Sensor Size

A friend recently asked me about the difference between APS-c and full frame digital cameras. They were expecting me to talk about image quality, I think they were surprised when I said that the big differences were that APS-c cameras were cheaper and smaller.

This is the Executive Summary when one assumes the lens surface area to sensor surface areas for APS-C and other sensor area formats are similar. Addressing the impact of sensor area on data information content without considering the impact of lens surface area data information content is incomplete.


Yes, all other things being equal (and they often are not) full frame will have a slight edge in noise level, brightness range and detail. But, with today’s technology, that difference is not overwhelming and you have to work carefully to take advantage of it. ...

I agree. As light levels decrease the advantage of increased sensor area increases. This is primarily because maximum lens apertures are limited by practical design and manufacturing considerations. The information content advantage for a 24 x 36 mm sensor over a APS-C is most obvious in shadow regions. Perception of rendered image quality do not scale linearly with signal-to-noise ratio. Shadow regions benefit the most from increased sensor areas.


So what sensor size do you use and, by far, more important, why?

I use APS-C for three reasons.

1. I enjoy using an optical view finder where I can take advantage of assessing what's outside the frame lines when I compose.

2. I can not abide Leica. This subjective decision is not driven by cost. I do not trust Leica.

3. If sensor surface area was a high priority I would skip 24 X 35 mm sensors and use 33 x 44 mm sensors.
 
APS-C has fine quality; given that most modern sensors produce 14-bit RAW files, which have lots of latitude for exposure, you get almost as good performance as FF up to a point of high ISO.

However I feel like APS-C is sort of the opposite of a "sweet spot" in terms of size and focal lengths of lenses. The lenses aren't a whole lot smaller than full frame, and the 1.5X crop means that familiar FF lenses, either modern or legacy, have less useful field of view. The easy example being a 50mm lens which becomes a 75mm on APS-C. A nice FoV but not a "normal" lens anymore, it becomes much less versatile.

When it comes to size of lenses, I think half-frame, AKA M4/3 in the digital world, is the sweet spot. Half frame Pen lenses in the film days were terrific in size and good in IQ. M4/3 has terrific sized lenses as well. But the sensor dynamic range suffers with current tech. If they could figure out a way to get similar DR out of M4/3 sensors, such as 14-bit RAW files with similar latitude to APS-C, I think things would be nearly perfect.
 
I like medium format (MF) in film - square format in particular - and I like the idea of MF digital. I also prefer the proportions of the MF frame to FF (full frame), as I'm more likely to crop the latter.

The main disadvantage I find in MF digital is the limited range of lenses, either by Fuji or Hasselblad. Neither one of them offers exactly what I would want, while the offerings in FF, both DSLR and even Mirrorless, are more ample.

- Murray
 
I don't understand all this concern over focal length and sensor size. Do you not look through a viewfinder and see the picture? What does it matter if you have a 35mm lens on a crop sensor camera, the picture in the viewfinder is what it is. The DOF issues and the noise issues have validity, but to me the focal length and ensuing calculations is just mind games.
 
I dislike seeing the small image in the viewfinder. Tiny weeny is plain difficult.

All else being equal. FF has more space to crop.

At usual print sizes, say 11x14, and both have modern sensors, the prints will look the same.
 
I don't understand all this concern over focal length and sensor size. Do you not look through a viewfinder and see the picture? What does it matter if you have a 35mm lens on a crop sensor camera, the picture in the viewfinder is what it is. The DOF issues and the noise issues have validity, but to me the focal length and ensuing calculations is just mind games.

Yes and no, or maybe. For instance making a quality 21mm lens takes some work, and a lot of elements typically. Suddenly on an APS-C this is cropped to an equivalent 31mm lens. Not a big deal, excecpt a 21mm lens for APS-C could likely have been designed with a lot fewer elements to get the same result,and likely could be faster, and have fewer artifacts (internal surfaces, etc.). On the other hand if the 21mm on APS-C works and creates a great image, then great, no issues.

This can be flipped of course. A 50-58mm lens on APS-C is a nice portrait lens, and for 35mm cameras and full frame digital cameras these (portrait lenses) tend to be expensive. For APS-C there are a lot of 50-58mm lenses that are great and relatively inexpensive to use. Of course you get the DOF of a 50mm lens, not of a 75mm lens, but that may be ok. In some other cases getting the tighter crop with more DOF can be an advantage too.

In the end it is not better or worse, just different, in some cases better, some worse, others neutral.
 
