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Old Jan 3, 2010, 11:13 PM   #31
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Originally Posted by AZK6er View Post
when I try to adjust magnification/focus the lens has this grinding sound as I move the focus ring, it does it with both the Kenko 1.5x's I have, it's like nails on a chalk board.
If those are autofocus TCs, put your camera in manual focus mode. You can damage the gears in the camera and/or lenses by forcing manual focus with the camera set on autofocus.
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Old Jan 3, 2010, 11:51 PM   #32
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I'd have to adjust the magnification b4 I mount the TC onto the Sigma 50 as when I try to adjust magnification/focus the lens has this grinding sound as I move the focus ring, it does it with both the Kenko 1.5x's I have, it's like nails on a chalk board. They and the Sigma 50 were bought new so I think that I might have to get a Sigma TC and use it with this lens instead. I got 2 Kenko TC's since I was reading of a few that were stacking their TC's and it sounded like a fun thing to do. It worked out OK but alot of PP afterwards, plus, only works on bright sunny days (I was testing this out with my DA 50-200 @200), even then NO AF, just Manual. Sorry, I degress. Thanks snostorm and mtngal, Ya'll have a good one.
I wouldn't worry about the grinding noise. It's just the lens's screw drive mechanism rotating the TC's screw drive shaft. As long as you have the body set to MF, and the screw drive shaft is not connected to the motor in the body (it would be very hard to rotate the focusing ring), there's nothing wrong and no unusual wear and tear. A Sigma AF TC would do the same thing. The only way that you would get a quiet focus ring rotation would be to get a manual focus TC, use a lens with an AF/MF switch turned to MF, or use a Quick Shift lens.

The reason why stacked TCs won't work well on your DA50-200 is mostly due to lens speed. At f5.6 at 200mm, it turns into a max aperture equivalent of f8 with a 1.4x TC, and with 2 of these stacked, you're at f11. most Pentax bodies need at least f8 to AF at all, and even then, you might need a reasonably sharp contrasty lens, at least medium bright daylight, and some contrast in the subject to get a reliable focus lock. The sensitivity of the K-7 allows AF to work with slower combos, but you'd still need the same combination of conditions for the AF system to work acceptably.

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Old Jan 4, 2010, 3:12 AM   #33
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My one TC is marked AF on the body but the first time I used it with my Sigma 50mm and my Super set to AF it made such a grinding noise that I just re-set the body to MF and use it like that, even though it sounded the same. With both TC's hooked up to my Sigma it's hard to Manual focus the lens (takes too much pressure to turn the focus ring even though the body is set to MF) so I set the magnification b4 I mount the lens, then just move the whole camera to focus, it's a hassel but it works. Stacked TC's are OK, but not great, maybe with a 70-200 f/2.8 Tamron SP or a Sigma EX that would work out a bit better for me.

penolta, snostorm, mtngal, TCav, ya'll have a good one and thanks for all your help. I've learned quite a bit of good info from this post.
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Old Jan 4, 2010, 7:15 AM   #34
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Can't really add much to all the excellent information already posted here. Just to let you know that I tried a number of different methods for Macro shots (extension tubes, bellows, Raynox lenses, etc), and have been happiest with the Sigma 105 macro lens. Got one used at KEH for a very reasonable price, and have gotten fine, sharp & detailed photos with it. Whatever lens or combination of devices you end up with, sure hope you enjoy it, and that you will share some of your macro photos here!
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Old Jan 4, 2010, 1:19 PM   #35
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A real Macro lens will always do a better job than anything else, and there's nothing stopping you from using a macro lens with extension tubes! I've gotten some great shots that way.

But since Macro lenses are always very sharp, it would be a shame to adversely affect an image by combining an excellent macro lens with a make-shift macro solution like close-up lenses, just to get a little more magnification.
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Old Jan 5, 2010, 11:01 PM   #36
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mole & TCav, I've read both your replies several times now and even though I struggle with the stand-off distance to my subject I'll stick with my 50mm for now and save up for a 105mm (prolly a Sigma) in the future. I've seen some of your work mole but didn't realize u used that lens and were that happy with it, your results speak for themselves. Puttin all that stuff tween my camera and lens means More PP, and I don't like do'in PP as it is. I have been called, uh uh, "Very Retentive", and have spent hours on a pic getting every hair in place and fiddl'in with the background do to not enough even light back there, I got frustrated after a while and realized that the fun for me was in the Camera, Not the Computer PP for hours. Special shots I'll get in there and do some PP on, but I don't want to do it to all my shots, so I try to get it right the FIRST time in the Camera. Thats why your comment really resonated with me TCav. You're right, you know it and I know it. Thanks to everybodies input on this post I have learned a lot more than just the simple opening question. I know I'm a little late, but, Ya'll have a Very Happy New Year.
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