Guide to scan color accurate cel

For the n00bs of cel collecting and production art . . . and for some of us old-timers, too. Post your questions on anything that puzzles you.
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lansing
Anime Geek
Posts: 31
Joined: Sat Mar 14, 2020 1:28 am

Guide to scan color accurate cel

Post by lansing »

Hi I have just started collecting cels and after surfing around looking at people's collection, it bugged me more and more to see that nobody was doing any proper color accurate scanning. What people usually do is scan their cels with a cheap scanner, and then tweak the curve/levels to make them look brighter, which is wrong. And then there are countless scans with black under RGB(10, 10, 10) or white close to RGB(255, 255, 255), those were also wrong. So I feel like there should be a guide on this for consistency sake.


Basic Setup

To start off, you'll need a good scanner. Scanner only comes with relatively okay color reproduction out of the box, so it will NEED to be tweaked(calibrated) to achieve accurate color. Though, only the good one are able to do this, they have better sensor that can capture more depth at raw so that the color can be fix in the post. Don't buy the cheap one or those all-in-one printer, they are bad. I had a Canon MX922 all-in-one and it failed miserably on saturated red/yellow/pink color and there's no way to fix them.

The second thing you need is a good scanning software, as it takes care of the color correction process (calibration). An icc profile needs to be applied to the scan to fix the color, so we'll need a scanning software that can create and load them. After testing a few of them, it's safe to say that the best one is Silverfast. With this program, you don't need to worry about creating icc profile on your own, it came with profiles for most popular scanners right out of the box. I had tested its accuracy with my Epson Perfection v600 scanner, and I must say that it is crazily good (for my model), with an average DeltaE of 2.1, the tldr is anything under 3 means very accurate, this shows that their developers really know their stuff. So basically with Silverfast, you don't have to do anything beside scanning the cel.


Advance Setup

Only do this if you can afford more investment.

Although Silverfast's builtin icc profiles are pretty accurate, more can be done to improve it. In my case, SF's profile is really good overall but a little too saturated on the red, which is a very common color in cels and the difference is noticeable that I need to do someht.

For this setup, you'll need an IT8 target and its reference file (usually a text file), and the program 3D LUT Creator for the tweaking.

Here is the basic process:
  1. Scan the IT8 target with icc profile attached (it should be attached automatically)
  2. Open the scanned image with 3D LUT Creator
  3. Go to its "color matching" gui and load in the reference file, a color grid will appear,
  4. Position the grid to match the position of the patches in the image
  5. On the top of the gui is the accuracy rating in average deltaE, mine was at 2.17
  6. The program offers different automatic color matching method, and my case here, the A/B method is the best. Click "match"
If you're still not satisfy, you can manually tweak the node on the A/B grid to bring the average deltaE lower. In my example here, I was able to get the average deltaE of 2.17 down to 1.14, getting rid of the saturated red problem along the way.

after-3dlc.jpg
after-3dlc.jpg (988.12 KiB) Viewed 1427 times

After that, just save the adjustment as a lut and apply it to all your future scans.


Summary

I hope all the Dragon Ball collectors read this because I really want to see how Goku's true color look like in cel in compare to the anime.
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oxypetalus
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Re: Guide to scan color accurate cel

Post by oxypetalus »

This is actually really useful to know. Can I ask where you bought your IT8 target from ? I am interested in doing this before I start scanning the bulk of my collection. I found this site (http://www.targets.coloraid.de/) but they are unable to ship overseas at the moment.
lansing
Anime Geek
Posts: 31
Joined: Sat Mar 14, 2020 1:28 am

Re: Guide to scan color accurate cel

Post by lansing »

oxypetalus wrote: Mon May 04, 2020 1:59 pm This is actually really useful to know. Can I ask where you bought your IT8 target from ? I am interested in doing this before I start scanning the bulk of my collection. I found this site (http://www.targets.coloraid.de/) but they are unable to ship overseas at the moment.
I got mine from Silverfast, around $50 I think.
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