My God it's huge

[piggsy]

Roger Cicala's blogs at lens rentals on lens vs sensor resolution and the concept of a camera "out resolving" a lens are right here :

https://www.lensrentals.com/blog/2017/07/experiments-for-ultra-high-resolution-camera-sensors/

https://www.lensrentals.com/blog/2019/10/more-ultra-high-resolution-mtf-experiments/

and almost certainly better than rolling with what sounds about right!

 

[wyk]

He's comparing high end lenses there with full frame sensors.. Which is to be expected from him.
And on the best glass, with the big MP full frame sensors, it probably doesn't matter.
Still that page doesn't answer the question of resolution on an MFT sensor that's maybe 40MP(which some are saying is coming) vs typical MFT lenses.
He's mainly speaking of the nyquist limit. Which a great lens will rank very well for.

My point is the medium is the limiting factor, not the equipment.

 

[RS86]

Roger Cicala's blogs at lens rentals on lens vs sensor resolution and the concept of a camera "out resolving" a lens are right here :

https://www.lensrentals.com/blog/2017/07/experiments-for-ultra-high-resolution-camera-sensors/

https://www.lensrentals.com/blog/2019/10/more-ultra-high-resolution-mtf-experiments/

and almost certainly better than rolling with what sounds about right!

I actually found and read those a few days ago, but missed the Appendix. Very good information.

Finally got an answer to this outresolving question.

"Summary:

I say summary, because there are no practical or useful conclusions to be made. The only thing of interest, probably, is that only really good lenses can resolve ultra-high resolutions you’ll never need. However, even among these really good lenses, you can’t assume how a lens will perform at ultra-high resolutions based on its results at normal resolutions. You can also see that ultra-high-resolution performance is a bit easier to obtain in short telephoto focal lengths than in standard or wide-angle lengths.

...

Appendix: Why Perceptual Megapixels are Stupid

I get asked several times a week if this lens or that is ‘capable of resolving’ this number of megapixels. Some people seem to think a lens should be ‘certified’ for a certain number of pixels or something. That’s not how it works. That’s not how any of it works.

How it does work is this. Any image you capture is not as sharp as reality. Take a picture of a bush and enlarge it to 100%. You probably can’t see if there are ants on the leaves. But in reality, you could walk over to the bush (enlarge it if you will) and see if there are ants by looking at a couple of leaves.

What if I got a better camera and a better lens? Well, theoretically, things would be so good I could see the ants if I enlarged the image enough. MTF is somewhat of a measurement of how sharp that image would be and how much detail it contains. (The detail part would be the higher frequency MTF.) That would, of course, be the MTF of the entire system, camera, and lens.

Lots of people think that will be ‘whichever is less of the camera and lens.’ For example, my camera can resolve 61 megapixels, but my lens can only resolve 30 megapixels, so all I can see is 30 megapixels.

That’s not how it works. How it does work is very simple math: System MTF = Camera MTF x Lens MTF. MTF maxes at 1.0 because 1.0 is perfect. So let’s say my camera MTF is 0.7, and my lens MTF is 0.7, then my system MTF is 0.49 (Lens MTF x Camera MTF). This is actually a pretty reasonable system.

Now, let’s say I get a much better camera with much higher resolution; the camera MTF is 0.9. The system MTF with the same lens also increases: 0.7 X 0.9 = 0.63. On the other hand, I could do the same thing if I bought a much better lens and kept it on the same camera. The camera basically never ‘out resolves the lens.’

You could kind of get that ‘perceptual megapixel’ thing if either the lens (or the camera) really sucks. Let say we were using a crappy kit zoom lens with an MTF of 0.3. With the old camera; 0.3 X 0.7 =.21. Let’s spend a fortune on the newer, better camera, and we get 0.3 X 0.9 = 0.27. So our overall system MTF only went up a bit (0.07) because the lens really sucked. But if it had been just an average lens or a better lens (let say the MTF was 0.6 or 0.8), we’d have gotten a pretty similar improvement.

If you have a reasonably good lens and/or a reasonably good camera, upgrading either one upgrades your images. If you ask something like ‘is my camera going to out resolve this lens’ you sound silly.

