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Post by michelb on Dec 6, 2018 19:40:31 GMT
I was unaware that I had such a filter; thanks for bringing it to light. Concerning Posterization and Banding, I often see these terms used simultaneously; are they just two ways to say the same thing, or two different meanings ? I often see the abrupt "steps" in color when trying to darken a too-bright sky, at which point I usually just replace the whole sky. Also, why the DNGs as opposed to camera RAW ? Banding is the visual effect you are describing. There are those steps instead of smooth gradients.
Posterization:
As described in that link, it's a similar visual effect which can be artistic and deliberate... or it can be the result of inadequate processing. If you want to experiment with posterization, use the filter posterize and play with the number of steps you'll keep in your image. You can play with black and white pictures, which have 256 levels (with color it's 256 for each rgb channel) or simply with a simple image of a black to white gradient. If you choose 128 levels (7 bits), your histogram will show combing, but you may not perceive banding. Try with 64, 32, 16, 8 steps to compare and see how the effect becomes visible. If you are after an artistic effect to mimic some poster pictures with few levels, do the same. Usually 256 levels are ok even for black and white work. The issue is with relatively wide gradients (not details). Let's say you use curves to increase the contrast of the sky only (you stretch the brightness range while keeping the same number of original pixels; then banding will become visible. Sometimes, the banding will not appear after such an edit, but successive edits may reveal it later. My advice with such pictures of sky is to make the most of the tonal edits in ACR or in 16 bits to start with. Beware of denoising: on the contrary, you can add noise to mask a slight banding.
About DNG or camera RAW: no difference. DNG files will be read and edited even with older PSE versions, recent Raw files may not be supported.
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Post by BuckSkin on Dec 6, 2018 21:16:55 GMT
you can add noise to mask a slight banding. Thanks; I had not thought of that. |
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Post by PeteB on Dec 6, 2018 21:27:05 GMT
How do you adjust the strength of the Equalize filter?
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Post by hmca on Dec 6, 2018 21:39:19 GMT
michelb , I appreciate your detailed response and your interest in experimentation. I suppose it would depend upon how you intended to use the image whether you would take the multiple layer route or try the equalizer filter which might work well enough for image sharing via the web. I have been out today or I would have responded sooner.
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Post by Bailey on Dec 7, 2018 4:27:44 GMT
Thank you for allowing us to download your dng file michelb  FWIW, this is what I came up with just some quick editing of the dng file in ACR with no other processing. Obviously I wasn't there when you took the photo but hopefully this is close to what you saw in real time. |
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pontiac1940
CE Members
Posts: 6,357
Open to constructive criticism of photos: Yes
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Post by pontiac1940 on Dec 7, 2018 5:59:50 GMT
michelb Thanks for this tutorial. Had never seen the equalizer filter before and your example shows how it can work with such images. Thanks Clive This is my go ...  |
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Post by michelb on Dec 7, 2018 10:53:50 GMT
How do you adjust the strength of the Equalize filter? You are right, Peter... There is no way to do that other than adding a layer copy and changing the opacity or blend mode. |
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Post by michelb on Dec 7, 2018 10:57:08 GMT
michelb , I appreciate your detailed response and your interest in experimentation. I suppose it would depend upon how you intended to use the image whether you would take the multiple layer route or try the equalizer filter which might work well enough for image sharing via the web. I have been out today or I would have responded sooner. As a matter of fact, it's good not only for web. The example show that there is no artifacts or banding. Another reason to prefer it to layer works blending is that it has a strong effect on colors. If you don't want it, you can desaturate or use the layer copy in luminosity mode.
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Post by michelb on Dec 7, 2018 13:29:31 GMT
Thank you for allowing us to download your dng file michelb FWIW, this is what I came up with just some quick editing of the dng file in ACR with no other processing. Obviously I wasn't there when you took the photo but hopefully this is close to what you saw in real time. Yes, we can agree that it is a 'true' view, dull, flat and not too bright. In a way, our eyes do adapt to the luminosity as happens with the camera meter. The difference is we are 'scanning' over different parts of scene to perceive details both in shadows and highlights. We are combining different pieces in our minds with our own 'HDR' builtin feature... I am sure that in reality I did not see the additional depth in the snow parts extracted from the equalize filter. It was what I felt was missing and what I wanted to render. In the same way, there is no texture in most of the snow parts, and I miss that. That would mean adding noise or texture. However the interesting fact about the equalize filter is that it does not add or create anything, it reveals and enhances very slight differences present in the scene.
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Post by PeteB on Dec 7, 2018 17:18:25 GMT
If I am not mistaken, this is equivalent to Photoshop’s Fade command (which is not available in PSE). The Fade command allows the user to reduce the full effect of a filter. In Elements this can be replicated by
• Duplicating the unfiltered layer,
• Then applying the filter to the duplicated layer,
• Adjust the filtered layer’s opacity and (if desired) change the layer’s blend mode
• Then merged down the filtered layer with the unfiltered layer
Also, the Fade command is available as an action in Elements+
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Post by Bailey on Dec 8, 2018 1:25:54 GMT
I can see now how the Equalise filter might be able to be used in this type of scenario. Thank you for the info/tute michelb After I applied the Equalise filter and adjusted the blending mode and opacity (Multiply and 56%) I could still see a subtle red colour cast especially in the snow and clouds. I used a mask on the Equaliser layer to control where the filter is applied (in the clouds and snow) and its intensity (50% grey brush on the clouds) I then used a combination of a Levels and Hue/Saturation Adjustment layers to remove the red cast. The only concern I have is that when I look at the snow at 100% magnification it appears a little too "grainy" which isn't obvious when the full ("compressed") image is viewd on my screen, but the graininess might or might not be an issue if making a large print. There are ways to remove the graininess but I haven't played with them yet.
The aim for me in this attempt was to extract detail in the snow and sky while keeping the scene looking as natural as possible.
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Post by michelb on Dec 8, 2018 10:42:25 GMT
Another personal challenge: Old style print effect using exclusively 16-bits tools in ACR and the editor:
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Post by Bailey on Dec 8, 2018 11:04:12 GMT
I have been playing with other methods to extract detail from the snow and sky, again with trying to maintain the scene as original as possible. Here I didn't use the the Equalize Filter at all. I used just a Levels Adjustment Layer and raised the black point, to add contrast, for the snow and sky. The effect on the sky was too great so I painted over the mask with 50% grey to reduce the effect of the Levels adjustment on the sky. I'm now suspecting using Levels will most probably be quicker and easier for me in similar scenarios because I shouldn't have to also play with blending modes and/or opacity as I did when using the Equalizer in my previous attempt.
The top 2 layers are used to remove a subtle red colour cast as mentioned previously.
The resulting image now has a near enough to full tonal range throughout. |
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Post by Sepiana on Dec 8, 2018 11:43:03 GMT
If I am not mistaken, this is equivalent to Photoshop’s Fade command (which is not available in PSE). The Fade command allows the user to reduce the full effect of a filter. In Elements this can be replicated by • Duplicating the unfiltered layer, • Then applying the filter to the duplicated layer, • Adjust the filtered layer’s opacity and (if desired) change the layer’s blend mode • Then merged down the filtered layer with the unfiltered layer Also, the Fade command is available as an action in Elements+
Pete, you are not mistaken at all; on the contrary, you are absolutely correct. I use both Photoshop and Elements. Check this out.
How to Edit>Fade . . .
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Post by PeteB on Dec 8, 2018 22:26:44 GMT
Sepiana Thanks for the link ... I somehow missed that explanation.  |
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