December 20, 2025
You edited your picture perfectly It shines, the shadows are full, the colors pop. Satisfied, you export it and send it to your smartphone or printer. But then the shock: on the cell phone it looks sluggish, and the expensive wall print in black drowns out. Did Darktable make a mistake?
no. The problem is not in the software, but in the Perception. In this article we will explain why your eye is deceiving you and how you set up your workplace in such a way that “white” really remains “white”.
1. The Base: Your Monitor Lies (Probably)
Most of the monitors are set far too bright from the factory. This looks great in the electronics store, but it’s fatal for image processing.
- The problem: If your monitor shines on 100% brightness (often 300-400 cd/m²), you edit your pictures unconsciously darkerso they don’t dazzle you.
- The episode: The image then lacks light on any normal device (or in print). It looks underexposed.
- The solution: Dramatically reduce the brightness of your monitor. For normal rooms, a value of 100 to 120 cd/m² recommended. For many monitors, this is more like a setting of 20-30% brightness!
Pro tip: A colorimeter (e.g. Datacolor Spyder or X-Rite) is mandatory for serious work at some point. It not only measures the colors, but also helps you set the correct brightness.
2. The boss: ambient light
Your eye is not a fixed measuring device, it constantly adapts to the environment. This is called “chromatic adaptation”.
Scenario A: The Darkroom
You sit in the completely dark room in the evening. Your monitor looks extremely bright. You lower the exposure in the picture.
Result: The picture becomes too dark.
Scenario B: The Sun Window
The sun is shining right into the room. Your monitor looks dull and dark in comparison. You increase contrast and brightness.
Result: The picture is burned out.
The practice solution: Ensure constant, dimmed room light. No direct light on the monitor, no direct sun in view. Professionals use standard light lamps for this, but a good LED lamp that does not shine directly on the shade is a good start.
3. The Trap of the “Dark Themes”
We love dark themes. They look professional, protect the eyes and do not distract. also Lightroom, Capture One and our own Pro Themes Use almost black backgrounds.
But be careful: The eye can be deceived (simultaneous contrast).
- One and the same gray acts on one black Background brighter than on one man background.
- If you use a very dark theme, you take your photo subjectively as Bright and high-contrast true than it actually is.
- As soon as you look at the image on a white website (e.g. news page), it suddenly looks dull and dark.
The “Reality Check” in Darktable
So do you have to use a bright theme? No! But you must ask Darktable to show you the truth before you export.
Use the Color Assessment Mode.
- Click on the light bulb icon at the bottom right (or press
Ctrl+B). - Darktable shows a white frame around your image.
- If your picture suddenly looks “dirty” or too dark: Correct the exposure (usually +0.3 to +0.5 eV) until it also exists against the light white.
4. The target medium decides
An image can rarely be perfect for all media at the same time. You have to decide:
| target medium | Special feature | Hint |
|---|---|---|
| Social media / mobile phone | Displays are very bright, high-contrast and colorful. | Here the picture can be “crisp”. Always export to sRGB. |
| Websites (bright) | On a white background, shadows act faster black. | Pay attention to good drawing in the depths. Use the color rating mode! |
| print (paper) | Paper does not light up! It only reflects light. | An image for printing often has to be on the monitor too bright and Too slack Appearance to appear printed correctly. Use the “Softproof” (icon in the bottom left). |
5. The smartphone paradox: “But all have bright displays!”
You might be wondering now: “Why should I dim my monitor when everyone uses an iPhone with a super bright OLED display today?”
This is a logical objection, but a trap lurks here:
Whoever edits lightly delivers dark.
- If your monitor is extremely bright, you perceive your image as radiant. So you will tend to take back the exposure a bit.
- The result: It looks good on your “floodlight monitor”. But on any other device (laptop in energy saving mode, cheap office monitor, tablet in the evening) is the picture way too dark And the shadows drown.
The strategy for social media:
Stay on your calibrated, moderate monitor (120 cd/m²) as a reference. This is your “safe haven”. But if you’re exporting specifically for Instagram or Web, you’re allowed to push the histogram a little more boldly to the right (“Expose to the Right”) than you would for an art print.
The final check: Send the picture to your cell phone before posting. If it looks good there with medium brightness, you did everything right.
Summary: Checklist for the right brightness
- Dim monitor: Down with the brightness (destination: approx. 100-120 cd/m²).
- room light: Avoid direct sun and complete darkness.
- Histogram trust: Your eye is lying, not the histogram. Make sure that the middles (the “mountain”) are in the middle or slightly to the right.
- The ISO check: press before export
Ctrl+B. Is your picture against the white frame? If yes -> Export!
