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11-03-2012, 08:40 PM   #1
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Pentax-F 1.7x Adapter, with AFs and M42s on K30?

I've spent a long while searching the Forum for all I can find on using the Pentax-F 1.7x AF Adapter. However, some threads date back quite a bit, and most posts aren't very recent. I'm actually wanting information relating directly to using it with the current K30.

The reason for all the "researches" being that I bought an as-unused 1.7x AF Adapter, in neat padded pouch, amongst a bundle of gear - as-new Pentax Z-50P with new battery + remote, Sigma 28-200mm lens with hood, and padded camera-with-mounted-lens, bag - for about $40.00 - on a local auction site.

The Adapter was apparently bought and used with that camera body and lens for a 'wildlife expedition' overseas.

What I didn't discover so far - is if the Adapter is used on a K30 with an AF lens - I assume the camera should be set to "AF.S" so it reads the Adapter - but, is the actual lens mounted in the Adapter - then in AF or MF mode? There is a switch on the barrel of the Adapter - is that a "Switch Between"...? If so - will it work with a K30?

Using M42 screwmount lenses was mentioned in some older threads. Can I take that to mean that I can install the Pentax M42 Adapter to the AF Adapter, then mount that combination safely on my K30, to then screw M42 lenses into? That would then work as just a 1.7x TC? Or can the "sheets of tinfoil" mentioned to "short pins", in one thread - get it AF-ing with the M42 lenses?

Seems to open up fascinating possibilities - any help and advice would be most appreciated, thanks...

Regards, Dave.

11-04-2012, 12:31 AM   #2
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The 1.7 AF teleconverter is meant to provide AF for non-AF lenses - it's unique in that regard. Don't use tinfoil for shorting anything. Mount your manual focus lens (either K mount or M42 + adapter), pre-focus so the lens is close, and the camera will fine-tune the focus with the screwdrive moving the teleconverter lenses. This TC is worth over $300 - you scored!
11-04-2012, 01:17 AM   #3
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Original Poster
Gabriel_bc - Thanks. Actually, I got the bundle for $120.00 - so just guessing, the camera about $20.00, same the plug-in remote, $40.00 the 28-200mm, leaves about $40.00 for the Adapter. The Adapter is "Japan" made - and the Accessories Database here accepted the serial number - so I think I have the genuine item.

Googling, I did find a Japanese / English guide-sheet for the Adapter - it says to mount the M42s in the Adapter, with the lens focus ring at infinity, and have the Adapter do the focusing. Now I know it's safe to mount that way, will try it with the Tak SMC 55mm f/1.8 in the morning.

From what I read here on-forum, you can use the Adapter as a 1.7x TC with AF lenses - but it wasn't too clear on how to do that safely.

The lens that was being used with the Adapter on the Z-50P is certainly an autofocusing Sigma 28-200mm - I tried it carefully (by itself) on the K30 - and all functions work with it... Might make quite a usable walk-around snaps-level lens. I can't fully identify it - it's not identical to the ones on the Database Reviews here - or to any I've so far Googled up...

As said, it's a Sigma 28-200mm, on the barrel, it says 'filter-symbol' and 72 - then SIGMA ZOOM - 28-200mm 1:3.8-5.6 - and, other side - LENS MADE IN JAPAN. Under that - the serial number, 1203852. There's no 'Macro' or 'Aspherical' or other writing. That includes inside the rim of the lens face - and there's a narrow flip-forward-back "hood" bayonet mounted. And a Sigma branded edge-pinch lens cap - inside that, it says, "72mm" and under that - "MADE IN JAPAN". Might it have been a short production-run Sigma did as a Pentax-mount kit-zoom back in the mid-90s? Can the "Lens-Sherlockes" here ID it from that?

The Z-50P seems nice, if I knew about film - all auto film advance, AF/MF switch, e-dial, and a centre LCD on top - clear, shows data crisply when switched on. Looks unused - spotless in front and in the film-bay area... Wish I knew how to use it - and film and processing was affordable....

Regards, Dave.

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1.7x, adapter, af, camera, k-mount, k30, lens, lenses, m42, pentax, pentax lens, pentax-f 1.7x, slr lens
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