Irvingite Charles Loc: Irving, Tx

Yes I know this subjest has been brought up before but I still have a question. First! I'm not looking for or want "opinions". If I want your opinion, I'll ask for it. I'm just looking for Facts! I use the Canon t4i with the Tamron 18 - 270. I spoke with Tamron yesterday and they said their teleconvertor won't work with this lens. Whiskey Tango Foxtrot, Over! Their unit won't work with their lens. Does anyone have experience with one that WILL work? I'm simply wanting to increase the focal length for some shots without paying $$$$$$$ for a lens that I won't use that much.
Go for it.

JR1 Loc: Tavistock, Devon, UK

If I want your opinion, I'll ask for it (a little blunt to be honest) so what are you wanting as a reply IS an opinion

haroldross Loc: Walthill, Nebraska

Why did they say it wouldn't work? Is your lens for cropped body or full frame? EF-S (cropped body) lens do not work in most tele converters because the back lens element will hit the lens element in the converter when you try to attach the two together. This is the way it is with Canon.

sbesaw Loc: Boston

See you're still waiting for the facts :-D
BY Facts (VS Opinion) I believe the OP means that you have taken the tele convertor, put it on the Tamron 18-270, put that on a T4i body and it either a.) it works (fact) or b.) it doesn't work (fact).
Why is that so hard to understand.

If you would like I can call my Tamron rep and ask. When I get in I will see if I have that Combo in the shop and If I do I'll set it up and let you know.

sbesaw Loc: Boston

They were correct. The rear element on that lens is only ever so slightly recessed. Althought I did not have a Tamron Teleconverter I did have Canon and Sigma. I tried the 1.4x and they both had the same set up, I assume that Tamron is the same. I mounted the 1.4x's on a T4i and there was no way that lens was going on. That lens was not designed to accomodate a teleconverter

GoofyNewfie Loc: Kansas City

Fact: teleconvertors were originally designed for use on telephoto lenses (not wide) to make the focal length even longer.

bull drink water Loc: pontiac mi.

go to a foto store that stocks some 3 rd party coverters for your camera and try til yu find one that works.

Irvingite Charles Loc: Irving, Tx

sbesaw Loc: Boston

Spent the last hour going over every option including adding extension tubes. Couldn't get anything to mountv that lens. Even if I did at the long end with a 1.4 your at f9.

Get a Canon 70-200 2.8 L then you'll be all set :-D :-D

BboH Loc: s of 2/21, Ellicott City, MD

Have the same issue with some of Nikon's lenses - they won't work with their teleconverter. I use Kenko's and it works with all of My Nikon lenses.

cheineck Loc: Hobe Sound, FL

I use a Tamron 1.4 teleconverter on my Tamron 70-300 on my Canon 5D Mark II... it works great! Just a little loner to auto-focus than without the teleconverter. It's a wonderful lens and teleconverter.

sbesaw Loc: Boston

From Kenko's website:

"The PRO 300 family are designed specifically to be used with prime telephoto lenses of 100mm or above, such as 300 mm f/2.8 lenses, and work best with telephoto lenses of 200mm to 500mm. The PRO 300 can be used with telephoto zoom lenses as well as prime lenses. However, Kenko does not recommend them for zoom lenses that have a range starting under 50 mm.

KENKO PRO 300 AF Teleplus converters have genuine Gate Array IC (Integrated Circuitry). It means that the converter’Äôs own unique circuitry maintains signal integrity between the camera body and lens. These converters are designed to electronically operate the same way as an original manufacturer’Äôs converter.1

Full AF operation with PRO 300 2.0x DGX is possible when using camera lenses with maximum aperture of F2.8 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’Äôs AF sensors. (Manual focusing is required when using lenses with smaller maximum f-stop value than those given above.)

With the PRO 300 1.4x, DGX full AF operation is possible with camera lenses having a maximum aperture of F4 or brighter. The same light and contrast requirements apply.

The DGX Teleplus converters have updated circuitry to record exif data more accurately. In the exif exposure data (meta-data recorded with a digital picture) DGX converters record the equivalent aperture and focal length of the lens setting plus tele-converter. Optically and mechanically they are the identical to the prior high-quality DG series converters.

Most Canon EOS camera bodies are programmed to shut down auto focus if the calculated effective aperture for the lens and teleconverter is smaller than f/5.6, the Kenko Teleplus PRO 300 converters work the same way.

Important Note:The Kenko DGX TelePlus converters are not compatible with the Canon Digital Rebel XT / EOS 350D camera body and will not function on them. All other Canon DSLR cameras bodies work with Kenko DGX converters.




Specifications 1.4X 2.0X
Model: PRO 300 AF DGX 1.4X PRO 300 AF DGX 2.0X
Magnification: 1.4x 2.0x
Depth of field: 1/1.4 of prime lens 1/2 of prime lens
Minimum focus distance: Same as prime lens Same as prime lens
Construction: 5E / 4G 7E / 4G
Diaphragm coupling: Fully automatic Fully automatic
Lens coating: Digital Multi Coating Digital Multi Coating
Exposure magnification: Approx 2 times (equivalent to 1 diaphragm) Approx 4 times (equivalent to 2 diaphragm)
Barrel length: 27.0mm approx. 51.0mm approx.
Weight: 4.6 oz.(132g) 6.4 oz.(184g)
Mount Available for: Canon-EOS* / Nikon-AF Canon-EOS* / Nikon-AF

*Canon EF-S lenses are not applicable. "

sbesaw Loc: Boston

That is true. Ther rear el;ement on the 70-300 is recessed back into the lens. This is no the case with the 18-270 where the rear element is almost flush with the end on the lens and the adapter WILL NOT FIT.

The only one that may is the Kenko as their element appears to be recessed but even they do not recommend a teleconverter on anything that has under 50mm. I believe but not positive that the design of that 88-270mm requires, to to wide angle, that the rear element be closer to the mounting ring.

sbesaw Loc: Boston

That is true. Ther rear element on the 70-300 is recessed back into the lens. This is not the case with the 18-270 where the rear element is almost flush with the end on the lens and the adapter WILL NOT FIT.

The only one that may is the Kenko as their element appears to be recessed but even they do not recommend a teleconverter on anything that has under 50mm. I believe, but I am not positive, that the design of that 18-270mm requires, due to the wide angle, that the rear element be closer to the mounting ring.

Swamp Gator Loc: Coastal South Carolina

Well alrighty then.