Take the highest MP count you can get....or

[uhoh7]

Guy mentioned if two cameras were on a table he would take the one with the highest MP. He is not alone, for sure.

But's it's very interesting to hear what the inventor of CMOS sensors has to say on exactly this issue:

https://youtu.be/JkBh71zZKrM

This is a long lecture at Yale I think, but you can just forward to 38 minutes where he talks about the problems with small pixels and how marketing is trumping engineering and physics with high mp cameras like the A7r2. It's really worth a listen as he basically says: high MP counts "sell", so we make them, despite the fact they are not better because of the diffraction limit.

I did not get to this video as a way to "bash" the A7r2, which is obviously a very nice camera. I'm not mentioning the "L" word here at all. What got me here was another discussion about whether lens performance in general can vary at an aperture like f/11 or F/16.

In trying to understand this issue I came across articles which claimed the diffraction limit was f/13 on a 12mp FF but f/11 on a 24mp FF camera. Several of these stated outright, that unless you planned on shooting fast all the time, a larger pixel was more desirable because diffraction did not set in so soon and thus you could use f/11 and f/16 to full effect when you wanted DOF.

Now some think when you downsize a 42mp to 24mp the diffraction effects, which are greater at f/11, will magically disappear and the two images will be the same.

I don't really know, but I would like to find out, because I do shoot alot of landscapes and I do use f/11 often

I can't say I don't find it interesting the inventor of CMOS basically says outright: the MP race is a marketing scam. I'm not qualified to say to what degree it's true or not, but again I'd like to understand the issues better.

 

[Vivek]

Why post it here? A 16mp m43 sensor has smaller pixels and a higher pixel density.

Other than the RX100 cams, Sony cams with interchangeable lenses all have larger pixels.

 

[hcubell]

Guy mentioned if two cameras were on a table he would take the one with the highest MP. He is not alone, for sure.

But's it's very interesting to hear what the inventor of CMOS sensors has to say on exactly this issue:

https://youtu.be/JkBh71zZKrM

This is a long lecture at Yale I think, but you can just forward to 38 minutes where he talks about the problems with small pixels and how marketing is trumping engineering and physics with high mp cameras like the A7r2. It's really worth a listen as he basically says: high MP counts "sell", so we make them, despite the fact they are not better because of the diffraction limit.

I did not get to this video as a way to "bash" the A7r2, which is obviously a very nice camera. I'm not mentioning the "L" word here at all. What got me here was another discussion about whether lens performance in general can vary at an aperture like f/11 or F/16.

In trying to understand this issue I came across articles which claimed the diffraction limit was f/13 on a 12mp FF but f/11 on a 24mp FF camera. Several of these stated outright, that unless you planned on shooting fast all the time, a larger pixel was more desirable because diffraction did not set in so soon and thus you could use f/11 and f/16 to full effect when you wanted DOF.

Now some think when you downsize a 42mp to 24mp the diffraction effects, which are greater at f/11, will magically disappear and the two images will be the same.

I don't really know, but I would like to find out, because I do shoot alot of landscapes and I do use f/11 often

I can't say I don't find it interesting the inventor of CMOS basically says outright: the MP race is a marketing scam. I'm not qualified to say to what degree it's true or not, but again I'd like to understand the issues better.

That other thread was shut down. It seems that you want to restart the arguments all over again. Why don't you just accept that we are all a bunch of fools buying a 42MP camera, declare victory and go home.

 

[bradhusick]

C'mon. Be nice.

It's a legitimate question - go for higher megapixels at the same sensor dimensions or not. I think that now that sensors are capable of managing noise very well there's little to recommend lower pixel count.

I can tell you from experience with the Sony A7R and the A7RII the extra pixels are a real benefit, especially in the case where you want to crop an image. I am not sure I could tell the difference in prints smaller than 20x30 (yes I have the prints).

I like the combination of a full frame 35mm sensor and 42 megapixels. The next camera I will look at will be the Leica SL, but with 24 megapixels it will be a hard sell to replace my A7RII.

 

[jagsiva]

It will be interesting to see a comparison of the Pentax 645Z (or IQ150/250 or any MFDB with Sony 33x44) sensor against the Sony A7RII. Based on OP, the 645Z with 1.7x the real estate should be noticeable better, but from what I have read so far (Lula review), this appears not to be the case.

 

[bradhusick]

You can always go up in megapixels and sensor size, right up to 80MP and beyond.

At some point it comes down to what you like to shoot. For me that has never pushed me into MF, but it's personal taste.

For me 35mm and small camera body is a sweet spot.

 

[uhoh7]

C'mon. Be nice.

It's a legitimate question - go for higher megapixels at the same sensor dimensions or not. I think that now that sensors are capable of managing noise very well there's little to recommend lower pixel count.

I can tell you from experience with the Sony A7R and the A7RII the extra pixels are a real benefit, especially in the case where you want to crop an image. I am not sure I could tell the difference in prints smaller than 20x30 (yes I have the prints).

