Resolution and Printing - a ?

[ReflectingGrace]

I obviously dont understand how this all works. Can someone break it down for me or at least just reassure me it will be fine?

I uploaded some pictures from a recent shoot on mpix. I have a D80. The pictures were cropped. In GIMP if I go to "print size" and put in 250dpi (what mpix's site say they print at) it gives me a max size of only 7x10 inches!!

BUT when uploaded, it tells me the max size is 16x24. even if I put it at 200dpi I cant get that size.

I emailed them and got this response:

"1783x2502 is how many pixels this has so this is why you can print up to a 16X24. The minimum resolution is 1600X2400 pixels and your is larger than this. Thank you!"

so will "minimum resolution" be crappy?

these are friends of mine. my fear is they spend a ton of money on prints, and a huge gallery wrap (which is her plan), and its horrible quality.

what am i missing?

[dcclark]

Setting the DPI in software is, effectively, irrelevant. From a practical viewpoint, DPI is determined by two things: First, the number of pixels in your image. Second, the printed dimensions that you want. These two determine how many pixels can be "squeezed" into each printed inch of paper.

Setting the DPI in Gimp or Photoshop just changes a number in the file, which tells the software how large to display the images onscreen. It doesn't affect what happens when you print on paper at all.

As far as image quality: 300 dpi is the "standard", but the larger the image, the less resolution you need. 300 dpi is very good for a 4x6 image which will be looked at very closely. By the time you get to 16x24, printing even as low as 100 dpi will be just fine. One reason is that people will be looking at the 4x6 from much closer than the 16x24 (you'll probably be several feet away). Another reason is that 100 dpi is still pretty high quality, and it's actually hard to see the difference usless you're literally inches away from the photo.

So, believe what mpix is telling you. They won't let you print below 100 dpi, and that's more than high enough quality for a large format print. If I showed you a 100 dpi large gallery wrap, and a 300 dpi large gallery wrap, the canvas would hide more details than the 300 dpi one would reveal.

[ReflectingGrace]

thank you David for the reply!!! its very helpful to know that setting the dpi in my software is irrelevant.

they told me to look at it at 100% and thats what it will look like enlarged???? (i had my iso too high, 400, and my pictures are noisy so they need some help if they will look like what they do at 100%)

i guess im just so nervous. this will be my first time to order a gallery wrap. this is a friend, Im not getting paid, but Id just feel horrible if it didnt come out well (and I dont have the money to pay her back). I guess mpix probably knows what they are doing too

ill save my emails and if they mess it up ill blame it on them LOL

thanks!

[fletch]

Just a bot of reassurance - I had a gallery wrap canvas printed at 100 dpi and it looks fantastic. Believe what MPIX are telling you. As for the noise unless its really bad I woudln't worry. The D80 should be more than capable a 400.

A usefull tip is if you want to see how it will look print a small protion of the image at 100% on your home printer as noise isn't as bad on paper as it is when you pixel peep on screen.