Saturday, April 25, 2009

File Types: Lossy vs. Lossless files for your artwork

This tutorial is to you show why you should always edit your photos in a "lossless" format, such as a .PSD file or a .TIF file. When you've completed editing, that is the time to resize and save as a .jpg for your blog or website.

As a kid, did you ever xerox a xerox, and then xerox THAT xerox...? And after about 20 prints you get this mooshy, funky, broken up picture?
Or here's another example: Your FAX machine. Ever notice how crappy faxes tend to be, barely readable half the time? That's because a FAX and a XEROX are both good examples of LOSSY formats.

  • LOSSY formats (.JPG, .GIF) LOOSE information-- poorer quality, but faster download
  • LOSSLESS formats (.PSD, .TIFF) SAVE information -- good quality, not appropriate for web, but good for print.

Here's a visual:

Sample A went through 6 types of edits as a 300 dpi .PSD file BEFORE reducing it to 72 dpi and saving it as a .JPG for the blog.

Sample B is an example of what might happen if the same image went through six types of editing and saving, all as a 72 dpi .JPG. See a bit of a difference?


JPG's are a LOSSY format. This means that every time you make a change to the file and resave it, the pixel data is compressed (meaning, the system 'throws out' anything it deems redundant). Pretty quickly, you will lose image quality if editing and saving only in JPG's. For this reason, I recommend to ALWAYS take your original digital file and immediately save it a PSD file. PSD's are a LOSSLESS format, so your pixel data is less prone to degradation.

Quick review:

  • Set your camera to record high resolution JPG's as in the last post, as per your camera's manual
  • Save the original digital image as a .PSD file before any editing.*
  • Once you've finished editing the photo, then you can save a copy of it as a JPG.

WHAT'S NEXT: I'll demonstrate how to save for both print and web in a later post.

*Alternately, can you set your camera to record TIFF's (another lossless format) and edit these safely? Yes, you can if you want. However, I have two things against TIFF's; one, the files can be so large on a standard setting (23 MB per picture) that they can be slow to work on, even with a well powered computer, and also take up a lot of storage space on your computer. But if you prefer TIFFs, then by all means use them.
.
.

9 comments:

  1. Thank you R! The tips are really helpful. I'm going to go back and read all your posts before I ask any questions, though. I'm glad you decided to do this blog too. But, how do you find the time?

    ReplyDelete
  2. I too wonder where you get your time and energy but am geting a lot out of this information and do thank you for your time in doing it. Believe me it is much appreciated. I think it will help me on my Outdoor Adventures Blog as well as my art blogs.

    ReplyDelete
  3. Sample B looks horribly familiar! I used to put up pictures like that on my websites. Still do with painted videos -- but will try not to edit JPEGs so much from now on. Thanks for nice clear explanation.

    ReplyDelete
  4. Hi Christine, Gary, and Charlene, glad to see someone's reading out there and that it makes sense (more or less).

    ReplyDelete
  5. Bless you, R. Finally, something clear to understand, what my problems might be!

    ReplyDelete
  6. I thank you as well, you are a wealth of useful information. Sounds like a time consuming pain to do all that file changing but it's obviously worth it.

    ReplyDelete
  7. Cathyann and Joyful, I'm happy to be of service. And really, the file changing is a simple step, just have to get in the habit of it. Thanks for reading!

    ReplyDelete
  8. This is all so very helpful! You are my photoshop goddess.
    I don't know how you find the time to do all this and complete all your wonderful paintings, but if you're ever wondering what to explain in photoshop, would you write something about "curves"? Thank you!

    ReplyDelete
  9. Hey This was just the information I was looking for on. I asked the question in class I sort of understood what she said. But this I understood. Cheers Thank you!

    ReplyDelete