Photography Forum: Digital Darkroom Forum: |
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Q. negative scanning by processing LAB
Asked by Michael Bain
(K=874) on 5/5/2004
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I have been having hassles here in SA with photo LABS. I tell them that I want my negative film developed and then scanned to CD, (not printed) at high enough resolution for me to print A4s. (for me this means output resolution of 300ppi at A4 size). Then I get stared at blankly. They don't seem to know that output size and ppi go hand in hand. When I ask them what resolution the output would be they say things like "the highest" or "800dpi" or "300dpi" which to me means nothing unless they say something like "300 ppi at a4 size". The answer I am looking for is "Your resolution will be 2048 x 1536 pixels" which is 3.14 MP or something similiar. But labs seem unable to quote either PPI at Size, MP or p x p resolutions and instead they tell me it will be scanned at 16base and stuff like that. So what Am I missing and how can explain this to them? If I tell them i want enough pixels that i can do a a4 print at 300ppi output resolution they tell me, "we scan everything at 1200dpi". Now as far as I know, if you scan a 35mm neg at 1200 ppi you can print it at 4 times the size of the physical negative with a 300ppi output resolution, right? - which won't be an a4.
So, what "photo-lab" scanner terminology or words like 16base etc can I use to explain to them I want an output file that is at least so many by so many pixels?
I promise you they just stare at me blankly!
Second part of the question: Assuming they get the resolution thing right, are negatives scanned at photo labs better or can I just do this better myself on a flatbed?
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Michael Bain
(K=874) - Comment Date 5/5/2004
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Ok . . I think I figured out a way to tell them what to do. I'll just ask them to scan the negative at 2700 dpi. Ho did i get to this figure? size of negative x dpi / size of output. this is thus +- 1.4" x 2700dpi / 12" = 315ppi output resolution and 12" wide - and that an A4 at basically photo quality!
Now just to find a place that can scan negatives at 2700dpi.
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Eveline Shih-Pitcairn
(K=4406) - Comment Date 5/7/2004
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The reason a photo lab staffer say "16 base" is because that is what the setting on their scanner states. This is based on file compression on the Noritsu machines that does the scanning. For instance, the 3001 Noritsu machine I scan on has the following conversions: 4 Base = 1024 x 1536 ~4MB file compressed to 1MB 16 Base = 2048 x 3072 ~17MB file compressed to 4MB 64 Base = 4096 x 6144 ~90MB file OKA -(bar)
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Chris Hunter
(K=25634) - Comment Date 5/18/2004
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visit http://www.superwarehouse.com/Minolta_Dimage_Scan_Dual_IV_Film_&_Slide_Scanner/2891-301/p/371702
and do the scanning yourself, leave the communication headaches out of the equation. Retails for $285US, scans at max. optical res. of 3600x3600, more than enough for your A4 enlargements, plus the satisfaction of performing your own high-quality scans and prints is great.
Chris
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Chris Hunter
(K=25634) - Comment Date 5/18/2004
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Minolta Dimage Scan Dual IV Film & Slide Scanner
search for this and you'll find it retails for under $300US, scans at max optical res of 3200x3200, and leave the communication headaches out of the equation. Plus, i find it very satisfying to perform your own high-quality scans and prints, if you have the know-how and storage capabilities.
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