Purple Sky and Green Ground ~ Portra 400 and Epson 700 workflow

[Frank Petronio]

I've been using Portra 400 since, umm, Portra 400NC, and scanning mostly on an Epson 700. While I do not do a lot of landscape, I've been finding that a lot of mine seem to end up with green(er) land while the skies have too much magenta. Or I'll correct the sky towards green to get a cleaner blue and the land will go magenta. The yellow-blue balance seems OK but we know how yellow affects the green....

Is it me or is this film prone to cross curves? I can fix it by isolating one or the other but it would be nice to know my film and workflow is getting the color relationship right without making heroic measures. Thanks

[John Rodriguez]

I run into that as well. It's not just Portra 400, I've seen it with Ektar and Portra 160 too, although the effect seems to be strongest with 400. I've only noticed it in sunrise/sunset lighting, and have assumed that the result was somehow due to the red layer getting overexposed. I haven't tried using a cooling filter yet to confirm, I just wind up doing local corrections.

[Brian C. Miller]

Frank, what color calibration have you done with your film? Have you photographed a calibration target and run it through your software to produce an ICC file for that film type?

[cabbiinc]

I would consider buying an iT8 target (transparency not printed) and profile the scanner. For me that made the biggest difference on my HP G4050 (I've only scanned 120 film so far).

Short of that you might look at ColorPerfect http://www.c-f-systems.com/Plug-ins.html a plug-in for PhotoShop. For me the iT8 target makes the biggest difference.

[Frank Petronio]

No, in fact I don't know how to profile my film. Can you point me in the right direction? I have one of those little XRite Color Checker Passport things I've used for digital and a Spyder 3 Calibrator.

[Brian C. Miller]

I use Profile Prism. It is used to create a profile for your printer, scanner, and "input device," aka film (or digital camera).

Photograph the target using whatever you consider to be "normal" lighting. I use outdoors noon day sun.
Have the film developed at your normal lab, and then scan the target.
Run the scanned image through Profile Prism to produce the profile
When you scan that film in the future, select that profile for your scanner.

That should reduce your need for drastic color correction.

[false_Aesthetic]

Bah.


Selective Color adjustment layer.

[Peter York]

Is C-41 amenable to profiling with an iT8 target? I thought this process only worked with E-6 films.

[J. Fada]

Profiling the film would be your best bet unless your lab is causing the crossovers. I don't know if Epson software has the facility but Vuescan does. I have never profiled a film through Vuescan though so someone else would have to answer how it goes. Personally I think you are better off with a profile built by yourself using your film and processor but you probably don't have the equipment you need for that. Maybe someone will offer to do it for you that is near you.

I don't use ColorPerfect but I have played with it and it works well. You may want to give that a go. It simplifies scanning too since you don't have to jerk around with adjustments in the scanning software. This may be another reason to use Vuescan if you don't already.

For crossover problems I have found that splitting the file into highlights and shadows makes it easy to fix. I do this in LAB mode but it should work fine in any color space. I know you are experienced in Photoshop but if for some reason you don't know how to make this split- in the channels palette on the bottom there is a little dotted circle. Click on that for the highlight 50% and use that as your mask. Invert it for the shadow mask. You can figure out the rest. Maybe that will help someone else too.

[polyglot]

Most likely you have the film base colour set wrong in your scanning/inverting software; that will always cause crossovers. What scanning software are you using and/or what software are you performing the inversion in?

Try with a demo copy of VueScan at least and first tweak the "Film base colour" sliders so that your shadows are neutral and only after that point, adjust highlight colour. The "Lock Colour" checkbox is your friend.