Posts: 378
Joined: Sat Jun 09, 2001 5:46 pm

Converters & Extenders

Wed Jun 11, 2003 12:22 am

Please forgive my inexperience in this domain, but I haven't actually ever used one of these.

I would like to know what difference do you make between a converter and an extender, if any?
As a French guy, my technical English is a bit limited, which definitely doesn't help if I want to avoid making any mistake when purchasing the item.

My problem is that I am going in a few weeks time to Africa for a photo safari in a wildlife park and I'm afraid that, although an excellent and powerful lens, my Canon 100-400mm f/4.5-5.6 L IS USM might be a bit too short sometimes.

I've checked the B&H website and found these two ones:

CANON Life Size Converter EF


CANON Extender EF 2x II


There is a 50 USD difference in price, which is not at all a factor in my choice.

I would really appreciate your help in this matter as well as some valuable advice.

Thanks to you all.

The sky has no limit...
Posts: 4586
Joined: Fri Aug 27, 2010 12:26 am

RE: Converters & Extenders

Wed Jun 11, 2003 6:40 am

The life size convertor is designed specifically for the 50mm macro lens to increase its maginifaction from 1:2 up to 1:1 - this is useless to you.

What you should be considering is either the Canon Extender EF 1.4x or EF 2x which will increase the focal length of your lens by either 1.4x or 2x at the cost of one or two fstops.

BUT in the case of the 100-400, applying either of the convertors will result in the loss of AF, and a distinct loss in sharpness and contrast. In my experience, the 100-400 + 1.4x provides acceptable quality, 100-400 +2x does not.

As a general rule, I'd suggest you would be better sticking with the 100-400 and enlarging the images where necessary. If the shot is sharp, a fair degree of enlargement is usually acceptable. A shot which fills the frame, but is of poor quality, is worthless.

I found the only (relatively!) affordable route while retaining sharpness was the Canon 300mm f4 LIS plus 2x extender.


Colin K. Work, Pixstel
Posts: 378
Joined: Sat Jun 09, 2001 5:46 pm

RE: Converters & Extenders

Wed Jun 11, 2003 1:18 pm

Thanks Colin for your reply.

Actually, you made me save some $: Although I knew about the loss of AF, I was not expecting any loss in sharpness or contrast.
I'll stick to your advice; anyway, if I find my pictures not good enough, it will give me an excuse to go back to Africa!  Wink/being sarcastic

The sky has no limit...

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