Second attempt: pentax 100 2.8 smc dfa sharpness

ericp
Posted 05/03/2009 - 15:37 Link
Here is my second attempt (after this one) to solicit views on the sharpness of this lens. I took advise from my previous attempt and taken pictures of a map at various apertures. Any help much appreciated.

I think it may not have been totally straight as the top left seems to be out of focus or that could be the lens??

All at iso 100 and jpeg from camera with contrast, sharpening and saturation all set to zero



f2.8 1/500
Comment Image


center 100% crop
Comment Image




f4.0 1/250
Comment Image


center 100% crop
Comment Image




f6.3 1/100
Comment Image


center 100% crop
Comment Image




f9.0 1/50
Comment Image


center 100% crop
Comment Image




f13 1/25
Comment Image


center 100% crop
Comment Image




f18 1/13
Comment Image


center 100% crop
Comment Image




f22 1/8
Comment Image


center 100% crop
Comment Image
https://www.flickr.com/photos/_cypher/

Pentax K10D, 50, 18-55, 28-70, 100, Sigma 10-20, Tamron 18-250, 28-75
Edited by ericp: 05/03/2009 - 15:39
johnriley
Posted 05/03/2009 - 16:08 Link
Within the limitations of the monitor image, it looks like a classic pattern of definition to me. The lens would appear to be sharp at all apertures, but it improves to a best of around f11 or f16 after which it drops in performance as diffraction effects become significant.

I would think that if you apply Unsharp Mask to the images then you will have sharp pictures.
Best regards, John
chirpy
Posted 05/03/2009 - 16:31 Link
My DFA 100mm Macro isn't particularly sharp wide open. f8 and beyond it is very sharp indeed. This is what I expected from a Macro lens. I always shoot RAW with Macro and use unsharp mask as John recommends to good effect.
shim
Posted 05/03/2009 - 18:25 Link
They look OK to me a bit flat but that may be the lighting, the top edge where it looks soft could be a bit out of focus.

shim
womble
Posted 06/03/2009 - 00:22 Link
Cannot see anything much wrong with these beyond what has been said. What is the issue?
Kris Lockyear
It is an illusion that photos are made with the camera… they are made with the eye, heart and head. Henri Cartier-Bresson
Lots of film bodies, a couple of digital ones, too many lenses (mainly older glass) and a Horseman LE 5x4.
ericp
Posted 09/03/2009 - 11:03 Link
womble wrote:
.....What is the issue?
I guess there isn't one

thanks for your responses. took some macro pictures this weekend and will post them in another thread. the lens seems to be good enough
https://www.flickr.com/photos/_cypher/

Pentax K10D, 50, 18-55, 28-70, 100, Sigma 10-20, Tamron 18-250, 28-75

Add Comment

To leave a comment - Log in to Pentax User or create a new account.



Proudly supporting Pentax User

Samsung Logo Asahi Pentax Logo