Question about blowing photo up for a poster

[bennyb98]

I found a thread about this but it was a couple years old and didn't really answer my question so I hope its ok to post but...
I'm looking at making some poster prints of photos of me and some characters from Disney to decorate my new room with. I've looked up both prices at KodakGallery and Wal-Mart to print out some 16x20 posters (20x30 would just be too big i'm afraid)
Anyways, according to Kodak the picture will come out fine but WalMart has a little caution flag next to that size (and all larger ones) so I got to wondering how the photo would look and due to me cropping the photo to edit out a misplaced water bottle its now an odd size.

Long story short I've been trying to make sense of pixels and megapixels ever sense and I have no idea if my photo will blow up correctly or not and don't want to order a bad poster.
So any one have an idea of how I can figure out if it will blow up correctly?

The main photo I want to have enlarged (according to the properties tab) is 1916x1544 and both resolutions are 230dpi.

 

[dolphindan1]

We did this a couple of years ago but I have a huge printer at work to print on...at 230 dpi it will be a bit grainy and maybe a bit blurry but will still look ok...it wont look like a poster you buy at a store but it will look good enough to frame and hang on your bedroom or kids bedroom wall...I did it with some pics right off the internet...some spiderman and basketball players for the kids oh and Jeff Gordon's car and they look fine...I think the DPI was about the same....the darker richer colors will look better if they print well, if not the will look very bad....I say try one and see what you think...

 

[dolphindan1]

DPI

http://en.wikipedia.org/wiki/Dots_per_inch

pixel

http://en.wikipedia.org/wiki/Pixel

megapixel

http://en.wikipedia.org/wiki/Megapixel#Megapixel

 

[MarkBarbieri]

You say that your picture is 1916 pixels by 1544 pixels and is 230 dots per inch. So if you print it exactly like that, it will be 8.3 inches by 6.7 inches. I got that by dividing the number of pixels (1,916) by the dots per inch (230). 1916 / 230 = 8.3.

To make it 16 inches by 20 inches, you'll have the same number pixels, but more inches. 1916 pixels stretched to 20 inches will be 96 dots per inch. That's getting to be a very low dpi number.

I prefer to print somewhere between 240 to 300 dpi. Fewer is OK, but the fewer you have the blurrier the picture will look. Whether that is OK depends on how far away you are. You could print your 1916 x 1544 picture the size of a billboard and it would look OK to someone driving past it 300 feet away on the freeway. If you print it at 16x20 and look closely at it, you won't be happy. On the other hand, if you mount it on a wall and look at it from 10 feet away, it won't look bad.

 

[bennyb98]

Thanks for the help! One thing I've been thinking about doing is waiting until i'm back at college at the start of the year and getting on a computer lab with photoshop and just enlarging the photo to that size to see what it would look like then on the screen. If all else fails its only about $12 which I wouldn't mind paying for a "decent" poster print.