As pixel density increases, there should never be a need for an AA filter and the pixel density alone should be a sufficient indication of the resolving power of a sensor.
As pixel density increases, there should never be a need for an AA filter and the pixel density alone should be a sufficient indication of the resolving power of a sensor.
We've now regressed to the point where lens tests are never separated from the performance of a particular model of camera, except for the manufacturers' theoretical MTF charts which rarely go beyond 30 lp/mm.If you are interested in the MTF of a lense at really high spatial frequencies, you might want to use a test-chart of e.g. a slowly swept sinoid, meaning that you know what (single) frequency is fed into the system at a particular spot. If you then use something like the D800E (or the D7100) without a AA-filter, you know that the camera sensor has a wider frequency response (even to aliasing frequencies).
I find the Photozone Imatest MTF 50 results quite useful, but they have warnings on their site against comparing lenses tested on different cameras, for the obvious reasons that different sensors have different pixel counts, different strengths of AA filter, and the processed RAW images may have been subjected to different qualities of processing according to the age and sophistication of the RAW converter used.
Reading DxO's latest review of the Sigma 35mm/f1.4 on the Nikon D800, it would seem that Sigma have really hit the mark with what appears to be a very superb lens. Looking at this as yet another example of where 3rd party manufacturers are upping the ante in terms of lens quality, I'm wondering if this is really the beginning of a period during which we see a significant upturn in lens performance & quality, especially now that there are companies/websites such as DxO that are putting lenses under the microscope and their flaws being bared for all to see.
Are we thus past the point where sensor changes and improvements (at least so far as megapixels goes) are they key determining factor in resulting IQ and into a phase where it is improvements in lens quality that will be dominant?
especially now that there are companies/websites such as DxO that are putting lenses under the microscope and their flaws being bared for all to see.It's nothing new. UK photo magazines were publishing MTF charts in lens reviews back in the 1970s.
Hi Ray,
That's correct, but it would require something like a sensel pitch of 1 - 1.1 micron to have diffraction dictate the resolution even at wide apertures. Also the different sampling densities for Red/Blue versus Green require very dense sampling to avoid all False Color artifacts. We're not quite there yet, and a good AA-filter is more effective than diffraction.
Cheers,
Bart
If you are interested in the MTF of a lense at really high spatial frequencies, you might want to use a test-chart of e.g. a slowly swept sinoid, meaning that you know what (single) frequency is fed into the system at a particular spot. If you then use something like the D800E (or the D7100) without a AA-filter, you know that the camera sensor has a wider frequency response (even to aliasing frequencies).
now that there are companies/websites such as DxO that are putting lenses under the microscope and their flaws being bared for all to see.
If you have to put a lens under the "microscope" before you can "see" the flaws what real world practical relevance does such a test have for most photographers?
Perhaps any difference that makes no real world practical difference, at least to most photographers, is no difference.
If you have to put a lens under the "microscope" before you can "see" the flaws what real world practical relevance does such a test have for most photographers?
Perhaps any difference that makes no real world practical difference, at least to most photographers, is no difference.
Here's a novel idea - snap on a lens take some pictures and see if you are satisfied with the results.
All this stuff is so damned academic that it's almost a joke. Where do I get to see the photographs that show the value of all this technical jargon and manufacturing 'progress' that's being bandied about? I see very few impressive new images but reams and reams of crap about bokeh, various curves and that's about it. The new photography, then, the beneficiary of all this stuff? The thrill is in the measurements? It's in the buying of something theoretically 'better' than what one already owns? It sure ain't in the printed pix.
you would not think that anything else could be better.
I see very few impressive new images but reams and reams of crap about bokeh, various curves and that's about it. The new photography, then, the beneficiary of all this stuff? The thrill is in the measurements? It's in the buying of something theoretically 'better' than what one already owns? It sure ain't in the printed pix.
All this stuff is so damned academic that it's almost a joke. Where do I get to see the photographs that show the value of all this technical jargon and manufacturing 'progress' that's being bandied about? I see very few impressive new images but reams and reams of crap about bokeh, various curves and that's about it. The new photography, then, the beneficiary of all this stuff? The thrill is in the measurements? It's in the buying of something theoretically 'better' than what one already owns? It sure ain't in the printed pix.
If you have to put a lens under the "microscope" before you can "see" the flaws what real world practical relevance does such a test have for most photographers?I expect my lenses to last 10 years +. I expect my cameras to "last" less than 5 years. Therefore it is relevant to have some insight into how any given lens will perform on the kind of cameras that is on the market 5-10 years from now.
Perhaps any difference that makes no real world practical difference, at least to most photographers, is no difference.
Here's a novel idea - snap on a lens take some pictures and see if you are satisfied with the results.
Hi h,
I'm mainly interested in the MTF results of lenses for purchasing decisions. Those Photodo MTF results were a great buying guide. If I already own and use the lenses, I know their strengths and weaknesses.
My main concern when I buy a new lens is that I can expect it to be better than what I already have, at least in some respects.
For example, ever since buying a Nikon D7000 about 18 months ago I've been searching for a telephoto zoom with Nikon mount and VR (OS or VC) that at least matches the performance of my Canon 100-400. The three main contenders were the old Nikkor 80-400 VR, the Sigma 150-500 OS and the latest version of the Sigma 55-500 which now has OS.
I find it somewhat ridiculous that in this modern age of sophisticated technological development I can't find any reliable MTF results that compare all four lenses, including the Canon 100-400 which is my benchmark.
