Epson Scan vs. Canon photo color correct

[sfgate27]

All,

Have stumbled on this forum after a LONG google search. Hoping someone here can help me out. I have recently taken on the task of scanning lots of old photos. In order to make my workflow faster, I've set up a basic photo studio to take photographs of album pages instead of scanning them with a flatbed. (I'm scanning albums with "sticky" pages not the sleeves you might first think of, so there is no plastic layer between the photo and the camera. Although there is a piece of anti reflection glass in order to keep the photo flat).

I have gotten some pretty good images from my set up using a Canon Rebel T2i and 2 75 watt Halogen bulbs. The flatbed scanner I had originally purchased for this task is an Epson V600. I am getting some very strange color differences with the Canon shot (especially in the red channel) and I'm wondering how much of this is uncorrectable and how much I can correct with various retouching. I have tried adjusting the red channel using Selective Color adjustment in photoshop in combination with other brightness/contrast/etc... adjustments but i havent been able to get an image from the camera that is close enough to the flatbed image (which is VERY faithfully reproducing the image, so i am considering that the "gold" standard for my Canon set up).

Can anyone help me make image 2 here (from the canon), as similar as possible to image 1 (from the Epson scanner). You will notice some distortion of the image in the Canon version that is a result of the photo not being PERFECTLY flat. That is NOT something I am trying to correct. Its just the color/brightness/contrast/etc.. that I'm trying to make similar to the Epson image. The reds especially are way out of wack in the Canon version. Too bright and not enough detail. But I can't seem to fix those without messing something else up (like the drapes in the background). Any help on how to do this, how/why these images differ so much, etc... would be extremely appreciated by me and by some very nice people I am scanning these for.

Thanks!

Image 1 - Epson V600 Scan (Original)

Image 2 - Canon Photograph (Original)

[Anthony Wood]

Have you tried adjusting the white balance in the camera? It might also be worth seeing what effect increasing the exposure a little has on the saturation of the reds... there is some detail in the blacks on the scanned version not seen in the other.

[sfgate27]

I have, thanks for the suggestion. The white balance is set to a custom value in the camera using a white card. its possible im doing that wrong but ive played with it in photoshop too and i cant seem to get all of the colors correct using just white balance. either the reds are wrong (the sweater is the best example of this) or the rest of the photo is wrong. the whites in both image are pretty close to white from what i can tell. but i have been staring at these for a long time so i have gone completely crazy too. does the white balance look off to you?

[Anthony Wood]

It doesn't look off as such I just wondered if having a very slightly cooler image to start with might help. It might even be the case that you'd get better performance using a daylight source with a daylight white balance. Although I'm not familiar with your Canon I've experienced some sensors performing better in one than the other. That's a bit of a long shot I know.

[sfgate27]

ok, thanks. yeah, lighting is something im thinking i need to work on. I'm using ge's "reveal" branded 75w halogen bulbs right now. any suggestions for something that would be better?

another question for you, while we're on the subject...can white balance be fully adjusted in a raw image or do i need to make sure i have the appropriate white balance set while shooting?

thanks very much for the help

[Anthony Wood]

Yes white balance can be fully adjusted in RAW but I still assume that if your going for optimal performance it is better to get everything as best you can at the shooting stage. I don't know if this is true at a scientific level.

However with your copying project it might be worth trying something with a wider spectrum. A simple test shot using daylight should be enough to tell you if your going down the right path. You can get specialist bulbs with daylight properties...although I can't name them off the top of my head.

EDIT: Thought I better add that this is based on what I would try if I had a similar problem - not a deep knowledge of sensor technology.

[Tony W]

I am assuming that you are shooting in RAW and manipulating in Camera RAW or similar and still getting poor reds is this correct?

In comparison of the two images the Epson is actually showing improved resolution over the Canon. This may be down to incorrect focus or camera movement however I suspect that the loss of resolution caused by shooting through the ANR glass due to its etched pattern. If possible ditch the glass.

I would also be tempted to increase exposure a little maybe 1/3 - 1/2 stop to bring the shadows up a little without of course clipping highlights.

Should you not be able to improve in camera it is possible that you may be able to 'subdue' the reds by using Apply image on a new layer and selecting the Green channel then change layer mode to Luminosity and reduce opacity a little (85% as starting point). This will bring some detail back into the reds although it will need more work to bring the image to match the Epson globaly. See attachment (Left hand image orig right hand Apply image.

IMO it may prove more accurate and in the end quicker to just use your Epson

[sfgate27]

Yes, I'm shooting in RAW. My experience level is low (as you can probably tell) so I'm not fully adept at the various factors to play with in a RAW image but I have definitely tweaked the white balance all over the place and can't get that to give me a great image by itself.

Will try ditching the glass and upping the exposure, thanks for the suggestions.

I do really like what you accomplished with apply image there. Just want to make sure I'm doing the right thing though, when I try this. First, I create a new layer which is an exact copy of the original. Then I change it to Luminsoity using the drop down box in the Layers window. Then I go to Image>Apply Image... and set Layer: to 'Background copy', Channel: to 'Green', Blending: to 'Normal' and Opacity: to '85%' and then I play with the Opacity in the Layers window? Is that what you did to produce the example you attached? Thanks again, this is a better result than I've been getting with a variety of more complicated stuff. Would you mind explaining to me exactly what this is doing?

I am trying a new set up today with a better lens and will try a few different bulbs and with and without glass. Will let you now how it goes.. Thanks again everyone for all the help. Much appreciated!

[Tony W]

As you are acquiring the image as a Canon Raw file I believe you should be able to get the best results by adjusting your image in Camera Raw prior to bringing into PS. This really should be your main editing move and with luck will solve the excess red problem and should result in very little (if any) work needed in PS.

Had a very quick play with your image by bringing the jpeg into ACR and adjusting the following parameters:
Exposure +15
Fill Light 21
Contrast -30

HSL/Greyscale tab
Saturation tab
Reds -30
Orange -15
Luminance tab
Reds - 85
Orange -35
Your figures will vary but by playing and fine tuning you should get a closer match than you have had to date.

By using the Apply image Green to a new blank layer (or a dup layer) and changing to Luminosity you are replacing the B&W component of the underlying image with a particular channel in this case the Green only channel. Reducing opacity serves to allow the underlaying Luminosity (B&W) to show through and mix with the new channel

[redcrown]

Two suggestions. First, diffuse the light. Don't use bare bulbs. Any translucent neutral material will do. Plain paper, wax paper are cheap ways. Special "light tents" are made for copy work.

Second, experiment with different profiles in your raw converter. If ACR, try Camera Faithful, Camera Standard, Camera Neutral. Each profile renders red quite differently.