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Diffraction, and its relationship to high-MP, high-density DSLRs ... does it happen sooner, or later?
Apr 13, 2019 10:55:02   #
Chris T Loc: from England across the pond to New England
 
The posts here seem to be numerous in relation to this topic. Some seem to believe there's more leeway with 46-50MP cameras. Others think you're better off with 12MP or 16MP sensor cameras. Am trying to sort it all out, here. What has been YOUR experience? Are you better off with high MP sensors or low MP sensors?

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Apr 14, 2019 06:33:31   #
CO
 
You're better off with a low resolution camera. It has to do with the scattering effect of light when it passes by the aperture blades and the Airy's discs formed. They become larger and begin to cover more photo sites as the lens aperture is stopped down. I did my own testing with a 12MP D90 once but I did not compare the images with a high MP camera. Here is an excellent article:

https://www.edmundoptics.com/resources/application-notes/imaging/limitations-on-resolution-and-contrast-the-airy-disk/

f/2.8 aperture
f/2.8 aperture...
(Download)

f/22 aperture
f/22 aperture...
(Download)


(Download)

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Apr 14, 2019 10:54:48   #
Chris T Loc: from England across the pond to New England
 
CO wrote:
You're better off with a low resolution camera. It has to do with the scattering effect of light when it passes by the aperture blades and the Airy's discs formed. They become larger and begin to cover more photo sites as the lens aperture is stopped down. I did my own testing with a 12MP D90 once but I did not compare the images with a high MP camera. Here is an excellent article:

https://www.edmundoptics.com/resources/application-notes/imaging/limitations-on-resolution-and-contrast-the-airy-disk/
You're better off with a low resolution camera. It... (show quote)


Well, thank you, CO … I suspected that was the case, as my 12MP T3 holds up pretty well against images I've shot with DSLRs (mostly the Nikons and Sony SLTs) having TWICE the Res. So, I think I agree with you.

Will take a look at the Edmund Optics site, though … thanks, again …

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Apr 14, 2019 18:28:03   #
Mongo Loc: Western New York
 
Chris T wrote:
The posts here seem to be numerous in relation to this topic. Some seem to believe there's more leeway with 46-50MP cameras. Others think you're better off with 12MP or 16MP sensor cameras. Am trying to sort it all out, here. What has been YOUR experience? Are you better off with high MP sensors or low MP sensors?


A low resolution display will mask the performance of the optics. You still get the same image with the same optics.

I think I posted it in a different thread, but as an example, some camera designers will aggregate pixels to get a higher sensitivity, and the spatial distribution of those aggregated pixels is usually 2x.

Me? I want all the gamut I can get! Low noise, high dynamic range, and lots of pixels packed really really tight together. Anything else is a compromise.

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Apr 14, 2019 19:27:05   #
Chris T Loc: from England across the pond to New England
 
Mongo wrote:
A low resolution display will mask the performance of the optics. You still get the same image with the same optics.

I think I posted it in a different thread, but as an example, some camera designers will aggregate pixels to get a higher sensitivity, and the spatial distribution of those aggregated pixels is usually 2x.

Me? I want all the gamut I can get! Low noise, high dynamic range, and lots of pixels packed really really tight together. Anything else is a compromise.


Mongo … first off - thanks for transferring here, so we can discuss this on MY OWN Topic Post, rather than another's … which was being seen as a "hi-jacking" - whatever the hell THAT means … anyway, I was most interested in what you had to say, there - but to dwell on it all was just to belabor the "hi-jacking" ….

Second - here's what you wrote over there - so you can refer back to it, if you wish ….

"Chris, the ringing artifacts are effectively a point spread function, similar to an MTF. The level of ringing is a quantum effect and creates a "blur." The size of that blur is more recognizable in high density sensors (such as on some dSLRs).

The point spread function (PSF) of an optical system (normally characterized on axis) is used as a quality metric of that system as it describes the input/output relationship of the optical system. Functionally, it is measured in the spatial domain, and MTF charts and other charts used to characterize system performance are used for this. Changing the aperture of a camera lens, changes the PSF, and it is normally at it's best at the lens' "sweet spot."

