as the title says ,why are some images from certain cameras really responsive to corrections while others hardly change even pushing 100% in ACR both file types raw and jpeg.
April 25, 2024
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Pushing 100% what exactly - the shadows? And what exactly does a colour response mean? Do you have concrete examples?
I can see why different raw formats can have different responsiveness to pushing the shadows in ACR, but jpegs will generally be the same, unless they're in different colour spaces.
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What are "responsive to corrections" and "pushing 100%", for the small minority of us who aren't telepathic?
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As others have commented, it's necessary to make quite a few assumptions about what you mean by this before answering, but as a general point there are four factors that generally affect ability to push shadows. The first is the level of read noise relative to 100% exposure (which is the exposure you actually used, not the exposure that produces 'full well capacity'. The second is the how the SNR increases with exposure above the read noise limit, which is a function of the level of the read noise, the efficiency of the sensor and its size. The third is the nature of the residual noise, whether it is nicely random or nastily patterned. The fourth is the pixel count, which determines how 'blocky' the noise is.
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If you could provide examples, then it would be much simpler to understand your question (and to answer to it).
In addition to Bob response - there are some cameras, which apply [different strength luminance and color] noise reduction to raw data; this may affect postprocessing options too.
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Thanks. Plus another I forgot - the implementation of the CFA affects things as well. The less selective is the CFA the greater is the 'chroma' noise with respect to the 'luma'.
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thats an awesome answer Bob, understand totally, the image i pushed was a red lighthouse half in shadow and half facing the sun. i only pushed the jpeg file and the colours where very blocky and showed very little colour. the guy has posted the raws now, im off to work and will have a play tonight.
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this is interesting too, will post a link to the images after i have had a play first 😁
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For starters, outdoor shade has very little red light, unless there are a lot of bright white or red things nearby in the sun. So, red items are always an extra challenge in shade. When you're in the shade, what color is the sky that you can see? Is El Sol, the orange part of the sky, available to shine on you in the shade?
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so i downloaded the sony a93 test image and transfered the tiff to Ps and pushed the shadows of the red lighthouse and got a much better result than the posted jpeg that was originally posted. mind you i also pushed a jpeg that i processed and it was near identical to pushing the tiff . that had me stumped.
i also took one of my red leotard dance images into ACR and Ps the is so much more control in brighterning deep shadowed reds on my a74, no comparrision.
here is the posted lighthouse images, see how you go at lightening the red shadows.
www.dropbox.com/scl/fo/60aw7rwxpcu3or6mtpd1x/AHNNMwDdpYk8IFXcGYHm3uw?rlkey=99uufmhcjsgyui1mej5kmbbds&st=fxqezdg8&dl=0 -
The sun is very, very white, not orange. It appears orange during sunrise and sunset due to the extremely large amount of atmosphere its light has to pass through but the rest of the time, it's white.
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White is very, very the sun.
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The sun blows out on your retina when it is very high in the sky so it is hard to see any color, but it is still less white than the totality of all light coming from the sky, as some of the blue light from the sun that would seemingly be in the disk gets randomly scattered, if you are down in the bottom of the atmosphere. Noon daylight "white" is the sum of the disk and the large blue sky, without which, daylight would be slightly warmer in color.