Roger’s rule: If you have either a crappy lens or crappy camera, improve the crappy part first; you get more bang for your $. I just saw a thread for someone wanting to upgrade to the newest 60-megapixel camera, and all of his lenses were average zooms. I got nauseous."

https://www.lensrentals.com/blog/2019/10/more-ultra-high-resolution-mtf-experiments/

 

[piggsy]

I actually found and read those a few days ago, but missed the Appendix. Very good information.

If you have a reasonably good lens and/or a reasonably good camera, upgrading either one upgrades your images. If you ask something like ‘is my camera going to out resolve this lens’ you sound silly.

Roger’s rule: If you have either a crappy lens or crappy camera, improve the crappy part first; you get more bang for your $. I just saw a thread for someone wanting to upgrade to the newest 60-megapixel camera, and all of his lenses were average zooms. I got nauseous."

https://www.lensrentals.com/blog/2019/10/more-ultra-high-resolution-mtf-experiments/

This bit also from the first is something I think is important :

Wait, wasn’t 30 megapixels about where we found camera metrology, you know those test charts and lens projectors, weren’t adequate anymore? Yep, that would be correct. Of course, video metrologists aren’t much different than photo metrologists. They all tell me that a lens test projector and some test charts will be all the testing they could ever need. Forgive me, but I’ve heard this one before. But for the first time, we’re putting all video lenses on the optical bench. It wasn’t necessary before, and probably isn’t now, but it sure will be at 8k.

I’ll be doing some write ups on that soon, but here’s a spoiler: some video lenses that looked fine for 4K are a bit tilted or decentered when held to 8k standards. Believe me, I realize that video is about the look, and focus accuracy, color rendition and a lot of things other than resolution. But trust me, that slightly tilted field of focus that isn’t noticeable at 1080p just screams at you in 8k. Similarly, that ‘good enough parfocal for 1080p’ becomes not quite parfocal at 4k or 6k.

For my purposes the only time resolution really comes up as a thing is doing focus stacked macro at or past 1x. But immediately you start noticing that opening up to a point where you have good enough resolution makes the individual slice of high res content 1mm or less! And that individual photo now has no context because of the comparatively huge section of the image that is totally out of focus. It also means you're going to really, really notice if those slices don't match up exactly, because it'll go from razor sharp to completely blurred to sharp again if there's any segment missing. And I think it's the same for other aspects of high res photography - immediately things like subject motion blur, camera motion during the exposure, etc etc become much more apparent and noticeable. So when we have any conversation about MP we have to also consider what the IBIS is up to, how accurate the focus/tracking is, what colour fringing shows up where in which contexts, blablabla, suddenly all this other stuff becomes relevant now that it can be noticed.

 

[wyk]

This reminded me of one of Chris Frost's lens reviews. He had a 22mm EF-M lens on both a 24mp M3(or is it an M6?) and a 32mp M6 mk2.
In his tests you can see the new 32mp sensor teased much better results out of the lens. So there's some good news there:

Something to note above is the edges of the lens wide open are super soft on both sensors.
Does this even matter for a wide open shot? Well, that's IQ is it? So that's up to you to decide?

Another thing also to consider is affordable lenses aren't always held back by the glass. Sometimes the poly carbonate holds them back(for light weight), the barrel design, mount, plastics etc. In other words, they can be decentered or not spaced correctly - something unlikely in expensive full frame glass.

 

[Machi]

Camera out resolves lens when 3 or more pixels covers linearly PSF at FWHM.
In practice that's what happens in current MFT cameras at ~f/16 and it's probably the reason why
Hires mode is limited to f/8.

 

[wyk]

Good reply sir. I shot some squirrels and swapped between Olympus and Canon.... the Canon looked better...or at least some thought it better. Others not. Still got more testing to do.

I meant to respond to you earlier about IQ. There are certain esoteric aspects to photography that can be expounded upon ad infinitum(I promise I'll stop talking like that for the rest of this post).
I mean, that's what the internet is primarily here for, it appears. My favourite is IQ vs rendering. Or to be specific, pixel peeping vs just letting the image wash over you(I'm sure there's a French phrase along the lines of mise-en-scène ).
IQ is a part. The image is the sum of the parts. It's up to you to decide which is important to you.

One of my favourite lenses is my Canon FD lens mounted on about any digital camera. It makes an image look natural, especially for video, and it puts you in the scene with that image like few other lenses can. It is not sharp. Does it's IQ matter? Well, that depends on what you mean by IQ.

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That image was taken with a 16mp camera made in 2013, unedited straight out of the camera.