Scanning Slides-What Size?

[rockyram]

I have a few thousand slides to scan.My scanner scans 4 at a time.What DPI should I scan at to view on a computer or TV?What if I want to burn the images onto a DVD,what DPI should I use?And finally,if I want to have images printed what DPI should I scan the original slide at?

[rockyram]

Sorry,but another question.What type of file should I be saving these scans as?A TIFF or BMP?

[Asylum Steve]

Welcome to the site RR,

A few thousand slides to scan, eh? Sounds like you've got some fun times ahead of you.

NOT!

Scanning (input) ppi is used simply to determine the pixel dimensions of your scan. IOW, a 1"x1" original scanned at 600 ppi will give you a 600x600 pixel file. Scan at 1200 ppi and you've got a 1200x1200.

Determining your output resolution (print or web dpi) is a completely different thing. To do that, you take your total image size, and using an editing program like photoshop, plug in the desired physical dimensions and optimum output resolution dpi and let the program resize the file.

Normal output resolution is generally in the 200-300 dpi for prints and 70-85 ppi for web graphics.

Still, the larger pixel dimensions your original scan, the better your output will be...

So, to answer your questions, if you intend to print all of your images, you will get the best results scanning at the highest ppi you can, then converting to 200-300 dpi output for your print files, or a lower ppi for web viewing.

As for file format, if at all possible you want a lossless (keeps all image info) format such as TIFF or PSD, although a large size, very low compression jpeg will also give you pretty good results. Make sure you leave your original scans untouched, and work off of copy files when you resize.

Burning onto DVD makes no difference, it's the file's intended use that counts.

Hope that clears some things up. Any other questions, just ask...

[another view]

I agree with what Steve said but... I don't scan slides too often because it's usually pretty time consuming. When I do, I use the highest resolution from the scanner, then save that file as a TIFF because there is no compression. Then I spot out the dust and anything else needed in Photoshop - the TIFF is the "master" file made after this work is done. From there I might make a small jpeg copy to post here or a custom sized print, etc. But I always have the master copy to work from.

Your situation is a little different - I guess I'd probably go for a lower resolution due to the quantity. Monitors are usually set to a resolution of 1024x768, so that's the maximum size they can show an image at. If it's bigger, it will just shrink it down to that size (or smaller). Not sure about a TV's resolution but I would guess it's lower than this anyway. So if you only want it for TV/Computer use, scan to a resolution of 1200. I think you could probably save these as jpegs at the highest quality setting and not have any problems. If you have a few you want to make prints from, then go thru the process I explained above.

[BigMacIain]

This is what I've been finding. With a Minolta Dimage III, my max resolution scans have been producing TIFF files in excess of 30MB. From what I have read and understood, the best approach is to use Photoshop to remove any dust etc. and re-save the TIFF files. Then move the files to CD or DVD in batches as the archive. Having done that, work from the read-only files to do any editing, then save the edited file to the required resolution for printing. For online work, these can then be re-sized to a lower resolution. I haven't played with iDVD yet, so I don't know what resolution is best for DVD-based slideshows. Any suggestions?