Teleconverter and IS

I have never used a tele converter but am tempted to get a 2x converter to get closer to wildlife. I understand that manual focus has to be used, but does IS still work with a converter?
Also what make of teleconverter works well (with 5D?)
Any help /cpmments appreciated.

Only a guess seeing as nobody has replied yet, but I would say yes.

Im using 3 extension tubes on my IS lenses & while the AF doesnt work the IS still functions perfectly, so I dont see why it wouldnt with a TC.

Nick

Pixels wrote in post #3676645
I have never used a tele converter but am tempted to get a 2x converter to get closer to wildlife. I understand that manual focus has to be used, but does IS still work with a converter?
Also what make of teleconverter works well (with 5D?)
Any help /cpmments appreciated.

Depending on the lens and body, yes usually MF has to be used with a 2x. But, for example, AF is fine with the 5D and a 7-2 f2.8 + 2x. On 1D bodies you can go up to f8 for AF to still function.

As for IS, it's independent of AF function, so yes, it works fine.

I imagine the quality would be pretty lousy with a 70-200 2.8 + 2x TC, or would I be wrong in thinking that? im thinking poor sharpness, smeared details..

Id love to try the 1.4x on my 70-300IS but I cant help thinking the quality will be really poor.

Nick

How about getting a 1.6x crop body? Would give you some effectively longer lenses and still quality.

Yes the IS works as long as the TC passes the IS connection pin through; AFAIK all the TCs do. You will need to scale your handholding speeds by the TC factor (1.4X or 2X); for longer telephotos my experience is you need to increase the shutter speed by more than that amount.

The AF will depend on the lens max aperture, the TC light loss and the body, non-pro bodies will only AF to f5.6 and pro bodies to f8.

So would a 1.4x AF on a xt with a 70-300 IS canon lens? Am am sure someone has tried it? Replacing a broken 80-400mm and thought that maybe a 300 with a 1.4x would be better.

The Canon 1.4x tc will not couple to the 70-300 IS lens. You can put a Kenko 1.4x tc on that lens but, in my experience with the 70-300 IS lens, the image quality is subpar with the 1.4x tc. I wouldn't even consider a 2x tc on that lens at all. IME, 2x tc's, as a general rule, do not deliver good image quality on zoom lenses. There are a select few zoom lenses (mostly "L" lenses) that can offer adequate image quality with a 1.4x tc but there are many, many zoom lenses that do not work well with any tc.

Teleconverters function best on 1D bodies paired with the Super-Tele's. The difference in IQ between my 300mm f2.8L IS + 2xTC vs. 70-200mm f2.8L IS & 2xTC is huge. The 300mm handles it very well while the zoom does get a tad "smeary" looking. Both lenses handle the 1.4xTC extremely well though.

I get a bit of focus-hunting when using the 2xTC, but it is no more than previous experiences I've had with the EF-S 60mm Macro and some third-party lenses (without a TC of course).

I probably would not have picked the 2xTC up if I didn't own the 300mm f2.8L IS, but I'm a bit "touchy" on where I want my image quality.