avg file size for photo to print larger than 16x20 inches?


Joined: 2006-12-28
Posts: 4
Posted: Mon, 2007-01-08 16:20


This question is geared to all the photographers out there. I am helping a company develop a site (using gallery) where users will be able to print their images in very large formats (up to 59.45 inches x100 feet!)

Of course, most images that people will want to print will be less than 24x36.

I was wondering how large a file I should plan on for 300 dpi printing (preferably .jpg) at a size of 24x36?



Joined: 2007-01-11
Posts: 3
Posted: Mon, 2007-01-15 00:40

Hi CDO4,

That is really a hard question to answer. There are so many variables to look at. For instance I took one of my pictures and increased it to 24 x 36 at 300dpi. It came out to 7200 x 10800 or a file size of 222.4MB. Now that is without any compression which will give the best quality print. The more a picture is compressed the more it is degredated. I am just building up my gallery and I am uploading the photographs from my computer. The maxium file size to upload for each picture is 2MB. If I was to take your 24 x 36 picture at 222.4MB I would have to use a compression factor of 75 using jpg to come up with a file of 1.89MB for upload.

I think that if you took a picture of 11 x 14 at 300dpi. It will come out to 3300 x 4200 or a file size of 39.6MB. If you turn it into a jpg with a compression factor of 10 you will have a file size of 1.91MB.

I think a lot has to do with the software thay will be used to enlarge the original picture for print poster size. That is a whole other issue and there are some very good articles on the subject.



Joined: 2006-12-28
Posts: 4
Posted: Tue, 2007-02-20 16:15

Hi Lee-

Thank you for your response. From what I have learned is that when printing larger images the DPI can be decreased. In fact for most larger images, the minimum resolution is as low as 150 DPI. This is because for anything larger than 11x17, the viewer will be standing at a distance and will not be able to see any pixelation. Of course, a lot of this depends on the image itself. Smugmug had an interesting article on this here: http://www.smugmug.com/help/print-quality.

Also, for your 222.4MB image, it would be less than 11MB when compressed JPEG-10, correct?

Could you please send me links to the articles that you mentioned above?