Educate me on Extenders

I have a 70-200 2.8 II, and love it. However, sometimes I need more reach. I am sure many others have the same problem.

I have heard that you have to manually focus when using extenders. Or is there some units that do auto focus and others that don't?

I guess I am wanting to know what are be best ones that do have AF features. Do both 1.4 & 2 have AF, or just one of them?

I use a 7D if that matters with extenders.

Also, does anyone know an information source on the subject?

Joel,

You 7D will still AF with both the 1.4x and 2x Extenders on you 70-200/2.8

Bob

Canon Bob wrote in post #15727831
Joel,

You 7D will still AF with both the 1.4x and 2x Extenders on you 70-200/2.8

Bob

Does that include all brands, or just Canon?

guntoter wrote in post #15727852
Does that include all brands, or just Canon?

Yes, all brands.

Here is a good reference: https://photography-on-the.net/forum/showthre​ad.php?t=41922

Keep in mind that even though the Mk III extenders "Have been redesigned to match perfectly the latest Canon MkII IS Super Telephoto line" , unfortunately the 70-200mm 2.8 IS II is not one of those Mk II "Super Telephoto" lenses.

msowsun wrote in post #15727856
Yes, all brands.

Here is a good reference: https://photography-on-the.net/forum/showthre​ad.php?t=41922

Keep in mind that even though the Mk III extenders "Have been redesigned to match perfectly the latest Canon MkII IS Super Telephoto line" , unfortunately the 70-200mm 2.8 IS II is not one of those Mk II "Super Telephoto" lenses.

Now that is a great resource. Thank you.

Thanks for all the help guys. I just bought the "Canon Extender EF 2X III" from B & H.
http://www.bhphotovide​o.com …2_Extender_EF_2​X_III.html

Let us know how the new extender works for you. I just tried using the 7D/70-200 2.8 ii with the Canon 1.4 ii and love the extra reach. The sharpness is still there and better than I had expected by using the extender.

I will let you know and I have some bird pics I want to do fairly soon, so I will post some.

In my last post on this thread I said I would post some pics of birds after I get the 2x extender. I put them in the bird forum here:
https://photography-on-the.net …/showthread.php​?t=1293714
Scroll down in this post, because I posted more lower in the thread.

I am very happy with the 2x TC.

It looks like the 2X is working well on the 70-200.

I notice a lot of discussion about getting a 100-400 over at that other thread... You are aware that it's not going to work with the 2X, aren't you?

amfoto1 wrote in post #15868197
It looks like the 2X is working well on the 70-200.

I notice a lot of discussion about getting a 100-400 over at that other thread... You are aware that it's not going to work with the 2X, aren't you?

I was aware that the auto focus would not work, but manual focus would work, right. I mean I would probably be f9 or some small aperture like that, but in bright daylight it could work, right? Or am I wrong?

guntoter wrote in post #15869235
I was aware that the auto focus would not work, but manual focus would work, right. I mean I would probably be f9 or some small aperture like that, but in bright daylight it could work, right? Or am I wrong?

At your longest you will be f/11.

GoodEye906 wrote in post #15869266
At your longest you will be f/11.

Hmm. I was liking the idea of 800mm, but f/11 is very restrictive. Chances are that if I decide to buy the 100-400 I will sell the 2x TC. Selling it would give me more money toward the 100-400.

Decisions, decisions.

I guess now I would like to know if anyone out there is using the 2x TC successfully with manual focus on the 100-400?

My kenko 2x works great at only 119 bucks

nothing beats native length. on most lenses that are not designed for TCs IQ will suck, tho you may convince yourself otherwise at least initially.

on some lenses not designed for TCs (any 70-200L) a 1.4 TC can provide excellent results in the right conditions. a 2x TC not so much but that depends on your pain and denial thresholds.