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If I open a raw image in Photoshop and Paintshop pro their histograms and their look is different. However, if I open a Jpeg image in both Software, then their histogram and look is the same. What does cause it? I am not familiar with photography, but, as I understood, the raw images need some sort of algorithm to apply color to them. Is it the origin of difference? How can I then apply different algorithms in Painshop pro 2018? Below are some examples for an image taken from here:

enter image description here

MOON
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  • In Paintshop Pro you are measuring only a Selection, not the entire image? – cmason Mar 01 '18 at 13:28
  • I opened the image and used histogram. I did not select any part of image. – MOON Mar 01 '18 at 13:30
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    In both cases, the images are visibly different, so why would you expect the histograms to not be different? Regardless of settings, your camera does some amount of processing before saving the JPG, so the RAW and JPG histograms are never going to be 100% matches. There's probably something similar going on between applications - different default initial processing when opening the file. – twalberg Mar 01 '18 at 13:35

2 Answers2

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It's all to do with the profile applied to the raw files and guesses other software makes as to what that profile ought to be...

RAW is not an 'absolute' format in terms of the image displayed, it's raw data to which an 'opinion' of what the image ought to look like can be manipulated from. It will already contain several view options added by the camera, based on the photographer's pre-determined settings, but these can be changed later, in software.

Adobe RAW in Photoshop will make a guess at what it thinks the Nikon default profile ought to be and what adjustments the photographer may have made to their settings, but frankly it usually makes a horrible mess of it, because it isn't the same as Nikon actually use, it's an attempt to reverse-engineer how Nikon does it. Photoshop interprets the profile as being Adobe RGB(1998).

By the look of it, Paintshop Pro has even less of a clue as to what it really ought to look like. I don't have Paintshop to be able to examine what its guess was.

The only app that can actually guess correctly is Nikon's own software suite, including ViewNX-i. ViewNX-i knows exactly what the camera's settings were, including that the photographer was using the Vivid enter image description here colour profile addition, for extra colour-punch...

enter image description here

To get that data into Photoshop or Paintshop correctly, the best way to do it is to export as a TIFF... then it will open looking something like it was intended, without having to make any guesses. The correct Profile is now showing as Nikon sRGB 4.0.0.3002 when imported to Photoshop.

On the other hand, the jpgs have been saved, imo [see below] directly from the camera, with the internet standard sRGB profile. This, allowing for variance in actual monitor calibration, is the closest you get to the artist's actual intent, without having Nikon software to interpret for you.

NEF interpreted by PhotoRAW

enter image description here

TIF after export from ViewNX-i with no adjustments

enter image description here

JPG, for comparison

enter image description here

As you can see, the TIF has more in common with the JPG, though the JPG is slightly darker in the greens.

I cant really post a picture of what the image actually looks like in ViewNX-i because the screen layout won't let me drop the size down and conveniently place the histogram over it like I can in Photoshop, but in fact the jpg is the closest of the three to what it looks like in ViewNX-i, so the camera has done a pretty decent job of conveying in a more 'portable' format [sRGB JPG] what the photographer's intent was according to his camera settings.

