1.4 Teleconverter with 400L f/5.6

So here is what I've discovered. The 400L f5.6 snaps into focus just great on tests. Then I put the 1.4 TC on it (either 40d or 5D2) and it won't autofocus and when I manually focus, it seems to focus about 5mm to the back of the focus plane based on these tests:
http://photo.net/learn​/focustest/

I assume it's either:
1. When I add the TC it changes the plane of focus or
2. Something it my eyes tells me I'm in focus but I'm really not, I'm 5mm out of focus in my eye/brain apparatus. I've had autofocus lenses since

Any thoughts or solutions? Can I set up a Micro adjustment for just the lens/TC combination? Should I get my eyes replaced?

AFAIK, cameras that offer MFA will recognize and remember settings for when the TC is mounted Vs when it is not. IOW, the TC is considered a "lens" unto itself.

You lose AF with any body other than a 1-series by adding the (canon) 1.4x TC, because you lose a stop (1-series will focus with centre point when using an f/8 lens).

How are you manual focusing? LiveView or through the viewfinder? I manual focus my 400 5.6 + 1.4TC combo all the time when focusing on something that isn't in the centre of the frame, and it's pretty easy to nail it (should be similar on your 5D2). BUT it took a lot of practice to nail that, I used to be just out of focus, both front and back, when starting out.

sheawyatt wrote in post #9934591
How are you manual focusing? LiveView or through the viewfinder? I manual focus my 400 5.6 + 1.4TC combo all the time when focusing on something that isn't in the centre of the frame, and it's pretty easy to nail it (should be similar on your 5D2). BUT it took a lot of practice to nail that, I used to be just out of focus, both front and back, when starting out.

Always through the viewfinder right now. I'll have to try with LiveView. I'm just a little stumped because of how I tested. Looking through the viewfinder with tripod, mirror lockup on, 2 second timer, and the middle line of the template (from post above) in sharp focus. Either eye. Its true I haven't had the lens for very long and am just getting used to manual focus after having AF for many years but it just seems weird that all the shots would be out of focus in the same way.

FlyingPhotog wrote in post #9934434
AFAIK, cameras that offer MFA will recognize and remember settings for when the TC is mounted Vs when it is not. IOW, the TC is considered a "lens" unto itself.

Does this mean that if I do MFA with just this lens setup that it will only work with this combo and not when I have my other array of lenses attached?

Any lens with an aperture smaller than 4.0 will not auto focus with your camera.You can try the tape
the pins trick or do what I do and use a non reporting TC that has only 8 pins instead of 10

halitime wrote in post #9940775
Any lens with an aperture smaller than 4.0 will not auto focus with your camera.You can try the tape
the pins trick or do what I do and use a non reporting TC that has only 8 pins instead of 10

Aperture smaller than 5.6

I did the pin tape trick with my 400L f/5.6 and 7d and it had a VERY hard time grabbing focus if it ever did even in decent light.

decrink wrote in post #9940718
Does this mean that if I do MFA with just this lens setup that it will only work with this combo and not when I have my other array of lenses attached?

No. The MFA system will remember this combo as lens + TC and will not confuse it with any other alternative lens or combo of a different length.. BUT, the camera database will not store and recognise two versions of the same focal length. It doesn't base its record on unique serial numbers.