Forgot Password
Pentax Camera Forums Home

Show Printable Version Search this Thread
09-02-2016, 05:56 AM   #1
New Member

Join Date: Aug 2015
Posts: 6
Rear Converter-A 645 1.4X - compatible with SMC Pentax-A 645 150mm F3.5?

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

Last edited by photolady95; 09-02-2016 at 06:02 AM. Reason: removed personal link
09-02-2016, 08:46 AM   #2
Site Supporter

Join Date: Mar 2016
Location: La Vienne (86), France
Posts: 143
I've just tried and can confirm that they can't be mated.

09-02-2016, 12:06 PM   #3
New Member

Join Date: Aug 2015
Posts: 6
Original Poster
Thanks Bob! I'm sorry to hear that (would have been handy), but you saved me a lot of bother.
09-02-2016, 12:55 PM   #4
Site Supporter

Join Date: Mar 2016
Location: La Vienne (86), France
Posts: 143
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).


09-02-2016, 08:47 PM   #5

Join Date: May 2010
Location: Sydney
Posts: 492
I have used it successfully with the 150 f2.8FA. Must be different in terms of rear clearance from the 150mm f3.5A.
09-03-2016, 06:10 AM   #6
New Member

Join Date: Aug 2015
Posts: 6
Original Poster
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.

  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
1.4x, 150mm, 645d, 645z, camera, converter-a, convertor, lens, medium format, pentax-a, pentax-a 645 150mm, smc, smc pentax-a
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Similar Threads
Thread Thread Starter Forum Replies Last Post
For Sale - Sold: SMC Pentax-A 645 Macro 1:4 120mm with Tiffen Haze-1 and 645-K Adapter Spenz Sold Items 5 07-06-2016 10:19 AM
Rear Converter-A 645 1.4X sc_john Pentax Medium Format 6 04-12-2015 02:04 PM
Rear Converter-A 645 1.4X, 2.0X (and any lens) club zantaphia Lens Clubs 2 07-14-2014 06:08 AM
For Sale - Sold: SMC Pentax-A 645 150mm F3.5 and Pentax -A 645 300mm F4.0 MalcolmL Sold Items 2 08-15-2013 10:10 AM
For Sale - Sold: Pentax 645 Leaf Shutter 75mm 2.8, 645-A 150mm F3.5 MightyMike Sold Items 13 04-03-2012 06:47 AM

All times are GMT -7. The time now is 11:47 PM. | See also:, part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]