Any 1.4X Teleconverters for F* Pentax 300mm f4.5 lens?

[calvinlo]

Hi,

I've very new to Pentax. Just got a Pentax K-r this morning.

I'm current thinking of getting a F* Pentax 300mm f4.5, but am concerned whether there is any 1.4X teleconverters that works with it and allow for AF? I have thoughts about the Pentax 1.7X, but not inclined because of the f-stop loss.

Appreciate your advise.

 

[istDeS]

Tamron 1.4X Pz-AF MC4 Teleconverter or Kenko 1.5X Pz-AF Teleplus SHQ Teleconverter. Both discontinued but the Kenko one still can be bought as old new stock at another forum.

 

[calvinlo]

Thanks for the reply! appreciate it.

What about this teleconverter below?

http://www.vivitar.com/products/28/auto-focus-tele-converters/861/14x-p

 

[darrrrrrrrrr]

Probably not a good idea to pair a Vivitar teleconverter with a F* lens due to the image degradation. Why don't you buy the lens first and see if you even need the teleconverter? If 300mm is long enough, and cropping does the trick you might not even have to spend the extra $

 

[detritus]

Probably not a good idea to pair a Vivitar teleconverter with a F* lens due to the image degradation. Why don't you buy the lens first and see if you even need the teleconverter? If 300mm is long enough, and cropping does the trick you might not even have to spend the extra $

i thought the vivitar 1.5x SHQ is not bad?

kengoh was using it for birding on an DA*300 before he got his new lens. its also the only one that is known to work on SDM lenses.

 

[istDeS]

Thanks for the reply! appreciate it.

What about this teleconverter below?

http://www.vivitar.com/products/28/auto-focus-tele-converters/861/14x-p

That one is manual focus as don't have any electrical contact pins.

 

[istDeS]

i thought the vivitar 1.5x SHQ is not bad?

kengoh was using it for birding on an DA*300 before he got his new lens. its also the only one that is known to work on SDM lenses.

Ken was using the Kenko 1.5X Pz-AF Teleplus SHQ teleconverter if i'm not wrong.

 

[detritus]

Ken was using the Kenko 1.5X Pz-AF Teleplus SHQ teleconverter if i'm not wrong.

thats what i thought too... we bought from the same supplier.

 

[toshio217]

Ken was using the Kenko 1.5X Pz-AF Teleplus SHQ teleconverter if i'm not wrong.

You are right. Ken is using Kenko 1.5X Pz-AF Teleplus SHQ teleconverter. I got the same one as him. Now mine is sitting in my dry cabinet for months after i change to Canon for my birding interest...

Kenko 1.5X works fine for AF with my Pentax DA 55-300MM F4-5.8 ED and also ok for Ken's Pentax DA* 300mm f/4.

 

[calvinlo]

Thanks for all the advice. I appreciate it.