Canon EF 2X II Lens Extender

Best 2x extender you can get for Canon lens

Strengths: Sharp and Contrast than any other 2x

Weakness: Price and you can only use this with certain tele lenses

If you in shopping for a 2x tele-converter look no further than Canon extender. I have used other brand but it's what you get for what you pay. I use this with my 100-400 with great results, you have to step-down for sharpness but in a good light it's a great combination for extra reach.

Get the 1.4TC

Strengths: Price.

Weakness: Image Quality

Get the 1.4TC instead. The 1.4 TC does what it promises. This 2x TC doubles, but the images look dark, and soft when you are done, so whats the point. Its really the only piece of Canon equipment I would like to sell that I have bought. Its not all about the mathmatics of taking a 200mm and making a 400mm with this, its about image quality, and this one doesn't cut it very well.

The best 2x extender - for those who need it

Strengths: Quality, quality, quality

Weakness: None

Extenders are a great thing - they multiply the focal length of a telephoto lens at a relatively small expense in both weight and money. However, there are no free lunches - extenders invariably result in some loss of optical quality. The two most obvious features that are affected are sharpness and speed, but other unwanted effects are not uncommon. Having said all that, the Canon 1.4x and 2x...

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Another Great Canon Lense

Strengths: The Canon name and the quality of the glass

Weakness: None that I could find

The Canon EF 2xII autofocus extender is a great lense accessory to have in your camera bag. Per a conversation with Canon, I learned that you can use the 1X extender (1.4) or the 2X extender (EF 2x II) with any f/2.8 speed lense and NOT lose the auto focus features of the camera. If you use either of these extenders with a f/4 speed lense or slower, you will have to manually focus.

Best Extender Ever from Canon

Strengths: Twice bigger image... Image quality stays... Work with all kinds of Canon lenes even close up... Dust protection design...

Weakness: Gets less light... Makes lens very long... Not having tripod holder...

I think, this is very good for outside picture such as sports...It is not good for indoor pictures...However, if you use for close up with bright condition then it is very useful for people who likes close up!!

Excellent lens

Strengths: Quality

Weakness: None

I am very happy to have this accessary. I am very satisfied with the quality of outcome even though this product drops sharpness. You can not lose autofocus with f2.8 speed. Plus you can not lose autofocus with f8 with ESO-1D/1D Mark II(N)/1Ds/1Ds Mark II.

Canon 2x II extender ef autofocus

Strengths: quality

Weakness: price, usage

I thought that it would auto focus with my 300mm prome f4 canon, but not the case. Makes for a much more heavy camera attached to the lens, because of the additional length, had i known it would not auto focus, I wouldnt have spent nearly 300 for it, I have a 1.6 Vivitar purchased from Ebay that works very well at a 30.00 price.