Help With Prints

jubbin2001 · Jan 31, 2012

Hey all,
I am really hoping you can help out. My sister-in-law was going through some of the images I have taken with my D80, and wants to put 2 up in her new house. She is looking at either a 16x20 or 11x14 with a matte, she is still undecided. The problem is, I have only ever done 8x10, and that was just at a local Wal-Mart just for relatives that didn't require getting them "professionally printed". So now I am looking at a bit larger format, and to be honest the price for a 16x20 scares the crap out of me if the images aren't good enough to be blown up that far. I have heard people refer to 100% crop on the monitor is equal to staring at a 40" picture inches away or something to that effect. When I put my images at 100% and step back from my monitor (24" wide @ 1900x1200) they look pretty good. Of course that changes when I sit down, as I know that my lens used at the time (Nikon 70-300 VR II) isn't tack sharp.

(100% crop)

It's still pretty good imho, but looks much better once PP'd. I am working on getting my free Designjet 30 running, just waiting on ink, and then at least I can test print an 11x14, to give me a better idea where I am at. So I am wondering if there is a good way I can tell if my images are going to be ok for her without spending $20 per print plus shipping only to find they didn't work and be out that money.

Thanks all!

KmH · Feb 1, 2012

A couple of issues:
1. Your computer display is back lit and uses the RGB color model to render colors.
2. Prints are front lit and are made using the CMYK color model.
3. Most prints can handle more sharpening than electronically displayed images can.

To address the above issue people calibrate their monitor and use the ICC color profile for the printing device to generate a 'soft-proof' (a computer displayed approximation of what a print will look like) in their image editing software .

The only other thing you can do is have a print made. At Mpix.com 11x14 prints on E-surface paper are only $7 each plus shipping.

The next consideraton is the pixel dimensions and aspect ratio of the photos you want to print. 11x14 and 16x20 are different aspect ratios, and neither aspect ratios are native to most DSLR cameras.

The pixel dimensions of the photos will determine how many pixels-per-inch (PPI) can be assigned to attain the print size you want. The minimum PPI each photo can be printed at is a variable depending on image content and image quality.
You don't mention, here or in your profile, what camera you made the photos with. For example purposes lets assume you used a DSLR having a 14 MP APS-C size image sensor that has native pixel dimensions of 4608 x 3072 pixels (Nikon D3100). APS-C image sensors have a 2:3 aspect ratio.

An 8x10 (16x20) has a 4:5 aspect ratio, and a 11x14 has a 11:14 aspect ratio. so a photo made by an APS-C sensor would have to be cropped to 4:5, and cropped differently to be 11:14.
When you crop you are throwing away pixels.

So you crop the original 2:3 the minimum it takes to yield 4:5 and 11:14, and are left with 3840 x 3072 pixels (4:5) and 3910 x 3072 pixels (11:14). By the way, the convention is to state the image width first, landscape orientation would be a 20x16 (5:4) - portrait orientation would be 16x20 (4:5).

I have 3840 pixels on the long side and want a print that is 16 inches on the long side. Some 5th grade math tells us 3840 pixels divided by 16 inches = 240 pixels-per-inch.
240 PPI should be plenty of resolution, and the 11:14 would have slightly more resolution - 3910 pixels divided by 14 inches = 279.3 PPI.

Pencil · Feb 1, 2012

If you want to test the water, you could size the photo up as it would be for your big print, then make a smaller crop out of the photo at say 8x10, taking only a representative part of it. Get that printed and you'll have a pretty good idea of how it might turn out.

As your lens will have a sweet spot, i.e. won't be uniformly sharp over the whole image, you might take one of the worse bits to give you a worst case scenario.

jubbin2001 · Feb 2, 2012

Thanks for the help. KMH, I was pretty sure that I listed the camera as a D80, so it's a 10mp camera. After doing a bit of research, I have found some good formulas on figuring out prints. As it is I am pretty sure that a 16x20 or 20x16 are probably streching it as far as I am concerned. I am probably going to be ok with 11x14 or 14x11, as I recently did a crop of the image at that resolution and printed it out on an 8x10 (Thanks Pencil) and it looked pretty good considering my printer is a PoS all-in-one atm as I wait for parts for my Designjet. Either way, they aren't gallery images and she's not looking for wall murals, so I think with a little matting, and a nice frame they will turn out well. Thanks again!!