|
|
Post by michelb on Dec 5, 2018 21:24:06 GMT
You have been interested by this recent thread:
Here is my question. I have been dealing with snow landscapes with extremelly flat and dull lighting. Mainly blacks and whites.
Here is a screenshot of my ACR display with its settings to get the most of the midtones range:
With the "default" settings, I would get this:
And now, here is the result in the editor with a mystery background layer copy.
A single filter has been added, with strength 40% and opacity 25%
Question: which is this filter?
(tip: look at the histogram)
 |
|
|
|
Post by hmca on Dec 6, 2018 0:00:56 GMT
I don't have the slightest idea....but great post and I'll be watching to see who knows what filter you used.  Keep thinking about your picture....not about the filter but about palm trees in the snow! Could you also tell us a little about them? |
|
|
|
Post by Bailey on Dec 6, 2018 2:18:19 GMT
Hi michelb,
I have no idea which filter you used, but the histogram shows that the filter has introduced banding into your image - 0 pixels at multiple brightness/luminosity values in the histogram.
Your "default settings" image is an excellent example of what I mentioned in this post - that all digital cameras will try to convert the image to 18% grey. So a predominantly white scene will come out dark with the whites a greyish colour.
To avoid having to fix this underexposure in post processing you simply need to add exposure to your exposure settings (how you do that depends on you and the scene).
Adding exposure will make the snow whiter by pushing the brightness/luminosity values of the snow closer to the right boundary of the histogram, where they should be, without banding being introduced. The reverse applies when shooting a scene with mainly black in it.
Imho, the in-camera histogram should be your best friend when taking photos.
|
|
pontiac1940
CE Members
Posts: 6,357
Open to constructive criticism of photos: Yes
|
Post by pontiac1940 on Dec 6, 2018 3:03:39 GMT
First off ... what a cool scene: palm trees and snow. No idea what filter. Snow and flat light are "difficult" ... the scenes lack contrast which you were able to pull up a bit in the last image...good. (Have you ever skied in flat white light? Hard to see any detail on the slope! .. last thing I needed when I skied 50 years ago.  ) It is very easy for cameras to underexpose snow (and white sand) scenes because the meters are programmed for 18% reflectance and they reduce exposures thinking a scene is overexposed..something like that. (M mode is good!) BUT it's better to work with a slightly underexposed snow image (it HAS to be underexposed!) than one with blown whites. The whitest white in a scene should still have details and should be just below white and that means everything else must be a titch underexposed. Has to be that way. BTW, the brightest whites in your image look good...nothing seems blown. Pray tell what the mystery background is and what filter you used. Thanks. Clive |
|
|
|
Post by Bailey on Dec 6, 2018 3:20:07 GMT
Hi Clive,
thank you for repeating/confirming what I posted earlier
|
|
|
|
Post by Sepiana on Dec 6, 2018 4:42:37 GMT
A single filter has been added, with strength 40% and opacity 25% Question: which is this filter?
(tip: look at the histogram) Going out on a limb here, taking a wild shot. (Making a fool of myself?)
Filter>Adjustments>Photo Filter>Warming Filter
|
|
|
|
Post by michelb on Dec 6, 2018 9:35:37 GMT
End of the mystery: The filter is Filter >> adjustments >> Equalize.
The scene is 200 meters from my home in Paris. It's a rare situation, we rarely get snow. That was in February this year.
I wanted to explain my choices but the very interesting comments already received make me want to wait a little for still other comments.
My purpose is to find the best ways to capture a scene and to render it. I have different ideas on the kind of final look I want, so I'll start with the 'natural' look of the scene and my 'enhanced' purpose. To get there, I need to state what camera and software I do use.
- the natural look is dull. No bright whites. No detail in most of the snow or in the sky. Hard to find a color spot. The 'default' view in ACR is the more realistic rendering. The "auto" is already a good choice, albeit too bright. The default with the Equalize filter at 100% is... astonishing.
- This scene can be rendered in a sketchy way but I want to render a good compromise between reality and dream. That means dealing mostly with the wide areas of snow and sky without apparent detail. - I am shooting with a Fuji 100S with good resolution, excellent dynamic range, no issues with noise. - I want to get the most of the ACR module in PSE 2019 and of the editor.
(what would be the best way to post a DNG version in this forum?)