Still, when you look through the viewfinder or even the rear screen, there's the picture. If you want wider, go wider, they make clear to a 5mm lens for some cameras. All the APS cameras offer a 10mm. The fact that a 21mm is equivalent to a 30mm hasn't a thing to do with what you see in the viewfinder. Maybe I'm just not that good that I will look at a scene and say that I need a xx lens to capture it. In all fairness, I'm a big fan of zooms. One of the neatest gifts from Nikon is the 24-200 Nikon Z lens. On the Z7 it's the only lens I really will need for 90% of what interests me.
 
I like medium format (MF) in film - square format in particular - and I like the idea of MF digital. I also prefer the proportions of the MF frame to FF (full frame), as I'm more likely to crop the latter.

The main disadvantage I find in MF digital is the limited range of lenses, either by Fuji or Hasselblad. Neither one of them offers exactly what I would want, while the offerings in FF, both DSLR and even Mirrorless, are more ample.

- Murray

Plenty of other lenses can be adapted to the Fuji. Even more so If you are shooting square.

Shawn
 
Good point. Thanks Shawn.

Would that include Canon EF and RF lenses, and would they have full functionality?

- Murray

EF only as the RF mount has shorter flange distance than the G mount.

The performance of adapted EF lenses is limited by the capability of GFX bodies. A slow contrast detection focusing 50S/50R cannot drive the adapted lens faster than they do with the native GF lenses. You otherwise have full functionality (like IS). The EF-GFX adapter scene is still evolving to include like phase detection AF capability of the GFX100/100S.

The Tamron 35/1.8 and 45/1.8 duo are very fine candidates for adapting to the GFX. Sharp, well corrected, cover the image circle well, and their VC work just fine. Relatively inexpensive too.
 
EF only as the RF mount has shorter flange distance than the G mount.

The performance of adapted EF lenses is limited by the capability of GFX bodies. A slow contrast detection focusing 50S/50R cannot drive the adapted lens faster than they do with the native GF lenses. You otherwise have full functionality (like IS). The EF-GFX adapter scene is still evolving to include like phase detection AF capability of the GFX100/100S.

The Tamron 35/1.8 and 45/1.8 duo are very fine candidates for adapting to the GFX. Sharp, well corrected, cover the image circle well, and their VC work just fine. Relatively inexpensive too.

Thanks, Archlich!

- Murray
 
I don't understand all this concern over focal length and sensor size. Do you not look through a viewfinder and see the picture? What does it matter if you have a 35mm lens on a crop sensor camera, the picture in the viewfinder is what it is. The DOF issues and the noise issues have validity, but to me the focal length and ensuing calculations is just mind games.

I don't understand this comment. Focal length matters a great deal when you are trying to fit what you want into the frame. Commonly available focal lengths in FF terms, such as the ubiquitous fifty, are less useful on a crop frame.
 
Depends on the task for me. If I know I'm shooting in low light or want to maximize my image quality, full frame. Am I just out and about? APS-C. Am I at a dinner/reception where I need a tiny camera? m43 (Panasonic GM1) or just my phone.

There is absolutely an image quality difference. It's so much easier to get a shallow depth of field on FF cameras and glass and at least a stop of noise difference, if not more. It's insane to say, but even the FF sensor of the 5D classic can still punch above its weight today, despite (or maybe because of) its low megapixel count.

So count me in with those who think there's no replacement for displacement.

I wish I could dedicate myself enough to photography to warrant a digital medium format camera.
 
I don't understand this comment. Focal length matters a great deal when you are trying to fit what you want into the frame. Commonly available focal lengths in FF terms, such as the ubiquitous fifty, are less useful on a crop frame.

I understand that and when I say that the picture in the frame is what counts is sort of saying the same thing. I guess what I'm saying here is that when someone says they want their 35mm to be a 35mm in the frame and that only a FF sensor will do it puzzles me in that a 23 on a crop sensor is the same. Why does the focal length have to agree with the sensor size? Is that too big a leap?
 
Good point. Thanks Shawn.

Would that include Canon EF and RF lenses, and would they have full functionality?

- Murray

I've only adapted a couple of EF lenses but they have *almost* full functionality. I use one of the cheaper $80 Viltrox knock off adapters with a Canon 40mm 2.8 STM and a Sigma 100-400 Contemporary. The adapter itself has too much play in it but the electronics/software of it works very well.

With the Canon 40mm the adapter allows AF (including face or eye), writes the lens ID into EXIF, aperture priority exposure and it even takes the lenses built in distortion correction profile and translates it to the Fuji so that the Fuji applies the distortion correct to JPEGs and writes it into the RAF files for Lightroom to apply the correction. This little canon lens does surprisingly well on the GFX.

With the Sigma lens I have AF, aperture priority, lens ID into EXIF and the Optical Stabilization of the lens is even active. It doesn't seem to translate the selected focal length back to the camera though, it always shows 100mm.

