85mm with extension tubes for closer portraits?

[electron]

I just got the 85 f1.8. The Min Focus Distance of 85mm is sometimes quite restrictive so I'm thinking of getting an extension tube set (Kenko/polaroid) just to get closer. I'm wondering if the AF using just one tube is acceptable for portraits? I am not interested in macro. But have read macro shooters using extension tubes makes AF almost useless preferring to manually focus in which case i will NOT get the extension tubes.

[megane2]

I have this combi, AF still works but limited. I remember its will lick AF with 12mm ET.

[electron]

I have this combi, AF still works but limited. I remember its will lick AF with 12mm ET.

What do you mean by 'limited'? Speedwise, accuracy or both? Do you mean it will work with the 12mm ET?

[megane2]

Limited as in focusing plane, it was very narrow and focusing sensor was not able stop the USM motor in time.

[Snoweagle]

I'm using 2x 12mm extension tubes for my 50mm for macro and so far AF is still gd except using extension tubes are similar to close up filters - they have only a certain focusing distance but the extension tubes give better results definitely.

[shawntim]

I tried, and I don't think it is very suitable for close-up portraits. YMMV.

1) With the DOF now alot thinner, you'll probably need to step down the aperture alot to increase DOF. Otherwise you'll get into problems with sharp eyes and blur noses. But step down too much and you'll hit into problems with handshake.. ppl are living subjects.. and they move..

2) 85 with 12mm extension tube - AF is barely usable, depending on your lighting conditions + your aperture. 85 with the other 2 longer extension tube - AF hunts.

3) Portraits are living subjects. If they move close to you, you'll start to lose focus. if they move too far, you can't focus coz with Extension Tubes you lose the focus to infinity. i'd rather extension tubes be used on more stationary subjects.