CS2 Camera RAW question

[akimartymar]

One thing I'm curious about when opening a photo using camera RAW. There is a box where you can choose the megapixels of the camera used. If I shoot with a 8mp camera and open it with those settings it gives me about a 8x12 image (I think). But if I change that to 25mp and open it I get around a 13x20 image, which would seem to be better if I'm going to be making a large print. Is there any reason not to do this? Which will produce a better image, starting with the "correct" mp's and upsizing from 8x12 to 16x24 or starting with the "wrong" mp's and only going up a few inches to a 16x20? Or does it matter?

[engstrom]

My personal choice is to always up-rez in PS and not ACR because you have the option of choosing between a few up-rez algorithms in PS whereas ACR just has the one.

[Bartman01]

If you are making a large print - call the lab and find out what they recommend. Most will tell you to send a 'normal' sized file and let the printer do the upscale. The only exception would be if the contents were not a pure photograph (as in you have added borders/text/etc).

The "MP" setting in ACR just lets you up/down scale the image when opening. I prefer to open the file in it native resolution and only re-scale after any initial adjustments.

[The Loft Studios]

I've done several test using an 8mp camera and have done the same exact image in Raw and Photoshop and allow my printer to upscale it according to their preferences and printed a 16x20 of each.....my conclusion, with the naked eye, YOU CAN NOT TELL THE DIFFERENCE!!!

[boxofrocks]

Nikon reccommends that you uprez in Nikon Capture first--they claim it will give you better results.

Dunno what Cannon says.