The 2x teleconverter (also known as a tele-extender) from Tamron will multiply the focal length of the existing lens by 2x, and will cut back the amount of light by 2 f/stops. For example, using a 2x teleconverter with a 300 mm lens will effectively increase the focal length to 600 mm. A lens set to f/2.8 will now be f/5.6.
Teleconverters are not recommended for lenses wider than 50mm, e.g. 28-105mm. However, full AF operation is only possible with lenses with open aperture of f/2.8 or brighter. Please be aware that AF will work properly only if there is enough light and contrast on the subject to activate the camera's AF sensors. Manual focusing is recommended when using lenses with smaller open f-stop value than those given above.
Most Liked Positive Review
Works just like a 2X Teleconverter outta
I bought the teleconverter to increase a 500 MM to 1000MM. Auto focus works fine wit my lenses; however, I use manual settings when I am shooting long distances. The loss of 2 f stops is consistent with teleconverter technology so, if you can live with that, the product is for you.
Most Liked Negative Review
Just buy a longer lens
Will not allow my combination to focus at all, and even if I manually focus the resolution is poor at best. I would rather shoot farther out and crop in photoshop, the end result would be sharper than using this. Nikon D200 W/Nikkor 80-200 2.8ED
Reviewed by 14 customers
I used this with a D90. It fit well but difficult to get acceptable images. As the distance increased the fuzziness became more obvious. Returned after using for several days in many different situations.
I got the Tamron SP AF 2x converter for Canon lenses yesterday, and took it out to the woods today for some test shots,... and am very impressed overall. Today I mounted it to a Canon 70-200 EF 2.8 L lens and was very impressed with the speed of focus and overall quality. The auto-focus was very fast and sharp with just a press of the shutter/focus. The unit is all black, and seems well built. The Canon 70-200 is a long and heavy lens, but it still feels nice and solid with the Tamron SP AF mounted between it and the camera body. For these tests today I took the Canon 7d out. Below are a couple of test photos, all hand-held no tripod,... the ducks are from about 100 or so yards away, at 200mm (or 400 mm with the 2x), shutter at 200, f stop at 8, and 320 ASA,... the close-up insert is of the same pic but digitally zoomed in to see the detail. The pic of the fence is at the same settings, but at 70mm (or 140mm with the 2x),... focus was set on the birdhouse,... notice sharpness of the grain in the wood fence from the center of the frame to the birdhouse. I've also attached it to a 28mm all-manual Prime Lens and the effective doubling of focal length was nice, as well as the sharpness of image and blurring of background. Not a bad piece for the price!
I use it in bird and wildlife photography, and occasionally with my Tamron 180 macro. When I purchased it, I was concerned that my images might be reduced in sharpness. Boy, was I surprised. I coupled it with my Canon EF 100-400 and tested it extensively. What I learned is this: I get tact sharp images. I attached the 2x teleconverter to the Canon EF 100-400, on my Canon 5D MII, and mounted it on a sturdy tripod. I used live view to raise the camera's mirror to focus. I closed down the lens two f-stops to increase the depth of field. With the mirror raised, the camera would not vibrate when the image was taken. I used two methods: cable release and 10 second timed shutter release. For testing, I manually focused on a pontoon boat outboard 150 yards distance. See attached image. The lettering on the outboard is sharp and easy to read.
I have trouble with auto focus. But I don't let that stop me.
Just got the Tamron 2X Teleconverter and used it to get close-ups of birds. It works well with my Canon 60D and Tamron 18-200mm telephoto. Have used it with and without a flash with no problems and good optical results.
I use the Tamron 2X on my T2i with my Tamron 18-250mm and my Sigma 105mm Macro. I use it hand held and on my tripod. I lived many years without automatic focus, so that is not a problem. It is ease to don and doff, it just takes time.
On a Canon xti model camera along with Tamron's 18 to 270 power zoom with I'm really pleased with. As other reviews have stated auto focusing isn't 100% with the 2X.
1st despite the adorama product image, this teleconverter is all black. Also, they failed to mention that EF-S lenses will not mount. However, it performs very well when coupled to my Tamron 70-200mm f/2.8, auto focus works just as it did without it and image quality suffers only slightly. I was going to buy the Canon 300 but for as often as I need that kind of reach, this works just fine for a fraction of the cost.
works in auto inside and outside d5100 nikor 55-300 and converter
Compared to buying a telephoto, using the converter is an inexpensive way to increase the focal length of my existing lens. I attached it with my Canon EF 50mm f/1.8II and had decent results-- although the auto focus does not work half the time. I have to use it on manual focus but that's okay. I tried it on my LensBabies Lens and it didn't work at all.