A Technical overview no images

Started Mar 13, 2014 | User reviews thread
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awaldram Forum Pro • Posts: 12,735
A Technical overview no images

Got my converter today so thought I'd try and answer all those questions that so far are missing answers.

Contrary to other 'previews' the barrel seems to be made of high quality plastic (like parts of the da*'s) not metal like the ltds.

The lens cap deserves a mention as it has a clever lock to avoid accidental removal in your bag.

1 The screw-drive is a reducing drive and so all screw lens should work without issue achieving lock in the same time the native lens would.

2 SDM operates without reduction so SDM lens achieve lock quicker with converter than without.

I won't cover off IQ as there are plenty of images posted just in summary IQ is somewhere between Good and Outstanding, With decent glass no discernible deterioration in IQ.

I won't cover any lens on the 'compatible' table as they work as designed but will cover a selection of screw and HSM that may or may not function.


FA 35-70 aperture corrected , focal corrected and AF OK if a little unsure

Tamron 18-250 Aperture corrected , focal corrected and AF OK but needs good light (hunts)

Sigma 50mm F2.8 Macro Aperture corrected , focal corrected AF Good

Sigma 400mm Telemacro F5.6 Aperture corrected , Focal Corrected AF Ok if a little unsure

Sigma 70-200 OS HSM Aperture unchanged, Focal Unchanged AF unusable focuses but needs numerous presses to lock (like the 300 with the Tamron 1.4 Pz)

For whatever reason looks like Sigma broke something when they implemented HSM into the PKA back engineering and so have some work to-do as all HSM PKA Sigma glass is no longer 'Pentax compatible'

All in all a great converter which though expensive may be able to justify its price.

 awaldram's gear list:awaldram's gear list
Pentax K-x Pentax Q Pentax Q7 Pentax K-3 Pentax smc DA* 55mm F1.4 SDM +15 more
HD Pentax DA AF 1.4X AW Rear Converter
Teleconverter • Pentax KAF2 • 37962
Announced: Feb 5, 2014
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