xiota
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Tetsujin
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  • Thank you. Why do you think Paintshop pro does a worse job than Photoshop in a guessing the profile? – MOON Mar 01 '18 at 17:27
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    It's not something I've ever used; I'm not on Windows [which has its own colour management issues] & I've had Photoshop since it was Mac only, back in the early 90s. My only guess is the ability of each team's R&D structure. How prepared each is to fully reverse-engineer the camera manufacturer's algorithms. I really have no information source, only guesswork, sorry. – Tetsujin Mar 01 '18 at 17:46
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    @MOON It's not worse, it's just less similar to what the camera's processing engine does. It actually looks a lot more neutral/accurate and less "punched up". – hobbs Mar 01 '18 at 23:17
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    @hobbs It's not worse in terms of human perception. It is worse at guessing the original color profile. Since you yourself said it is less similar to what the camera does it is by definition worse at trying to guess what the camera does. – slebetman Mar 02 '18 at 00:11
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    Sometimes I downvote because of some technical inaccuracy or not really answering the question or some such. (It wasn't me.) Sometimes I'm just bored and randomly click around the screen. Then when it occurs to me I should upvote, the system has locked the vote. I find nothing wrong with this answer, except that saying Photoshop makes a "horrible mess" might offend someone. Or perhaps someone doesn't like TIF? Made some minor edits in case someone wants to take backsies. – xiota Aug 23 '18 at 09:46
  • Or perhaps quibbling about phrasing about what exactly raw files are and how they're processed? – xiota Aug 23 '18 at 09:52
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    I wouldn't downwote but there are a few technical issues. Most obviously, Photoshop doesn't "interpret the profile as being Adobe RGB". The whole process of RAW color conversion is mapping from the source color space (which is very individual and may need to be reverse-engineered, but in any case has nothing to do with sRGB or AdobeRGB) to the target space, which in Photoshop you can set to whatever you want. This conversion uses many parameters, many of which are user-adjustable, so in the end it's a matter of taste. Arguably, Photoshop does a better job than manufacturer's converters... – Zeus Apr 17 '19 at 07:59
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    ...There is simply no particular reason to follow the manufacturer's (camera) settings, because they are, well, just another bunch of settings. Some of them are more technical and some more creative, but for the most part you sitting in front of the monitor adjusting the sliders are in a better position to choose them than the camera 0.01 s before the shot. For this reason, when shooting RAW, most of the in-camera color/effects-related settings (including white balance) are irrelevant and I never bother to set them. – Zeus Apr 17 '19 at 08:07
  • So you'd be happy with what Paintshop made of it & start from there? – Tetsujin Apr 17 '19 at 08:32
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    @Tetsujin Why not? Maybe I'm not a fan of any of the profiles provided by the camera manufacturer. Point being that one of the flexibilities afforded by raw formats is precisely that you're not reliant on one vendor's software, so you should use the raw converter that suits your needs, produces adequate image quality for your use case, and provides a look you like and/or can be used as a reasonable starting point for further editing. Sure, Nikon's software will match the built-in profiles most closely, but that's a rather narrow definition of artist's intent. – Graumagier Jun 02 '20 at 17:45
  • @Graumagier - the photographer wouldn't have dialled in Vivid if he wanted flat. He was looking at the rear screen while he was working, so we have to assume that was his intent. Any other start point would be just random. Paintshop's start point doesn't even manage to get the leaves green. Why would anyone want to start from there? – Tetsujin Jun 03 '20 at 09:40
  • @Tetsujin Maybe the photographer didn't care that the camera was set to 'Vivid' because the photographer was saving raw files? I've shot in daylight with CT set to 'AUTO' when I know good and well when I begin raw conversion I'm going to set a specific CT and WB setting. I've even shot with the CT set to something like 2700K because it makes no difference to the actual raw data, only to the JPEG previews, 95% of which I'll never even look at. – Michael C Apr 25 '23 at 06:19
  • I never trust the rear LCD screen with regard to color, contrast, brightness, etc. anyway. They are set by manufacturers to make the flat, horrible light in camera stores look good when a prospective customer snaps a few sample photos of aisle 4 which ends at the camera counter. Rear LCD screens lie like politicians! – Michael C Apr 25 '23 at 06:40
  • @MichaelC - you do seem to have a bee in your bonnet about this, whenever it's mentioned. The OP asked why. I answered why. If the original photographer had wanted it to look significantly different, then the jpg & nef they put online would also look significantly different. They don't in ViewNX-i …they are different, but not by a great deal. We don't have access to the sidecar file to see exactly what was further tweaked, only the two images they finally posted. Opened directly in Photoshop they are significantly different. My argument stands. – Tetsujin Apr 25 '23 at 08:46
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Raw image files contain enough data to create a near infinite number of interpretations of that data that will fit in an 8-bit jpeg file.¹ Anytime you open a raw file and look at it on your screen, you are not viewing "THE raw file." You are viewing one among countless possible interpretations of the data in the raw file. The raw data itself contains a single (monochrome) brightness value measure by each pixel well. With Bayer masked camera sensors (the vast majority of color digital cameras use Bayer filters) each pixel well has a color filter in front of it that is either red, green, or blue.² For a more complete discussion of how we get color information out of the single brightness values measured at each pixel well, please see RAW files store 3 colors per pixel, or only one?

How the image you see on your monitor when you open a raw file will look is determined by how the application you used to open the file chose to interpret the raw data in the file to produce a viewable image. Each application has its own set of default parameters that determine how the raw data is processed. One of the most significant parameters is how the white balance that is used to convert the raw data is selected. Most applications have many different sets of parameters that can be selected by the user, who is then free to alter individual settings within the set of instructions used to initially interpret the data in the raw file.

The histogram is almost always based upon the image in the form it is displayed on your screen. It is not usually based on the entire contents of the raw data contained in the file. Since the histogram measures the image as displayed on your screen, when the raw data is interpreted differently and the image looks different as displayed by the viewing application, the histogram will reflect those differences of interpretation.

¹ Sure, you could take a picture that contains a single pure color within the entire field of view. but most photos contain a wide variation of hues, tints, and brightness levels.

² Except the "red" filter is really more of a yellow-orange color, the "green" filter is more a yellowish-green color, and the "blue" filter is a violet-tinted blue color. In other words, the colors of the filters in a Bayer mask do not correspond to the three colors our RGB monitors emit and blend to reproduce the response in our retinas that many other colors do. In fact, the colors of the filters in a Bayer mask are much closer to the three colors that each of the three types of cones in our retinas are most sensitive to than they are to the three "primary" colors we use for our RGB color reproduction systems.

Michael C
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    I know I've quibbled with you for years about phrasing around this. This answer I can get behind. :) – mattdm Mar 03 '18 at 14:28