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-   -   Pentax Mount Converters. (https://forums.steves-digicams.com/pentax-lenses/141125-pentax-mount-converters.html)

Craig66 May 11, 2008 7:04 PM

I need some advice on conpataible tele converters for my K10D.

I am looking at the Sigma APO 1x4 converter.

Does anyone know if this converter works with other pentax mount lenses or just with Sigma APO lenses. ? {EG; would it work with my Pentax DA*200mmf2.8}

Does anyone know of a converter thatwill work with all pentax mountlenses.



:?

robar May 12, 2008 3:30 PM

the sigma only works with compatible lenses. sigma has a list on their site.

roy

danielchtong May 12, 2008 5:21 PM

Craig66 wrote:
Quote:

I need some advice on conpataible tele converters for my K10D.

I am looking at the Sigma APO 1x4 converter.

Does anyone know if this converter works with other pentax mount lenses or just with Sigma APO lenses. ? {EG; would it work with my Pentax DA*200mmf2.8}

Does anyone know of a converter thatwill work with all pentax mountlenses.



:?
I have DA200mm and I only have Kenko 1.5x. It works 100% even with AF and the sdm. Hope that helps.

I would believe Pentax 1.7x works with all Pentax lenses. Not all Pentax mount lenses though

Daniel

dnas May 12, 2008 10:33 PM

robar wrote:
Quote:

the sigma only works with compatible lenses. sigma has a list on their site.

roy
The Sigma APO converters actually have the elements protruding from the converter, so it is likely not to even connect with some other lenses, or even damage itself or the attached lens.

Craig66 May 13, 2008 4:19 AM

All my searching has only found the Sigma that will fit a pentax.

My main use will be with Bigma and the Sigma70-200mmf2.8 when it's out. But would have been nice if it worked with the DA*200 also. I will look at the Kenko for that. May be hard to find down under.

Didn't know Pentax had one of their own. Will check that out too.

Thanks for your help.:cool:

danielchtong May 13, 2008 4:51 AM

Craig66 wrote:
Quote:

All my searching has only found the Sigma that will fit a pentax.

My main use will be with Bigma and the Sigma70-200mmf2.8 when it's out. But would have been nice if it worked with the DA*200 also. I will look at the Kenko for that. May be hard to find down under.
On paper, pairing a TC to a prime of F2.8 or faster is more effective than to a slower zoom.

A stop less (only 1.5x) for a Bigma has given very little little light for the AF to work. It may not work for any serious work at all as a TC is a major add on to the optical setwork.

Daniel

jachol May 13, 2008 10:39 AM

Craig66 wrote:
Quote:


Didn't know Pentax had one of their own. Will check that out too.
Hi Craig,
If you do find the Pentax ones, they cost an arm and 2 legs. Especially the SMC-F 1.7X AF adapter ... I see that on Ebay sometimes but oftener than not bidding goes ballistic. There's also the Tamron-F 1.4X Pz-AF in PKA fit which works well with any of the Pentax fit lenses I have, and I don't think you'd have any problems with your 200mm/2.8, but they don't seem all that readily available on Ebay, I don't think it's too expensive as a new item. ... Jack

robar May 13, 2008 11:51 AM

the kenko and the tamron 1.4 or 2x will work.. as jack said, if you get the pentax branded, made by pentax, TCs be sure you can open your pocket. i've got the 1.4 and i think it cost me about 140usd. it is superb tho. i got the tamron mc4 2xand it works fine on some lenses.. primes mainly. tamron also has the mc7 version.

bilybianca May 13, 2008 3:59 PM

jachol wrote:
Quote:

Craig66 wrote:
Quote:


Didn't know Pentax had one of their own. Will check that out too.
Hi Craig,
If you do find the Pentax ones, they cost an arm and 2 legs. Especially the SMC-F 1.7X AF adapter ... I see that on Ebay sometimes but oftener than not bidding goes ballistic.
There are five different Pentax converters. First the SMC-F1.7X AFAdapter , which gives you 1.7 times the focal length of the lens and converts manual focus lenses to auto focus. Seemingly it has just been discontinued, it was recently available from the two major internet sellers here in Sweden. And then it was actually a bit cheaper than the ones on ebay. Still, I'd say it's worth a premium, there is noting like it in any other brand. I have it and use it with an 85 mm and a 200 mm lens, making them 144 mm and 340 mm auto focusing lenses with very good image quality. I got mine for free bybuying a package of used equipment, selling what I didn't need with a profit and got to keep the adapter and two fine lenses for nothing.

And then there are the manual focus SMC-A Rear Converters in four varieties. 1.4X S and 2X S (s for short, for lenses up to 300 mm) and 1.4X L and 2X L (for lenses 300 mm and longer) All these are still available new, costly, and marvellous qualitywise. With the smaller sensor area of digital bodies the S converters work well with longer lenses too, the main issue being vignetting which only affects the corners of full format film negatives. I have the 2X S and use it with a 600 mm lens, no problem. Found it at reasonable price on ebay, but that was a few years ago.

Kjell

bigdawg May 14, 2008 10:00 AM

1 Attachment(s)
The Sigma APO TC works great with the Bigma and I've found it works very well with my Vivitar 300mm f/5.6 TX mount lens. The element does protrude and whatever lens you use must be recessed enough at the mount base to receive it with out the lens elements bumping into each other. I'm sure you know this but I say it so other folks might understand. Really wish Sigma hadn't done it that way but they did. With the TC both the Bigma and the vivitar need to operate wide open...The best I've done with autofocus using the Bigma TC combo is f/8 in very bright sunlight. Manual focus is a must if you plan on using it above wide open a lot. An example of a shot from 40 feet distance using the Bigma-TC!
f/6.7, 1/350 sec, ISO 400.
Dawg



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