scanning 8x10" film by Epson V700 scanner

[Brent Long]

Another thing for all posting here . . .

First, Linhof's problem, I think, is only a perceived one. The only thing different between the 800 dpi scan he was happy with, and 1200 dpi scan that he wasn't, was the dpi setting. He apparently just isn't used to looking at files at different magnifications which inherently look softer (or reveal the inherent softness) as the dpi is increased. Both scans were of film on the glass.

Unless he was scanning different images and comparing something that was misfocused to something that wasn't, it isn't a focus problem at all, either of the scanner or the image.

Anyway, what I really want to point out, is that when using Vuescan and outputting Raw tiffs, I noticed that setting the dpi to 2400 did not give me a 2400 dpi file! This, I think, may be a very significant finding. What I got was a 3200 dpi file, and that's because with a Raw file, there is zero processing done to the scan. It takes the image in as analogue a fashion as possible. This leads me to believe that the scanner hardware, natively, only scans at fractions of 6400 dpi; so 6400, 3200, 1600, 800, 400, 200 . . . (I don't know how low it actually goes, but considering how bad the preview images are natively, probably lower even than 200).

So, if this is the case, then asking for a 1200 dpi file is also asking for the scanning software to resample the scan; something that would probably be better performed by Photoshop or similar.

With my V700 I scan my 6x9 film at 6400, 48bit, and downsample to 2400. They do look much better than asking either Epson or Vuescan to scan at 2400 dpi (though I haven't tested, I don't recall, scanning at 3200 dpi and downsampling, which would be great if it works because opening 1.5 gig scans, even just to downsize to 2400 dpi, is not fun . . . at least when I'm doing many scans anyway).

So, this was on of my findings, and I wonder if some of you may experiment and see if this is likely correct. It would seem likely, to me, that the scanner hardware does indeed only have a certain number of steps it can operate at natively.

[earlnash]

I am told that the accuracy and precision of the scan is superior if you should scan at the final, desired resolution of your largest print, and specify the size of that print. The scanner does a better job that way. For example, if you're going to print a 16x20 from a file that has 360 dpi resolution (optimal for an Epson printer), the negative size is 8x10, the final size is 16x20, and the resolution is 360 on the scanner settings. It will give you the same file size as if you scanned 1440, but the result will be superior.

[Lenny Eiger]

I am told that the accuracy and precision of the scan is superior if you should scan at the final, desired resolution of your largest print, and specify the size of that print. The scanner does a better job that way. For example, if you're going to print a 16x20 from a file that has 360 dpi resolution (optimal for an Epson printer), the negative size is 8x10, the final size is 16x20, and the resolution is 360 on the scanner settings. It will give you the same file size as if you scanned 1440, but the result will be superior.

I question this. I don't think an Epson printer has any need to go at 360, 363 or anything else. I have seen Epson printers do better at higher resolutions - with my own eyes. I think this is a lot of misdirection.

Lenny

[Frank Petronio]

Scan high and resample it down. You won't know your final crop until after you scan it anyway.

[Brian Ellis]

I am told that the accuracy and precision of the scan is superior if you should scan at the final, desired resolution of your largest print, and specify the size of that print. The scanner does a better job that way. For example, if you're going to print a 16x20 from a file that has 360 dpi resolution (optimal for an Epson printer), the negative size is 8x10, the final size is 16x20, and the resolution is 360 on the scanner settings. It will give you the same file size as if you scanned 1440, but the result will be superior.

OT but 360 is one view of what's optimum for an Epson printer. There are different views, including my own (based on my own tests), which is that it doesn't make a bit of difference what ppi you send to the printer as long as it's above whatever you think the minimum should be for the print size, viewing distance, etc.