I'm planning to buy Sigma (Bigma) 50-500 APo DG Lens for my Canon 20D and also want to use 2X Teleconverter. In this respect I need your expert advice on following :
1. Whether the 2X TC works perfectly with 50-500 ?
2. I heard that anyone can get AF with this Lens while using TC. How it can be achieved ?
3. Which Brand and Model works perfectly with Sigma 50-500 APO DG on Canon Mount.
4. How much this combination will cost ?
5. If tripod is required then Which brand and model works perfectly with above combination?
I look forward to all of you experts advice.
1. Depends on what you mean by "works perfectly". If you mean stacking the 2XTC on the Bigma, snap a picture and the picture comes out. Then the answer is "yes". If "works perfectly" means AF still works, can still get great image quality, then the answer is "no".
2. Technically it's doable but i would say don't even bother because it requires a lot of light and a very contrasy subject/background. Even with that it hunts a lot and you will lose the opportunity if you are shooting wildlife or sport. You can achieve the AF by using an older version of Sigma 1.4TC like mine. Or, tape three of the eight pins if you use the newer TC. I think 2xTC definitely requires MF but i don't have one to try.
3. I have a Sigma 1.4TC that works, and have seen a Tamron 1.4TC that works great too.
4. I bought my TC used on eBay. Costs me US$70.
5. IMHO, tripod/monopod is required regardless if TC is used or not. At 500mm, it's difficult to shoot handheld. It's not impossible. It's just the number of keepers is rather low. I use a Dynatran CF tripod.
Hope that helps.