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Participant
November 20, 2024
Question

Color issue with PS

  • November 20, 2024
  • 2 replies
  • 354 views

Hi guys. I photo stuff up close for an auction company and I am having the absolute hardest time getting the colors right on some of the stuff I photo. I am using a Canon Rebel T7, then using their EOS utility 3 software to be able to view what I'm shooting on my computer. I'm shooting in raw mode and everything comes out in a .CR2 file until I start doing any editing to it. I havent tried the latest version of PS that just came out, but I'm running the previous one.

 

I'm sorry, I'm a novice at all of this stuff. Any help I really, really appreciate. Thank you.

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2 replies

Conrad_C
Community Expert
Community Expert
November 21, 2024

Below is a demo of how this can work. I photographed a scene under low quality, unbalanced lighting. But a color checker chart is in the scene, so in any good photo editor (Photoshop is shown), there should be a tool that will color-balance the image based on an area in the scene that’s supposed to be dead neutral. That’s the purpose of the gray patches on the chart, to be a calibrated neutral reference. In the demo example, one click of the gray sampler on a gray chart patch gets most of the way there, but some manual tweaks will still be needed because the light source was so bad. If the lighting was studio quality, it might be close to perfect after clicking the gray square.

 

If you shoot in raw, for higher quality this should be done in a raw processor such as Adobe Camera Raw or Lightroom.

 

You don’t have to put the color checker in every picture, but to achieve that, you must enforce consistency. The white balance in the color checker image is valid only under the specific lighting conditions in that shot, so as long as both the lighting and camera settings are locked down so that they’re held constant for all photos (not allowed to auto-adjust), you could in theory apply the same white balance to all of the images and you should be fine. But for color-critical images, maybe take an alternate shot with the chart in it and apply the same correction to the shot without the chart in it.

 

 

If you look closely at pictures of space probes like the Mars landers, they use the same type of tool: They attach a calibrated color checker chart to the vehicle in view of at least one of its cameras, so that they can calibrate their pictures and know when an image is showing actual, corrected colors of Mars.

 

Calibrating Mars
Two Colorful Calibration Targets Will Help Scientists Measure Martian Scenes

https://www.planetary.org/articles/calibrating-mars

D Fosse
Community Expert
Community Expert
November 20, 2024

You need to process your raw files to get a good visual match. That's necessary no matter which raw processor you use. You can't expect any automatic process to fix this.

 

Start with good neutral and even lighting! That's the most important thing of all. Include one of these in the shot, so that you have a reference. The color patches have standardized values (although you will mostly use the neutral patches to get the gray balance and tone curve right). You may still need to tweak individual colors and tones until it looks right:

 

All of this is still rather uncertain until you have a calibrated and profiled monitor, so that your file is correctly represented on screen:

 

At this point, you're over the hurdle. From here on in, there are standard color management procedures to preserve the colors downstream to final output.

Participant
November 20, 2024

Thank you so much for responding to my message. And is the color checker something that I would be photoing in EVERY photo too along with what I need to photo for work, and editing it out later, or is that just being used to calibrate colors at the start of each session?

D Fosse
Community Expert
Community Expert
November 20, 2024

If you need accurate color, you include it in the shot - or a separate reference shot. Use it as a guide for adjustments.

 

You can use it to make camera profiles, as long as you don't make the mistake of assuming this profile will always produce "accurate" colors. It won't. The main use for these profiles is for light sources with irregular spectral distribution, like LED or flourescent.

 

This is a huge subject, and the answer depends on which aspect of it you concentrate on. My answer was just "here's the big picture" seen from high above. But I would still maintain that without good lighting, most of it is moot. Setting up lights for studio work - photographing "things" indoor - is a skill.