Sensor Format Size and Image Quality

[deleted]

Couldn't agree more

I have done a lot of 'blind testing' with people who look at photos (not photography gearheads and nerds). People find it almost impossible to tell differences in 'image quality' between mft to 3mm equivalent. As most images that I come across are viewed on 1) phone screens 2) pc screens and 3) small printed photos in albums printed by 'low end' photo printers...It is just not in most people's minds that IQ is important. They are looking to see if the image resonates with them.

[deleted]

Yes, I think that's part of Jim's definition of equivalence. As an example, I was doing a comparison yesterday between my D500 and Sigma 50-100mm f/1.8 Art and my D850 and Tamron 85mm f/1.8 VC with the former wide open and around 58mm and the latter set at f/2.5, and at the pixel level the D500/Sigma combo was more ready to view/print, but the D850/Tamron combo had more pixels so actually had more resolution. But again, when I resized both to 4K then the differences came down to bokeh (the Tamron is, to my eyes, noticeably better).

I have just over 24,000 examples right here: www.flickr.com/photos/maoby/albums/page3

1991-2022 ... by Marc Aubry, sur Flickr

www.dpreview.com/forums/post/67089283

I have APS-C images that I won't print larger than 11x14. I have GFX 100 images that I'm happy to print 30x40.

I'm going to harp a little about my recent experience with my D850 and D500. Both are clearly professional tools, even though some might diss the D500 as "less" professional because of its smaller format (thankfully, we're not at the original, fanboy infested DPR where that sort of thinking predominates). When I go to photograph my girlfriend's agility class (for fun, so not professionally) I have always brought the D500, and I still think it has a marginal advantage of more fps and the files are a lot easier to manage, so its quicker on both fronts; OTOH, I have been using my recently acquired D850 lately and it affords me more latitude in framing and that results in a lower S/N ratio in the shots I take with it (though Topaz evens the playing field there quite a bit).

It seems we are in the same situation as in film photography times. All high quality cameras with different formats have the same Sony 3.76 µm pixel pitch BSI sensor, only in different sizes. So, it's easy to compare the IQ of different format cameras for different purposes, isn't it?

Are we comparing sensors that have different width and height but the same number of pixels (for instance, 24 Megapixels) ? Or sensors of various sizes with the same pixel pitch (so that the number of pixels is proportional to the area) ?
Don Cox

I don't think a high quality 24-Megapixel APS-C sensor can have the same pixel pitch as a high quality 24-Megapixel FF sensor.
Don

To be truly equivalent, that's what we'd have to do. Aspect ratio needs to be the same too. Microlens design needs to scale. Fill factor has to be the same. Hard to set up.

Indeed.

Falk Lumo posits two types of equivalence here www.falklumo.com/lumolabs/articles/equivalence/index.html

Type-1 for the same pixel count
Type-2 where the count is factored by the square of the crop factor ... so 4 for µ4/3 vs. FF**

Type-1 seems to assume different pixel pitches
Type-2 seems to assume same pixel pitches

** yes, I know they have different aspect ratios ...

Regarding aspect ratio, I just go with the shortest axis. It's quick and dirty, but avoids opening up the can of worms that is cropability.

Give or take, due to different lenses and technologies, it has been proven that equivalence works. It is just that it doesn´t because a) the lenses, b)you don´t have equivalent setup for the smaller system. 35mm f/1.4 at ISO100 on FF means 22mm f/0,88 ISO62 on Canon APS-C, or 17,5mm f/0,7, ISO50 on MFT. Many MFT cameras start at ISO200. So you are already two stops into amplification to get the same image brightness as from FF, and there is nothing you can do about it. Then obviously, small lenses do not scale with resolution. The smaller these are, the less overall resolution they can transfer (again, all else being equal). There is no consumer grade small lens, that can resolve what FF or MF lenses can.

Sure thing. That's also what pros are used to for movies / video.

classic answer (im a highend tradie)😁 i just dont say anything anymore and just let the handyman photographers think they know better.

You are a legend in your own mind.