Neg size and DPI

Blasted

Blasted

Suspended / Banned
Messages
927
Edit My Images
Yes
I have recently started to experiment scanning some old negatives. These comprise mainly of 110, 126 and some 2 ¼ inch.

Having experimented with the 126 negatives I found that using 24 bit colour, at 3200dpi, including colour and exposure correction, plus backlight correction gave me a nice image with a file size of about 30mb per shot.

I then tried some of the 2 ¼ inch B&W. I switched to 16bit greyscale and dropped the dpi down to 1200; this gives me a file size of about 20mb.

Is it reasonable to drop the dpi with larger negatives? Conversely for the 110 negs would I need to up the dpi to get a decent image size?

Currently using a V500
 
I usually scan everything at 1200 dpi, 2400 if I think the shot might have some interesting detail. I think the smaller negatives you just end up with more noise, a larger file and (perceived) larger grain than more image.
 
Well I can answer in a general way.......No matter what you read the V500\V750 is limited to about 2400 dpi max for detail, all you get if scanning at say 9600dpi is less pixel break up of the image and not more detail...so if you want a large print you would get better quality (remember not detail) scanning higher. Now with a smaller neg you have to use the best effort your scanner can give you so I would scan at least 3200 dpi.......a larger neg has easier detail and quality available so your V500 has less of a problem (well ignoring getting the neg flat in the holder), so you can scan at 2400dpi maybe even less.
The above is easy proved by scans from a £24,000 Fuji machine at supermarkets.... the scans are set very low for Joe public and 6X4" prints (but fortunately very good for yer average sized computer screen), so a very large print looks carp (well to me) and it amazes me (at my supermarket) people paying large sums for these enlargements.
 
Last edited:
Thanks guys,

The large neg 2 1/4 inch, I scanned at both 1200 and 2400, I then opened each image up side by side and zoomed pretty close in and to be honest there wasnt anything that noticiable. That why I dropped to 1200 as it reduced the file size from silly to managable.

I havn't yet done any of the 110 negs.

Any recommendations for replacment neg holders? 110 and 126
 
I've never tried it but I've seen anti glare glass used to hold the negative flat, I think you sandwich the neg between two layers as the scanner can't focus when the negative is lain on the bed.
 
The maximum detail that can be resolved from most film types (excluding specialist high resolution films like Kodak Technical Pan) is about 4000 dpi, ordinarily I would recommend scanning at that but seeing as you want a smaller file size I would usually recommend dropping to 2400dpi. In actuality with a V500 you would not see any difference apart from the file being bigger as when test targets are scanned, the maximum that it can resolve is about 1600 dpi as although the CCD sensor can resolve 6400 dpi as advertised, the optics in the pathway (especially the high pass filter) limit the resolution that can be actually resolved by the scanner. The V700/V750 is a bit better though as it can actually resolve about 2400 dpi with no real difference between the two.
As for scanning 110/126, just scan them as high as you like because even at 4000dpi you still only get about a 4 megapixel image.
 
You must log in or register to reply here.
Back
Top