[oscaletrains]

Of course it is your list and your criterion--but since a major use of teleconverter is for macro--and that likely the one area it does best in, the need for AF is odd IMO.

I think a lot of people want to explore the use of these things to extend their reach without resorting to purchasing a new expensive lens also, so those people are going to want to know if it will auto focus.

---------- Post added 09-19-16 at 06:04 AM ----------

The Albinar-ADG Auto 2X has to be T H E worst TC ever. I've got one and it's now used as a door stop. Although come to think of it even as a door stop it fails.

I've got the Tamron-F AF 1.4X Pz-AF MC4 and it works very well with my F*300. And for $100 more than the Albinar (6 bucks) it should.

Just deglass it and use it as an auto extension tube?

---------- Post added 09-19-16 at 06:06 AM ----------

I've re-read your list a few times and can't see this one in there...

Pentax Rear Converter-A 2X-L (manual Focus)

...although I'm spectacularly good at missing the obvious

I never knew there was one!

---------- Post added 09-19-16 at 06:09 AM ----------

Speaking of which, you might add the Vivitar 2X MACRO FOCUSING TELECONVERTER which integrates a helical extension tube with the 2X optical magnification. There are two Pentax types, PK and the PK/A with data pins. Neither provides auto focus function.

(This project reminds me of the '28mm lens 'bestiary' which attempted a similar comprehensive catalog. ) The Great Vivitar 28mm Bestiary - PentaxForums.com

This omission is particularly embarrassing since I currently own NONE of the teleconverters listed EXCEPT that one(PK/A). I have a Panagor macro focusing one also that is old school and does not have contacts or anything. It is different from the Vivitar one in that it does not extend in and out when "focusing" it.

---------- Post added 09-19-16 at 06:16 AM ----------

Sigma APO 2x EX DG ??

Thanks. Seriously, that's quite a long list of these things. More than I'd have thought.

---------- Post added 09-19-16 at 06:20 AM ----------

Some of these have to be rebaged duplicates, but in reading various peoples reviews of them there seems to also be confusion on that point with some too. So who knows for certain?

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Last edited by oscaletrains; 09-19-2016 at 06:23 AM.

[Driline]

Oscaletrains? I've got a portable O scale layout but HO is my main focus. Let's see some pictures of your layout

[Digitalis]

Kenko Pz-AF 1.5x Teleplus SHQ

I have come across an 1.7X version of this with both SDM and screwdrive and full set of lens contacts.

[oscaletrains]

I have come across an 1.7X version of this with both SDM and screwdrive and full set of lens contacts.

Another unheard of one. The list keeps growing.

---------- Post added 09-19-16 at 06:49 AM ----------

Oscaletrains? I've got a portable O scale layout but HO is my main focus. Let's see some pictures of your layout

More of a model builder here than a running layout person...Lot's of photos here of O Scale models at this link. If you could call it a "layout", look in the folder "Turntable Project".


Yahoo! Groups

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Last edited by oscaletrains; 09-19-2016 at 07:07 AM.

[oscaletrains]

I just found a Tamron-F 2x KR MC4 in an old camera bag, so now I have 2 of these things listed...starting a collection!

[Digitalis]

Another unheard of one. The list keeps growing.

Interesting, I'll have to post a review. It was an impulse buy, I got it with the notion that if it degraded optical quality too much (realistically, all non-dedicated TCs reduce image quality ) I could at least remove the elements from it and have a 16mm AE and AF capable extension tube. From what I can tell the magnification from this TC is about 1.64X, and it works very well with the Sigma 180mm f/3.5 EX MACRO. It performs well with the Sigma 100-300mm f/4 APO EX DG at focal lengths below 250mm, but image quality degrades rapidly when you approach 300mm. It doesn't report accurate focal lengths, but that is an inherent issue with the pentax K mount rather than a fault of the TC.

[oscaletrains]

Interesting, I'll have to post a review. It was an impulse buy, I got it with the notion that if it degraded optical quality too much (realistically, all non-dedicated TCs reduce image quality ) I could at least remove the elements from it and have a 16mm AE and AF capable extension tube. From what I can tell the magnification from this TC is about 1.64X, and it works very well with the Sigma 180mm f/3.5 EX MACRO. It performs well with the Sigma 100-300mm f/4 APO EX DG at focal lengths below 250mm, but image quality degrades rapidly when you approach 300mm. It doesn't report accurate focal lengths, but that is an inherent issue with the pentax K mount rather than a fault of the TC.

The list has grown over 40 of these things, and I am sure we are still missing some of the obscure rebranded ones. Amazing.

[oscaletrains]

The Albinar-ADG Auto 2X has to be T H E worst TC ever. I've got one and it's now used as a door stop. Although come to think of it even as a door stop it fails.

I've got the Tamron-F AF 1.4X Pz-AF MC4 and it works very well with my F*300. And for $100 more than the Albinar (6 bucks) it should.

Actually there is an already deglassed teleconverter from China named KOOKA KK-P25. Advertised as a 25mm AF Extension Tube for about $30. Screw drive and all.

[fwcetus]

Pentax Rear Converter-A 1.4x-S (no screw drive)
Pentax Rear Converter-A 1.4x-L (no screw drive)
Pentax Rear Converter-A 2X-S (manual Focus)
Pentax Rear Converter-A 2X-L (manual Focus)

I don't think that I see why two of these are listed as "no screw drive" while two are listed as "manual Focus" -- I believe all four of these are functionally the same (i.e., manual focus only, with no screw drive).

EDIT: Of course, there ~is~ a difference significant difference between the two S TC's (that work with most K-mount and Ka-mount lenses) and the two L TC's (that work with a restricted number of tele lenses).

[oscaletrains]

I don't think that I see why two of these are listed as "no screw drive" while two are listed as "manual Focus" -- I believe all four of these are functionally the same (i.e., manual focus only, with no screw drive).

EDIT: Of course, there ~is~ a difference significant difference between the two S TC's (that work with most K-mount and Ka-mount lenses) and the two L TC's (that work with a restricted number of tele lenses).

Agreed. I'd like to know for certain if any of these function correctly with electronic focusing and or exif data.

[aslyfox]

I have two "tele converters":

Vivitar MC Tele Converter 2X PK-A/R-PK (I have no idea where I got it or when, nor do I know anything about it)

and

HD PENTAX-DA 1.4 AW AF Rear Converter

[UncleVanya]

Agreed. I'd like to know for certain if any of these function correctly with electronic focusing and or exif data.

The Pentax rear converter a 2x-s/-l and 1.4x-s/l both have no autofocus capability. They do allow for aperture automation so they permit the body to control aperture. You need to set adjusted focal length for proper shake reduction.

[oscaletrains]

I have two "tele converters":

Vivitar MC Tele Converter 2X PK-A/R-PK (I have no idea where I got it or when, nor do I know anything about it)

and

HD PENTAX-DA 1.4 XW AF Rear Converter

Yours says "XW"?

[aslyfox]

Yours says "XW"?

whoops typo

HD PENTAX-DA 1.4X AW AF REAR CONVERTER

is what it says

[oscaletrains]

whoops typo

HD PENTAX-DA 1.4X AW AF REAR CONVERTER

is what it says

Thanks, I was afraid there were two different ones!