Unicolor c41 color cast problem.

ewsphoto · Jun 12, 2013

Hi all,

Just developed my first roll Kodak pro 160 , 6X6 format using Unicolor C41 kit.
I follow instruction carefully. Scan using Epson V600 and vuescan.
seems something wrong, any one help me please?

eriklovold · Jun 12, 2013

Looks fine to me. Getting colours right from colour neg scans can be quite hard. Try opening the tiff in Photoshop and play with Curves to see if you can get a result you're happy with.

ewsphoto · Jun 12, 2013

Hi eriklovold ,

thanks for reply. I'm using vuescan for years, I scanned a roll of commercial developed film yesterday, with good result. Anyway, thanks for your idea, and I will try to edit tiff file and see if I can correct the color fading problem.

here's the commercial developed film , and I scan it with epson V600.

Regards,
Ew

ewsphoto · Jun 12, 2013

hi，

color corrected in photoshop. looks much better now. thanks !

Rudeofus · Jun 12, 2013

Color negative film can register much higher contrast than a JPG file or photographic paper. When you scan negative film, and especially with motives that have a high scene brightness ratio, the scanner post processing software will compress contrast to make it fit into 8 bit color space. As a result, the image will look faded and contrastless, just as if you print a b&w neg on gradation 0 paper. Get the negs printed optically and you'll see that colors are most likely fine and dandy. If you insist on hybrid work flow, plan for digital post processing on your computer.

PS: I realize that this topic reaches deeply into DPUG area. Reason I think it should still be discussed here on APUG is because many people judge color negatives based on poor and unprocessed scans and reach very wrong conclusions about the film material and its development.

Clovis Blevins · Jun 12, 2013

I'd be interested in seeing a manually corrected wet print from that negative for comparison.

pentaxuser · Jun 12, 2013

Clovis Blevins said:
I'd be interested in seeing a manually corrected wet print from that negative for comparison.

"manually corrected" tends to imply that the neg is "wrong" which I suspect it isn't and therein lies the problem with terminology when scanning is involved and confusion arises.

I'd like to see a wet print with the correct colour filtration applied in the enlarger. I see no reason why it shouldn't match the scan-corrected image.

pentaxuser

ewsphoto · Jun 12, 2013

In our local area , only one shop can process c41 , but then films that processed by them looks dirty and scratches sometime. otherwise films that developed by them can be really easy to scan with correct color reproduction.
I purchased Unicolor c41 kit recently, just because I want to get rid of scratches and dirty film from local shop.
No manual enlarge service in our country now, they will just scan it either Noritsu or Fuji Frontier scanner and print it .
I used Acer scanwit 2740 for years, ( with vuescan software ) and bought Epson V600 recently, for medium format scan.

Can't afford to invest RA4 print equipments yet.

wblynch · Jun 13, 2013

With home developed C-41 I find I am happier with an extra 15 seconds in the color developer.

polyglot · Jun 13, 2013

wblynch said:
With home developed C-41 I find I am happier with an extra 15 seconds in the color developer.

That may make it very difficult to make wet prints, should you ever wish to do so. Current papers are all high-contrast and you're effectively pushing your film half a stop.

For portraits I know I'm going to wet-print, I often find a 1-stop pull valuable.

ewsphoto: have a read of the C41-scan link in my FAQ; it may help you with colour correction in scanning. I wouldn't assume that your chemical process is wrong just yet.

Shootar401 · Jun 13, 2013

I hate to say it, but it looks like colour neg. I've tried the Unicolor & Tentenal kits and I've gotten the same results, colours a bit off at scanning. Getting colours 100% correct with colour neg can be a bit tricky, this is the reason I've gone back to chromes.

ewsphoto said:
Hi all,

Just developed my first roll Kodak pro 160 , 6X6 format using Unicolor C41 kit.
I follow instruction carefully. Scan using Epson V600 and vuescan.
seems something wrong, any one help me please?

View attachment 70058

wblynch · Jun 13, 2013

polyglot said:
That may make it very difficult to make wet prints, should you ever wish to do so.

Perhaps, but I don't optically print and no one within reasonable pricing optically prints either.

If not for "electronic enlargers", photographic film would be gone altogether.

Chris Douglas · Jun 13, 2013

This has been a good thread. I also use the Unicolor kit, and wet print on crystal archive. I regulate the water bath at 100 degrees F, but the temp in the tank runs about a degree low. I start developing an extra 15 seconds too, adding 5 seconds for each successive roll. I like the results, and can develop twice the recommended capacity. I'll have to try the V600 and see if it looks the same as wet printing. I've only used it for B&W so far.

polyglot · Jun 13, 2013

Shootar401 said:
I hate to say it, but it looks like colour neg. I've tried the Unicolor & Tentenal kits and I've gotten the same results, colours a bit off at scanning. Getting colours 100% correct with colour neg can be a bit tricky, this is the reason I've gone back to chromes.

Nah, it's just (well mostly) wrong gamma, which causes that milky look. You do a wet print and it won't look like that at all. You do the scan right, it won't look like that either.

These are both scans from C41.

ewsphoto · Jun 14, 2013

Hi all ,

Thanks for all inputs, appreciate all opinions.
Polyglot > I'm quite familiar with film scanner and how to get good scan out from it. Its true that most of film scan will not look good strait out from raw scan, low contrast from raw scan means I can get more detail out from the file. I need to adjust from vuescan software to get it right.
I checked my digital thermometer just now, which I used it for check the temperature of C41 chemical. compare with an Omron medical thermometer, I found that my old digital thermometer shows 1.7 degree celsius higher than Omron. Thats means I develop my film 3.30 minutes in 36.2 degree, and blix 6.30 minutes in 36.2 degree celsius too.
I think my film must be a little bit off already ?
I will shoot another roll this Sunday and try to develop again and see if it will be more easier to scan.

Thank you.

ewsphoto · Jun 14, 2013

hi again,

After read Polyglot's FAQ about film and scanning, I really learnt a lot of knowledge regarding c41 process , and black and white as well.
thanks for the marvelous FAQ page!

Regards,
EW

polyglot · Jun 15, 2013

Glad that it's useful.

Unicolor c41 color cast problem.

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