Question about adapting MF lenses

[sbghms]

Hey everyone! I just bought a T2i after using a NEX-5N and a GH1 for awhile. As y'all know, people with GH1 and GH2's are nuts about adapting lenses.

Well I'm reading countless articles and they all seem to mention problems with adapting lenses. One thing that I'm confused about it where they say that you'll lose X stops of light when adapting. Is this true for all adapted lenses? I never heard anything about this when using my GH1.

Could someone explain the differences between adapting lenses on a M43's and a T2i would be?

Sorry if this has been covered, I just can't seem to get the facts straight by piecing together information.

[gonzo_entertainment]

With a glass-less adapter you shouldn't lose any light, maybe a REALLY small amount. What causes light loss is extra glass or moving the lenses a greater distance from the film/sensor. The tiny amount most adapters move the lens forward isn't enough to lose even 1/4 stop.

The only problems I have had with M42 to EOS mount is some focus past infinity (can't just rack to the hard stop at infinity you'll actually be slightly out of focus) and mirror interference (on wide lenses, 35mm and below) FD lenses are the only mount I am aware of where you just can't use them because of mirror interference.

[sbghms]

Awesome, thank you! I was thinking the light loss issue might have been with the glass adapters only but nobody really made that clear. Most cheap adapters for M43's didn't allow me to focus to infinity either... but that never really bothered me!

[c3hammer]

Virtually all M4/3 adaptors guarantee infinity focus on a GH1/2.

Vintage Canon FL & FD, Yashica/Contax and Minolta SR lens mounts with an adapter have a flange focal distance SHORTER (edit said - longer) than the 44mm EOS mount and require a piece of glass to acheive infinity focus on a modern Canon dslr. These adapters with glass tend to soften up the image terribly and aren't worth the effort or even the $20 adapter. Pentax K mount lenses can work, but the apurture pin hits the mirror on all full frame EOS cams.

Nikon F and Olympus OM are the only popular vintage lenses that have redily available adapters with a flange focal distance long enough to allow an adapter in between and still acheive infinity focus.

Cheers,
Pete

[gonzo_entertainment]

M42 are the most popular for a reason. They virtually all work with only occasional mirror interference on wides. They do focus to infinity with a $7 adapter, they just focus PAST infinity. You can't just rack to the hard stop. You have to actually check the focus as infinity will be slightly BEFORE then end of the rotation.

[sbghms]

Thanks a lot guys! As I'm reading more, I realize that this has all been covered a million times haha. From what I was reading before it seemed like none would be adaptable, but now I'm seeing that many are.

@gonzo - Do the M42's still have a chance of mirror interference on non-FF cameras?

I suppose it doesn't really matter since I'm not going to be buying any MF wides because I just picked up a Sigma 10-20.

[Samuel H]

you really want to use adapters without glass in them... check this out for a table of some mounts what will work this way on your Canon: http://www.similaar.com/foto/lensmount/lensmount.html