After getting one of my images printed on a 20x16 for the first time, I was thrown into the world of 'printing sizes'. I searched the net trying to find what the largest size I could print from my 18mp camera.

A few sites differed with their info ... some said 10x8 was optimal but anything bigger will not look as good (unless super sharp image), others, as epicaricacy mentioned, said 20x16 is great and beyond!!

So, I am wondering this....how do photographers get to print LARGE poster sized images (larger than 20x30)? Are their cameras 40mp? Do they only use film?

Also, how can I ensure that my images are super, super sharp to get them at a 20x16 or 20x30? (yes, using a tripod etc)

I read that you do this ....

1. a small sharpen at the RAW converting stage (Lr or Camera Raw) of 40 or so
2. when in Ps you use an USM to sharpen to how you like
3. convert the image size (which may make the image a bit soft)
4. use a USM at a small % and only .5 pixel to bring the sharpness back.

This, they say, will ensure super sharpness on the image!

What are you thoughts and your process??