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Old Aug 17, 2007, 9:44 AM   #1
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I can't post a link to the ones there as I'm at work and we can't use the site, but has anyone tried these extention tube sets advertised there for their pentax? It's very vague in the description, I assume they are as basic as can be but shipped you can pick them up for $15 US or so. As long as they can attach to the body and lenses I'd be happy, going all manual for exposures is more fun than a headache
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Old Aug 17, 2007, 10:20 AM   #2
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CC, you did not leave a link. if these do not have the mechanical linkage for the aperture i would suggest not getting them because for macros you need a small aperture for DOF.

roy


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Old Aug 17, 2007, 11:10 AM   #3
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http://cgi.ebay.com/Extension-Tube-M...QQcmdZViewItem

Can't tell from the limited pics if there's a aperature adjustment, doesn't look like it. They mention the focus limitation but nothing more..

I'm probably on the death list at work for finding an ebay back door :evil:


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Old Aug 17, 2007, 11:16 AM   #4
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i think i'd pass on these.. f16 is pretty dark. i'll send a ?? off to them and see

roy
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Old Aug 17, 2007, 11:24 AM   #5
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Hmm, can't set up wide open and stop down.. actually my lenses don't even have a manual aperature adjustment on them. Hmm..

Ooh.. nice pentax bellows for sale, though.. Gotta get back to work..
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Old Aug 17, 2007, 3:33 PM   #6
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CyberCoyote wrote:
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Hmm, can't set up wide open and stop down.. actually my lenses don't even have a manual aperature adjustment on them. Hmm..

Ooh.. nice pentax bellows for sale, though.. Gotta get back to work..
what lenses are you using ??? K mount ?? M42 ??

roy
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Old Aug 17, 2007, 3:55 PM   #7
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I've got the kit 18-55 and the j75-300. They're out in the car (sure, I bring 'em on the day there's NOT a Fisher hunting in the back lot!) but didn't think there was anything on them to adjust the aperature manually without some kind of special linkage.

However, I spotted this on eBay.. http://cgi.ebay.com/ws/eBayISAPI.dll...:IT&ih=009

which looks like it's got the mechanical mechanism to crank down the aperature. I've not played with older lenses yet so I'm not really savvy on the pros and cons of the older mounts and what they can and can't do so forgive me if some of my comments seem total mindless
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Old Aug 17, 2007, 4:46 PM   #8
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Sorry CC, but I'd say no no no to these.

There are some extension tubes on the market that actually can transfer aperture info electronically from lens to body, but they are rarely seen (I think Kenko has one). These are the only ones that would work with your current lenses, since they (the lenses) don't have an aperture ring and must be controlled from the body.

All M42 (screw mount), M, K, A, F and FA lenses would work with extension tubes with or without a mechanical lever to transfer the aperture info from lens to body. It's much more convenient, though, to have one with the lever. It allows you to focus with the aperture at max, and then the camera will stop down when you press the release button.

So what you need is a rare extension tube to work with your current lenses, or a new (old) lens and some cheaper tubes. Any lens would do, but a dedicated macro lens will of course give you the edge. Auto focus is of little interest in this case.

Kjell
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Old Aug 17, 2007, 5:00 PM   #9
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Thanks for the info, guys. Yeah, I was trying to circumvent the cost of a dedicated macro lens, although ext tubes and an older lens might be the bombo I have to work towards. I love the butterfly/dragonfly chasing but seeing the results from true macro lenses makes me feel like I'm wasting my time with what I take.

FIRST I'll hunt a nice dedicated macro or a decent prime that'll work wioth the less expensive ext tubes. Chicken and egg


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Old Aug 17, 2007, 7:48 PM   #10
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chicken came first with egg inside
thought everyone knew that..

roy
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