I have much to comment about exposure, ETTR, posterization, banding, histograms, bit depth... but what is important is your personal assessment of the qualities of your 'digital negative' and the rendering you are after. I have other pictures taken the same day, same lighting, which call for very different renderings.
 |
|
|
|
Post by Sepiana on Dec 6, 2018 9:51:00 GMT
|
|
|
|
Post by Bailey on Dec 6, 2018 9:53:43 GMT
Hi michelb what would be the best way to post a DNG version in this forum? I'm not sure if it's the best way, but it will definitely work. You could upload the original DNG file to Dropbox.Then navigate to the file on dropbox and post the link to it. When someone then clicks the link, they should be prompted by their browser to download the file. hth
I used Mega to upload my DNG file in hmca's recent Creative Effects challenge (I have since deleted the file after the final "judging"). There's lots of ways to upload any types of files for others to access.
|
|
|
|
Post by Bailey on Dec 6, 2018 10:05:10 GMT
Hi Sepiana For the sake of clarification, this post points to the bridge photo I submitted. The link to the DNG file of the bridge (which I have since deleted) in hmca's post is actually the Mega link to the DNG file I uploaded (not hmca) and sent to hmca for the Creative Effects challenge as I mentioned in my previous post. |
|
|
|
Post by Sepiana on Dec 6, 2018 10:11:23 GMT
End of the mystery: The filter is Filter >> adjustments >> Equalize. Thanks, Michel! Now I can see what you did. |
|
|
|
Post by michelb on Dec 6, 2018 13:20:29 GMT
Hi Sepiana For the sake of clarification, this post points to the bridge photo I submitted. The link to the DNG file of the bridge (which I have since deleted) in hmca's post is actually the Mega link to the DNG file I uploaded (not hmca) and sent to hmca for the Creative Effects challenge as I mentioned in my previous post. Thanks to you and Sepiana for suggesting Dropbox.
Here is the link:
|
|
|
|
Post by hmca on Dec 6, 2018 15:42:26 GMT
I was able to get close to the same results using PSCC with the Equalizer filter at 40% fill and 25% opacity. I would appreciate a little info as to when and why you would use this filter over other pp choices.  |
|
|
|
Post by michelb on Dec 6, 2018 17:45:07 GMT
I was able to get close to the same results using PSCC with the Equalizer filter at 40% fill and 25% opacity. I would appreciate a little info as to when and why you would use this filter over other pp choices. Yes, you got the same result.
I have used the equalizer filter intensively a few years ago, not really to improve images, but to experiment with bit-depth (16-bits mode), histograms and posterization. The purpose of the equalizer is to transform a normal histogram (usual bell shape or two peaks...) into a flat one. Lets say you divide your brightness range in ten graduations, the result will be to get the same number of pixels in each of the ten steps. That's rather a mathematician concern than a photographer's one...
If you start with a relatively flat histogram, the result will be less striking than with one with a distinct peak like in my image. Play with the filter and look at the histogram (be sure to click the small icon to refresh the histogram). The new histogram will show 'combing', many vertical lines like in a comb. That 'combing' is a sure warning that there is a risk of posterization, which means that the stretching of tones (the simplification into less graduation steps) will make 'banding'. The eye can discern easily those 'bands'. Instead of a smooth gradient, you get clear different steps. The 'combing' in the histogram is a serious warning, but it does not mean that you'll see banding in your image. In the present example, I don't see any. However, further edits stretching tones (levels or curves for instance) may reveal it later.
In my experience, the equalizer filter is the most prone to combing. It depends on the normal histogram of the image. It proved interesting in images with a flat range of the image to give more depth. Snow scenes on cloudy lighting are typical. Anyway, the equalize filter is generally too strong and needs to be applied to a layer copy in low opacity. It's not the only way to stretch a given flat range. The conversion in ACR already helps, especially the 'auto' choice. The most efficient and flexible way is to work with various layers and masks like in HDR processing. However, the equalize solution is much easier and faster. In this image, there is no 'underexposure'. There is plenty of room in ACR before you get the out of range warnings for whites or blacks. The exposure is voluntarily optimized for highlights. Shadow details are meaningless in the image and noise is not a problem, it's even beneficial to the snow. Less so for the sky where you can mask.
So, the main reasons why this filter is not more used are: - understanding the relation between the change in histogram and the image - the fear of posterization - finding the image where it can be useful.
For advanced users wanting to fiddle with the equalize filter, I would suggest to compare both the histogram and the resulting image in 8 or 16-bits from the original DNG, at 100%. Remember that when there is a risk of posterization, it's better not to use any noise reduction to start with (adding noise is the second remedy to posterization after 16-bits editing). Also, the equalizer alone is not recommended if you want to get final 'low key' or 'high key' images (either no real black or no real white).
|
|
|
|
Post by BuckSkin on Dec 6, 2018 18:34:09 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 ?
|
|
) 
