[robski]

Christine

The 72 and 300 settings are related to printing. As Stephen has mentioned this is not related to your problem. Resize the image to 800 pixels as you have been doing. The problem is the way that your are saving the image. Tell us what you are doing at this stage.



I've just seen your comment asking what jpeg artefacts are.



Look at the noise in the bottom image. The 3 images are at different levels of compression.
Going from top to bottom the settings are Maximum, medium and lowest quaility.

http://www.worldphotographyforum.com...2&d=1142529726