If one has a low resolution sensor, the optical system impulse response, which can be described by the PSF, matters less, because the sensor has less spatial resolution. In some cameras, adjacent pixels are aggregated, to create a larger pixel size. This tends to make the "blur" less apparent when looking at the aggregated pixels. However, it hasn't gone away, it is still there, it is just the sensor will not let you resolve it.

Everything is interrelated. There is a trade between resolution and dynamic range. So a camera with a lesser spatial resolution but a higher dynamic range can be perceived to perform as well as a camera with a higher spatial resolution with a lesser dynamic range. (A certain camera manufacturer lost market share over that issue, because most of the people buying cameras looked at the spatial resolution, not the color gamut. A story for a different day.)

With a suitable density (spatial resolution) imaging system, the ringing from diffraction effects can be seen near high contrast edges. I used the twigs in the trees when I looked at the OP image.

So to go back to the OP's question, there may indeed be diffraction effects which are limiting the resolving capability of the camera, but the area inside the red circle is something else. To me it looks like some kind of flare. It could be caused by many different things, but I have seen flare like that from filters, such as a UV filter, which tend to have less optimized anti-reflective coatings than the lens elements. Perhaps a lens system designer could provide suggestions as to what source might be more probable."

Now, then … first - which camera-maker lost market share for dwelling on this issue?

Second - could you please elaborate on what you mean by a) the spatial resolution b) color gamut … and how that relates to the Topic here - which is the relationship between diffraction, and high-MP, high- density DSLRs … and whether it happens sooner or later … meaning - is there greater leeway with LESSER RES cameras, as you have implied - with your comments, earlier. I understand you want as much RES as you can get … so, you would be an advocate of 46MP or 50MP designs - right? … But, is there some logic to the idea a lesser res camera like the 12MP D700 may actually be an advantage in this regard?

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Apr 14, 2019 20:11:28   #
User ID
 
Mongo wrote:
..........
Me? I want all the gamut I can get! Low noise, high
dynamic range, and lots of pixels packed really really
tight together. ..........

What does that get you in terms of a
viewable final product ?

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Apr 15, 2019 02:03:05   #
Chris T Loc: from England across the pond to New England
 
User ID wrote:
What does that get you in terms of a
viewable final product ?


User, I think Mongo is advocating HIGH-MP designs, like the Nikon D850 (46MP) or the Canon 5Ds R (50MP).

However, his explanation seems to border on CO's point - which is that the LESSER RES designs - like, say - the Nikon D700 (12MP) the D3s (also 12MP) or the D4 (16MP) or Df (also 16MP) - may, in fact - have an advantage over the HIGH-MP, High-Density designs, as there is a wider spreading of the individual pixels on the sensor, as there is LESS of them - thereby, contributing to a cleaner, clearer image, overall ….

Sony's best sellers, of their FF MILCs, incidentally - are the ones with 12MP sensors (NOT the ones w/ 42MP)

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Apr 18, 2019 21:30:41   #
Mongo Loc: Western New York
 
In my opinion, the camera should do the best it can at capture. Effects accomplished after capture may be done on the camera, or in post processing. So I would advocate the highest spatial resolution one can afford, the highest bit depth one can afford, the lowest noise, and the best lens MTF that one can afford. Softening images, adding degradation and other effects can be readily performed in post processing.

Everyone's system desires and price point are different. I could probably afford a D850 if I felt I had to have one, but I bought a D7200 recently to have a camera to play with. It doesn't do everything I might want, but rather is a compromise, given my situation.

The highest quality capture device will provide the best opportunity to get a desired product in the end. To me, but not necessarily to everyone, having higher resolution, gamut and MTF and post processing when I need to, are very reasonable trades. But not for everyone.

It would be very easy for a camera manufacturer to offer a blur function, if they knew that consumers wanted one.

