Stacking two (2) Pentax 1.4X HD AW TC's.

Started 5 months ago | Discussions thread
ForumParentFirstPreviousNextNext unread
Flat view
brandrx
Forum ProPosts: 25,805
Like?
Stacking two (2) Pentax 1.4X HD AW TC's.
5 months ago

Hi folks,

I received my second Pentax 1.4X HD AW about 30 minutes ago. Before I did the tests below I made sure that each Pentax 1.4X HD AW worked properly. They do.

Stacking two of these Pentax 1.4X HD AW teleconverters corrects the aperture as if only one of them was attached. In other words, it is no different than stacking a Pentax 1.4X HD AW on top of a Tamron-F 1.4X Pz_AF. It's the same on SDM or screwdrive.

Stacking two of the Pentax 1.4X HD AW TC's shows the following for autofocusing as compared to stacking one Pentax 1.4X HD AW on top of one Tamron-F 1.4X Pz_AF.

(1) - Pentax DA*300/4 sill works crappy with stacking two.

(2) - Pentax DA*60-250/4 still works good with stacking two.

(3) - Sigma 300/2.8 still works good with stacking two.

I have not looked at IQ other than on the back of the camera. However, I predict that the IQ is not going to be that much different than stacking the Pentax 1.4X and the Tamron 1.4X.

In a nutshell, the purchase of two Pentax 1.4X HD AW teleconverters for stacking purposes is not worth it IMO.

Cheers.

Ron

-- hide signature --

Ron - 'We don't have time to go take pics this afternoon Carl.'
Carl - 'What do you mean? It will only take 1/1000s.'
'Keep your eyes looking forward. However, glance back now and then to see where you've come from. It will put a smile on your face.' ~ brandrx

ForumParentFirstPreviousNextNext unread
Flat view
ForumParentFirstPreviousNextNext unread
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark post MMy threads
Color scheme? Blue / Yellow