JPEG Artifact?

[Swat2]

Hi!

I've been doing some compression comparisons between Super Fine, Fine, and Normal, all at Large resolution. I'm supposed to be looking for jpeg artifacts at the lower quality, but since I haven't the slightest idea of what one looks like, I can't find any, even at the Normal setting. They all look alike to me on the screen. (I haven't printed out).

Can anyone give me a hint of what to look for? Are they little green things, or fuzzy dust balls or what??

Any help would be appreciated. Thanks!

Don

[Daniel Mott]

Hi!
This is what jpeg artifacts look like (although I've exceeded them here):

http://devil.swebase.com/~skywalker/testartr.jpg

You see it like the image getting split apart in smaller 8x8 pixel squares in which colors that are near eachoter are flattened to just one color. Not very nice, but on the other hand, you rarely see this strong artifacts even on the "worst" setting in the camera. :)

[Swat2]

Okay, Daniel! Thanks to your info, I finally got it!

For a while there I was thinking I could get 220 perfect shots on 1 128 chip, but I found the 8x8 pixels in the Normal compression at 2X, but almost none in the Fine. However, I picked up quite a few in Fine when I went to 4X.

This tells me that on a long trip I can get good, acceptable quality at Large/Fine when I need to conserve chip space, but I better stay away from Large/Normal if I want decent pictures.

And of course, use Large/SuperFine (or RAW) at all times when file size isn't critical. There is a difference, by golly!

Thanks for your help!

Don