Hi,
When I open a raw file and am in the camera raw screen (CS2) at lower left is resolution set at 240ppi. What's happening if I change this?
Thanks in advance.

Nothing whatsoever.

That's not exactly true -- it tags the file with the image dimensions appropriate to the resolution selected. IOW, your file will read 8x12 at 360 PPI while it might be 12x18 at 240. But it does not alter the base file in any way other than adding the sizing information.

Thank you. So I accomplish the same thing in image size dialog.

That's right...does nothing. Just tags the file with a ppi number but doesn't do anything to the actual resolution as there is no actual size in inchesXinches defined.
What I do is set it to 1ppi which sounds silly but this lets me crop to a fixed aspect ratio just entering the dimensions as inches in the crop tool with no math required. For example if I want to crop to fit a 1024X768 screen I just set the crop dimensions to W=1024in and H=768in this gives me a crop area I can drag around the image and resize while maintaining a set aspect ratio. There are probably easier ways to do this but I'm still a PS rookie.
Please reply if you want to tell me the easy way to do this.

Thanks. Steve.

Just set your crop tool to 1024x768 and you will get that exact sized box regardless of image size or view!

I remember having problems cropping to a fixed aspect ratio the first few times I tried it . Somehow setting res to 1pix/inch seemed to help at the time but I can't remember exactly what the problem was. Maybe that was before I noticed that you can enter the dimensions in tool options and was just cropping freehand.

It's probably best to ignore my last post .

OK. It took a couple hours but I remembered why I set the ACR resolution to 1px/in. If you leave it at the default 240px/in, then open the image in PhotoShop and try to crop by entering 1024inX768in (the default is inches) PS tries to generate a file that is 1024X768 inches at a resolution of 240 dpi. This would be about 45Gb and you'll probably get an error message saying unable to complete task because the scratch disk is full.
Setting the crop size to pixels instead of inches would also prevent this from happening.

Steve.

Uhhhh... You can set the crop dimension or rectangular marquis in inches or pixels -- just write in either "in" or "px" after your number; 1024px x 768px...