Interestingly the two scanning flows are somewhat different and I wanted to compare them. I normally use Vuescan which can be unclear sometimes but has lots of controls. For instance I have scanned for 48-bit color for a very long time. It was only after using ColorNeg that I discovered all my scans were saved as 24-bit files. This is because there are separate scanning and saving options. The tutorials with ColorNeg straightened all this out. These experiments relate to color negative flow.
Alex on the other hand uses EpsonScan and then Photoshop. Reading his scanning flow I decided to see what differences there might be. The recommended flow for Vuescan is to set for 48-bit scans and save as Raw only. This results in a linear scan, that is one with no gamma applied. Most scanners default to adding a gamma (1.8 or 2.2 is common) but ColorNeg works best with linear scans. I also use Image mode as I don't want Vuescan to perform the inversion as you want ColorNeg to do this as that is most of the value.
Balancing the filter layers in the film in VuescanNegative film has a strong orange filter cast and for different films this varies. To capture the best dynamic range one can change the gain (or amplification) of each color channel. For Kodak Porta films I settled on Red=1, Green=1.6, and Blue=2. For this experiment I used a very old negative of my brother's that was Kodak Vericolor . For this negative it scans well with the Porta gains I have outlined here. Using these settings I get the scan below. Note the lack of orange cast and the cyans and magentas are quite visible.
|Vuescan 48-bit negative|
|ColorNeg Inversion of Vuescan Negative|
|EpsonScan No Color Correction.|
|EpsonScan No Color Correction Histogram|
|EpsonScan No Color Correction with ColorNeg inversion|
|Color correction dialog before|
|Color correction dialog after|
|Color Corrected Scan|
This is the histogram. Not much different though brighter than the non-color corrected version. There is some spread in the dynamic range particularly the separation of the red channel which might impart more dynamic range.
|Color Corrected Histogram|
|Color Corrected Inversion with ColorNeg|
For completeness I also used EpsonScan in Negative mode (it performs the inversion) with color correction turned off.
|EpsonScan Negative Scan (EpsonScan Inversion) No Color Correction|
|EpsonScan Negative scan (EpsonScan Inversion) No color correction Histogram|
|EpsonScan Negative scan (EpsonScan Inversion) No color correction ColorPos conversion|
ConclusionsAll of these methods produce what I think are acceptable starting points for image manipulation. A jumping off point with reasonably accurate colors where contrast and saturation and other adjustments can be made to capture the mood of the scene at the time. This is not a challenging image having a fairly narrow range of exposure values across the image.
A couple of observations.
- I am more confident in the Vuescan raw mode for ColorNeg work as it is the recommended flow from the folks at ColorPerfect. That being said I think the EpsonScan results would work well as well. (ColorPerfect's instructions actually says that turning off the color correction does not disable the gamma correction. ColorPerfect can deal with this by reverting the correction which is why the results here are OK.)
- EpsonScan does a much better job than Vuescan at negative conversion. In fact before I found ColorPerfect I would use EpsonScan to convert color negatives because Vuescan made such a hash of the conversion and Photoshop wasn't up to it as well. EpsonScan makes a very good low cost alternative and is indeed what Alex Burke uses as the basis for his excellent film work.
|Vuescan Final version|