Neither lens gives distance info back to the Fuji so if you have the focus scale up nothing shows up on that. With the adapter I have you also don't have full 'P' mode since the lenses doesn't have that option. The Viltrox adapters have a button that lets you switch from what would be 'A' on a Fuji lens to selecting aperture but on my adapter the button doesn't do anything.

I've also adapted Nikon F mount, Leica M mount and Pentax 645 lenses to the GFX.

Shawn
 
I don't understand this comment. Focal length matters a great deal when you are trying to fit what you want into the frame. Commonly available focal lengths in FF terms, such as the ubiquitous fifty, are less useful on a crop frame.

Or you can use any of the speedbooster type adapters and then get basically the same FOV with APS-C as that lens would give on a FF camera.

Shawn
 
My first digital camera was an Olympus C-5060WZ in Dec 2002. it's sensor size is 1/1.8" (~ 7.11 x 5.33 mm). Max resolution is 1944x2592 pixels or 5mp. In 2004 I decided to find out what the maximum print size the C-5060 could make. I took a typical (for me) travel photo and I sent the file to a lab and had 4x6, 5x7, 8x10, 11x14, and 16x20 prints made. Then I could look at the prints and find out at what point did the image fall apart and I would know the limits of the C-5060WZ.

When the prints arrived I laid them and started looking at them with my eyes and a loupe. The 4x6, 5x7, & 8x10 were outstanding (as expected). Then the 11x14 was examined- It to looked outstanding. When I looked at the 16x20 it too was outstanding. What? I must have made a mistake. I had my wife look at them. She said all of them looked fine. Then I had friends look at them. Same response - all looked great.

Since then I sopped worrying about megapixel counts and just bought whatever camera I liked to use.and could afford. I still use my C-5060WZ and it's big brother the C-7070 7mp version.

My DSLR of choice is my Olympus E-5 12MP 4/3 format (not m4/3) camera. I never had an editor complain about the quality of my images (they never even asked what camera did I use). AP did ask once what was the longest lens I had and my answer was "600mm" for my 300mm actual lens. I still use my E-5s as I am heavily invested in 4/3 glass.

Last year I bought a mirroless camera - the Sony A7 III. Why? Because I can use all my 35mm glass on it including my L39 & M Leica glass. I have a ton of Olympus OM and Pentax M42 SMC Takumars that now have new life. The senor size was important, not for the pixel count but because my 21mm lenses would still work as 21mm lenses. No crop factor! It's fun using my Nikon Nikkor S 35mm f/1.8 for my Nikon SP rangefinder on the A7 III.
 
My first digital camera was an Olympus C-5060WZ in Dec 2002. it's sensor size is 1/1.8" (~ 7.11 x 5.33 mm). Max resolution is 1944x2592 pixels or 5mp. In 2004 I decided to find out what the maximum print size the C-5060 could make. I took a typical (for me) travel photo and I sent the file to a lab and had 4x6, 5x7, 8x10, 11x14, and 16x20 prints made. Then I could look at the prints and find out at what point did the image fall apart and I would know the limits of the C-5060WZ.

When the prints arrived I laid them and started looking at them with my eyes and a loupe. The 4x6, 5x7, & 8x10 were outstanding (as expected). Then the 11x14 was examined- It to looked outstanding. When I looked at the 16x20 it too was outstanding. What? I must have made a mistake. I had my wife look at them. She said all of them looked fine. Then I had friends look at them. Same response - all looked great.

You must have had a magical 5mp camera...
 
Here are cameras I was looking at, tried recently, one I have for more than one year.
I switched to Canon RP from 5D MKII and 500D. Mostly because of time of the year while it is getting dark and will be awfully dark. And now I'm just totally lazy to use flash.
You know, 500D build in flash, but FF is so much better... And no build-in flash. Maybe on some exotics like Pentax DSLR and expensive Sony fixed lens FF camera.

So, one of my main criteria was, is high ISO. Not 3200 high, but 25600+ high.

51563426858_83e3809e87_z.jpg


51563426833_a20435858a.jpg


Even at ISO 400, super duper X-T4 is kind of soft or blurry.

51563426843_e70e17a37a.jpg


Check on DPR: https://www.dpreview.com/reviews/canon-eos-r6-review/5

But if you are not lazy, flash photography is the key. Times I was not lazy and used flash indoors gave me best low light photography. Because with flash here is no low light and no high ISO noise, but good and natural saturation.

I think X100V is the best FujiFilm camera in this regard for lazy people like me. It is weather and dust sealed and it is the only FujiFilm X camera with weather sealed body and flash I'm aware of.

How many weather sealed cameras we know of with build in flash, still in production?

How many switched back from FF to lower ISO crops and using flash? Because flash still gives cleaner, well saturated images than super high iso/

Or screw it all and get 21 1.5 for M-E 220. :)
 
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