Dear All,
Thank you for your useful and interesting replies.
Several posters suggested that I scan at the optical resolution of the scanner for best results, but Epson state that for the V850 this is 4800dpi for flatbed photo scanning, which would create an unfeasible file size when scanning an 8 x 10 inch print. I had been scanning at 2400dpi which was already creating 1Gb file sizes.
I don't believe the that the original prints are 300dpi as someone said. These are chemical photographic prints, not printed images from books (which would commonly be 300dpi) A chemical print would have a much higher resolution than 300dpi.
Also contrary to some posters replies I am planning to print images at sizes much larger than the original print, up to 1 metre exhibition prints. This is the main reason why I want to scan at the best quality possible (taking into consideration the limitations of very large file sizes) It may be that the 2400dpi resolution I had used until now for scanning 8 x 10 inch prints is the best compromise between resolution and file size.
There was a very useful suggestion that I should just try scanning at different file sizes and see what difference it makes to the final prints, but I was hoping there may be some scientific way of knowing when getting the best possible scans. This is an archive, and I will only be able to scan these images once.
Thanks again to everyone. I look forward to any further replies and suggestions.
Best wishes,
Richard