scanning slides???

[MRCPix]

I have 35mm slides I want to scan to print 11x14 and 16x20 prints.
what is the resolution I need to scan it? will a 3200 dpi slide scanner do the job?

I have scanned a few slides on a minolta scan dual 4 they came out at 4312 x 2864 at 300dpi will this get me where I want to be?

thanks for your thoughts.

[DEMDeepEllumMusic]

16x20 at 300 dpi = 4800x6000 then adjust for the size of the film which is .9449 x 1.378 inches (size of 35 mm film). You will have to reduce the dpi to get a super sharp print.

[epronske]

I do a lot of film scanning and I always scan at the maximum resolution and size at 16-bit. I do my corrections in Photoshop and then keep that large file as my master copy. That way I never have to re-scan the image if I want a different sized print. When printing, I will make a copy of the image and then resize the image according to what the final print size needs to be and do the final sharpenning on that size at that time. I set the final print resolution of the resized image to be 300 dpi or 360 dpi, but 240 dpi is supposedly acceptable. Hope this helps.

[MRCPix]

I do the same thing in photoshop, but I just need to make sure the scan is high enough quality that I can get larger prints out of it without having to rescan the image. I generally use 300dpi on my prints so I need to figure out what image size it has to be scanned at to get 16 x 20 prints from the scan.

[epronske]

A 35 mm scan out of your and any other scanner will be about 1.4 inches by 0.93 or 0.94 inches (a 1.5:1 aspect ratio of 35 mm film) at whatever resolution you set your scanner. So if you set your scanner to full resolution at 3200 ppi, your image in whatever image program you use, e.g. Photoshop, will be about 1.4 x 0.93 inches. The pixel dimensions of this scan are about 4450 x 3000 give or take about 30 pixels either way. If you resize this image uncropped and without resampling to 20 inches you will actually get a 20 x 13.5 inch print (again, the aspect ratio of 20 x 13.5 is 1.5:1) at about 275 dpi. Now some say that 240 dpi for most printers is OK but that 300 or 360 is a bit better, in which case you will need to up rez the image some. I doubt there would be any decrease in image quality as I have also up rezzed film scans some without problems. If you truly want 20x16 prints you will need to crop the image to that ratio because that is not the aspect ratio of 35 mm film, and keep in mind that will result in a smaller image that will be upsized for prints. With your scanner at 3200 ppi you are in the right ball park to produce good 20 x 13.5 or 20 x 16 prints. You will need to experiment with it a bit. Here is a link to Outback Photo that talks about uprezzing images and is a technique that I have been using that works well: http://www.outbackphoto.com/workflow/wf_60/essay.html
Hope this helps.
Erik