I recently borrowed a Silverfast resolution target to measure the performance of my scanners. The target is a slide that is printed with a series of black bars which get progressively smaller and closer together (the pattern is based on the USAF-1951 test pattern). The slide costs approximately $60 at B&H Photo.
You scan the target and read off the group and element number where the gap between the bars is just discernable. Based on the group/element you look up the resolution from a chart.
My first test was my Canon Canoscan 9000f flatbed scanner. According to the specs it claims 9600dpi resolution. Here’s the scan of the target:
Based on the scan it looks like the bars are just discernable at group #5 element #2 (1825 dpi). This is much lower than the technical specification for the scanner (9600 dpi) and is a prime example of why manufacturer specifications can be extremely misleading.
I also tested my Minolta Dimage 5400 film scanner. This is a dedicated scanner but has long been discontinued.
Based on the scan, I read group #6 element #6 which corresponds to about 5800 dpi. This is actually a little higher than the claimed resolution. I was pleasantly surprised as I had expected to get a little less than 5400 dpi. Given that many film scanners are now discontinued (we are well past the golden days of film scanners and they are going extinct), I’m going to be hanging on to my Minolta.