I have been brutally curious about how different lenses would perform in a 61MP camera. I only have an A7 II 24MP one, but I am biting my nails like a total nerd, about which lenses will hold out better, or how much the downsampled version would be improved in detail versus a pure 24MP file. From about 80 lp / mm ( 40 lp / mm for full rgb at each "pixel") to about 130 (75 lp / mm) is quite a jump. Of course, An A7R III would also be a good vector/ indicator.
Has anybody ever done resolution tests on older lenses? There's very scant if none at all regarding any lens prior to Contarex, except for some tests I've seen in magazines that are always hard to find and I have no idea how the tests were done.
I was thinking, maybe there's a process to extract an MTF from a well lit shot of a chart with a A7R IV which would give a good indication at 10/20/40/80 lp / mm using an A7R IV.
I am interested as well - more from curiosity than essential need.
When I bought my Panasonic S1 its sensor resolution seemed good enough to me and as the S1R is identical to the S1 in every way other than the sensor (as far as I know) there seemed no need to pay the extra for extra resolution that I don’t really need. Ie: the S1 was not dumbed-down in features or quality to meet a market price.
I think that there is a dearth of adapter comparisons simply because adapters are cheap (and third party) and manufacturers ultimately wish to sell expensive oem lenses as that is where the money is.
Consequently any testing has to be done privately with “own money” and there is such a wide field that to give truly comprehensive results would be a big ask.
Manufacturers publish their lens MTF and maybe someone with expertise could interpolate the potential results statistically from the published data?
In any case I don’t know where the leap frogging pixel densities will end up. It seems that we can never get enough hugely populated sensors to make us satisfied.
The only real end to this that I can see is the single fixed prime lens where a very highly populated FF sensor can be crop sensor into an infinitely variable zoom lens. After all 16mp seems to have been some sort of sweet spot and even 8mp (or less !) will still produce an acceptable image (at least for my purposes).
I can even remember when the 4mp sensor was exciting .....
But .... maybe I am not rigorous enough.
I think of it in part is being able to digitally "zoom" (aka crop), and a factor is that legacy zooms require manually telling the camera around which FL one is at every turn. Also, I like some lenses renderings, and allows, as an example, to use a 28mm retrofocus to operate like a 50mm lens (just cropping).
i agree with all that - superzooms with micro-size sensors managed the huge range of zoom that allowed them to apparently reach magic zoom reaches beyond the otherwise profound laws of physics seem to have had their day when the end results did not meet even their credulous market.
I suppose that if FF sensors were taken that far then we might indeed be able to see life on Mars for ourselves
But it might all be a bit fuzzy.
I would give highly populated FF sensors a big plus and I might in the end try one myself.
But the other end of the coin is the increasing storage capacity needed for the burgeoning size of the files created.
One of the issues of large sensors heavily populated by pixels is the ability to use a more limited number of lenses by using crop sensor to either make multiple different images out of one capture and also the super-zoom of crop capture. Even a resulting 8mp image can be quite good enough for purposes - so it should be used quite widely. But .... but we all know “photographers” - can we be assured that we will use these facilities? No way - extra mp on a FF sensor must be used to create huge detailed files for the sole purpose of being able to zoom into detail and amaze our Mobile Phone Camera friends or to produce a single print that will cover a wall of the average home (provided we can find a large enough printer and we have plenty of walls ....)
Furthermore are we going to give up our lust for more lenses - when technically a “61mp” sensor will allow us to manage quite well with less lenses?
No doubt the Camera/lens makers realised that photographers would never stop buying lenses (no matter what) before they rushed down the “more pixels on the FF sensor” track.
The other factor was the first reaction to dpreview reviewers to the start of the more pixels on the FF sensor race is that such sensors require more technical skill on the part of the camera user as little technical errors disguised by lack of pixels to identify them will surely show up on zooming in to an image. Subsequently these sort of comments seem to have not been repeated. Maybe more photographic skills were found?
So if the 61mp sensor is super-great but requires more applied skill by the user will we then start blaming the poor old lens for any fault in an image - as we often do already.
Ok - I know that there are all sorts of known issues that are the result of optical geometry.
But I have my own issues with “perfection” - a perfect picture moves the soul and does not need to be a perfect reflection of the subject that is seen. Otherwise painters who are artists would have been out of business many years ago because their work is worth nothing without precise replication. However “anyone” can buy an expensive camera complete with astounding megapixels, add an expensive lens, and with a modicum of application get a lucky shot or three. But most need two out of the following three to succeed - good gear (can be bought); the photographic opportunity (it doesn’t always “just happen”); and some acquired or native skill in using camera equipment (cameras become more “automatic” every month).
With only one factor present we might struggle.
Another is looking at detail. I like exploring photos as an interactive movement frozen in time, equivalent to be able to walk closer to a very print, and observe from a different FL. Like..."the viewer chooses the FL" with his/her feet, not the photographer. of course, the scene needs to be atractive enough.
All photography is the capture of one moment in time in one particular place from one particular viewpoint. Time is the fourth dimension and the greatest imponderable known to mankind. Capturing one of these moments is the greatest gift as it effectively allows us to move backwards in time as memory is usually faulty and needs correction.
But another entirely different motivation, and it is less related to photography, is admiration for the engineering and craftmanship of lens makers 60, and even 100 years ago. It is a bit fascinating to see how a 80 year old optic calculated on pen and paper, and the 0% automated process back then with lots of manual work, could achieve a level of precision, performance and usability that still dazzles me today. But it's not like they could anticipate we'd have 100MP digital sensors that do what they do today. In many cases, they didn't even had access to color processes. So for me, it's like an ode to engineering and manufacturing ingenuity that makes me amused and very respectful of our inventiveness and craftmanship. Today, the amazing thing is shifting a bit more to the logical side of thing (the the "software" side of reality). But touching some of these objects and using them is rewarding. But if a lens is really a very limiting factor at 61MP, I won't think less, but a lens that does and was built so long ago, it's in some way remarkable beyond words.
I read somewhere in relation to Russian lens design but it applies to any lens - that it took up to ten years to do all the ray tracing calculations by hand to properly design a new lens - this was why successful lens designers were regarded as part genius’ in their own time and part “magicians” as they must have relied on considerable intuition and lots of experiment to short cut the technical calculations.
Petzval was supposed to have had a number of clerks seconded to hime from the Austrian Army to assist him in his calculations (if I remember correctly - should have taken a photograph
).
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Tom Caldwell
