I have Pentax K5 system with some nice lenses. I also have Olympus e-pl5 with standard zoom and 9-18. I want to invest in better Olympus M43 camera/lenses because Pentax has become too heavy. I do not make prints. I use only the computerscreen (1920*1080). Does it make sense to buy some nice primes or is it hard to see the difference with cheaper lenses on a computerdisplay.