index.php?act=findpost&pid=212996\"][{POST_SNAPBACK}][/a]

Not at all, Rob. You should know me better than that. The fact that you've never owned an autofocus lens explains why you might think they are unnecessary or over-rated. I think it's also probably true that in the controlled environment of shooting models, autofocus probably is unnecessary. Don't modern photographers with MFDBs often have their camera tethered to a computer monitor?
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