canon telephoto
Aug 4, 2015, 12:15 pm
#1
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canon telephoto
i have a 600mm lens(non IS) on a tripod for my wife to take photos of the osprey and the babies down their nest. the canon 6D will auto focus, she has shot a couple thousand images over the past 3 years. and we get quite decent photos. i bought a 1.4x IS extender for her. works great. i bought a 2.0x extender, and the camera will not autofocus. (all canon equipment) need help.
Aug 4, 2015, 5:53 pm
#2
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Chances are that ownership of such big glass is relatively rare among the travel photographers who frequent this forum. I suspect you will get more and better responses posting this question on a Canon-specific photography forum or perhaps one of the Canon groups on http://www.dpreview.com/ .
Off the top of my head, I suspect the addition of the 2x takes the maximum aperture beyond the capability of the equipment. But that is just a guess.
Off the top of my head, I suspect the addition of the 2x takes the maximum aperture beyond the capability of the equipment. But that is just a guess.
Aug 4, 2015, 6:10 pm
#3
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Yup, very few lenses actually support the 2.0x extender. And even those that do lose two stops of light.
So a 70-200 f/2.8 would be a 140-400 f/5.6.
Of the short list of lenses that support the 2x extender the majority lose AF as a result. Check the extender manual for approved lenses.
The 1.4x is much more kind regarding AF exclusion and only loses one stop of light.
If money is no object and you want 1200mm I would suggest this lens.
So a 70-200 f/2.8 would be a 140-400 f/5.6.
Of the short list of lenses that support the 2x extender the majority lose AF as a result. Check the extender manual for approved lenses.
The 1.4x is much more kind regarding AF exclusion and only loses one stop of light.
If money is no object and you want 1200mm I would suggest this lens.
Aug 4, 2015, 8:55 pm
#4
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Autofocus on the 6D does not function below f/5.6. This means AF stops working if you use a 1.4x extender with a lens with a maximum aperture darker than f/4, or if you use a 2x extender with a lens with a maximum aperture darker than f/2.8, because they cause you to lose 1 or 2 stops respectively.
Last edited by javabytes; Aug 4, 2015 at 9:02 pm
Aug 4, 2015, 10:55 pm
#5
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I presume it's a 600/4. A 2xTC on an f/4 lens yields an effective aperture of f/8. The only Canons that will autofocus at F/8 are the 1's, the 5DIII and the 7DII. Others are limited to f/5.6, which is what you get with f/4 plus a 1.4xTC.
It's possible to tape one of the pins between the lens and body to prevent the communication of the aperture and the AF system will try to work (Google will find it for you). But there's a reason Canon disables f/8 focus - it doesn't work very well. I've taped my 400/5.6 + 1.4TC. It works well shooting under bright sun, but starts hunting when light fades just a bit.
If sounds like the subject you're shooting is fairly static, from both the description and the fact that it's tripod mounted. If accurate, just use Live View to focus. It's not limited by the aperture, and it's also more accurate than phase-detect auto focus.
It's possible to tape one of the pins between the lens and body to prevent the communication of the aperture and the AF system will try to work (Google will find it for you). But there's a reason Canon disables f/8 focus - it doesn't work very well. I've taped my 400/5.6 + 1.4TC. It works well shooting under bright sun, but starts hunting when light fades just a bit.
If sounds like the subject you're shooting is fairly static, from both the description and the fact that it's tripod mounted. If accurate, just use Live View to focus. It's not limited by the aperture, and it's also more accurate than phase-detect auto focus.
Aug 7, 2015, 3:03 pm
#7
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Complete instructions in the sticky at the top of the forum.
http://www.flyertalk.com/forum/trave...phy-forum.html
In general, you can't post directly from your computer. You need to link from a photo hosting site like Flicker, Smugmug, etc. There is a list of some of the more popular hosting services, including a couple through FT, at the top of the first page.
http://www.flyertalk.com/forum/trave...phy-forum.html
In general, you can't post directly from your computer. You need to link from a photo hosting site like Flicker, Smugmug, etc. There is a list of some of the more popular hosting services, including a couple through FT, at the top of the first page.