# Thoughts on a doubler ... ?



## Spec-Rig.006 (Nov 2, 2007)

7D EOS body - EF 100-400 II + an EF 1.4x or a 2x ... ?

The doublers aren't much different in cost between those two options.

Caribou in September on the Arctic Shield in Quebec ... obviously I have time to rent and play to make a decision but ... anyone have any thoughts or experience with these combinations?

Long distance critters, birds, fish and hopefully some action with the Northern Lights (which I'll obviously need a different lens for).


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## stargazer (May 24, 2004)

I have both Mark IIIs and use them with a 7DII and 1DIII, with a 300 2.8 IS II. I get the best results with the 1.4, but also get acceptable results with the 2.0. Just be sure and micro adjust the setup.. Thats a lot of glass in front so adjusting is really needed.

watch this video, very easy to do


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## Pocketfisherman (May 30, 2005)

The downside of the 2X doubler on many canon bodies is that the increase in minimum F stop precludes the use of the most sensitive and accurate dual cross type Autofocus sensor points. AF still works, but not very well in less than ideal light, and not as fast. It causes a noticable difference on my 5D MKIII body, so much so that I hardly use the 2X and go for the 1.4x when I need the extra reach.


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## BobBobber (Aug 29, 2015)

Sony makes an (almost-doubler) 1.7X doubler VCL-HGD1758 for Cyber-shot DSC-F707 / F717. It's a big and heavy chunk of Carl Zeiss optics; HOWEVER, it does not affect the f-stop range of the camera prime lens.

Therefore, you can shoot from *f-2.0 to f-2.4*. That's* FAST* for any telephoto, regardless of brand. But you'd probably use a tripod for those long reach telephoto shots, so the weight should not be a problem.

Another bonus is the camera's ability to use infrared for photos in the dark! I've got the tele-adapter but seldom use it, because I hate using a tripod. And I seldom photograph wildlife.


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## Spec-Rig.006 (Nov 2, 2007)

BobBobber said:


> Sony makes an (almost-doubler) 1.7X doubler VCL-HGD1758 for Cyber-shot DSC-F707 / F717. It's a big and heavy chunk of Carl Zeiss optics; HOWEVER, it does not affect the f-stop range of the camera prime lens.
> 
> Therefore, you can shoot from *f-2.0 to f-2.4*. That's* FAST* for any telephoto, regardless of brand. But you'd probably use a tripod for those long reach telephoto shots, so the weight should not be a problem.
> 
> Another bonus is the camera's ability to use infrared for photos in the dark! I've got the tele-adapter but seldom use it, because I hate using a tripod. And I seldom photograph wildlife.


Interesting ... it's got to be Canon compatible though. I already own a 7D.


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## BobBobber (Aug 29, 2015)

Spec-Rig.006 said:


> Interesting ... it's got to be Canon compatible though. I already own a 7D.


You can probably pick up a decent used F717 camera and tele lens for less than $200. About the cost of a Canon lens cap, right?:rotfl:

Keep the SONY outfit on a tripod ready for action . . . at a really fast f-stop other telephotos can never give you.


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