I like the combination of a full frame 35mm sensor and 42 megapixels. The next camera I will look at will be the Leica SL, but with 24 megapixels it will be a hard sell to replace my A7RII.

TY Brad

For Fossum, the issue is not noise but the lower diffraction threshold of smaller pixels. I agree, noisewise the A7r2 seems around the same performance as A7II, but it can't compare to the A7s, which is shooting with much less noise at high ISO. But 10mp is really a big difference vs 24, 36 or 42.

I'm not trying to insult anyone here. But the 42mp is considered a major selling point of the camera, and taken for granted as "better" by many good shooters. I should not mention evidence to the contrary? Not the right place for it?

I own and shoot Sony every day, and certainly I have considered the A7r2. This seems totally relevant as a topic of discussion here. I honestly do not yet understand how this limitation of smaller pixels effects us, but it certainly seems like a good question, some might want to understand before they spend 3 grand.

People disagree about all sorts of stuff on photography forums, much of what I've learned has been when somebody has cared enough challenge my pre-conceptions. If everyone always agrees, what is there to discuss?

 

[Guy Mancuso]

Okay let me take a stab at answering this. Actually he is correct but slightly misrepresenting a little.

Let's take a Phase One IQ 180 back which is a 80 MPX back with a believe a 5.4 micron sensor. This baby is big but and this will depend on lens and its resolving power , very important . But with a Rodenstock tech cam lens you will start seeing diffraction coming in around F8. Sony and most of there high quality lenses it starts at F11. In all my tests I have done I see it every time on the Sonys that the image is starting to degrade. It's very slight and yes you start losing a little resolution but not down to a 24mpx sensor and even those sensors it's about F11 also. So yes once you start getting past F11 things will degrade to lower levels. Now it may happen slightly faster on the 42 MPX sensor over a 24mpx sensor because of the smaller pixel pitch but by and large that is very small. Now many landscape shooters will go to F11 to gain the DOF but knowing there in that diffraction range. Best technique is to focus stack. Most 35mm lens there optimum resolving power is F5.6 to F8. So best practice to gain the best resolving power is to shoot right in that zone but to gain DOF you do a focus stack of maybe 3 zones of focus. Also I should point out this is where Tilt becomes a very valuable tool both in Medium format and 35mm is you can tilt to gain a wider path of DOF without stopping down more. Why many landscape shooter will Cary TSE lenses or MF folks use tech cams.

Now he is correct but I would not go as far to say what's the point of higher MPX cams both 24,36 and 42 MPX sensors will diffract but given this format size it's very small when that will happen.

Honestly most folks would never know the difference unless there looking at things 100 percent on screen and even than its a little underwhelming the effect. To really see it shoot something at F8 and F22 you should see it a lot easier.

No question I would pick a higher MPX. My client just emailed me tonight letting me know one of my shots there CEO loved and wants it printed really big in his office. As I said you just never know when you get that amazing shot and you need to go big. But I agree 24mpx is a very nice sweat spot until someone wants big or crop the hell out of your image. Rather have that elbow room myself. Besides all the technical reasons we are gear sluts it big or go home. Lol

Now having said all that 24mpx most folks may never need bigger why the comment on the marketing from him and he is correct. Let's be honest if your a OEM your going to market it no question. That's marketing we will never get away from it. Everyone of them do it and no one is excluded either. I read some of this marketing stuff and some of it is a joke to think we are that stupid but in general the average Joe des not know any better and it becomes a big selling point. We can't blame anyone for any of that because people will buy it.

 

[Guy Mancuso]

It will be interesting to see a comparison of the Pentax 645Z (or IQ150/250 or any MFDB with Sony 33x44) sensor against the Sony A7RII. Based on OP, the 645Z with 1.7x the real estate should be noticeable better, but from what I have read so far (Lula review), this appears not to be the case.

The real difference will come down to tonal range and smoother transition because of the bigger sensor. Better said it looks smoother but that gap is getting smaller. They really are Sony sensors . I tested the leaf cmos back , same sensor as the Pentax and it's a great sensor but it's not really night and day, it's close.

 

[Guy Mancuso]

Something I should point out. Lenses have a maximum resolving power at a given aperture you get past that aperture you start losing the resolving power and at the same time your getting into that diffraction area , so your getting dinged twice just by going past the point of optimum IQ. Case in point I would rarely if ever go to F16 and the only reason would be I'm forced too because I can't focus stack let's say. Most high quality 35 lenses the highest resolving power is in that F 5.6 to F8 range but need to know once you hit F11 your on the downward slide like diffraction. So it's a balance of lens and diffraction.

 

[hiepphotog]

TY Brad

For Fossum, the issue is not noise but the lower diffraction threshold of smaller pixels. I agree, noisewise the A7r2 seems around the same performance as A7II, but it can't compare to the A7s, which is shooting with much less noise at high ISO. But 10mp is really a big difference vs 24, 36 or 42.

I'm not trying to insult anyone here. But the 42mp is considered a major selling point of the camera, and taken for granted as "better" by many good shooters. I should not mention evidence to the contrary? Not the right place for it?

