lens tele extenders

I doubt you will get an answer.

Last Login: 14th December 2007 - 04:25

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My FLICKr
My PENTAX GALLERy
Camera: Gripped Pentax K10D MKI (Now with designer red tape door catch)
AF Lenses: 10mm-500mm
Manual Lenses: Pentax M 50mm f4 Macro, Tamron Adaptall 2 SP 17mm f3.5 (151B), SP 35-80mm f2.8-3.8 (01A), SP 90mm f2.5 Macro with 1:1 adapter (52BB), SP 90mm f2.8 Macro (72B), SP 70-150mm f2.8 Soft (51A), SP 70-210mm f3.5 (19AH), SP 80-200mm f2.8 (30A), 6 PK/A Mounts. Pentax A* 300mm f2.8 & Pentax 1.4X-L, 2X-L & AF 1.7X.
Flash: Metz 58 AF-1, Sigma EM 140 DG Macro Ring Flash, Pentax AF-280T, Pentax AF-200T.

NOTE TO SELF: Must stop buying lenses (soon)

Yes, I did not expect one from the OP but thought someone else might know.

Greg

I am one of the TC junkie's. I have tried various TC to some degree of success. But the lost of light and image quality lead to more bad images than good one. But I still stick to the TC for a few simple reasons -- portability and great bargain for occasional use on that silly birds.

My most favorite TC is the Pentax AFA 1.7x TC as it really work well with MF lenses and turn a MF lens into partial auto focus. I prefer it to use with 'A' capable lens.

There are few other TC's worth noting and I listed here in order of my frequent use
1. Pentax AFA 1.7x TC
- magical in turning MF to partial AF
- I prefer it to work with MF lenses with A setting
- allow you to enter SR focal length
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2. Tamron Pz-AF 1.4x TC
- this has the least lost of light
- one of the few TC working with SDM lens.
- I see a lot of PF/CA from this TC

3. Promaster 1.7x AF TC
- works with AF, not on DA* 50-135mm f/2.8
- I see some claim it to work with DA* 60-250mm f/4.0
- has less PF/CA when compared to Tamron 1.4x TC


With a 2x AF TC MC7 from Kenko, I can hardly get it to AF with Pentax F* 300mm f/4.5, but the combo is hand-holdable




Thanks,
Hin

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I can verify that the Promaster 1.7x Pz-AF TC and the Tamron 1.4x Pz-AF TC will work successfully on a K20D and DA*60-250, I have the Promaster and had a Tamron. I believe they also work with the same lens TC combination on the K-7 and K-x. Reasonable light and subject contrast is neccessary.

I haven't tried them on all SDM lenses, but can verify that they don't work with the DA 17-70, DA*16-50 or DA*50-135.

Only TC's with the designation Pz-AF have the power contacts used by the SDM system.

Some test shots using the Promaster here - Promaster 1.7x test shots

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Best regards
Richard Day

Profile - link - (click on About for equipment profile) - My Flickr site - link

"Only TC's with the designation Pz-AF have the power contacts used by the SDM system."

But not all with the designation Pz-AF work with SDM. Kenko TC's have to be Pz-AF and SHQ, I think. There has been other threads about it, if you want to check.

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Regards
Barrie
K20D K200D DA*300 A50/1.7 FA50/1.4 FA135/2.8 FA35 DA70/2.4 DA18-55 DA17-70 DA55-300
Samsung12-24
Tamron 28-300XRDi 70-200/2.8
Sigma 50&105mm Macro 170-500 400/5.6MF 24/2.8

I believe he means that if the TC had previously autofocussed to either extreme and then been disconnected and connected to a manual camera, then you may find that it affects your minimum focus distance or infinity focus as it won't be able to correct itself since the camera doesn't have AF.

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Tim
K20D, Sigma EX DC 10-20/4-5.6, Tamron XR Di II 17-50/2.8, Super Takumar 50/1.4, Pentax-A 50/1.7, S-M-C Takumar 85/1.8, Tamron AD2 90/2.5, S-M-C Takumar 135/2.5, Tamron Di LD 70-300/4-5.6, Tamron AD2 500/8, Samsung SEF36, Cactus v4, Nikon SB24, Raynox 150, Pentax 1.7x AFA, Kenko 2x macro TC, Redsnapper 283 tripod
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Feel free to edit any of my posted photos!
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Yes, that makes sense, I wonder how one determines the neutral position of the 1.7AF before mounting it to a manual focus body. I'll have to do some playing around this coming weekend.

Greg

Hi Hin,
That a lovely shot of a pelican in flight, how far was it.

Greg

I would think about 40 to 60 feet but that is a guess on my part. I may have a small crop on that picture. With the 2x mounted, my 600mm can't go AF, and I was using MF for the shot panning the moment I saw the Pelican coming into view. I hand-hold the shot and I got an off focus on 1st shot and the above shot was the 2nd shot in a series in AF.S. I was not using AF.C at the time.



Pentax F* 300mm f/4.5 + Kenko 2x MC7 AF TC

Here is a shot using the Pentax-F 1.7x AF TC on a Soligor 200mm f/2.8 in M42 mount. Darn it, I sold the Soligor due to too-many lenses.




My biggest problems with TC are usually on heavy CA/purple fringing seen in high contrast area such as the tree branches and bird's white feather

Thanks,
Hin

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