(Example of contrarian view: Someone who is doing news gathering, and needs to have a short shoot to show time, may want a lower resolution imager, and gamut may be less of a concern publishing in a newspaper or on TV. Most of the media people I have talked with, however, prefer high resolution and high gamut, and argue that they can post process in minutes, and can wait.)

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Apr 19, 2019 06:46:36   #
Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)
 
Chris T wrote:
The posts here seem to be numerous in relation to this topic. Some seem to believe there's more leeway with 46-50MP cameras. Others think you're better off with 12MP or 16MP sensor cameras. Am trying to sort it all out, here. What has been YOUR experience? Are you better off with high MP sensors or low MP sensors?


sooner

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Apr 19, 2019 11:34:25   #
Chris T Loc: from England across the pond to New England
 
Gene51 wrote:
sooner


Sooner, huh, Gene?

You mean - that diffraction occurs sooner with a high-res, high-density camera (like the D850/D5s R) than with cameras with less density …

Interesting!!! … Thanks for your input, Gene …


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Apr 19, 2019 12:00:24   #
Chris T Loc: from England across the pond to New England
 
Mongo wrote:
In my opinion, the camera should do the best it can at capture. Effects accomplished after capture may be done on the camera, or in post processing. So I would advocate the highest spatial resolution one can afford, the highest bit depth one can afford, the lowest noise, and the best lens MTF that one can afford. Softening images, adding degradation and other effects can be readily performed in post processing.

Everyone's system desires and price point are different. I could probably afford a D850 if I felt I had to have one, but I bought a D7200 recently to have a camera to play with. It doesn't do everything I might want, but rather is a compromise, given my situation.

The highest quality capture device will provide the best opportunity to get a desired product in the end. To me, but not necessarily to everyone, having higher resolution, gamut and MTF and post processing when I need to, are very reasonable trades. But not for everyone.

It would be very easy for a camera manufacturer to offer a blur function, if they knew that consumers wanted one.

(Example of contrarian view: Someone who is doing news gathering, and needs to have a short shoot to show time, may want a lower resolution imager, and gamut may be less of a concern publishing in a newspaper or on TV. Most of the media people I have talked with, however, prefer high resolution and high gamut, and argue that they can post process in minutes, and can wait.)
In my opinion, the camera should do the best it ca... (show quote)


Mongo - not everyone can afford a D850 - nor should they be expected to. The D7200 is a very capable DSLR (I have the D7100) and although they both have their limitations - either one - is capable of producing some extraordinary images, in the right hands, and with the best glass. Your point about media people being happy with less Res cameras is noted, as they are quicker to print, but I suspect those who prefer HIGH-Res bodies don't really understand that - once those images are converted to newsprint - much of that higher-Res - is lost, anyway … but, of course, the argument could be made - the higher Res the image you start with, is - the less, the apparent loss … when conversion is done to newsprint ….

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Apr 19, 2019 14:29:44   #
Mongo Loc: Western New York
 
Until you have a cover shot...

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Apr 19, 2019 15:02:04   #
Chris T Loc: from England across the pond to New England
 
Mongo wrote:
Until you have a cover shot...


Well, of course - if you're shooting a cover shot (which doesn't really apply to newsprint, anyway) the best way to go - is - with an 8x10 … but, I suppose you could get away with a Medium Format, too ….

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Apr 19, 2019 15:30:43   #
RichardTaylor Loc: Sydney, Australia
 
Chris T wrote:
Well, of course - if you're shooting a cover shot (which doesn't really apply to newsprint, anyway) the best way to go - is - with an 8x10 … but, I suppose you could get away with a Medium Format, too ….


Not if it is for a motor sport magazine (I don't see anything larger than a 35mm full frame body when shooting trackside), or birding photography book (think Arthur Morris).

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Apr 19, 2019 17:20:42   #
Chris T Loc: from England across the pond to New England
 
RichardTaylor wrote:
Not if it is for a motor sport magazine (I don't see anything larger than a 35mm full frame body when shooting trackside), or birding photography book (think Arthur Morris).


Right, Richard - but for static shots - which will become cover shots - a view camera is the best instrument!

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