extenders....

BraCas · Mar 30, 2014

I am trying to do this economically so I want to get a tamron 70-200 2.8 for sports and action and I was going to get a 2x extender so it becomes a 140-400 4.5 for wild life. I hope to save the $$$ rather than getting a canon 100-400 for $1600. has any one done this??

how is the quality of the image??

robbins.photo · Mar 30, 2014

BraCas said:
I am trying to do this economically so I want to get a tamron 70-200 2.8 for sports and action and I was going to get a 2x extender so it becomes a 140-400 4.5 for wild life. I hope to save the $$$ rather than getting a canon 100-400 for $1600. has any one done this??

how is the quality of the image??

Well I use a 2x and a 1.4x on my 70-200mm quite a bit myself and at least in my experience I would say the iq loss is minimal and fairly easy to compensate for in post.

Now in the interest of full disclosure I shoot a nikon and my 200 is a sigma. I use the sigma teleconverters and it makes for a fabulous combination.

For teleconverters I'd try to stay with the same folks that manufactured the lens if possible and recommend you check keh for used.

A lot of folks buy them new without realizing they really don't work well on slower glass so you can usually find tons of them used for about half or less of what they sell for new.

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robbins.photo · Mar 30, 2014

BraCas said:
I am trying to do this economically so I want to get a tamron 70-200 2.8 for sports and action and I was going to get a 2x extender so it becomes a 140-400 4.5 for wild life. I hope to save the $$$ rather than getting a canon 100-400 for $1600. has any one done this??

how is the quality of the image??

Oh, forgot to mention, on a 2x you actually lose 2 fstops so its a 140-400 at f/5.6 but even so it works great.

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BraCas · Mar 30, 2014

opps...you are right on it losing 2 stops. I plan on getting the matching Tamron extender.

table1349 · Mar 30, 2014

Personally I don't like the IQ I get with a 2X on my 70-200 f2.8 LII. The 1.4X is fine. Perhaps I am to picky since I have a 400mm f2.8 and know what razor sharp IQ is.

Derrel · Mar 30, 2014

I've bought a number of 2x TC's over the years. NONE of them have ever impressed me on any zoom lens. There's a two f/stop loss of light transmission with a 2x converter. I think most people would agree that a 1.4x converter is a better option. Less light lost, only one f/stop worth, and "some" length gained, from 200mm at the tele end to 280mm with the 1.4x converter installed. I think it's smarter to use a quality 1.4x converter and then crop in at the computer to make up the difference, rather than degrade images with lost light transmission and lowered image quality with a 2x converter.

"Most" zooms lose a good deal of image quality with a 2x added. Many fast, higher-end prime lenses can do "okay". I'd still rather have an actual 100-400mm Canon than a 2x slapped on a 70-200.

I think you could do better with say the new 150-600mm f/5~6.3 Tamron zoom lens. MUCH longer reach, and early reports I've seen showed pretty impressive stabilization from the 150-600. It's also in the $1,100 price range new, with a good long warranty, I think 6 years for USA buyers.

ruifo · Mar 30, 2014

Here two RAW image samples for you to test and see for yourself.

1st file: _DSC4851.NEF
"D5200" + "Tamron SP 70-200mm f/2.8 Di VC USD" => @ 195mm, f/2.8, ISO 100, 1/500 sec.
Download: _DSC4851 - Download - 4shared

2nd file: _DSC4855.NEF
"D5200" + "Tamron SP 70-200mm f/2.8 Di VC USD" + "Bower 2x DGII Teleconverter (7 Elements)" => @ 390mm, f/5.6, ISO 100, 1/90 sec.
Download: _DSC4855 - Download - 4shared

So you can play around in your raw editing software to test the quality of the raw files, one without and another one with the 2x TC.

The problem with this specific TC and this specific lens is that AF does NOT work when they're coupled. Using other lenses, no problem, this TC has full AF just normally, but not with this Tamron lens...

Lens reference:
Tamron SP 70-200mm f/2.8 Di VC USD Zoom Lens AFA009N-700 B&H

TC reference:
Bower 2x DGII Teleconverter (7 Elements) for Nikon SX7DGN B&H