Scanning paper photos 2400dpi v 4800dpi.
I'm choosing between two cheap scanners to acquire some printed photos. One photo is a B&W previous enlarged photo with a lot of physical damage. Resolution looks very low.
But the others are regular 6 x 4 prints you get back after sending a film to the lab.
One scanner claims 2400 x 4800 dpi, and the other is about double the price and accordingly claims. 4800 x 4800 dpi.
My instinct is telling me 2400 is going to get all the detail there is to be got and I may as well get the cheaper one. It's physically a bit smaller too, and obviously if I use 2400 x 2400 the files I have to work with will be 1/4 the size and therefore faster to process. So it seems like a win win.
Am I missing something obvious; is there anything I'm likely to scan that would benefit from 4800 dpi (I'm guessing slides/negatives would need a backlight attachment which neither seems to have so ignore those) and if so do these scanners really do that (these are cheap Canon flatbeds) do they actually really pickup that much detail these days or is it marketing-speak/interpolation.
Thanks in advance (I used to write TIA, but guys started calling be Tia and hitting on me, sigh).
I rarely scan as high as 1200 lpi for a lot on enlargement, so either should be fine for resolution. You might find a big difference in speed though; check the Canon website.
The resolution of a print is much lower than 2400 dpi, so the 4800 ppi scanner will only give you more pixels, not more information. Just to give you an idea of how much overkill you'd get: scanning a 4 x 6 inch print @ 4800 pixels per inch will give you a 4 x 4800 by 6 x 4800 pixels file. That's 19,200 x 28,800 pixels, or 553 Megapixels...
It matters with film, not so much with prints.
But even with film, a lot comes down to the quality of the scanner; Nikon's discontinued series of 4000dpi film scanners simply stomps on most of the competition including both film scanners and flatbed scanners with transparency attachments that advertise much higher resolution. Basically, the Nikon scanners have better optics, better lenses.
For prints, I'd just run the scan at 600dpi and enjoy the result. Getting the color balance right is going to be more of a challenge than getting it appropriately sharp.
Almost any flat bed will give you a very good scan of reflective media. I found an old umax in the trash and for kicks cleaned it up and did a scan - slow but very detailed.
As to the size/resolution - I'd do some math and see if the final results will be large enough for what you want.
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