MROAK Loc: NH now, MA adult life, NY child

I was reading a post on this forum about teleconverter's and got interested in the "Kenko 2.0X PRO 300 Teleconverter DGX for Canon EOS Digital SLRs".
I have a fairly new Canon EOS Rebel T3i with a Canon Zoom Lens EF 75-300mm 1:4-5.6 IS , will this teleconverter work well with this set up?
I posted this question on Amazon and so far I have received two answers. The first was "Yes it will, as long as it is not a EF-S . It may hunt during auto focus, just focus manually, you lose a couple f stops with a converter. I personally love mine".
The second reply suggested that I research the subject more before I buy.
So if anyone has experience with this combination please contribute to this post.
I RV for about 5 months a year. I bought my first DSLR when I started RVing in 2008. I take most of my photos when RVing and a lot of them are scenic wonder and wildlife. It seems like I keep wanting a bigger lens. I own a Nikon Coolpix P510 because of it's 42x telephoto. I use both cameras but like the Canon T3i due to its speed when just taking a quick shot.

imagemeister Loc: mid east Florida

The 2X Kenko will "work" using manual focus - but you will not like the results - also, forget about handholding with a 2X. A 1.4X will work better - still manual focus - and still needing support ( monopod/tripod) - AND lots of light ! You really need a faster/longer lens.($$)and/or a better camera body.

haroldross Loc: Walthill, Nebraska

The teleconverter will work somewhat on that lens/camera combination. You will lose two stops of light. The f/4 at the wide end becomes f/8 and the f/5.6 at the tele end becomes f/11. The Canon T3i will not be able to auto focus. All focussing will have to be done manually. Using Live-View is probably the easiest way to manual focus with this camera/teleconverter/lens combination.

The resulting photo will probably not be very good- not very sharp. I would not waste my time with this combination.

Jakebrake Loc: Broomfield, Colorado

I use that teleconverter on my EOS 60D and a Tamron 70-200 F2.8 USD DI VC with great results, and mine will autofocus. I do use it on a tripod with the VC disabled though. I like the extra reach.

johnmowry Loc: Northern Indiana, USA

I recently got a Kenko 1.4x TC and was pleasantly surprised at the results with my EF 70-300 at 300 mm. Your lens may behave differently. You could get one from a store that will allow "no questions" returns and test it with you lenses to see if it meets your needs.

MROAK Loc: NH now, MA adult life, NY child

Thanks for the reply. I am sure you are correct. I need to do more research. Thanks

Marilyng Loc: Lorain,Oh.

I purchased the 2x Kenko for my Nikon 300 lens & wasn't happy with the results so I sent it back & got the 1.4 Kenko.I am very pleased with my photos!😊

Rbode Loc: Ft lauderdale, Fla

CHG_CANON Loc: the Windy City

MROAK - I'm a little unclear on the zoom you have. There is not an IS model at 75-300. The 75-300 model is relatively old and cheap. It can produce good results at certain focal lengths and smaller apertures, but will not focus fast. Other than going non Canon, you will not find a relatively modest option for a longer reach beyond 300. Assuming you don't have the IS enabled lens, one change might be to the EF 70-300mm f/4-5.6 IS USM. This will offer IS that is very helpful in a moving environment or lower light where your shutter speed is close to the zoom length (focal length). Used models can be found in the $300 neighborhood. The references from others about manual focus and lesser image quality are probably not the direction you're looking to go ....

amfoto1 Loc: San Jose, Calif. USA

It will fit and work.... sort of. It will only work marginally technically is not compatible.

Adding a 2X to a 75-300mm 1:4-5.6 produces a combo that's an effective 150-600mm f8-11 lens. Your camera cannot autofocus less than f5.6 (well, actually f6.3 lenses "fool it" into still focusing). In addition, your viewfinder will be dark, making it a lot more difficult to focus manually.

Even a 1.4X teleconverter that "costs" only one stop of light, making a 75-300 into an effective 105-420mm f/5.6-8 that still will not be able to autofocus on your camera at the focal lengths where it matters.

Someone cited using a 2X with a 70-200/2.8 on a Canon camera... Well, YEAH, that combo makes for an effective 140-400/5.6 lens... and all Canon DSLRs are able to autofocus an f5.6 lens.

A few Canon camera models can autofocus an f8 lens or effective f8 lens/TC combo. Currently those models are the 7D Mark II, 5D Mark III and 1DX. Even these cameras are limited to focusing with just one or a few of the center AF points, with f8.

Adding a teleconverter also "costs" some image quality. How much depends upon the quality of both the lens and the teleconverter, and how well they work together. In general, zooms are not good to use with teleconverters, especially stronger TCs such as 2X that costs more image quality.

You would probably be better off just saving up for a Tamron or Sigma 150-600mm lens... just under $1100. Image quality will be much better and autofocus will work. These are relatively large lenses, though... so you might want a tripod or at least a monopod to help with it.

Alternatively, Sigma has 120-400mm and 150-500mm lenses on sale presently, for about $800 each. These are a bit smaller and lighter, too.

MROAK Loc: NH now, MA adult life, NY child

Thank you everyone that has responded. I am learning just listening to the responses. Now I am leaning toward skipping the teleconverter and just getting a big lens. If anyone has a recommendation for a midrange lens that will replace my 75 to 300 MM lens I would like to hear about that. I have another camara that came with the 300 mm lens and I will be selling that camara maybe with the lens.

churchchef

Canon USA has a great Teleconverter page with compatibility, limitations and recommendations - bottom line: unless the camera has a higher end sensor AND the lens is fast (and expensive), your better off to put the cost of a Teleconverter into an expensive, longer lens. ie., the Tamron or Sigma 150-600 (triple your current reach) or the older or newer Canon 100-400 (double). Then if you still can't fill the frame with a bird's eye from 150 feet away, get a TC. But that's seems like putting a spindly stick shift on the steering column when you really have an itch to lay 60 yards of great scratch - the least expensive solutions for more reach would be disappointing. A tranny rebuild cost 1 to 2 grand...choices, choices.

CHG_CANON Loc: the Windy City

mroak - I try to avoid contributing to gear lust .... You might look at this review and comparison. I sold my own 100-400L involved in these tests. This review is based on the old model that was no slouch and the prices have been dropping as used copies are sold and people change to the new II version that is a wonderful lens at twice the price.... So, if you are looking to move up, look at the prices of all these lenses used and see if they're what you're thinking about...

http://www.lensrentals.com/blog/2014/01/tamron-150-600-telezoom-shootout

peter cook

The 70-300 MM is a better choice or get a faster lens like a 2.8 Is lens
There is a 70-300 Is Lens with a green band around it do not buy it if you can afford it get the 70-200 2.8 IS II it is a much better lens

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

None if you care about image quality, want to retain autofocus and have a problem trying to manually focus through an F11 lens. Bad idea.