[Tim Murphy]

Staff note: This post may contain affiliate links, which means Pentax Forums may earn a small commission if a visitor clicks through and makes a purchase. If you would like to support the forum directly, you may also make a donation here.

---

Dear Board,

I own a Spotmatic F and an ES-ll. I really like the full aperture metering. I've done the workaround and composed and then metered, but it's not the best way for me.

Is there a teleconverter that works with the SMC M42 lenses with the square tab and allows full aperture metering?

Regards,

Tim Murphy

Harrisburg PA

[UncleVanya]

I don't know the answer - but can you clarify how you want to use the Teleconverter? Is it for a specific lens combo?

---------- Post added 04-29-23 at 12:41 AM ----------

Vivitar M42 2x Teleconverter - PentaxForums.com

Looks like the 2x-8 Vivitar might work.

[Tim Murphy]

I don't know the answer - but can you clarify how you want to use the Teleconverter? Is it for a specific lens combo?

---------- Post added 04-29-23 at 12:41 AM ----------

Vivitar M42 2x Teleconverter - PentaxForums.com

Looks like the 2x-8 Vivitar might work.

Dear Uncle Vanya,

I like to shoot birds and wildlife. The longest lens I have for a film camera is a 300mm F4 SMC Takumar. I like the idea of more reach and on good days with adequate light I can deal with a 450mm F6, or 600mm F8 if there was a teleconverter that made full aperture metering possible.

I realize that may not be possible, but figured it was worth asking.

Regards,

Tim Murphy

Harrisburg PA :-)

---------- Post added 04-29-23 at 01:31 PM ----------

I don't know the answer - but can you clarify how you want to use the Teleconverter? Is it for a specific lens combo?

---------- Post added 04-29-23 at 12:41 AM ----------

Vivitar M42 2x Teleconverter - PentaxForums.com

Looks like the 2x-8 Vivitar might work.

Dear Uncle Vanya,

Since the link you posted seemed to suggest that I can retain full aperture metering I took a chance and spent less than the cost of a meal at McDonalds to get one.

Time will tell!

Regards,

Tim Murphy

Harrisburg PA

[UncleVanya]

Good luck! I hope it works out.

[EssJayEff]

I very recently bought an SMC PENTAX-M 400mm 1:5.6 to photograph birds on my property (i.e., I'm neither a birder nor a bird photographer), and I was curious about the SMC Pentax-F 1.7x AF Adapter. Would this work for the OP . . . or me for that matter? I know NIL about teleconverters.

[UncleVanya]

I very recently bought an SMC PENTAX-M 400mm 1:5.6 to photograph birds on my property (i.e., I'm neither a birder nor a bird photographer), and I was curious about the SMC Pentax-F 1.7x AF Adapter. Would this work for the OP . . . or me for that matter? I know NIL about teleconverters.

That is a K Mount adapter. He is using m42 lenses and cameras. Additionally the F 1.7x is a quirky thing, it is meant to add limited autofocus to manual lenses. To do this it has shifting elements inside and requires an autofocus camera to allow these elements to be moved. The photographer has to manually focus semi-close to the range needed and then the AFA (auto focus adapter) can finish fine focusing. Finally it needs a fairly fast aperture lens as the base for reliable autofocus. I personally have used it in the FA* 300 f4.5 (you can use it on an autofocus lens but it limits the lens to be limited autofocus like a manual lens mounted on the adapter) and that works in good light. I’ve used it stacked with the Hd 1.4x TC but only for moon shots and only with f4.5 or faster lenses and only after predicting the rig to infinity during the day and then using only manual focus and focus peaking that evening.

The F1.7x AFA works well for the intended use, but I think f5.6 wide open is going to push its performance a bit.

[kypfer]

For reference if nothing else, this might be of interest :-


Soligor Auto Tele Converter 2x with Leather Case to fit Pentax ES made in Japan | eBay