Originally posted by Marc Sabatella Perhaps not, but most of us have shot text much sharper than yours, and comparisons that show little difference at f/8 compared to even the best primes.
Perhaps, but this is what I got on the 14MP sensor using default settings (no sharpness or contrast boost). I'd be interested in seeing unprocessed results from any Pentax sensor from anyone that did similar shots.
Doing these tests is not easy. First, they can be attacked on many fronts:
- the methodology - it's not focused right, camera is not stabilized, etc
- the subject - if the methodology is good, you can always blame the subject - the lens is a bad sample, etc
- the purpose - if all else fails, bring the heavy artillery - 14MP images are not meant to be observed at 100% - doing that is equivalent to reading a newspaper wrapped around your face
So, it's fun stuff. But really, I'd like to see more shots from anyone, and just to share my experience, this is what I observed in my tests (flawed as they may be)
1) at 100%, even at f/8, the DOF will be thin (the higher the sensor resolution, the thinner the DOF)
2) it's difficult to maintain the same shooting conditions:
- lens perpendicular on chart plane
- lens at same distance from chart plane when testing same focal length
- perfect focus
- same exposure settings
- same lighting
3) Shooting b&w charts produces different results than shooting a normal scene
- it doesn't stress purple fringing weaknesses
- it doesn't show color contrast differences
For my chart tests, I realized it's hard to control all variables, so what I decided to do is to take a series of shots, several with each lens and just try the best. If nothing else, this would be representative of what I would most likely get with my shooting style from those lenses. I used LiveView to maintain the same focusing method across all lenses (the primes I used are manual focus). I fixed the exposure settings and I shot under daylight with overcast sky with AWB. I always tried to focus on the "50" in the middle chart using the top magnification. The end results were that overall the primes came out as looking cleaner than the zooms. In some cases the difference was minimal - I expected the K200 to be much better than the DA50-200@200 but it's only minimally sharper. But this type of difference that I've noticed between zooms and primes is also present in many other shots from the-digital-picture.
Combining those resolution tests with other regular shooting, these were my overall conclusions:
- the old primes are more susceptible to purple fringing and have less contrast
- the M40 is sharper than it is given credit for
- the K200 is not much sharper than the DA50-200
- the zooms don't show purple fringing and have better contrast