I can eliminate the old Nikkor 80-400 because there's so much anecdotal evidence that the Canon is the better lens. Both lenses have been around for a long time.
I can eliminate the Sigma 150-500 OS, but with less confidence because there are no comparisons at either Photozone or DXO. That leaves the Sigma 55-500 OS which, anecdotally, seems to be more highly regarded than the 150-500 and is also more expensive than the 150-500, which tends to imply it should be sharper.
Of course, now that Nikon has upgraded its 80-400, that would seem to be the logical choice for me. However, the Sigma 55-500 is about $1,000 cheaper and has a more useful range of focal lengths. I'd really like to know, for example, whether the new Nikkor at 400mm can produce the same or better detail than the Sigma at 500mm. If it can, and is also sharper than the Sigma at other focal lengths down to 80mm, then the matter is settled. I'd be prepared to pay the extra $1,000 and save a few hundred grams in weight, which is also a consideration for me.
Cheers!
I hear so many tales of product variation, folk having to buy multiple lenses in order to get anything like a decent copy. Seems particularly prevalent for the 135 format.
Perhaps the next area of focus should be quality control?
I hear so many tales of product variation, folk having to buy multiple lenses in order to get anything like a decent copy. Seems particularly prevalent for the 135 format.
Perhaps the next area of focus should be quality control?
That would be nice, but even nicer is self calibrating equipment because that could avoid price increases caused by tighter QC limits.I agree that in-camera corrections are economic solutions for some problems, and that they should be less tedious (and error-prone) for the user. But I think that such solutions will only ever cover a minor subset of the QC-issues that can affect lenses. If a lense is either sharp on the right-hand side or the left-hand side but not both at the same time, no camera correction will fix it.
I agree that in-camera corrections are economic solutions for some problems, and that they should be less tedious (and error-prone) for the user. But I think that such solutions will only ever cover a minor subset of the QC-issues that can affect lenses. If a lense is either sharp on the right-hand side or the left-hand side but not both at the same time, no camera correction will fix it.
-h
Ray,
Interesting read: http://www.lensrentals.com/blog/2013/03/quick-take-on-the-new-nikon-80-400-vr
Best regards
Erik
Where do I get to see the photographs that show the value of all this technical jargon and manufacturing 'progress' that's being bandied about?Try getting off the bar stool and going to see some proper work, not just cheap fashion magazines.
Try getting off the bar stool and going to see some proper work, not just cheap fashion magazines.
The technical standard of prints at last year's landscape photographer of the year in the UK was outstanding. The very few shots from film were pretty obvious from their lower quality.
e. in case you missed my point, it was that some of the people who obsess about the technicalities of equipment are often the very same people who fail to post anything remotely interesting by way of illustration of the product of all that wondrous gear...You said "Where do I get to see the photographs that show the value of all this technical jargon and manufacturing 'progress' that's being bandied about?".
e. in case you missed my point, it was that some of the people who obsess about the technicalities of equipment are often the very same people who fail to post anything remotely interesting by way of illustration of the product of all that wondrous gear...
Indeed.
And here I was, thinking it was all about money and market share!
Silly me - it was all altruistic all the time! I should have realised that the moment I observed so many people writing about having to return so many duff bits of equipment: it's just an illlustration of how much they care about us in those boardrooms: they want the buying experience to continue and continue, just like in the Barabarella movie mentioned in another thread... why make one purchase when you can keep on rebuying the same thing over and over again? Spread the joy!
;-)
Rob C
Speaking for myself, I only ever buy the same thing after having consumed it or used it, or after giving it as a present, or sometimes after selling it. Everything else I buy is always different, like a D800E is different from a D700, and a D7100 is different from a D7000.
Now where would we be without consumerism, Rob? May I suggest, the simple, but awful life of the hunter/gatherer. Would you prefer that, Rob? ;D
Now where would we be without consumerism ;D
Well, we may have a planet we are not eventually turning into a gigantic strip mine
"Not even nearly close!"
I assumed "strip mining" would be understood metaphorically not literally - apparently not.
"Not even nearly close!"
I assumed "strip mining" would be understood metaphorically not literally - apparently not.
Why don't you enlighten me.
"And where more strongly than in photography, where the reality is that a photograph is either good or it sucks; there is no middle ground. But, if you accept that truth, then what's left to say about the thing, and when the saying becomes the point of the interchange of opinions, the truth, the worth of the picture becomes secondary.
Rob C"
Sounds like you are talking more about opinion than criticism.
Good thoughtful criticism can be an art form in it's own right getting close to that middle ground where the "truth and worth" of a image is found.
And the question that is now popping up in my head is what will Leica and the makers of other "premium" lens brands do to counter the increase in IQ from Sigma/Tamron?
Some of the newer Sigma/Tamron lenses are proving to deliver higher IQ than Zeiss, etc, so while there is still a certain amount of cachet with those premium brands, is that all that they have going for them considering that they pretty much never do auto-focus and a lack of new models with competitive IQ?
I, for one, studiously avoid 'auto' anything that I can, other than two 'autos' that are wonderful: auto ISO and auto diaphragm.
;-)
What about auto-beating? ;)
Auto-beating
http://www.youtube.com/watch?v=jeEHQzyUdC0&playnext=1&list=PLB8BCBE8957E817F3&feature=results_main (http://www.youtube.com/watch?v=jeEHQzyUdC0&playnext=1&list=PLB8BCBE8957E817F3&feature=results_main)
Must be something I eat: right over my head.
;-)