extension tube help

I can't seems to get my camera into focus (all blur) using extension tubes. I am sure it's user error but could use some guidance. I did ensure I followed the tube's instructions to mount the tube to the camera prior to mounting the lens.

Equipment:
Canon 60D
Canon 100 2.8L
Kenko Extension Tubes

I tried various combinations of the tube sizes and also for curiosity tried an 18-135 lens just to see what would happen.

Any guidance would be appreciated it.

Justin

What tubes do you have? Some do not have electrical contacts which will force you to shoot wide open with any lens that does not have a ring to manually set aperture on the lens itself.

Edit: Not sure about the Canon EF 100, but there are tricks aroud that. Something like set the apertute, diconnect lens and then put it back on tubes. (If this is needed, someone else may know how. I have only read about it, never done it.)

Other than that, shooting closer than 1:1 pretty much requires manual focus. Also realize your DOF will be razor thin. That is why most avid macro photographers will get into focus stacking. To help this problem strong lighting is necessary so you can stop down to at least f9.

In summary if you have good tubes (with electrical contacts) DOF and no AF are likely your problems, not the inability to focus.

you have to get a lot closer than what you are trying...at least that's my guess...when i first got tubes years ago, i thought they didn't work...i probably put the whole set on too...you need to get really close with tubes...you'll start to see it come into focus

Sorry. Missed seeing you have Kinko tubes. They do have electrical contacts. Ignore the part about no aperture adjustments.

You lose infinity focus, and anything past a few feet, when you mount a TC.

Thanks all - got close and it works perfect!