Calibrate Color Negative Film

[Ed_Ingold]

Is there a way to shoot a color target (e.g., Gretag-MacBeth) or a

grey card and objectively set the color balance when scanning color

negative film? I understand that there are a lot of variables, but I

only use a couple of emulsions regularly, Fuji NPH400 and Reala, with

a limited variety of lighting conditions.

 

Perhaps it's as simple as shooting a grey card and using the middle

eye dropper. I think, though, it would be better to test a gamut of

color.

 

I use a Nikon 8000, and find that the scanning software reacts to

the "average" values of the image, and I try hard not to

be "average." Consequently, I spend too much time adjusting color, in

a subjective manner. Silverfast, with "NegaFix" helps (compared to

NikonScan), but I'd like to get a little closer.

[ronald_moravec1]

I`m not too good with fixing computer problems yet. So far I just scan with my MINOLTA 5400, check and maybe a little crop in PhotoShop Elements, and print. Color balance, saturation, contrast, and density are all fine. I must be lucky or follow instructions well. My computer and monitor are E Machine which is probably not the best, but Color balance on the CRT matches the prints which seems to be a hugh problem for a lot of people.

 

Many people at work who are not photographers seem to get decent prints and they do not even know what they are doing. I figured I could improve on what they get so I took the plunge. I can.

 

Having done color darkroom for 30 years, I can tell you, I know when something is off.

 

So much for my credentials. The emulsions in color neg for a given film type do not change from batch to batch, but what does seem to vary is the color of the orange mask. I had my best luck color printing by doing the color balance on the mask between frames or on the end. I tried white, black,flesh, and grey boards. The orange was the ticket. Some pros I know would balance for their backdrop. Color balance the orange and everything worked.

 

I would attack the digital darkroom the same way. Copy the Macbeth or an outside scene with lots of colors, scan it with no adjustments, then adjust the monitor so it looks ok. Now make a 2 x 1 1/2 small print on a 4x6 paper of the type you will use. If it is ok you are home free, if not there are color adjustments in the printer driver. Adjust the colors there along with density. Write down the setting you use for that kind of paper so you can repeat it without retesting if you use more than one kind of paper.

 

The adjustments for the Epson are in the advanced settings tab they caution you not to touch.

 

My advice is forget all the fancy tools and profiles etc, just make it come out right and record how you did it just like a real darkroom.

[steven_clark]

Vuescan has a feature where you can scan an image of an IT8 camera target and generate a profile which it then uses to interpret the film color. It works, but last I checked the profile kinda restricted the contrast to the range represented in the target. This might have changed in one of the updates of course, and my Wolf Faust camera target has since died (got left in the car and melted) so I can't do it myself anymore.

[3d-aeropanoramic project]

http://www.fotowand.de has the best greycards of the world(above all the structure card with reflexion points-worls unique).

that clever calibration man has a lot of calibration solutions.

erik krause has also detailed descriptions how to deal with calibration.

http://www.erik-krause.de/

i am inmidst these calibrations. you will need that structure card and must do the procedures erik describes in one of his 3-page-instructions.

[ivan_dzo]

I'd second the vuescan with wolf targets. They provide both the target and a computer file reading what the scan should show. You simply photograph the target, scan it in and ask the vuescan programme to produce an icc profile. Simple to do for every film you use. The service from wolf is excellent, very fast and good value for money.

[Ed_Ingold]

Thank you for the responses. Ronald, I'm doing it manually now, reasonably well. Unfortunately, what looks good to me one day may be different than the next. I save Levels and Curves in Photoshop, which helps consistency within a shoot.

 

I sometimes take digital images at the same time, which nearly always look better than film, that I can use for comparison. I've gone so far as to use Photoshop/Colormatch, but levels and curves produce better results. If I had the resolution ($$$), I wouldn't be using medium format film.

 

The Wolf-Faust targets are for IT-8 calibration, which is for positive film or reflective scans. The profiles work within a narrow framework within SilverFast, outside of the normal scanning procedure. There's no way to apply the calibration procedure to a negative scan. Perhaps Vuescan is different. Has anyone used Vuescan with negative film for IT-8 type calibration?

[ivan_dzo]

Yes, as I said in my post, you have a reflective target from Wolf (an it8) and you photograph it on your favourite film, develop it and scan the negative. Vuescan then reads it to produce an icc profile that you then use each time you scan negatives of that film type. Very simple and fairly cheap.

[roger_smith4]

Don't waste your time with CN film and IT8 targets. There are too many variables beyond your control to make it work. IT8 is fine for slide film- I have a Wolf Faust Provia target.

 

Erik Kraus has a good workflow to get balanced colors using Vuescan. Works for me.

 

http://www.erik-krause.de/tutorial/part1.htm

 

The summary- find and lock the film base color using the advanced workflow.

Next, shoot a white piece of paper and a neutral gray card under midday sun (or diffused flash) on whatever film you want to get test values for. Use the eyedropper on the white card to set white balance. Look at the histograms and the greycars should be the hump in the middle. Change Red and Blue Brightness levels to try to get the curves identical for the grey card.

 

End result- save and lock the settings and you should have some very neutral results! It's worked well for me with Reala, NPZ and even Sensia slide. Thanks to Erik Kraus for setting me straight and largely ending my frustration with my Canon FS4000US scanner.

[bill_tuthill]

NPH is the film I have trouble Vuescanning. The problem is that

green/cyan/blue midtones (especially river water) look too muddy.

Roger, have you tried Erik Kraus's method with NPH yet?

[roger_smith4]

I have tried it with NPZ and it works fine. I will get back my first rolls of NPH and UC400 next week and will scan both then. This technique seems to work with every film I throw at it- it's not film or scanner dependent, and saves me time in getting usable, consistent scans.