Problem to obtain "true colors" with photolab 9

[Ray.ishido]

Hi,

I am using an X-Rite ColorChecker Passport to calibrate my camera (Sony A7III), and I am encountering an issue. According to the X-Rite chart, the colors on the ColorChecker should correspond to specific RGB or LAB values.

I have no problem obtaining those values (or at least getting very close) when using Darktable with all processing disabled except Exposure and White Balance.

However, I haven’t been successful with PhotoLab. I disabled everything except Exposure and White Balance, tried the default settings, attempted to import and create a color profile, and even checked the exported files—but each time, the colors are off (sometimes significantly).

It seems as though PhotoLab is applying some kind of processing on its own, regardless of the user settings.

So, is there a way to obtain “accurate” colors in PhotoLab, similar to what I get in Darktable? This is quite important, as the photos are used for technical purposes, not artistic ones.

[LVS]

I’ll give this a try in the morning and see if I get the same results.

I found this which may be useful: Using X-rite Color Checker™ in DXO PhotoLab 8™ - Ed Ruth Photography Instructor in Bakersfield California

[platypus (Canon & Mac)]

Use PhotoLab’s calibration tool.

Learn more about the tool here:

Edit pictures with the Customize tab – PhotoLab

[calvingrinder (M4 ◦ Nikon ◦ USA)]

@Ray.ishido

It seems as though PhotoLab is applying some kind of processing on its own, regardless of the user settings.

I asked my butler about this, having no experience of my own, and this is what it said (ignore personal context bias):

To achieve technically accurate color with your Sony A7III in DxO PhotoLab 9.6, we will utilize the built-in Color Calibration tool. This tool bypasses the need for external software by generating a custom profile (DCP) directly within the app.

As a professional restorer, think of this as “digitally cleaning” the sensor’s bias before you begin your archival work.

1. The Capture Phase (In-Camera)

To ensure technical accuracy, the “baseline” image must be captured perfectly.

1. Lighting: Place the X-Rite ColorChecker Passport in the same light as your subject. Ensure it is flat to the camera to avoid perspective distortion.

2. Exposure: Avoid glare on the patches. Use your Sony A7III zebra settings or histogram to ensure no patches are clipping (especially the white patch).

3. Format: Ensure you are shooting in RAW.

4. Initial Setup in PhotoLab 9.6

5. Open DxO PhotoLab 9.6 and navigate to the Customize tab (Press D).

6. Locate the Color palette on the right-hand side.

7. White Balance: Select the Raw White Balance tool (Press W for the picker) and click on one of the light-grey patches (usually the second or third from the white patch) on the ColorChecker. This neutralizes the light source.

8. Using the Color Calibration Tool

This is the technical heart of the process.

1. In the Color palette, find the Color/B&W Rendering sub-palette.

2. Click the Calibration icon (it looks like a small grid/target) or the Create Profile button at the bottom of that box.

3. An overlay grid will appear on your image.

4. Alignment: Drag the four corners of the grid to align precisely with the corners of the 24 color patches on your physical ColorChecker Passport.

• Tip: Ensure the small central squares of the overlay match the center of each physical color patch.

5. Chart Type: In the tool options that appear, ensure the Chart Type is set to ColorChecker Passport Photo 2 (or the version you own).

6. Click Save and Apply.

• Give the profile a descriptive name, such as Sony_A7III_Studio_Daylight.dcp.

4. Applying and Verifying the Profile

5. Once saved, the profile is automatically applied. You will see the Type in Color/B&W Rendering change to DCP Profile.

6. Technical Verification: Check the HSL Tool (Press S to open the palette). With the profile active, the colors should appear natural and “flat”—this is your mathematically accurate starting point.

7. Batch Processing: To apply this to the rest of your shoot:

• Right-click the calibrated image and select Copy Correction Settings (Cmd + Shift + C).

• Select the other images from the same lighting setup and select Paste Selected Corrections (Cmd + Shift + V), ensuring Color Rendering is checked.

[calvingrinder (M4 ◦ Nikon ◦ USA)]

I also asked my butler “Describe how to ensure that PhotoLab is not applying some kind of processing on its own, regardless of the user settings, for that type of calibration.”

This was it’s response (but don’t blame me if the butler got into my shroom stash and is hallucinating):

To ensure that DxO PhotoLab 9.6 is not applying “hidden” corrections that could skew your technical calibration, you must move the software into its most neutral state. By default, PhotoLab applies the “DxO Standard” preset, which includes exposure and contrast enhancements.

