Originally posted by maxfield_photo It really depends on how large you intend to print. 24MP allows you to make larger prints if your lens will resolve enough detail. It won't make old lenses any worse, but the lens may become the limiting variable in the equation. If you could make an acceptable 11x14 print with a certain lens on the K5, you'll be able to make an acceptable 11x14 with the same lens on the K3. Now will you be able to make an 18x24? Maybe, maybe not.
But, people already make much larger prints using less than 16mp, so why would 18x24 be a limit any way
At some point to view a larger print you need to step back, and lens resolution will not be an issue any way unless you view a huge print from 12 inches, and at that point you need to shake your head side to side just to take it all in. Let's get real, they are making a 24MP to stay current, the 16mp of the K5 is already more than enough even for most pros and serious armatures.
I can remember a time, not so long ago, where some mags drew a limit at 10mp and above. This was only to block shooters of first generation DSLRs who were still producing excellent work but some j&(&@$$ thought 10mp for a 4 inch print in a magazine printing at 300 dpi was necessary