Seeing how big prints well without printing?

marlinspike

Am I understanding this correctly? If I want to see how big still prints well can I set the dpi to 72 without resampling, see what size image that gives me, then using that to know what zoom percentage equates to what print size?

Andy

marlinspike wrote:

Am I understanding this correctly? If I want to see how big still prints well can I set the dpi to 72 without resampling, see what size image that gives me, then using that to know what zoom percentage equates to what print size?

Hi Marlinspike - can you run this by again, I'm not totally following you....

Thanks

Mike Lane

marlinspike wrote:

If I want to see how big still prints well ...

:uhoh :oogle :confused

marlinspike

Wow...um, I don't think they're even called typos, I don't know what they are...just not english and not the words I meant to type.

Ok, so lets say I have a photo that has a res of 3072x2048 and it has a little motion blur in it so I know I can't make a great 24x36 with it, but I want to see how big I can go without the blur being a problem. Is it valid to...

go to image size in PS
uncheck the resample image box
set the "resolution" (really the dpi) to 72 (which I'm told is the dpi of a monitor)
see what the document size is (28.444x42.667inches in this example)
close the image size window
then play around with zoom and find that it looks good at up to 50%
then with this knowledge can I rightly assume that the image will print well up to 14.222x21.3335inches (aka 50% of 28.444x42.667)

I realize this isn't good english either. Not sure why I'm having trouble phrasing this. For the recond, in the original post I meant "If I want to see how big a photo will still print well...."

cletus

marlinspike,

I think I see what your getting at, but I don't know how well it's going to work. A pixel on your monitor is quite a bit different than a dot on a print... so I think you would have a hard time judging what the print quality would be based on how the image looks on screen.

Also, your monitor might not be 72 dpi. I know that macs used to have 72 dpi screens, but that might have changed If you're using a PC there really isn't a standard screen resolution... you would have to try and calculate your screen dpi.

jfriend

Try this

marlinspike wrote:

Wow...um, I don't think they're even called typos, I don't know what they are...just not english and not the words I meant to type.

Ok, so lets say I have a photo that has a res of 3072x2048 and it has a little motion blur in it so I know I can't make a great 24x36 with it, but I want to see how big I can go without the blur being a problem. Is it valid to...

go to image size in PS
uncheck the resample image box
set the "resolution" (really the dpi) to 72 (which I'm told is the dpi of a monitor)
see what the document size is (28.444x42.667inches in this example)
close the image size window
then play around with zoom and find that it looks good at up to 50%
then with this knowledge can I rightly assume that the image will print well up to 14.222x21.3335inches (aka 50% of 28.444x42.667)

I realize this isn't good english either. Not sure why I'm having trouble phrasing this. For the recond, in the original post I meant "If I want to see how big a photo will still print well...."

Here's what I would suggest if you really want to test it out. I'm assuming you can easily make an 8x10 print yourself at home. If you can, then you can crop your image, print an 8x10 of the cropped area and see what thta part of your image would look like if it was blown up.

Here's an example:

Suppose you want to see what a 12x18 looks like. Then just make a copy of your image and crop it down to just the upper/left quarter of your image (if it was 3072x2048, then crop it to 1536x1024). Then print that as an 6x9 image on your home printer. This will show you what 1/4 of your image would look like if the whole thing was printed at 16x20. In fact, you could even simulate a 12x18 by printing each quarter of the image this way and then taping them together. If you want to control the up-sizing rather than letting the printing software do it, then after the crop, up-size the cropped image to 1800x2700 pixels to give you 300dpi at a 6x9 inch print.

If you want to try out even larger like a 24x36, then just take a smaller crop, up-size that crop and print what fits on a single page from it. For that specific size, you could take a crop of 1/16th of the image (768x512) up-size it to 1800x2700 (300ppi at 6x9) and then print that as a 6x9 image.
That will show you what 1/16th of your image would look like if printed at 24x36.

As you can see from the numbers, you don't have a lot of pixels at that size. We're talking about printing a 6x9 from 512x768 original pixels that's been upsized. But, at the right distance away, it might be acceptable. You will have to avoid the temptation of examining it up really close because almost nobody does that with a 24x36 print.

Good luck.

edgework

It also depends on what you mean by "printing". If you're talking about an actual printing press, with halftone dots, the rule of thumb is twice the dpi in your image as the screen frequency. A 150 line screen (high quality printing) would call for a 300 dpi image.

There are plenty of large format devices out there, however, that can get away with far less resolution. As with most issues surrounding Photoshop, so much depends on what it is you intend to do with the image.