http://www.scantips.com/basics09.htmlhttp://en.wikipedia.org/wiki/Image_file_formatsSometimes different programs can use a specific file format differently.
It may be a fault , different interpretation
(i remember a thread in the photoshop forum that was quite amusing how one of the coders of Photoshop though different about the use of alpha channel in TGA (?) files) ,
open formats like EXR that get implemented differently etc.
But mostly it is about lossless+lossy formats , 8 , 24 , 32 bits, layers or not , transparency and how much your preferred program is good in using them.
You will probably end in using one of these TGA, TIF , HDR (openEXR) , PNG. And probably because of Photoshop you will use PSD but will output to one of those probably.
In the past i used TGA and TIFF mostly. Now i use PNG and EXR .
No one holds you up from using JPG but it is lossy and with each edit you are destroying more pixels in it (
http://en.wikipedia.org/wiki/Generation_loss ).
And i think any software uses JPG in memory much the same as any other one with the same dimension and bit depth .
When you read the above wiki link for example the TIFF part you will understand it better.
Actually there isn't an 100% standard in the digital world regarding file formats. 3D object formats etc too.
Some times it is bad you get headaches why this or that wont work in your output (black image,black-white lines in the contours in alphas etc)...
Sometimes good because you get better and more ways to use them.
For example i am curious what format Matt will use for the render passes if he will use them in one format.
Maybe EXR again ?
We have EXR output in TG 2 Michael but then there is this too for example :
http://www.db-w.com/products/exrtrader/aboutIt isn't so complicated as it seems first and you end up using what suits your needs and software the best in the end.