Proper Image Type for Editing - Several Questions

When you save an edited file, what is logically the best format to save your work in (not export, just save your changes in a lossless format for the future)?

I've got PSP 8 & X, so would a PSP file be the best choice for saving my work (like a PSD file if I had photoshop).

Is there an accepted standard like PNG or TIF that most photographers stick with?

What are the downsides of PNG and TIF files as opposed to PSP and PSD (other than the fact that there's no layer support)?

Thanks!

There are advantages and disadvantages to all of the file formats you mention. For your purposes, if all you're going to do with the image is re-open it for use in PSP, then the PSP file format should be fine. The only downside I see from a photographic viewpoint is that the PSP file format does NOT support HDR (high dynamic range) images. But then, neither does the PNG format.

As far as accepted standards go, I'm probably not the best person to speak for the majority. My archives are as follows: I use my camera's native RAW format (CR2) for offline longterm storage, 16 bit PSD format for images I antcipate using in the foreseeable future, and JPEG format for printing or export to the web.

Actually, the TIFF format does support layers. The biggest drawback to the TIFF format is that developers can pick and choose which aspects of the file format they wish to support, so the same file can be interpreted differently depending upon how the format is read. TIFF also does not support animation. (PSP doesn't either, but PSD does)

The main downsides to the PNG format are that it doesn't support layers, there's no HDR support, no animation support, and that files size tends to be larger than other lossless formats. All lossless formats tend to be somewhat larger than say, a JPEG compression, but PNG files can be up to 10 times larger than JPEG, a significant consideration when discussing archiving.

Hope this answers some of your questions.

-Joe U.

Thanks a lot for the info! I read a ton of articles about high quality JPG vs RAW, and for now I'll just be using JPG from the camera. For editing I'd like to not step down from the original JPG quality so I think after reading what you said, I'll just use PSP for the files that are changed. Thanks again!