Product Description

This extender has been re-designed optically and offers excellent performance with compatible EF lenses (same as the Extender EF 1.4x II). It features a new seven-element design, and same weather-resistant design and anti-reflection internal construction as the new EF 1.4x II. The EF 2x II doubles the focal length of any lens it's mounted to, and reduces its effective aperture by two stops. With the EF 2x II, AF is possible with any EOS body if the lens has an f/2.8 or faster maximum aperture, and compatible Image Stabilization lenses maintain the IS feature when used with any current EOS camera.

Product Details

• Brand: Canon
• Model: 6864A004
• Dimensions: 3.50" h x 3.80" w x 5.30" l, .58 pounds

Features

• Telephoto extender designed to double Canon EF lens focal length
• Ideal for shooting close-ups from a distance at sporting events
• Weather-resistant and anti-reflective internal construction
• Maintains autofocus with any EOD body with f/2.8 or faster aperture
• Measures 2.8 inches in diameter and 2.3 inches long; weighs 9.3 ounces

Amazon.com Product Description
Designed to double the focal length of any compatible Canon EF lens, the Canon EF 2x II extender telephoto accessory is ideal for sporting events and nature photography. The lens boasts a new seven-element design, along with the same weather-resistant and anti-reflective internal construction as the companion EF 1.4x II extender. More significantly, the extender supports autofocus with any EOS body provided the lens has an f/2.8 or faster maximum aperture (the EF 2x II reduces effective aperture by two stops). The EF 2x II--which also maintains an EOS camera's Image Stabilization technology--carries a one-year warranty.

• Magnification: 2.0x
• Lens construction: 7 elements in 5 groups
• Dimensions: 2.8 inches in diameter and 2.3 inches long
• Weight: 9.3 ounces

Customer Reviews

Fantastic add-on
It should be obvious - this extender really needs to be used with a tripod. That alone will increase your image quality. It's also designed for the higher quality Canon lenses - the EF series. 90% of the complaints about this accessory ignore those two facts. The next biggest complaint - autofocus. Again, Canon is clear that you need a lens with an aperture of 2.8 or faster in order for autofocus to work. Basically, so what! If I'm on a tripod shooting my subject, I'm going to pre-focus . The depth of field is in such a compact area and you're zoomed in so much, autofocus is really not that important. What did people do before autofocus? Skip the photo?

So if you understand what you are purchasing and know how to use it - well, like with any great tool - you'll produce fantastic results. If you don't know how to use it, try and do a hand-held 400mm zoom, or attempt to catch that bird as it swoops past, forget it. This is not a $5,000 lens. It's a $300 add on that extends your current lens.

If you could afford that 10 lb, 800mm telephoto lens - at $12,000 - you would not be looking at this accessory. I'm not trading in my car for a lens any time soon - and this little accessory does the job just fine. I've tried it on action shots freehand - even though I knew better. Forget it. Handheld when it's added on to my 200mm? Almost as bad. On a tripod? Fantastic. Even better if you have the remote trigger.

The bottom line is that if you are looking for an affordable alternative, know how to use it, and are willing to spend the half hour it takes to master this multiplier, you will get great results. If you expect to point and shoot, then buy a point and shoot camera.

Twice the reach at what price?
This extender is limited to which lenses it will work with, most of them L lenses. The II model features a new seven-element weather-resistant design, and improved anti-reflection internal construction. Auto-focus is possible with any EOS body if an f/2.8 or faster maximum aperture lens is used. Image Stabilization lenses maintain the IS feature when used with current EOS cameras. Using this extender with any lens will eliminate one or two f stops and decrease sharpness to some degree.

I rented this extender to use with the Canon EF 100-400mm f4.5-5.6L IS USM telephoto zoom lens. This lens while sharp and high in quality, is not the sharpest L lens out there. I found adding this extender with the 100-400mm caused the sharpness to suffer too much for my tastes outweighing the benefit of having extra reach. The minimum 7.6 f-stop limits creative abilities with this combination too.

I would imagine that using with an extremely sharp lens like the Canon EF 70-200mm f/2.8L IS USM telephoto zoom lens would be able to handle the reduction in sharpness with minimal effect. I didn't own this lens when I used the extender, so I cannot say for sure.

I would suggest renting or taking your camera and lens to the store and trying this extender out before buying. I can see where certain combinations may benefit the photographer. In my case, it didn't work out for me.

PROS:
Provides extra reach

CONS:
Eliminates one or two f-stops
Decreases sharpness of the lens

Must have for sports and nature shooters.
If you have the big lenses (400mm f/2.8L IS USM or even the 70-200mm f/2.8L IS USM) this is totally worth the addition. The 2x does NOT kill the autofocus on the f/2.8 and effectively doubles your lens with very little distortion around the edges. Check compatability on Canon's website. You won't be disappointed!