Follow these steps to establish a “Zero-Base” for your Sony A7III calibration:

1. Set Global Preferences for a Clean Start

To prevent PhotoLab from automatically processing images upon import:

1. Open Preferences (Press Cmd + ,).

2. Go to the General tab.

3. Under Correction Settings, change the “Default preset for RAW images” to 6 - No Correction.

4. Uncheck the box Automatically use camera rendering if color profile is available (if visible) to ensure the software doesn’t try to guess a look before you apply your X-Rite profile.

5. Force the “No Correction” State on Your Calibration Image

Even if you’ve changed the global preferences, existing images in your library might still have the “DxO Standard” preset applied.

1. Select your calibration image in the Image Browser.

2. Go to the Apply Preset button (top right) and select 0 - General Purpose > 6 - No Correction.

3. Verify the Palettes: Ensure the following tools are explicitly Off in the Customize sidebar:

• DxO Smart Lighting (This is the most common “hidden” processor that alters tonality).

• DxO ClearView Plus.

• Selective Tone.

• Contrast / Microcontrast.

3. Neutralize the Color Rendering Palette

Before you click the Calibration icon to align your grid:

1. Locate the Color/B&W Rendering sub-palette.

2. Ensure the Category is set to Generic renderings.

3. Set the Rendering type to Neutral color, neutral tonality (if using the Classic Legacy color space) or simply Neutral color (if using DxO Wide Gamut).

4. Set the Intensity slider to 100 (this ensures you are seeing the “pure” base rendering before the DCP profile takes over).

5. Bypass Optical Corrections (Optional but Recommended)

For technical archival work, you may want to disable lens-specific processing during the profiling stage to ensure the color patches are measured exactly as the sensor saw them through the lens:

1. Go to the Detail palette.

2. Turn Off the Lens Softness (or Lens Sharpness) tool.

3. Turn Off Vignetting (Note: If your ColorChecker is large and near the edges of the frame, vignetting correction might actually help accuracy, but for technical “linearity,” most archivists prefer it off during the profiling step).

Pro-Archivist Tip: The “Linear” Check

If you want to be 100% certain the software isn’t adding a “S-curve” to your data:

• Open the Tone Curve tool (Press T).

• Ensure it is a perfectly straight diagonal line from the bottom left to the top right.

• If the 6 - No Correction preset was applied correctly, this curve will be untouched.

[gserim]

DXO could implement the “Butler” feature, since the necessary GPU capacity is available. Based on the original question, I would like the process steps listed here to be executed automatically. The individual steps could start with a default setting that can be adjusted by the user or interactively via the Butler.

[LVS]

I followed the instructions above and managed to create a clean profile. It’s not exactly the same as the chart the OP posted though. So I suspect something is a little off, whether its noticeable on a final image I could not say.

[LaoT]

@Ray.ishido

那么，PhotoLab 中是否有办法获得类似 Darktable 那样“准确”的色彩？这一点非常重要，因为这些照片是用于技术用途，而非艺术创作。

My ColorChecker Passport is over two years old and not very accurate anymore, but that doesn’t affect comparisons between different apps.

Below is my rough comparison, which I feel is quite close.

• 1，Average measurement of all ColorChecker Charts

• 2，DxO PhotoLab 9.6 Calibrated Color Profile

• 3，DxO PL9.6 Color/B&W Rendering

• 4，Camera Raw

• 5，Darktable

DxO PL9.6 is very close to CameraRaw, while Darktable is slightly different from the former two.

macOS

[Wlodek]

If you switch Working Color Space to Classic (Legacy), you’ll get different RGB values. I would rather rely on the RGB values in the exported output, using sRGB ICC profile.

[Ray.ishido]

Well, something is definitly off.I have followed all the instructions and yet, all my colors are wrong (and sometimes by a lot). Even the grey are off!
I attached the orinigal file if you want to try.

DSC01447.ARW (47,0 Mo)

[Ray.ishido]

Thanks but for some reason the problem still persist even following every steps. There is rreally somthing I don’t understand going on.

[Ray.ishido]

Your butler seems to be more performant than mine as it’s answers were way more advanced than the one mine gave me…
But for some reason it didn’t solved the issue. it’s very weird and I don’t understand why..

[gerarto]

@Ray.ishido

Well, something is definitly off.I have followed all the instructions and yet, all my colors are wrong (and sometimes by a lot). Even the grey are off!
I attached the orinigal file if you want to try.

There are several possible causes for what you’re seeing.

• Your color chart is probably quite old (X-Rite was acquired by Calibrite a while ago). Therefore, the colors may have lost some of their intensity.

• You’re trying to retrieve values ​​given for an sRGB profile… while using the DxO Wide Gamut working space.

