AF Converter

[Simplytimo]

I am looking at getting a Tamron 2X PZ AF 07 converter to use with manual lens.

Any advise?

Will that make the manual lens 'AF'?

[fengwei]

Originally Posted by Simplytimo I am looking at getting a Tamron 2X PZ AF 07 converter to use with manual lens. Any advise? Will that make the manual lens 'AF'?

If you really want a teleconverter, better stick to a 1.4x one. A 2x one will compromise IQ too much, don't really worth it imo.

The only teleconverter that can convert a Pentax MF lens to an AF one is the 1.7x AF TC from Pentax:

[Ben Loke]

Originally Posted by fengwei If you really want a teleconverter, better stick to a 1.4x one. A 2x one will compromise IQ too much, don't really worth it imo. The only teleconverter that can convert a Pentax MF lens to an AF one is the 1.7x AF TC from Pentax:

Can share the principle of how the 1.7x AF TC that convert Pentax MF lens to an AF?

I was searching www.pentaximaging.com to know more but the AF TC not listed.

[fengwei]

Originally Posted by Ben Loke Can share the principle of how the 1.7x AF TC that convert Pentax MF lens to an AF? I was searching www.pentaximaging.com to know more but the AF TC not listed.

The Pentax 1.7x AF TC has moving glass elements which move back and forth abit so to achieve AF when working w/ a fast lens. Even working w/ an AF lens, AF will still be done by moving the glass elements inside the 1.7x TC This of course only works w/ fast lens (w/ an aperture of F4 or faster, but sometimes F5.6 also works when the light condition is good).

Optically the 1.7x AF TC is very good, probably on par of those high quality 1.4x TCs by third parties. But still, it's not as good as those non-AF 1.4x TCs by Pentax themselves: 1.4x-S and 1.4x-L

Some people claimed that this TC has been discontinued already. But I think you can still find it new in Japan. It won't be cheap though, cost somewhere between $275 to $450USD used or new ...

[Simplytimo]

Thanks.

Does it mean that a Tamron 2x AF or those teleplus pro AF converter does not work with Pentax lens to AF?

Many thanks in advance

[hjbyeo]

Tim, the only 1 converter that actually helps turn your MF lens to AF is the one that FengWei suggested (please note the caveat). No others available currently until the new one appears on the market.

Quote: ...The Pentax 1.7x AF TC has moving glass elements which move back and forth abit so to achieve AF when working w/ a fast lens. Even working w/ an AF lens, AF will still be done by moving the glass elements inside the 1.7x TC...

If your question is on hooking up AF lens on the AF teleconverters of Tamron and teleplus pro, my quess is should still work but you may also have to adjust focus on TC along with the AF lens...

Correct me if I am wrong, guys...

[fengwei]

Originally Posted by Simplytimo Thanks. Does it mean that a Tamron 2x AF or those teleplus pro AF converter does not work with Pentax lens to AF? Many thanks in advance

Depends on the lens. If it's an AF lens w/ fast enough aperture, the camera would be able to do AF. But if it's an MF lens, or it's a slow AF lens, then it won't do AF.

The unique about this Pentax AF 1.7x TC is its AF capability when mounted w/ a fast enough lens (no mater it's AF or MF lens)

[Simplytimo]

Originally Posted by fengwei Depends on the lens. If it's an AF lens w/ fast enough aperture, the camera would be able to do AF. But if it's an MF lens, or it's a slow AF lens, then it won't do AF. The unique about this Pentax AF 1.7x TC is its AF capability when mounted w/ a fast enough lens (no mater it's AF or MF lens)

In other words whether they are AF TC or normal TC, if your lens is not fast enough, it is useless (AF or MF Lens).

Thanks guys.