Originally posted by claudefiddler I for one am looking forward to 645 test/reviews from members of this forum. DXO didn't reveal much. 11.5 stops of dynamic range I can really live with. What an improvement over chromes.
Can anyone comment on the 80 to 160 telephoto for 645. The 1.4 tele converter. Does the lens have an infinity stop? Is it sharp, specifically corner to corner. Quality build. Does the autofocus work? and work well or is a manual focus lens the way to go. How does it stand up to weather. Anything else... I'm completely unfamiliar with Pentax lenses. The one thing that I do know is that I'm interested in the medium/normal range telephoto.
On a different note note diglloyd.com just did an extensive Leica S2 review. This is a subscription based website. The review is excellent and in my opinion is a good benchmark for the type of comprehensive info that needs to be published on the 645D.
Thanks in advance.
Claude Fiddler
wildernesslight.com
The Pentax 645 1.4X was designed for the 300+mm focal lengths, due to mechanical position of elements some lenses will not work.
80-160 - The MF focus feels a little more solid due to not having AF mechanism and the AF/MF clutch. I believe the optic design is the same in both versions of this lens.
All the 645 AF lenses focuses a bit beyond infinity like all AF lenses. Considering the mass of optics needed to be move for focusing it is a good performer, not super speed like smaller camera/lenses. It does lock onto a good focus target accurately. I never had issues when shooting with AF point on the eyes.
However, to speed up AF speed the optical engineer sacrificed focus throw. This will take a bit getting used to in my work when I went with the 645N and AF optics back in 1997/98. The viewfinder was bright and easy to focus with, I usually use the grid screen with a pop-up eyepiece magnifier.
With proper technique I never had issues with mirror slap/vibrations in the image. Sometime we feel the slap vibration but they are post shutter mirror return vibrations. However I have not had a chance to pixelpeep the 40MP images as the above comments applied only to the 645/N/NII.
These are the lenses that I have had extensive experience using on my 645, 645N/II over the last 25 years:
A - 35, 45, 55, 75LS, 120Macro, 80-160, 150
FA - 33-55, 45-85, 80-160, 150, 300/4
67 with adapter - 400/4EDIF (Digitalis: if you can find your this is a great combo, very rare on used market)
Others with P6 Adapter - 30 Fisheye(Arsat), 45TiltShift(Hartblei)
Adapted to work with bellows - Nikkor M120/5.6, Macro Sironar N 210/5.6