Strange noise on the background, appears after processing raw images

Mike Engles said:

What am I missing?

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I don't know what you are missing because you haven't provided me with your RAW file. There is no point in continuing this conversation unless you provide a RAW file as requested.

CatchingTime said:

Mike Engles said:

Well I have a picture of the moon 5D2 RAW, a lot of black and noise. I pushed the shadows as well as brightness and applied in Lightrroom the Adobe profile for my 100-400 lens at 400 mm. I have panned all over this and just see pixels move as I switch between correction and no correction. I see no interference patterns anywhere.

None at all like the concert picture, nor the circular smearing in the comet picture. What am I missing?

No correction

If this is the result of decoding digital images and lens profile correction, it eludes me. Take one of your images and go through the steps, like I have.

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You're missing a lens with ample distortion shot wide open; I'm sure you know that telephoto lenses have much, much less distortion than UWA lenses. Pick a wide lens, shoot it wide open, and repeat. Also, viewing at 33% in LR vs. 25% can show the interference pattern, which gets hidden with downsampling (by the graphics card).

You can do it right now, sitting at your desk. Just follow my instructions above.

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Well I was trying to replicate the concert pattern.The OP took the same lens to the concert and got that pattern

You know I am not going through these hoops. No one mentioned all these special qualifications before. It was supposed to be any image to varying degrees.

Also the comet picture was a 70-200 at 70. The image exposure was 10 secs,

If you follow the 500 rule, the exposure should be 7.14 secs to avoid rotation and start trails. That image has rotation, That is why the corners are smeared.

Please show the effect with one of your pictures. You are the expert in doing this

Mike Engles said:

CatchingTime said:

Mike Engles said:

Well I have a picture of the moon 5D2 RAW, a lot of black and noise. I pushed the shadows as well as brightness and applied in Lightrroom the Adobe profile for my 100-400 lens at 400 mm. I have panned all over this and just see pixels move as I switch between correction and no correction. I see no interference patterns anywhere.

None at all like the concert picture, nor the circular smearing in the comet picture. What am I missing?

No correction

If this is the result of decoding digital images and lens profile correction, it eludes me. Take one of your images and go through the steps, like I have.

Click to expand...

You're missing a lens with ample distortion shot wide open; I'm sure you know that telephoto lenses have much, much less distortion than UWA lenses. Pick a wide lens, shoot it wide open, and repeat. Also, viewing at 33% in LR vs. 25% can show the interference pattern, which gets hidden with downsampling (by the graphics card).

You can do it right now, sitting at your desk. Just follow my instructions above.

Click to expand...

Well I was trying to replicate the concert pattern.The OP took the same lens to the concert and got that pattern

You know I am not going through these hoops. No one mentioned all these special qualifications before. It was supposed to be any image to varying degrees.

Also the comet picture was a 70-200 at 70. The image exposure was 10 secs,

If you follow the 500 rule, the exposure should be 7.14 secs to avoid rotation and start trails. That image has rotation, That is why the corners are smeared.

Please show the effect with one of your pictures. You are the expert in doing this

Click to expand...

My point was that there are many aspects to the equation that affect how noticeable it is, not that every condition has to be met to see it. I already showed the effect with a real-world example, above. In this case, the effect wasn't as pronounced because I was using a camera with decent high-ISO performance (R5), and a great lens that needs little correction; even so, you can see the effect of applying the lens profile. I then further demonstrated the effect with a camera that has poor high-ISO performance (5Ds), with two different lenses that require more distortion correction than the Sigma 40/1.4.

I don't care one way or another whether you actually do the test I suggested above, using parameters that make the effect more noticeable to you. That being said, coming back and throwing your hands in the air because you don't see the effect in your existing images isn't productive for any of us, nor does it prove you right. If the shadows aren't 3-5 stops underexposed, it will be hard to see, and this effect may not show in every picture taken, as I outlined.

If, however, you want to learn something about this topic post-bloviation, do as I suggest and take a few shots with the lens cap on with several different wide lenses. The method I outlined should only take about 5 minutes and is reproducible, which I believe is what you asked for, a few posts back.

Mike Engles said:

If he is correct, then the effect should be able to be reproduced consistently.

Hypotheses are only valid if confirmed by experiment

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Lots of hypotheses are wrong but still needed to get closer to the core. Science is more often about blind alleys than not.

Another hypothesis is that the colorful flaws are caused by scaling different color channels individually to compensate for color shift from center to edge in ordinary photographs. Color shift by intensity is also a nasty issue.

Some cameras also have shading compensation (not vignetting) to compensate for light hitting the outskirts of the image sensor at an angle.

Quite a few suggestions are floating around. More hypotheses are needed to pin down what is going on here. Falsified hypotheses also have value.

Tristimulus said:

Lots of hypotheses are wrong but still needed to get closer to the core. Science is more often about blind alleys than not.

Another hypothesis is that the colorful flaws are caused by scaling different color channels individually to compensate for color shift from center to edge in ordinary photographs. Color shift by intensity is also a nasty issue.

Some cameras also have shading compensation (not vignetting) to compensate for light hitting the outskirts of the image sensor at an angle.

Quite a few suggestions are floating around. More hypotheses are needed to pin down what is going on here. Falsified hypotheses also have value.

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Good point. Prove it.

CatchingTime said:

Mike Engles said:

Well I have a picture of the moon 5D2 RAW, a lot of black and noise. I pushed the shadows as well as brightness and applied in Lightrroom the Adobe profile for my 100-400 lens at 400 mm. I have panned all over this and just see pixels move as I switch between correction and no correction. I see no interference patterns anywhere.

None at all like the concert picture, nor the circular smearing in the comet picture. What am I missing?

No correction

If this is the result of decoding digital images and lens profile correction, it eludes me. Take one of your images and go through the steps, like I have.

Click to expand...

You're missing a lens with ample distortion shot wide open, and possibly a camera with poor high-ISO noise characteristics. I'm sure you know that telephoto lenses have much, much less distortion than UWA lenses, and any lens shot 2+ stops from wide open will have less vignetting. Pick a wide lens, shoot it wide open (with lens cap on), and repeat. Also, viewing at 33% in LR vs. 25% (etc.) can show the interference pattern, which gets hidden with downsampling (by the graphics card).

You can do it right now, sitting at your desk. Just follow my instructions above.

Click to expand...

I was able to reproduce it sitting at my desk with an EOS 6d ii. It doesn't matter what lens you shoot with, just apply the correction for a wide-angle lens. Actually, the EF70-200 (either version) is particularly bad. Use a dimly lit scene and auto ISO (auto iso with the lens cap on doesn't work). Add sharpening to enhance the effect.

Why would I want to apply the wrong profile. No wonder there is banding if you use the wrong profile to correct..It means that the image has not been fully corrected and you now have bits of 2 distortions interfering in the same image.

Mike Engles said:

Why would I want to apply the wrong profile. No wonder there is banding if you use the wrong profile to correct..It means that the image has not been fully corrected and you now have bits of 2 distortions interfering in the same image.

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You are not trying to correct the image for publication! You just need to reproduce the effect, so any raw file will do as long as it has enough noise to work with. It doesn't matter what lens was in front of the sensor, we are looking at sensor noise--the signal is irrelevant.