Canon 5D Mark 11, jpeg, tiff or raw for Large Posters?

richardmayoff · Nov 18, 2011

Just bought a 5D Mark 11. Doing a fashion shoot next week & need mu customer to have the best quality for making very large posters. The camera capturesa jpeg file from 3 to 6 megs right from the camera. When I open it up, in P/S I get a file size of 60 megs. The default size is 78 wide x 52 height at a res of 72. To save space for my clients, I have been switching the res to 300 and the fike now becomes 18.72 x 12.48. For customers that aren't blowing the images up big, I save it as a jpeg with no compression ( 12). It keeps the file small until they open it & it then becomes the 60 meg file at 300 res 18.72 x 12.48. What is the best format for printing posters 60" x 100"? Opening the native jpeg, converting it from 72 res to 300 and then saving it as a tiff, ( which will now become the huge 60 meg file or the jpeg no compression and 3-6 meg file size. I have 3oo garments I need to shoot and would rather have the smaller jpeg files which are quicker burning to DVD's. Or should I shoot in Raw and then save as a jpeg or tiff?
Thanks for your thoughts.
Cheers Richard

MLeeK · Nov 18, 2011

Shoot in raw. Save as tiff.

Big Mike · Nov 18, 2011

When you are changing the 'res', you are changing the PPI (pixels per inch). That is really only a setting that tells a computer how large to display the image. You could change it to 10, or you could change it to 10,000....it really doesn't matter.

The important number to be aware of, is the actual size of the image in pixels. The maximum resolution from the 5D mkII is 5616 x 3744.

The rule of thumb for top quality printing is that you want 300 pixels per linear inch. So that gives you an 18" wide print, no problem. But of course you could make larger prints. You don't have to stick to the 300 pixels rule. 240 pixels per inch will still look good in most cases and many labs will accept files as low as 100 pixels per inch. You also have to consider the size of the print and the proper viewing distance. Bill boards are huge, but they certainly aren't printed at 300 PPI....they don't need to be. They look terrible from close up, but as you back up, they look better and better.

Also, you can use software to up-sample your image. Adding pixels to increase the resolution. Obviously, the more you try to enlarge it, the worse it will look, but you can certainly do it.

Big Mike · Nov 18, 2011

There are many other advantages to shooting in RAW. But it's your choice. The maximum resolution is the same whether you shoot in RAW or JPEG.

The size of the image file, will depend on several factors. RAW files are rather large, JPEGs are smaller. When you process the image, if you save it as a TIFF, the file size will be large, but you retain maximum quality. Saving as JPEG will 'toss out' some data, but vastly reduce the file size. It's very unlikely that anyone could tell the difference between prints made from JPEG or TIFF...so it makes sense to use JPEG because of the smaller files. But if you are giving the file to someone who will edit it, or you plan on opening & closing & saving it many times, then TIFF might be a better choice.