I own and shoot Sony every day, and certainly I have considered the A7r2. This seems totally relevant as a topic of discussion here. I honestly do not yet understand how this limitation of smaller pixels effects us, but it certainly seems like a good question, some might want to understand before they spend 3 grand.

People disagree about all sorts of stuff on photography forums, much of what I've learned has been when somebody has cared enough challenge my pre-conceptions. If everyone always agrees, what is there to discuss?

The thing is I thought you already got your answer from your recent FredMiranda thread on diffraction. Lens's diffraction doesn't depend on the resolution of the sensor. It's an optical phenomenon. If a lens peaks at f/4 (we're talking about center here), it will peak at that aperture on any recording medium. Higher resolution sensor just makes thing easier to spot the drop in higher frequency contrast (smaller details).

Of course, physics-wise, as the sensor gets denser, each pixel would receive less total light. Hence the noise at pixel level is always worse with the higher MP of the same tech generation. BSI in the A7RII helps because it reduces the travelling distance of photons from the microlens to the electron converter.

But realistically, is there anyone here going to look at photo at 1:1 all the time? So pixel-level noise is irrelevant. That's why people are comparing different MPs at a common size (whether for web display or for print). Scaling down a picture would average out the noise; the more you scale, the smoother it looks.

And I do hope this is not about Leica (24MP) vs. Sony (42MP) again.

 

[k-hawinkler]

IIRC isn't diffraction simply a function of the width of the lens opening?
Diffraction is not a function of the f number, i.e. width/focal length, or the sensor.
So larger formats than FF will suffer later, at higher f-numbers.

My FF Leica lenses seem to be affected by diffraction typically by f/8 or f/11.
However, the APO-Telyt-R 280/4 is already diffraction limited wide open.

High MP FF sensors can nevertheless still be very useful and desirable, at least to me.

 

[rhern213]

To add, the talk is regarding capturing an image on the sensor, it doesn't take into consideration making prints.

If you have a 24mp camera and need to print 30", a 200% enlargement has a more negative impact on IQ than the diffraction impact on a 50mp camera at it's native 100%. This is where mp's matter, however if you're never going to make prints, then yes there's no need for anything higher.

 

[k-hawinkler]

Well, how about cropping?

 

[Annna T]

TY Brad

I'm not trying to insult anyone here. But the 42mp is considered a major selling point of the camera, and taken for granted as "better" by many good shooters. I should not mention evidence to the contrary? Not the right place for it?

I don't think that the 6+ MP is what sells the camera. The slight IQ difference with respect to the A7r is rather due to the new technology used :

1) The back side illuminated sensor (BSI).
2) Then the on sensor PDAF, which is very efficient working in tandem with CDAF.
3) Add IBIS

and this body ticks all you need for a good picture (except those needing tracking AF for fast action). Personally I see too many pixels as a draw back for many because it eats storage space like mad and suppose higher processing resources. People are very aware of that.

Also diffraction kicking in earlier with higher pixels density is nothing new. It has already been abundantly discussed with the Nikon D800 and the A7r (F8 being judged the sweet spot, smaller than that diffraction begun to kick in). It has even been discussed for MFT sensors where you try to keep your lens at F5.6 or wider to avoid it.

One can use focus stacking to avoid the lack of DOF. Olympus for instance has announced they would implement that feature directly in the body with a firmware update for both the E-M1 and E-M5II. Rumors say that the E-M1II will get 20MB, which could explain why they are working on that feature.

 

[Slingers]

Sony advertises the A7RII has diffraction-reducing technology. What it does is a complete mystery but since there is some solution of either hardware or software I don't think you can just single out the A7RII as a sample of high megapixel causing diffraction. I believe BSI also increases diffraction.

 

[k-hawinkler]

Deleting all images except for the best keepers certainly will free up a lot of disk space for me! :grin: :thumbs: :banghead:

 

[k-hawinkler]

Sony advertises the A7RII has diffraction-reducing technology. What it does is a complete mystery but since there is some solution of either hardware or software I don't think you can just single out the A7RII as a sample of high megapixel causing diffraction. I believe BSI also increases diffraction.

No, diffraction is a lens property AFAIK!
It is a function of the opening diameter of the lens.
It just reflects the wave nature of light.
Of course with good lenses and sensors one notices it earlier.

IIRC Olympus does something similar for their native lenses.
I read somewhere it's a form of convolution sharpening.
Can somebody please fill us in with the correct info? Thanks.

 

[Slingers]

No, diffraction is a lens property AFAIK!
It is a function of the opening diameter of the lens.
It just reflects the wave nature of light.
Of course with good lenses and sensors one notices it earlier.

IIRC Olympus does something similar for their native lenses.
I read somewhere it's a form of convolution sharpening.
Can somebody please fill us in with the correct info? Thanks.

I believe diffraction is from a combination of lens and sensor.

Also I don't think diffraction is not all of a bad thing as it's the reason for sun stars.

 

[Vivek]

I believe BSI also increases diffraction.

I would think the opposite since the active photosite area is larger with no vignetting from the circuitary above such a one in a regular CMOS.