teleconverter for 70-300 1:4-5.6 is usm

<p>I hike alot with my camera equipment. I chose the 70-300 as my telephoto for hiking. I am investigating adding a teleconverter to the hiking gear.<br>

I carry a wide angle for the landscapes and the telephoto for birds and other wildlife as well as far away objects like old mine remains etc.<br>

From many other postings I decided to look at the 1.4x not the 2x. I am not a practiced manual focuser and would find that a real problem. I can live with some reduced quality for the few shots for which I would use the TC.<br>

Any insight would be greatly appreciated. Since Canon does not make a TC for this lens, any 3rd party TC's you think I might want to consider for my needs would also be greatly appreciated (Tamron, Sigma, ...)</p>

<p>As far as autofocus goes, with a 70-300 the difference between 1.4x and 2x is academic - AF will be gone or unreliable with either one. But you'll probably be happier with the 1.4x image quality and ease of manual focus.</p>

<p>The TCs from Tamron, Sigma, and Kenko are generally considered pretty good. Some useful links -</p>

<p>http://www.bobatkins.com/photography/reviews/tcs.html<br>

http://www.bobatkins.com/photography/reviews/ef_70_300is_review.html (review has samples with Tamron 1.4x)<br>

https://www.lensrentals.com/news/2009.01.06/teleconverters-101</p>

<p>I own a 70-300 IS and also have a Sigma 1.4X TC.<br>

You can mount the Sigma 1.4X TC on the 70-300, but you have to be very carefull:<br>

From 70mm to around 130mm the 70-300's rear glass element touches the converter front plastic protection and you always<br /> have to remember not to turn the zoom ring to the lower end.<br>

In practice that isn't a big problem because you only need a TC to get more reach and are only going to use it at the long range, to get 300-420mm focal lengths.<br>

Regarding autofocus, this converter provides autofocus over the entire range (the converter simulates a max 5.6 apperture), but at the long range (more than 200mm) it isn't accurate and tends to hunt a lot except with lots of light.<br>

In conclusion: it works but I wouldn't recommend it.<br>

Fernando</p>

<p>My personal opinion is a SHARP 300mm photo enlarged is better than a 420mm poor quality shot. I would like to hear other opinions.<br>

Unless your 300mm zoom is very very sharp, I would not put a 1.4 tc on it.<br>

RON</p>

<p>The 70-300is is better with a Tamron 1.4x TC at 300mm (420mm) than it is when a 300mm shot is enlarged.</p>

<p>See examples here - <a href="http://www.bobatkins.com/photography/reviews/ef_70_300is_review.html">http://www.bobatkins.com/photography/reviews/ef_70_300is_review.html</a> and here - <a href="http://www.bobatkins.com/photography/reviews/canon_EF_70-300_II.html">http://www.bobatkins.com/photography/reviews/canon_EF_70-300_II.html</a></p>

<p>This wasn't the case with the old 75-300is as is shown here - <a href="http://www.bobatkins.com/photography/tutorials/tc3.html">http://www.bobatkins.com/photography/tutorials/tc3.html</a></p>

<p>Forget about teleconverters completely unless you're shooting with L series primes. That's my blunt but experienced opinion. Crop your images instead. You'll save money, you'll save weight and you'll retain autofocus.</p>

<p>Alan, Fernando, Ronald, Bob, and Jamie - thank you very much for taking time to share your experiences with TCs.<br>

Does the Tamron easily mount or are there tricks needed?<br>

Does the Tamron significantly degrade auto focus or is there a trick to tell the 50d to focus with the Tamrom mounted?<br>

When mounted does the Tamron hit the lens glass when the zoom ring is not extened as Fernando experieced with the Sigma?<br>

Again, thanks to all for the help - Dave</p>

<p>Sometimes I use 7-300 IS with kenko 1,4 DG Pro 300 and it works beautifuly. It even autofocus at 300 ( 420) with the central point on a 20D. And at f8 ( which is f 11 in reality) it manages to be very sharp. The level of details you got in a long distance shot is much more than any possible crop you may try. The cheapest way to have the equivalent of a good 670 mm.</p>