Tamron 1.4X TC + Sigma 500 f/4.5 EX APO HSM

I got my Tamron 1.4 TC(not SP) about an hour ago from B&H. I tested it on the 1DM2 and the 20D. AF worked fine on both. Image quality was maintained with no difference that I could see on a monitor. The 20D was slower to lock focus in low contrast then the 1DM2. The actual f stop is not reported back to the cameras, which is most likely why it works. I will post samples after I have something better then some backyard plants on a cloudy day. I'm glad now that I don't have as much urge to buy the Canon 500 f/4, 'cause that just aint gonna happen!

Good to hear, Scott.

I can confirm that the combination will also AF on a 10D, although like the 20D it doesn't have the same "snap" as on the 1D Mk II.

I guess the point is that the 10D/20D is working outside of it's AF specification whilst the Mark II isn't.

The whole AF/aperture range is marketing limitation to try and upsell the lenses.

It should not matter at all what aperture you're on, given enough light it should still be able to lock.

$79, who'd a thunk it?

It will be interesting to see if the combo is fast enough to track a race car... I might have a go this weekend if the conditions are favourable.

I use the 400 f/5.6 and Canon 1.4X on a 1DM2 (f/8 max)to track birds without a problem. Then again they aren't going 200mph.

If the cars I'm shooting are doing 200mph at the corner I'm gonna be standing at.... they'll be scraping the driver off the armco with a shovel...

Canon state

I can get away with a 1.4x on the Sigma 120-300mm but with a 2x the AF speed isn't quite good enough to be dependable. I think the 500mm is fast enough to be safe.

Two shots at ISO 1000 with 20D + Tamron 1.4X TC + Sigma 500mm f/4.5, lousy overcast lighting, AI Servo AF.

Those look great!

I am so glad this is working! Makes a great lens even better to have functioning 1.4X T-con!

CyberDyneSystems wrote:
I am so glad this is working! Makes a great lens even better to have functioning 1.4X T-con!

Absolutely!

Cute pups! WOuld this be possible with any 1.4TC of just the tamron?

The Sigma 1.4 and Canon 1.4 won't work on a 20D because they transmit the actual F stop to the camera with the added f stop of the TC. The Tamron works because it doesn't tell the camera it's there. Why they won't work on a 1DM2 and the Tamron does is anybody's guess. Sigma won't say why and neither does Canon.
I notice you have a Keko Pro. It won't work either. I believe an older plain Kenko 1.4 would because it is made by Tamron.

Just to add flames to this particular little debate... examine the cap of your Tamron 1.4x TC. The one that covers the "body" side of the TC. Do you, by any chance have a large "Σ" embossed onto the plastic? ... the capital form of the greek letter "Sigma" I wonder who really made this TC?