Optimum scanning res for photobox?

Threeracers

Threeracers

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Mark
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Whats the optimum for scanning and uploading to Photobox?

Tempted by a 70% offer that has just come through my email for a photobook but not sure what is best to send up.

TIA

Mark
 
There are a lot of subjective and objective factors to be considered and I couldn't give any figure that couldn't be argued with (even I could argue with anything I suggested with so vague a brief).

The best rule of thumb I can suggest is that you take the maximum size of the print in inches (long size), multiply that by 300 (to give an assumed image with 300 ppi), and then divide that by the negative size in inches,

If using 35mm for a 10 inch print, that would work out at 10 x 300 = 3000 divided by 1.5 = 2000 ppi.

This is a rule of thumb and is open to challenge and interpretation depending on circumstances.

The scanning resolution to use for optimum scan quality is a different subject.
 
2000dpi for a 10 inch print?!


Assuming an 8x10 print that comes out at 320 megapixels... A little excessive no?
I wouldn't even scan 8x10 film at that resolution.

Stick to 600 dpi for prints, should give you plenty of detail before the paper texture comes into play
 
Thanks both. I called them and they suggested 300dpi but I think they were thinking of prints rather than negatives as deep in their help page was this;

"If you scan a 35mm film, we recommend scanning the film at a 2700 dpi.

The ratio of (scanning resolution/printing resolution) is the enlargement factor. For example, scanning film at 2700 dpi and printing scaled to 300 dpi gives 2700/300 = 9 times enlargement of the original film size. 9X is about 8x12 inches (near A4 size) from full frame 35 mm. This enlargement requirement is why film needs high resolution."

On that basis I have started using 2400dpi for my 120 negs as I arrived at 8 x enlargement factor on 56mm being 448mm. The pages are roughly 12" x 12" so that should cover it. But then maths isn’t my forte!

Now I just need to work out sharpening / PP / adding a bit of contrast for a printed page……

Mark
 
robhooley167 said:
2000dpi for a 10 inch print?!


Assuming an 8x10 print that comes out at 320 megapixels... A little excessive no?
Click to expand...

I accept that. I was foolishly assuming that the OP was going to scan negatives; and the 10" figure was one I plucked out of thin air as the most likely size to select for the final print.

Prints are indeed different. A glossy paper should resolve about 30lpm, and that roughly works out at 300 dpi. Allowing for the Nyquist limit, 600 seems reasonable.

We obviously scan to different standards - I use full resolution on my Epson V700 for everything - even 5x4 negatives. Yes, the scans are 1.3 GB each, but I'm all for scanning once rather than finding at a later date that I need higher resolution.
 
Threeracers said:
"If you scan a 35mm film, we recommend scanning the film at a 2700 dpi.

The ratio of (scanning resolution/printing resolution) is the enlargement factor. For example, scanning film at 2700 dpi and printing scaled to 300 dpi gives 2700/300 = 9 times enlargement of the original film size. 9X is about 8x12 inches (near A4 size) from full frame 35 mm. This enlargement requirement is why film needs high resolution."
Click to expand...

What it boils down to:

Aim to have 300 ppi on the print.

If the negative needs to be enlarged x times to produce the print, you need a scanning resolution of 300x to achieve it. Hopefully, that's a simple piiece of maths.

Depending on your scanner and software, you should be aware that getting the scan right can take time; but it's possible to produce a scan that simnply can't be corrected afterwards.

I haven't worked out how to post images here, but assuming these links work, here are a couple of scans of the exact same negative differening only in scanner settings.

http://www.photoanswers.co.uk/Community-Landing/Media/Media-Gallery-Detail/?mediaItemId=86

http://www.photoanswers.co.uk/Community-Landing/Media/Media-Gallery-Detail/?mediaItemId=85
 
Thanks Stephen, can I have the settings for the first please....?

I am a bit of a newbie with regard to scanning (hence some of my basic questions recently!) but I have a V700 and am on the steep learning curve! For quite some time I have just scanned without tweaking anything but I am starting to look a little further into the settings - more to correct the changes that scanning itself makes rather than make an image. If that makes any sense.

Mark
 
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It does indeed.

When I started, I was using a relatively underpowered computer with 512 MB of RAM and Win2000. My 5x4 scans took around 4 hours a time (although roll film and 35mm was faster :)) and I soon swapped from the bundled software to VueScan. I've moved up in scanners since then, but stuck with VueScan.

The killer feature for me is that you can save the raw scan data, and reprocess it as many times as you want with however many settings you want without having to even turn the scanner on again. So I can scan once, and tweak settings to my heart's content afterwards.

VueScan (Hamrick software) is cheap, upgrades are free (unless it's just been changed) and virtually every scanner ever made is supported on modern platforms.

I'll admit I never gave SIlverfast and Epson scan a fair crack of the whip, but the scan times meant that I wasn't really prepared to take the time. Four hours and find you need to make a small adjustment; another four hours and a further tweak... Life's too short, even if you're a tenth my age :)
 
robhooley167 said:
2000dpi for a 10 inch print?!


Assuming an 8x10 print that comes out at 320 megapixels... A little excessive no?
I wouldn't even scan 8x10 film at that resolution.

Stick to 600 dpi for prints, should give you plenty of detail before the paper texture comes into play
Click to expand...

Rob... I think he meant 2000 dpi at the 35mm negative in that case, translating to 300 dpi for the print. 2000 dpi on 35mm is 6 mp, which seems reasonable to me!
 
With a V700 you don't gain any resolution going beyond 2300 dpi anyway (when test cards are scanned and analysed, this is because although the sensor can resolve 6400 dpi the optics in the path limit the actual resolved resolution) so I would just scan the negs at 2400 dpi and upload them like that. A 6 mp image at 300 dpi output is enough for 10x8 size so I think that will be ample for what you want.
 
Mark, I think what ever you send to the site for production they will do what they need to print.

My last purchase from this company was for three posters for a wedding and if I remember correctly they send yes are no on the up load, having said all that they came out in great quality and very well presented.
 
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