Toronto Photography Meetup Group

Do any of you have any experience with this? I find that my 70-200 2.8 IS often doesn't get me as close as I would like to be when taking sports and wild life photos. My only real concern is that I have heard that there is quite drastic quality loss. I'm already aware of the two stops that I will have to sacrifice while using the extender. B&H is selling is for $309 Canadian + tax and shipping. Which is quite amazing when you consider that it retails for $450 + tax in Canada.

maybe a 1.4 and 40D instead of 5D will do the trick, dunno if you shoot FF

I got one. Haven't tried it on my 70-200 yet but I can give it a test tonight if you want.

Average price for a used one is $250US right now and they pop up all the time on FredMiranda.com

I figured it's worth the extra few dollars for the 2 rather the 1.4. Then again I would be able to shoot at F4 if I purchased the 1.4. I'm shooting with a 40D at the moment, but I want to purchase a FF in the near future.

I would greatly appreciate if you could do that Carlton.
I want to take a trip to the zoo in the near future and i think picking up one of the extenders would be quite helpful.

I've shot the 2x on my 70-200 f2.8IS on my 5d MkII, the drop in quality wasn't enough for me to notice but I resized the images for the web. I had the 1.4x but if there is going to be a drop in quality I might was well go big.

I've used various 2x's with my Sigma 70-200/2.8, and the quality is okay. It's noticeably softer in sharpness and contrast and AF is significantly slower. With a 1.4x on the other hand, AF, sharpness and contrast are all much better.

The biggest factor, is the AF speed for sports and wildlife. You may find the 2x simply too slow.

If your used to the sharpness of L glass you won't be happy. Go with a 1.4x. You make up for the lack in magnification with the ability to zoom in on the digital file. With a 2x extender you won't like what you see at 100%.

I took this at the 2007 President's Cup in Montreal using my old 70-200mm f2.8 and a Tamron SP AF 2x Pro Teleconverter. I had to bump up the sharpness and contrast a little bit.

I knew someone who had one of these and he liked it:
http://www.bhphotovideo.com/c/product/3 ... o_300.html

and apparently it works on way more glass than the Canon ones, which are limited to particular lenses.

Now this is really pixel peeping and not real world shooting so take with a grain of salt. Shot in RAW and saved as JPEG. Both instances the target was used to fill the frame at 200mm and 400mm (with 2x TC II) and shot wide open (f2.8 and f5.6 respectively).

Sharpness Test ISO122333 chart. Red square indicates sampled area.

Thanks a lot Carlton
That's not bad at all. I was expecting it to be quite a lot worse to be honest.
I suppose the extension tubes are very much like lenses in the sense that you can get good and bad versions of it.

No probs. Extension tubes are a different beast compared to teleconverters. For one, you lose infinity focus and secondly, you don't lose sharpness/contrast quality because there are no lenses inside an extension tube.

I've had a Vivitar 2x TC in the beginning and it was crap. I then bought the original 4 element Tamron 2x TC and it was okay but not great with lots of CA. Then I got the Tamron 2x SP AF Pro TC and it was sharper (possibly a hair sharper than the Canon 2x TC II I have now if you can believe that) but had a bit more CA than I wanted in some situations. The Canon 2x TC had better contrast and less CA than all of the above AND it is weather sealed.

I'm thinking of upgrading my Tamron 1.4x SP AF Pro to a Canon 1.4x TC II for the weather sealing and a little less CA but the used ones get snatched up REAL fast.

I've got class tomorrow but supposed to be at a location shoot in the afternoon. Not sure if I will have the opportunity to use the 2x TC but I'll take it with me regardless and see if I can get some "real world" tests for comparison.

But don't the Canon TCs have a short list of compatible lenses? What about the Sigmas?

You are correct. Canon TC's have a protruding front element which limits which lenses it can be used with. One work around is stacking it on an extension tube but losing infinity focus. Sigma, Tamron and Kenko work with basically any lens.