# Printing 20x30 with the OLD Dp2: Possible or No?

Started Jan 31, 2013 | Discussions thread
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 Re: Printing 20x30 with the OLD Dp2: Possible or No? In reply to One River, Feb 1, 2013

One River wrote:

Does the image need to be "upsized" or anything along those lines (no idea what this process entails but have seen some mention it)? Would such a process allow or even larger printing than 20x30?

It's not too difficult if we take the dreaded word "resolution" out of the equation, leaving only simple arithmetic.

The DP2 makes 1760 x 2640 pixel images. If you want, for example, 20" x 30", then the number of dots per inch at 100% pixel size (no upsizing) will be 1760px/20" which is equivalent to 88 printer dots *** per inch. Yep. Sometimes written as dpi, sometimes as ppi, both equally confusing to many folks. I'll call them ppi from now on.

Now, 88 ppi will be pooh-poohed by most people who print things, being only slightly "better" than my own 86 dpi monitor. So anything "better" than that for a print of 20" x 30" (ignoring correct viewing distance) will involve up-sizing your image. How much does depend on how you intend to view the print. A "correct" viewing distance is where the picture is 60 degrees wide from your eyeballs point of view. And we can resolve 60 things per degree (20/20 vision) = 3600 things horizontally. This is the basis of the opticians test chart, BTW. So, 2640px at the "correct" viewing distance means that the print would look almost OK at 100% = 88 ppi.

However, many prefer more ppi, so they can stand closer, let's say half the viewing distant, so about 160 ppi. To get that ppi, the print shop will up-size your image X2 approx - which adds pixels not there in the original image but are the average of their neighbors, sorta kinda like. I call it blur, ho, ho.

For 320 ppi, they'd up-size 4X, even more bluuurrrrr . . I'm going to get jumped for saying that, I know.

You can print larger, BTW - for example, 100% original at 72 ppi would get you quite close to 24" x 36".

*** by "dot" I mean a printer pixel, not a squirt of ink.

Hope this helps, from he who never prints anything but test patterns, lol.

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Regards,
Ted http://tcktek.blogspot.com
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