Check my 'rithmatic please

[VirtualAdept]

I was chatting to a chap in a camera shop while purchasing some 120 colour film, and we were discussing developing options.
They dont develop instore, naturally, but the guy recommends getting scans (which was the plan since my scanner is 35mm only). When asked what sort of res and dimensions the resulting scan would be, he replies with 300dpi which should be plenty.
Am I right in thinking from a 6x6 negative, 300dpi scan will give me an image of around 700x700ish pixels?

 

[donut]

i thought 300 dpi refered to printing not scanning

 

[robhooley167]

Near enough 700x700 yes

 

[VirtualAdept]

Cheers Rob... seems a bit of a waste to get MF negs scanned so small

i thought 300 dpi refered to printing not scanning

No mate, scanners details are normally given with something like "4200dpi resolution" sort of taglines, with big exclamation marks

 

[excalibur2]

H'mm something doesn't make sense to me if I'm reading this right, in that the man is the shop is saying "scan at 300dpi"........well maybe for a 4X4" print.

 

[VirtualAdept]

The impression I got was that the negative, which is a 6x6cm frame, will be scanned at 300dpi, making it around 700 and a bit pixels per side

 

[steveo_mcg]

6cm is ~2.4" so yeah 720 pixels which will get you a contact print.

 

[ChrisR]

This can be very confusing, you often see scanning quoted with reference to the image size you want to produce, at 300 dpi. So if I have a 35mm frame (1 inch by 1.5 inches), then a 6*4" print at 300 dpi means scanning the negative at 1200 dpi. But you rarely see the 1200 dpi mentioned! It's bonkers, the most important parameter and they insist on leaving it out.

For the "handy price estimator" in the UK film processing sticky I've assumed 1200 dpi as "small" for 35mm, and around 2000 dpi as "medium" (in practice it's anywhere from 1800 dpi to 2400 dpi, AFAICT). Not nearly so confident on the 120 stuff; I've been scanning most frames at 1600 dpi, and better-looking ones at 2400 dpi.

 

[excalibur2]

This can be very confusing, you often see scanning quoted with reference to the image size you want to produce, at 300 dpi. So if I have a 35mm frame (1 inch by 1.5 inches), then a 6*4" print at 300 dpi means scanning the negative at 1200 dpi. But you rarely see the 1200 dpi mentioned! It's bonkers, the most important parameter and they insist on leaving it out.

For the "handy price estimator" in the UK film processing sticky I've assumed 1200 dpi as "small" for 35mm, and around 2000 dpi as "medium" (in practice it's anywhere from 1800 dpi to 2400 dpi, AFAICT). Not nearly so confident on the 120 stuff; I've been scanning most frames at 1600 dpi, and better-looking ones at 2400 dpi.

Well introducing prints into a debate is something new as we tend to talk about best dpi for 35mm and medium format from home scanning. But for a 6X4" print from 35mm and for good quality the jpg file has to be about 1800X1200px, but I've got quite good results from a home printer at A4 with this size ...my memory is shaky about scanning and prints from medium format as I did home chemical printing.

 

[donut]

with my limited understanding (get that in early just in case anyone thinks i know what i'm talking about ) printing was dpi and that 300dotsperinch was a good print resolution ,but that could go down to less depending on viewing distance . scanning is done as ppi ,and ( as Chris said ) it should be scanned to make a print at 300dpi for the size of print required .