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Forum: Sold Items
04-10-2020, 06:13 PM
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Forum: Sold Items
10-07-2013, 04:51 PM
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Great lens. I have the SL II but always loved the SL's still with the three colored rings.
Even though the sale's pending I can't help it. I'll always bump Voigtlander! :)
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Forum: Pentax SLR Lens Discussion
08-12-2011, 02:08 PM
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The flange/lens illustration above is that of a KF mount that was only ever used on one Pentax body, the ME-F, and is not a KAF auto focus mount. AF lenses used on the ME-F had motors etc, inside the lens itself. Pentax AF bodies since the ME-F have had the motor inside the body with a mechanical screw coupling to provide lens motion.
Drawing of the KAF mount from Bojidar Dimitrov's K-Mount web site
Pentax lenses having an F, FA, FAJ, DA, DA* suffix (EG: smc Pentax-F or smc Pentax-FA) are all AF lenses. Pentax lenses having the suffix A, M, or no suffix are manual focus lenses.
Most of the Pentax AF lenses use a screw drive mechanism with the motor in the camera body. The mechanical coupling takes the form of a slotted hole in the lens mount, and a narrow blade in the body mount. Some newer DA & DA* lenses are SDM only and can only be used in MF mode on older bodies.
With no lens fitted to your camera, look at the mount whilst changing the focus switch from AF to MF. You will notice that this pin is retracted in the MF position, and proud of the mount face when in the AF position.
Looking at the lens mount of an AF lens, holding it with it's red dot uppermost (12 o'clock), the slotted hole can be seen at the 8 o'clock position approx.
Finally, if a lens has the letters AF printed somewhere on it, it is likely to be an auto focus lens, but not all AF lenses have AF printed on them. From memory, none of the Pentax lenses are labelled neither AF or Auto Focus.
Hope that helps.
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Forum: Sold Items
05-03-2011, 11:21 AM
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Cool shots! Looks mint too!
Free bump to make sure the right person sees this :)
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Forum: Pentax SLR Lens Discussion
04-26-2011, 04:23 AM
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Here you go then: https://picasaweb.google.com/bonhommed/18135Vs18250#
I used auto exposure, It was a cloudy day so light was changing. I took two shots of each scene and posted the sharper one, I repeated the brick wall shots in manual focus (two shots per scene) but took the photos down because they didn't add anything. All the AF photos were as sharp or sharper. I used a tripod and 2s lockup for the brick wall shots. I squared the camera to the wall for the brick closeups, it was not square for the photos of the entire house, focus was on the window in the middle of the wall.
For those who can't be bothered to peep, the 18-135mm has better resolution than the 18-250mm in every photo, at 18mm and 135mm, in the center, border and corners, wide open and stopped down. I had the same result vs my 18-55 II, the 18-135mm beats it in every possible way.
Mechanically the 18-135 is a dream. It makes the 18-55 feel cheap and comparing it to the 18-250 is like comparing a modern rifle to a blunderbuss.
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Forum: Pentax SLR Lens Discussion
04-26-2011, 02:03 AM
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Hi everyone. It's been a little while since we have posted because of a nasty weather freeze here in New Mexico(I meant to post pics from the Tamron 70-200 2.8, but y'all beat me to the punch!). Karen got the 18-135 lens and I have to agree with the resolution tests from Photozone, as our sample is comparable. BUT: This lens is also sharper than the 18-55WR that Karen's K7 came with, and faster at the longer focal lengths also(35-55mm). This lens is also the only choice in roughly the 18-135mm range that is 1. Weather resistant, 2. has a 7 or 9 bladed diaphragm(Karen and I like to do multi pointed sun stars on bright points of light, and the 18-55 has 6 blades for 6 pointed stars vs 7 blades for 14 pointed stars) and 3. Has a pretty silent and fast focussing motor. At 70-85mm this lens gets pretty sharp in the corners, a bit less so at 100mm, thought f16 helps there. It never gets sharp extreme corners at 135mm, but so what? She has the Tamron 70-200 f2.8 for more detailed pics. Also, the 50-200mm WR is weaker at 100-135mm from wide open to f8, but then becomes fantastically sharp at f11-f16. What this lens gives is a big range in a great build that is also WR. And there is no other choice for all that in one lens at the moment. And she does own all the lenses described here. Another note, this was my third choice for a walk around lens to replace the 18-55 WR for Karen: I tried the Sigma 18-70 OS because it started at f2.8 but it was really decentered and it had a huge amount of field curvature at 70mm(maybe the decentering did that also?), then tried the Pentax 17-70 DA but it was horribly miscentered also, so she chose to try the 18-135, and it does very well IMHO and Karen's as well. I did not post pics as everyone here has shown what the lens is like, as always, YMMV!
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