Scanning negatives: optimun parameters?

[Marsopa]

Hi:

I've just started using my plustek scanner with silverfast. Now I'm in te way of finding optimun scanning parameters, mainly output size and resolution. I've noted that commercially scanned negatives on my usual lab came as a huge size (82cm horizontally) and 72 dpi. That makes me wonder which could be the right way: leave the output size as original size and increase resolution or, on the other hand, use a high output size and less resolution.

Any thoughts/experience/proposal?

Thanks

P.S. I use to excuse always I post smth. about english being not my mother tongue, again, apologizes

 

[Pherdinand]

It does not matter, really.
For the size of a digital image, only the pixel count matters. You can change the "resolution" (dpi number) to anything you want, the quality will not be changing. That is, you will not be resizeing the image by that (as long as you keep the pixel count fixed).

Example:
A 3000x2000 pixel image - scanned or digitally made does not matter - is always a 3000x2000 pixel image on the screen,no matter what resolution it has.
The dpi resolution only matters when you print the image. Then, a 3000x2000 pixel image at 300 dpi will give 10xsomething inches in print size. At 100 dpi resolution the same image will give 30x20 inches printed size but lower resolution if you look from close... And so on.

Some funky software that displays an image on a computer screen takes into account the resolution set to the image and displays it as it would be printed; in that case the higher resolution image might seem smaller than the same image, same pixel count, but set at lower resolution.