Originally posted by dlhawes A fuzzy bird may be a good picture, but I'm not interested in the picture, I'm interested in how the light perceived by the photographer communicates with me.
Pentax actually softens their internal processing and lenses so birds wouldn't look so sharp. Their opinion is that overly sharp feather don't look natural. It doesn't take a lot sharpness to render life like looking bird feathers.
Check out the kit lens at 28 mm
@ ƒ8 ( where it's sharpest) the numbers are 2604 Center, Border 2155
Now the DA 35 2.4
@ ƒ5.6 2679 Center , Border 2320
So the difference is 60 lw/ph
That's about a 2% loss in resolution.
Each line line from the 35 2.4 takes 2679 / 16 inches for 163 lines per inch is 1 line in every .00613 inches
Each line from the 18-55 at ƒ8 is 2604 inches/16 162.75 lines per inch 1, each line takes .00614
Do you honestly think you can see a difference 0 .00001of an inch?
I think not.
This is the reason for not worrying about sharpness with modern lenses. Not some kind of preference for fuzzy images, its more about how little extra res you get by buying great glass. People really need learn to work out the math between what they have and what they want to see I it's worth while. By my guess you'd need between 100 to 150 lw/ph to have even a remote chance of seeing a difference, depending on the image.
I've always pointed out, buy the focal length you want, zoom or prime and the aperture you want, then see if the ou o focus areas and transitions are to your liking, and it's usually out of focus areas and traditions that are the most critical to my lens selection. Most of the time the sharpness of the lens won't be a huge factor.
You would probably have to take 100 to 1000 images before the DA 35, sharp as it is, gave you an image that looked better than the kit lens.
Ok, so I picked an extreme case you might think.... at 10 MP the DA 50-200 centre @200 is 1906 at it's sharpest, ƒ11.
The DA*200 at 5.6 is 2074. Hard to believe but at their best, their sharpness is comparable. Not at the same ƒ-stop but at their best. At ƒ11 the DA*200 is measured at 1956, not a whole lot of difference, like 50 lw/ph, even less than the DA 35 agains the kit lens.
So don't even hit about fuzzy. That's not part of the conversation. Think about cheap lens sharpness compared to expensive lens sharpness. That's the real word. You can't buy a modern fuzzy lens.