Teleconverters ???? (kenko 3X)

[Dr Bird]

Can anyone out there tell me how good ( or bad ) the Kenko 3X teleconverter
works on the Canon EOS 1-D Mark II preferably attached to the 500 4.0 I S
lens . The main reason I ask for this is I photograph Birds ( you can NEVER have
to big of A lens for Birds ) . I am NOT intrested in the 20D ( not 8.5 fps ) .

[robertwgross]

George Lepp wrote an article some months back about this, since he often shoots nature with long lenses. He said that if you start with a really sharp long lens, you can add a single 1.4x teleconverter and still get very good results (he called it a 10% degradation, whatever that means). With 2x, the results aren't quite so good, maybe 20%. I don't think he would want to go to 3x and still expect sharpness.

---Bob Gross---

[CyberDyneSystems]

Hi Dr. Bird,.
Welcome to the forum ;)

The Kenko 3X is an odd duck that has very little info circulating around the net.. I believe this is the first time it's been mentioned on this forum in a looong time.

One thing to keep in mind.. even on a 1D body you will lose autofocus for any lens slower than f/2.8! (and even on an f/2.8 your pushing things)

I also found these two very well written reviews;
http://www.pcphotoreview.com/35mm,Converters/Kenko/PRD_88999_3132crx.aspx

Do you allready have the Canon 1.4X and 2X T-cons?
If you are a 500mm owner,. I would recomend you getting both of these first.. then you will have two usefull tools for your 500mm... and you will be able to discern for yourself the dramatic difference in quality there is between a super telepohoto with the 1.4X and one mounted to a 2X... this should shed some insight onto the usefullness of the 3X...

Lastly..
You may want to check out the info thread I put together on T-cons;
-=Teleconverters De-Mystified=- (http://photography-on-the.net/forum/showthread.php?t=41922)

[DaveG]

Can anyone out there tell me how good ( or bad ) the Kenko 3X teleconverter
works on the Canon EOS 1-D Mark II preferably attached to the 500 4.0 I S
lens . The main reason I ask for this is I photograph Birds ( you can NEVER have
to big of A lens for Birds ) . I am NOT intrested in the 20D ( not 8.5 fps ) .

That Kenko is going to be BAD optically, so you can start there. But look what else it does: It'll cost you three stops so your 500 is now a 2000mm f11 lens. That means that you'll be using a very high ISO in order to get all the shutter speed you can, and that may not be high enough. Even with IS your subject's are likely to be moving quickly so shutter speed for freezing their action will be as important as for freezing camera motion.

I'm afraid that the results will be disappointing to you. I'd go with the Canon 1.4X extender and be reasonably happy with a 900 mm f5.6 lens. Then the results would be worth looking at, the ISO lower and optically you'd be in a lot better shape. If you need more focal length than that then you are out of luck.

[Dr Bird]

Dear Fellow photographers

Thank you very much for the input , I think my best thing to do is to use
both the telconverters stacked together ( on the Canon type II ) I will
still have auto-focus ( center-spot only ) on the the 1-D series , NO
auto-focus at ALL on my current Canon EOS 10D , this is A 5.6 camera
body not like the EOS-3 or the other 45 point cameras .

[FlyingPete]

One thing to keep in mind.. even on a 1D body you will lose autofocus for any lens slower than f/2.8! (and even on an f/2.8 your pushing things)


A quick question on this statement, do you mean loose performance, or loose AF all together, if the second, what happens with the majority of zooms that are generally no faster than f/3.5? I know my AF still works.

[phili1]

The only Kenko I can commen t on is the 2X and it is a good one. I bought it for my 100=-400 zoom and at 400(800) it is a little soft but at 350mm it sharpens up allot. I would say that if you have a 500mm lens and you put a 2X you'll have a 1000mm and that should get what you want.

I know a guy named Lou who is an expert on eagles and he shoots 800mm and get great shots.

I know another guy Les who has the 500 F 4 and stacked both the Canon 1.4 and 2X and got great results but the auto focus was hit or miss.

Hope that helps.

Her is Les's shot with stacked extenders.

[CyberDyneSystems]

A quick question on this statement, do you mean loose performance, or loose AF all together, if the second, what happens with the majority of zooms that are generally no faster than f/3.5? I know my AF still works.



Yes I mean total loss of Autofocus.
What T-con do you have that you are talking about?

[CyberDyneSystems]

That Kenko is going to be BAD optically, so you can start there. But look what else it does: It'll cost you three stops so your 500 is now a 2000mm f11 lens..

... a 1500mm with the "new math" ;)

[FlyingPete]

Yes I mean total loss of Autofocus.
What T-con do you have that you are talking about?

Sorry no T-con, just making a general misguided statement :o

Wouldn't mind one though, not sure how it would fare on my 75-300IS