My ongoing frustration with viewing scanned images on my Light Moments blog and Flickr with my MacBook Air led me to spend a day experimenting with various methods of scanning and processing 35mm negatives.
Whether or not the method I use to scan and process my negatives has any bearing on their being viewable on any particular device is unlikely to be determined by these experiments but it might at least give me an idea of what output quality is achievable from my scanning setup.
My scanner is a flatbed Epson Perfection 4990 Photo, capable of scanning negatives up to 10″x8″ at up to a claimed optical resolution of 4800 dpi and a Dmax of 4.0. My scanning software is Epson Scan as supplied with the scanner and my editing software is Serif Labs’ Affinity Photo.
Poor weather during the week left me effectively snowed in at work for three days with little work to do. Fortunately I’d taken my camera and a couple of rolls of film with me and was able to spend some time taking pictures of the snowy scene in which I found myself. I’ve chosen a single frame from the processed negatives to illustrate the results of my experimentation.
The film is Kentmere 400 developed in Ilfosol 3 at the standard dilution of 1+9 and at 20°C, Ilfostop and Ilford Rapid Fixer. Scanned frames were output to TIFF files for processing. The files uploaded here were all resized to 1200dpi wide JPEGs at 85% compression quality.
For my scanning experiment I started with a 16-bit greyscale scan at 1200dpi to a TIFF file. Exposure and image adjustment settings were the standard auto settings provided by Epson. The resulting TIFF was so rough that I didn’t bother attempting any further processing. Scans 2 and 3 were made with the same settings but at 2400dpi and 4800dpi respectively. At full size they show some improvement in resolution which is just discernible here, but not in image quality.
Based on what I could learn from the first three scans I decided to use 2400dpi for the next three.
Scan 4 was also a 16-bit greyscale scan but with manual over-ride of Epson’s auto adjustment of the histogram. I set the black and white points to just left and right respectively of the ends of the histogram, the grey point value to 1.00 and set the output to stretch the histogram from 0 to 255. I also unchecked the unsharp mask setting. The output gave me full histogram values to work with using Levels in Affinity Photo and to my eye produced a much more acceptable result.
Scan 5 was made just as Scan 4 except as a 48-bit colour file. Not only does this give me the option to make adjustments to levels but also allows control over the conversion to Black & White and the opportunity to emulate the use of filters on the camera.
Pleased with the progress I seemed to be making, Scan 6 was also 48-bit colour but this time with all Epson settings turned off: No auto exposure or colour management, no auto histogram, no unsharp mask and no auto setting of the scan marquee. I was able to manually select for scanning, a little more of the negative than had been automatically selected by the Epson software, hence the slightly larger file size. I was also sufficiently pleased with this one that I took the time to spot and straighten the file once in Affinity Photo.
I was really very pleased with this. So much so that I repeated it at 48oodpi just to compare the resolution. The 4800dpi at full size is just noticeably better. I also made a slight change to the brightness – not sure I made the right call on that but like everything else that’s a subjective judgement!
As I said at the top, none of this is likely to have any bearing on my MacBook Air problems (I’m beginning to see the problem being something to do with it, either hardware or operating system) but it’s been an interesting day making these comparisons. For the extra effort and disk space, scanning at higher resolution in 48-bit colour and with no Epson software intervention makes a huge difference to what is achievable. And the beauty of making edits in Affinity Photo (and I guess any Photoshop-like software) is the flexibility and ability to go back to make adjustments.