upsizing images

[nerk]

Hi all,

I was wondering if anyone here can help with some general settings for upsizing images in photoshop (cs5) and using genuine fractals.

When i crop an image i sometimes end up with some crazy numbers in the image size tab in CS (e.g. resolution of 1500 odd!) then when i try to change it to 300 (for printing) im worried that CS is resampling the file in a way that throws away huge amounts of info.

Ideally i would like photoshop to keep the same resolution throughout the editing process i.e. it remains the same from ACR to photoshop and then when its cropped later at the end but it doesnt... any ideas as to why this might happen and if i was to leave the resolution as it is would it be ok?

[Dave Humphries]

Hi Chris,

I'll do my simpleton's view until Colin, or someone that prints more than I do, comes along with a proper answer.

Personally I don't worry my head with DPI/PPI, mainly because I use web images 99% of the time, I only concern myself with absolute image size, in pixels, not inches or cm.

In round figures ...
Thus I start with say 4800 x 2800, so I crop a bit in PP and end up with say, 3000 x 2000.
To display on web, I would down-size this to say 1000 x 660, but if good, I would save a full size version too, for printing.

When I want to print this, then (in my head) I divide the 3000 by a dpi figure (like 300dpi) to arrive at a quality vs size compromise, so 10 inches in this case, on the longest side.
However, you really don't need 300 dpi, so I would print A4 11.6" without a second thought and could easily go to A3 or even A2 (if my printer did ). I would say you'll notice quality loss if you go below 100dpi AND view it close.

I have an image, I click print, following these rules of thumb, it comes out fine, so why complicate life?

I never bother to set a ppi figures in Elements, and I don't worry about what dpi the printer can do either - I just don't see the benefit, but others who print more, may disagree.

Cheers,