which teleconverter

[bballboy30]

I am planning on getting a 1.4x teleconverter for my sigma 50-500. The manufacturers suggest only using the sigma 1.4 teleconverter. Is that my best option or should I go with the canon version. What about third party t-cons like Kenko?

Thanks.
Alex

[CyberDyneSystems]

The Sigma is good and about half the cost of the Canon.

You will not get Autofocus with either.

[Tom W]

You could use a 3rd party unit like the Tamron or Kenko and theoretically maintain autofocus. But, I don't think you'd get good AF results. The Bigma is already f/6.3 at the long end (though it fools the camera into allowing AF) - adding a teleconverter is going to cost you another stop of light and may make the AF very unreliable.

[Starfleet_EMH]

I use a Sigma 1.4x TC with my Sigma 70-200 and notice visible purple fringing in bright daylight at the long end. Maybe it's just my sample, but be prepared for some picture degradation :cry:.

EMH

[ScottE]

I have a Sigma 50-500 and both Sigma 1.4x and Tamron SP AF 1.4x teleconverters.

I have taken comparative shots with both teleconverters on that lens and there really isn't any significant difference in optical quality.

I understand that the better Kenko teleconverters are of similar quality.

I use the Tamron telecoverter most of the time because you do not have to remember to lock the 50-500 at longer than 100 mm when using it. That means you can zoom back to 50 mm and lock it in that position when moving the camera and lens around. With the Sigma teleconverter you have to lock the lens at greater than 100 mm or the back end of the lens will contact the front teleconverter. This makes a very annoying grinding sound that I am not fond of hearing.

Another advantage of the Tamron and Kenko teleconverters is that you can use them on other lenses that are not compatible with the Sigma teleconverter. For example, because the front element of the Sigma must mate into the rear of the lens it will not fit on lenses such as the Sigma 105 macro lens. The Tamron fits just fine and can give some great shots.

Be aware that auto focus will not work when using a 1.4x teleconverter on your Sigma 50-500. Manual focus works great though and with HSM full time manual focus override you do not have to worry about moving the AF/M switch. Also not that this combination give the effect of a 700 mm lens (1120 mm in 35 mm camera terms) so you will need to use a steady tripod and good technique if you expect to get sharp pictures.

Scott

[condyk]

Very good advice above all of which fits with my own experience of using the Bigma and a Kenko Pro 300 1.4x. Use MF only or you'll end up eating your own feet in frustration. Hand-holding isn't a viable option most of the time (I won't say never!) and so beanbag, monopod or tripod.

[bballboy30]

Thanks everyone for all your help!!