Are my i5 2500K Temps ok?

I have a new build with a i5 2500K on a Gigabyte GA-Z68XP-UD3 motherboard. The CPU has the stock cooler. I used the optimized default settings in the BIOS and my processer is clocking at 3.4 GHZ.

Touch Bios shows a sytem temp of 29-32C most of the time. Core Temp shows that the CPU cores are idling in the high 40s to low 50s. Under load it gets up into the mid 60s. During a 5 min fairly processor intensive test (file conversions where core loads varied from 55 to 90% on all cores) the max temps were in the 69-75C range for the cores. While typing this message with only IE 10, TouchBios, and Core Temp running the temps are between 49 and 57C.

I built this for photo editing and will not be doing any gaming. I do not plan to overclock.

Should I be concerned about these temperatures and look at installing a better cooler? Or are these temperatures acceptable?

If a new cooler is needed what about a Corsair H80? Are these easy to install? What temperature reduction could I expect to see?

Thanks for any help offered!