Pickles & print size.

[Rich Rosemann]

Good morning,

 

I have a question regarding the necessary render size needed to print out to a 24in x 36in print, well.

I understand that the license version does not have a limit to the X-Y pixel size to render, but there must be (could be?) a point where more is just pixel size and render time wasted. 

 

And at what point does the DPI come into the picture?  Most print makers suggest 300 DPI, minimum.  Am I correct in assuming that multiplying the required DPI by the length or width gives me the necessary number of pixels?

Or 300 x 24 = 7200 and 300 x 36 = 10,800?  Seems --- not right, or at least a very large number.

 

I seem to be missing something I should'nt.

 

Rich Rosemann

 

[Roy Hirshkowitz]

A 77 megapixel image, which is what you're suggeting, is overkill IMHO. It will take forever to render and won't be worth it. The image buffer will require gigabytes internally.

75 DPI yields an 8.5 megapixel image-- that's a big one already. 60 DPI will give you a 3.1 megapixel image-- if it were me I'd probably go for something around that size.

[Rich Rosemann]

Hi Roy,

75 DPI seems to be the default for the image editors I've seen. Image files are quite large at the DPI. I havn't generated 24in x 36in prints before, so I wasn't sure if this DPI would be adequate. Thanks.

Rich Rosemann

[Roy Hirshkowitz]

I think it's still a little too big-- you'll need to do a little experimenting.

[Ros. Riha]

the desired resolution very much depends on the type of printer you are going to use. See here.

[Peter Milner]

300 dpi is generally used for publications. A poster is designed to be viewed from a greater distance and so may not need such high resolution.
Inkjet printers only need 150dpi.
A4 = 297 x 210mm. Divide the numbers by 25.4 to get inches and multiply by the desired dpi. So 300 dpi = 3508 x 2480.

[Ros. Riha]

Peter, check the wikipedia link above - generally speaking, all printers that use separate dots of primary colors are able to use its full dpi for BW prints, but for color output you have to divide it at least by two - three as an allowance for halftone screen. So if your printer is capable of 300dpi, it is enough to have 1753x1240 image for A4 print...

[Peter Milner]

That's what I said. 150 dpi for inkjet printers. The 300dpi was just an example of the calculation.
Sorry for the confusion.

[Rich Rosemann]

Good morning,

I sent a render to the printer yesterday created at 3072 x 2048 @ about 150 passes for a 24in x 36in print and the results are quite acceptable to me. I may try rendering again at some lower resolution, say 2304 x 1536, and do a compare. As you all seem to suggest, the lower resolution will do the job and shorten the rendering time. Thanks for the input.

Rich Rosemann