Canon lens questoin...

[gparr]

Interesting. Have never had trouble with my Kenko tubes and have never heard of anyone having trouble. They're just metal cylinders with some contacts. There's really nothing that can go wrong. I've used my one set on Sigma and Canon lenses with perfect performance. Those Canon tubes are awfully expensive for metal cylinders.
Gary

 

[H@rry]

I've got Kenko tubes that I use on a Nikon D40 with no problems. Really I think the only things that could go wrong with extension tubes are they don't fit, they don't make the electrical circuit between camera and lens, or they leak light. No optics at all.

Really, after I got them and saw what they were I think I could probably make one from a piece of toilet paper tube (except for the contacts).

 

[Tremont]

If you want a good example of what the MP-E 65 mm is for/good at, see my short film:

https://www.reef2reef.com/forums/f54/time-lapse-montipora-23573.html

Pretty much the entire thing was done with the MP-E 65 mm. I love the thing because it let's me see what I can't see with my own eyes. But it is absolutely *not* a general purpose macro lens. You must be able to get within a few inches of what you are shooting for it to be in focus.

 

[Tremont]

Oh and regarding that review's take on sensor dust + the MP-E 65 mm - I couldn't agree more. While shooting my film I was in a constant battle against sensor dust, and even many of the shots that made it in there is a huge amount of visible dust (if you start looking for it, you will see it everywhere). Using other lenses I never have this problem (I think it's because to make this lens work you usually need to use higher f-stops and the effective aperture is magnification times aperture pulls more sensor dust in focus...at F16+5x you have an effective aperture of f96).