• You think you need to retrieve the exact values ​​from the chart. But in reality, this is difficult due to exposure: change the exposure and the values ​​will be different… without the colors necessarily being wrong!

In practice, simply check that the RGB values ​​of the black/gray/white squares are identical to within +/- 1 to 2 units (this depends on the eyedropper tool’s position).

[calvingrinder (M4 ◦ Nikon ◦ USA)]

You could prompt the AI as to why it thinks this is happening, also upload the images to it, and tell it to provide you additional things to try.

I use Gemini Pro. I don’t know if Pro provides better thinking than the free version.

I’ve also uploaded the user manuals for PL, Nik, VueScan, my Z8, and my iPhone 17 Pro Max and told the AI to reference those before utilizing other sources. It seems to have cut down on errors and hallucinations.

[LaoT]

@gerarto

@Ray.ishido

Well, something is definitly off.I have followed all the instructions and yet, all my colors are wrong (and sometimes by a lot). Even the grey are off!
I attached the orinigal file if you want to try.

There are several possible causes for what you’re seeing.

• Your color chart is probably quite old (X-Rite was acquired by Calibrite a while ago). Therefore, the colors may have lost some of their intensity.

• You’re trying to retrieve values ​​given for an sRGB profile… while using the DxO Wide Gamut working space.

• You think you need to retrieve the exact values ​​from the chart. But in reality, this is difficult due to exposure: change the exposure and the values ​​will be different… without the colors necessarily being wrong!

In practice, simply check that the RGB values ​​of the black/gray/white squares are identical to within +/- 1 to 2 units (this depends on the eyedropper tool’s position).

Agreed, that’s how it should be.

[George]

@gerarto

You’re trying to retrieve values ​​given for an sRGB profile… while using the DxO Wide Gamut working space.

Saying so, does that mean one can’t use wide gamut for “true” colors? I always wondered about that difference between classic gamut and wide gamut. Mostly due to the red channel.

George

[Ray.ishido]

@gerarto

• You’re trying to retrieve values ​​given for an sRGB profile… while using the DxO Wide Gamut working space.

I think there must be something along that line: When I activate “Soft Profing”→ ICC profile “ProPhoto RGB” the RGB values are clother to what is expected (and clother than when it’s off or on on sRGB.) but are still off and sometimes by a lot.

Even when I export the picture (TIFF 16bit ICC color profile ProPhoto RGB) and import them in Affinity Photo, the colors are wrong (on the bright side they match what I can read in Photolab).

It’s really frustrating. I will contact the support because either there is something I miss or there it’s a bug in Photolab that prevent to obtain true color with my camera.

[Wolfgang ([ Win11, PL9, FP7, VP5, Nik8 + 3.3 ])]

Before you … …

@Ray.ishido

It’s really frustrating. I will contact the support because either there is something I miss or there it’s a bug in Photolab that prevent to obtain true color with my camera.

Get a new Color Checker IF you really want to rely on it. Your current device appears to be from 2017. Then try adjusting your camera’s output IF you have the necessary knowledge.

---

I calibrated your image → DSC01447_dop_dcp.zip (4.1 KB) (with WB), rechecked the WB using PL’s color picker (which very lightly adjusted color temp & tint) and finally reduced the exposure by 0.5.
Now the colors seem to be closer to what they should (?) be.

---

My ColorChecker is from 2019, but I hardly ever use it. For me (no studio work), it’s more important to calibrate the monitor regularly and, when I’m working with ProPhoto RGB, to set it up accordingly, etc.

My main goal is printing: With the monitor set to 80 cd/m² I check the colors (screen and print) using well-known and reliable test images,
e.g. from https://www.northlight-images.co.uk/printer-test-images/ …

or

And please note: This is a general suggestion and is not intended as an insult or anything similar!

[gerarto]

@Wolfgang

Get a new Color Checker IF you really want to rely on it. Your current device appears to be from 2017. Then try adjusting your camera’s output IF you have the necessary knowledge.

I agree with your analysis.

I think the color chart being used is no longer accurate. I have the same chart but a more recent one (Calibrite), and I have no difficulty obtaining a DCP profile that gives me correct values—identical RGB values ​​(within +/- 1 or 2) across the white-to-black range.

Here, with your DCP or mine, there is a more significant difference in values. However, I don’t see any noticeable drift: it’s visually quite close to reality. This was verified on a calibrated screen, with my chart under a 5000K light source.

[Ray.ishido]

Hi,
I would also suspect the color checker if the results in Darktable weren’t in accordance with what is expected.

I have contacted DXO support and they are working on the problem. They have been very reactive so far and I will post the solution for the problem (if it can help somebody else…) as soon as they give it to me.