Scanner

MP Guy

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I use a 2800dpi scanner for my images. As I am new to this and do not know much about scanning, is this a fairly good resolution? I would like to get the best image possible but then I think I am limited by the display scxreen resolution. What good is a high dpi if your monitor can only do x?

Any comments on this woul d be appreciated.

Thanks,
 
Is 2800 dpi enough...

Is 2800 dpi enough...

Jorge,

Before really answering this type of question, you(we) need to understand why you are scanning - that is; what is your end purpose.

Scanning, at 2800 dpi the resolution is not that high for scanning 135 format film as a general statement. However, having said that, if all you want to do is see it or show it on your monitor then its not an issue - at the 72 dpi resolutions typical of web based image sizes a 2800 dpi scan of a full-frame 135 format image will give you a massive ~38" x 58" image - Sorry! how big did you say your monitor was :). This dpi is probably more than enough for monitor/web/email purposes only.

For printing, this is a different matter! About the acceptable minimum resolution for printing is 150 lines per inch, and as it takes two points to resolve a line, this translates into 300 dpi. Therefore, for printing purposes your resulting image would be about 9" x 14" or a bit less with some cropping - about A4 size which personally I find too small for producing a good print.

My scanner ouput is eventually destined for a A3 format printer configured for B&W Piezography using a Photoshop plugin that LOVES resolution (I can throw 1400 dpi at it and it doesnt complain!). As I consider the print my total objective, even when taking the original shot, more resolution is what I look for - I'm currently running at 4000 dpi.

Which brings me too another, almost more important, aspect of scanning - bit depth! Scanners today seem to represent one of (per RGB Channel/Pixel - bit depth) 8/24, 10/30, 12/36, 14/42, 16/48 with each increment here providing 4x the tonal information of the previous.

Most final output can live quite well as 8/24 but within a digital workflow that performs any tonal manipulations, this is usually not enough. For converting colour images to good B&Ws I have personally found that 14/42-bits is about the minimum I can live with. My previous scanner was a 12/36-bit machine and I used to regularly destroy the histogram with combing effects and posterisation through moving the tones around.

So after some rambling, hopefully I have answered you question; it just depends what is Your objective for that scan!

regards
 
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