Tele Extender Question

tacomadm18 · Apr 30, 2010

Was looking at a Bower SX7MAX 2x Telextender,, to go with a Tamron 90mm 2.8 Marco,,,,, I can't fine alot of info on the Bower,,, Thoughts thanks

table1349 · Apr 30, 2010

Never heard of it and don't know much about it. If I was making the choice I would look at this instead. Kenko | 2x Teleplus Pro 300 DG Teleconverter | K20PRO300DGM

The Kenko pro 300 line is a well thought of line of TC's

Derrel · Apr 30, 2010

The Bower is said to be made in Japan, and is a 7-element design. Seven element TC's are considered the current standard of "best" quality designs. The Kenko line of TC's is well-regarded as being an excellent brand of 3rd party TC units, with many happy users.
The thing about TCs is that sometimes they make a great pairing with a particular lens, but not with another lens that uses a different optical design. "some" TCs will work very,very well with "some" lenses, but not nearly as well with other lens designs...that's what's weird about it. The only way to tell which TC has better optical quality is to test it out very carefully and evaluate the photos. I have a Tamron 90, but have never used it with a TC unit, so I can't offer any suggestions for specific TCs.

I wonder if perhaps the Bower and the Kenko are made on the same assembly line? Not saying they are,or are not...the weight of one of them is not mentioned...they look similar to me,and that Bower looks oddly familiar...

table1349 · May 1, 2010

Derrel said:
The Bower is said to be made in Japan, and is a 7-element design. Seven element TC's are considered the current standard of "best" quality designs. The Kenko line of TC's is well-regarded as being an excellent brand of 3rd party TC units, with many happy users.
The thing about TCs is that sometimes they make a great pairing with a particular lens, but not with another lens that uses a different optical design. "some" TCs will work very,very well with "some" lenses, but not nearly as well with other lens designs...that's what's weird about it. The only way to tell which TC has better optical quality is to test it out very carefully and evaluate the photos. I have a Tamron 90, but have never used it with a TC unit, so I can't offer any suggestions for specific TCs.

I wonder if perhaps the Bower and the Kenko are made on the same assembly line? Not saying they are,or are not...the weight of one of them is not mentioned...they look similar to me,and that Bower looks oddly familiar...

I wondered the same thing after googling the Bower.

tacomadm18 · May 1, 2010

I going to try it,,, I think,,,

tacomadm18 · May 1, 2010

well i tried it with the tamron 90mm 2.8,,, it just kept trying to find the focus,,, I guess it will not work,,,,,,,,,,,,,

will the kenko work,,,,

Overread · May 1, 2010

Wait wait wait how did you test it with the 90mm? What sort of shot were you trying to get and what were the conditions (eg the lighting)

tacomadm18 · May 1, 2010

I tried it indoors from 2 foot to 10 feet away,,, just seemed like it was hunting for focus all the time,,,,,, I kinda throught the 2x might be to much,,,,

Overread · May 1, 2010

Macro lenses are not famed for their AF (though the canon brand ones appear to do quite well for macro lenses) so it might be that 2* is just too much for the tamron in most conditions, unless the lighting is very good.
I would be very surprised if the other teleconverter gives you better AF performance - what might be the only difference is the overall image quality that you are able to achive with the combo.

Joves · May 1, 2010

Well then low lighting did not help it at all. You are losing light with a 2x as it is by 2 stop with that. THe Kenko may or may not work with that lens. I know their 1.4x works with my Nikon 80-400 lens. I havent tried it with my Tamron lens at all but, if it made it any slower Id be retired by the time it got there.

table1349 · May 2, 2010

Overread said:
Macro lenses are not famed for their AF (though the canon brand ones appear to do quite well for macro lenses) so it might be that 2* is just too much for the tamron in most conditions, unless the lighting is very good.
I would be very surprised if the other teleconverter gives you better AF performance - what might be the only difference is the overall image quality that you are able to achive with the combo.

My 100 f2.8 Macro focuses just fine. Of course I don't know how it focuses for macro since I MF my macro shots. But for portraits etc, it does quite nicely.

Overread · May 2, 2010

Gah it was late and I missed that it was done indoors - repeat the test outside! As Joves said lowlight won't be helping and indoors is most often very dark compared to the outside world in terms of photography.