Promaster 1.7x AF Teleconverter Pentax

2008-07-29
Promaster Spectrum 7 1.7x AF Teleconverter Pentax
I bought this item brand new from ebay store Wolfes-Camera and the price I paid was fairly decent for $69.99. I doubt initially if the AF would work at all when I purchased this item. And I tried it on both of my Tamron 28-75 f/2.8 and Tamron 70-300 Di LD Macro and auto focus works though there is more obvious focus hunting for the long Tamron zoom in the long end


Promaster Spectrum 7 1.7x AF Teleconverter PentaxThe TC has all the 7 electrical contacts on the rim outside along with two golden SDM contacts inside. It has 4 groups with 4 elements and it has MC coating as noted in the specification.

Auto focus is slower than the Tamron 1.4x Pz-AF MC4 TC. Perhaps the field of view is narrow at 510mm, a busy surrounding and low light will have it hunt for focus. Once target is in focus, it is not as bad. And I am more than thrilled to have a 510mm for bird photos from a good distance. Some test shots with Tamron 70-300 Di LD Macro in ISO 400 and mostly f/8.0.

Hummingbird with Tamron 70-300 Di LD, Pentax K10D,Promaster Spectrum 7 1.7x AF Teleconverter Pentax
Hummingbird with Tamron 70-300 Di LD, Pentax K10D,Promaster Spectrum 7 1.7x AF Teleconverter Pentax

Hummingbird with Tamron 70-300 Di LD, Pentax K10D,Promaster Spectrum 7 1.7x AF Teleconverter Pentax


Hummingbird with Tamron 70-300 Di LD, Pentax K10D,Promaster Spectrum 7 1.7x AF Teleconverter Pentax

Hummingbird with Tamron 70-300 Di LD, Pentax K10D,Promaster Spectrum 7 1.7x AF Teleconverter Pentax
Impressions & Notes:
  • AF obviously works and I have tried it successfully on Tamron 70-300 Di LD and Tamron 28-75 f/2.8
  • AF is slower in Promaster 1.7x as compared to Tamron 1.4x TC
  • I am extremely surprised that PF/CA are not seen yet with the TC. I shot the similar locations when the bird is resting with backlighting branches, Tamron 1.4x TC all end up in purple tree but not so with the Promaster 1.7x. I am hopeful that this TC works better with PF/CA control.
  • Color and contrast are a bit flat but reasonable in the shot
  • 510mm is very achievable with the TC and IQ are yet to be confirmed with more use
  • I am happy as a clam to get a 510mm rig with this TC
  • The Promaster weighs 4 oz and it is not that much bigger than the Tamron 1.4x TC and hand-holding with Tamron long zoom is very feasible. Though SR stays at 300mm for the long end and my short trial seem to have reasonable sharpness.
  • Most of my initial test shots range from 10 to 15 feet away from the birds, a longer distance testing will help to judge the TC.
  • IQ with shots in close range shorter than 30 feet seems very good, SR at 300mm in long end still helps in shorter distance shooting.
  • IQ at full extension to 510mm with subjects at far distance seem to have more problems with blur images.
  • In all testing, AF works effectively in good lighting condition.

Related:

1 comments:

Mainmast2 said...
This comment has been removed by the author.

Post a Comment

 

About

Welcome to Hin's Photo Corner, this is my learning blog on photography, blogging and advertising. And I hope you enjoy your visit. For contact, please comment in blog post or email me directly hintheman at gmail.com.

 

B&H Best Deals

Statcounter