[rdeloe]

I found a couple previous thread talking about which lenses will work with the Rear Converter-A. Several other than the 300mm lens for which it is designed seem to work.

The issue seems to be physical compatibility, in other words, whether or not the lens and the convertor have elements that stick out to far to join.

I'd like to get a bit more reach out of my SMC Pentax-A 645 150mm F3.5, but it's never mentioned as being compatible (or not) with the Rear Converter-A 1.4X.

Can anyone who has the lens and the convertor comment on whether or not they can be used together, and how well they work if they can? Can you reach infinity? Is IQ degraded just a little, or a lot?

Thanks, Rob

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Last edited by photolady95; 09-02-2016 at 06:02 AM. Reason: removed personal link

[Bob L]

I've just tried and can confirm that they can't be mated.

Bob

[rdeloe]

Thanks Bob! I'm sorry to hear that (would have been handy), but you saved me a lot of bother.

[Bob L]

An A- 200/4 is probably not much more expensive than a 1.4x rear converter, will be a little faster and likely give better results (had the first option been possible).

Bob

[Ed Hurst]

I have used it successfully with the 150 f2.8FA. Must be different in terms of rear clearance from the 150mm f3.5A.

[rdeloe]

The Pentax-A 200/4 is definitely the next option. In fact, that plus the 1.4X TC would give me a few more options. Thanks all.