Ed. If you missed part 1 of this series, you can find it here.
Part 2 - The Basic Workflow
First off, let me apologize for the cliffhanger end to Part 1.
In this installment, I'll describe the workflow I used to go from this:
...without using ColorPerfect.
The method I'm using is based on the method described by Mark Segal and Todd Shaner in their article on DSLR scanning, published on Luminous Landscape. Even if you're not scanning with a DSLR, I highly recommend this. My hope is to take this excellent workflow and build upon it. The fundamentals of the workflow are as follows:
- Correct for the orange (or red, or pink, or what-have-you) mask
- Invert the negative to a positive
- Correct the colour bias
- Correct the gamma
This can be achieved using 4 (possibly 5) Photoshop layers, as previously described. Briefly,
- With the negative open in Photoshop, create a 'Levels' layer. Select the White eyedropper and set the 'Sample Size' (top left of the PS window) to "11 x 11". Now, use the eyedropper to click on a region of unexposed film (NOTE: if possible, you want to leave some unexposed film visible in all of your scans. If your scanner doesn't allow this, create one extra scan of this region. You can apply this correction to all of the shots on a given roll). This sets the unexposed film as "white" (RGB 255, 255, 255), which will be "black" (RGB 0, 0 ,0) once we've inverted the image.
- Create a new 'Invert' layer. Your image will now be a recognizable positive, albeit with a very limited range of tones, clustered in the highlights. This is normal; remember, negative film takes a scene with a large dynamic range (Portra 400 will do 15+ stops of actual DR) and compresses it into a very small density range on the film. It's your job to expand this density range into the full range of tones. The key thing to note here is whether the unexposed film border looks black. If it doesn't, you need to go back to your 'Levels' layer and redo step 1. Be sure you're clicking on pure film border (sometimes, if you've got a particularly overexposed sky, for example, some of the exposure will spill outside of the 24x36 frame).
- Create a new 'Curves' layer. Click the little arrow at the top right of the Curves properties window, and select "Auto Options...". Click "Enhance Per Channel Contrast" and "Snap Neutral Midtones", and set the shadow and highlight clipping to "0.01". Click "Save as Defaults" and then "ok" out of the Auto Options window, and now click the "Auto" button. You should now have a reasonable looking positive. What you've just done is to normalize the R, G, and B curves for the negative film. A little background: essentially, negative film has characteristic curves for R, G, and B light. But these are not coincident with each other, as they are (or should be!) for slide film. If you were to take a photograph of a neutral grey patch (more on that in Part 3...) and look at the histogram of the negative, you'd find that the blue channel would have the highest intensity, followed by green, and then red. What you need is, for a neutral grey patch, to ensure that R = G = B (that, indeed, is the RGB *definition* of "grey"). So in this curves layer, you're correcting for this R, G, B curve offset by forcing the histogram for each colour to use the entire histogram range (that is, you are enhancing the per channel contrast...as per the Auto Option box you checked above).
- Select the crop tool and remove ALL of the unexposed film border. All of it. Once you've done that, go back to the 'Curves' layer you created in Step 3 and re-click 'Auto'. This will regenerate the positive, except without taking the border into consideration when correcting the RGB offsets.
- At this point, you should be looking at a negative that is reasonably close to your intended output, though it may have a colour cast (in my experience, usually a cyan cast), and it may still be fairly bright and/or low contrast. Assuming your C-41 development was ok and didn't shift your colours substantially, this is generally the result of either (a) lighting that does not match the white balance of your film (i.e. tungsten light shot on daylight-balanced film), (b) mixed lighting, or (c) over- or under-exposure, both of which can shift the colour response of your film. If you have a cyan cast (again, this is most common), simply open the 'Red' channel in your curves layer and drag the midpoint of the red curve to the right, to boost the gamma of the red channel. Be careful here: a little goes a LONG way.
- Finally, create a second 'Curves' layer. In this layer, you're going to normalize the RGB brightness (gamma) of the entire image. If your image is too bright, grab the middle of the linear RGB curve and drag it right, along the midline. If the image is too dark, do the opposite (ie. drag left). In my experience, you generally end up with images that require a decrease in brightness.
- (OPTIONAL) Create a third "Curves" layer. This is strictly for contrast manipulation, and is really an aesthetic/artistic alteration. Add a slight "S" curve to increase contrast.
That's it. This method is completely agnostic to the film type (or even the batch of a specific emulsion), because you sampled the actual film mask in step 1. It should work (and, in my experience does work) equally well for Portra 400, Portra 160, 400H, Kodak Gold, Fuji Superia, etc. It even works for more esoteric films like Kodak 500T (a.k.a. 'CineStill 800T'), although these may take a bit more work in the post processing if you happened to shoot them in mix lighting, simply because of the colour temperature mismatch. But it does work.
Here's what it looks like, step by step:
In my experience, this works best with images in which the light source is closely matched to the white balance of your film. In this case, the photograph of Gen (taken in front of the Pantheon in Rome this past February) was in full afternoon daylight on Portra 400 - a daylight-balanced film. If you have, for example, tungsten light contamination, you're going to have colour shifts that require some work. But that's true of ColorPerfect, as well.
All of this (including the points in Part 1) can be made into a Lightroom preset and Photoshop Action, with the only routine user intervention being the selection of a grey point in step 1 and pressing "Auto" in step 3. The (huge) benefit to this is that you can quickly preview the positive (but uncorrected) images before proceeding with the full conversion, which itself is only 2-3 clicks away.
My target, however, is to remove even this much intervention.
Targets. Yeah. That's the ticket.
More to come in Part 3...