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Old Apr 29, 2006, 7:30 PM   #31
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Interesting way Sigma chips report to the camera. When I briefly owned a 70-210 f4-5.6 Sigma UC ZOOM it accurately reported the focal length in use but the Pentax Browser would report the lens itself as a Pentax F35-135mm zoom (really strange when the next line says the image was shot at 210mm). My 24-135mm Sigma now shows up as a Pentax F 28-80mm f3.5-4.5 but again the correct focal length is reported (such as 135mm or 24mm). I guess that is what you get with reverse engineered firmware.

On a positive note I have not yetobserved any of the strange behavior in my DL that some others have been reporting with their cameras. One suggested problem may be poor electrical contact between the camera and lens, but this was just a suggestion, I haven't heard any more on the issue.

I am very happy with this lens so far, it really is a wonderful combination of zoom range and aperture speed for the price. Definitely my choice for a walk-around lens that is affordable.

Ira
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Old May 1, 2006, 12:08 AM   #32
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Hi all. I've just purchased one of these lenses and noted the same problem with the both the Menu and Fn buttons. It doesn't blank the LCD screen every time, which made me think it was an intermittent electrical problem. All other functions (metering, aperture setting, focal length reporting, etc) appear correct. I use an istDS with ver. 2.00 firmware, and an istDL. The problem happens on both cameras.

Do all these Sigma 24-135mm lenses exhibit this behaviour on the Pentax D-SLRs? I'm just about to post mine back for an exchange, but don't see the point if this proves to be a systemic design problem.
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Old May 1, 2006, 4:17 AM   #33
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perigee

I haven't observed that problem yet, but the number of people reporting it is making me a little wary. Did the problem show up right away or is it intermittent?

Ira
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Old May 1, 2006, 1:24 PM   #34
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I'm still an SLR newbie, so excuse the question..on the ring where the Lens attaches to the Camera, there is a selection that goes from A - 2.8.* my camera will only function on A.* How do you change these?**
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Old May 1, 2006, 1:51 PM   #35
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Quote:
I'm still an SLR newbie, so excuse the question..on the ring where the Lens attaches to the Camera, there is a selection that goes from A - 2.8. my camera will only function on A. How do you change these?

1. Go to the Custom function menu [C]

2. Choose "Using Aperture Ring"

3. Set to "2 Permitted"

This will allow you to use the aperture ring, however if you leave it on A you can still set the value using either the Av mode or the M mode.

Ira
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Old May 1, 2006, 2:01 PM   #36
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wow,*thanks
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Old May 1, 2006, 7:08 PM   #37
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Glad to help.

Ira
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Old May 2, 2006, 3:51 AM   #38
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I noticed the problem immediately on my DL, as the first thing I went to do was change the camera settings. Initially thought my camera had developed a problem, but swapped my 28-70mm EX lens back on and all was well again. Then tried it on my DS, and also noticed that it causes the AF point to wander around a bit in my viewfinder - even though I have set it up in the menu for manual steering. Very strange indeed! Interestingly, it doesn't misbehave all the time. I would say in about 9 out of 10 attempts the display will blank, sometimes immediately, at other times after a few seconds.

A question for others who own one of these lenses - Does it really stop down to F/57 @135mm as indicated by my cameras? I'm guessing it would be correct as F/32 @24mm would be pretty small at 135mm. It's just that I've never seen a small format lens with such a small aperture. I assume that it wouldn't be very usable at F/57 (well past the diffraction limit), making it almost a pinhole lens.

Greg

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perigee

I haven't observed that problem yet, but the number of people reporting it is making me a little wary. Did the problem show up right away or is it intermittent?

Ira
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Old May 2, 2006, 7:04 AM   #39
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Perigee, according to the article here http://www.popphoto.com/article.asp?...article_id=816 it does stop down to ridiculously small apertures,DOFmust be immense. Diffraction may not be a big problem because of the long focal length, the f57 at 135mmis a physicallyequal openingto f16 on a 38mm lens. I would say that sharpness definitely suffers at those apertures however.

Ira
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Old May 2, 2006, 11:32 AM   #40
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Dr. C

Beautiful Pictures from RMNP. Just as beautiful as i remembered. My Wife and i honeymooned In Denver 24 Years ago and the park was one of our trips. We actually took an 8 hr Horseback ride throught the park.

Thanks for the peek

BK
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