A DA 40 peaks out at 2475 lw/ph in photozone testing... the 18-135 reaches over 2600 lw/ph in several categories, including 24mm and 50 mm. I'd also point out that resoluion can also be expressed as a percentage of the thoeretical max.
A K-5 has 3200 pixels of resolution. The best lens (I beleive it was a Sigma 70 macro , I've seen tested in any test produced 2900 lw/ph but the average is around 2200-2300. Based on observations of what I've seen to date... with the vertical resolution on a 7100 increasing to 4000 (from 3200 on a K-5) I would expect the increase in resolution to be somewhere in the range of 75% of that or 3000 lw/ph. The only test I've found of an actual 24 MP APS-c sensor suggested it could achieve, 2500 lw/ph, (
Nikon D3200 Camera Exposure - Review ) Considerably less than the 75% of max vertical res, I expected, but still 200 to 300 lw/ph increase over a 16 MP sensor. We've definitely hit the wall of diminishing returns when it come to APS-c apparently. When you consider that it's been suggested that the increase in using a K-5 IIs over a K-5 is about 10% , and I'm really interested in seeing what the increase in the K-5 IIs is over the K-5, with the D3200 being about a 10% increase over the D7000, I need a little bit more information to write 24 MP off, but not much. The only way it pans out for me would be a 24 MP filterless APS-c Pentax, where it turned out you got he 10% for being 4000 pixles deep, and an additional 10% for the lack of filter, making a 20% increase over K-5. For at least a total of a 20% increase in lw/ph. If they cancelled each other and all you got was an additional 10% I'd rather stay with 16 MP and virtually the same resolution. A lw/ph increase of 200 is visible, a lot of times the difference between one lens and another can be that much....but not critical. IMHO you'd have to get at least 400 to be worth buying another camera for. Like the difference between a K-5 and a D600 or D800.
Last edited by normhead; 05-15-2013 at 02:18 PM.