using adapters??

just a quick question,since most adapters move the lens away from the body do they act some what like a extension tube?making a 50mm lens maybe 75-100mm.i have a minolta adapter for my a7 and i am purchasing a eos to nex and a olympus to nex and they all look pretty thick,do the higher priced adapters metabones etc come thinner?do u lose any f stops of light with an adapter also.thanx

genesimmons wrote in post #17593679
just a quick question,since most adapters move the lens away from the body do they act some what like a extension tube?making a 50mm lens maybe 75-100mm.i have a minolta adapter for my a7 and i am purchasing a eos to nex and a olympus to nex and they all look pretty thick,do the higher priced adapters metabones etc come thinner?do u lose any f stops of light with an adapter also.thanx

Extension tubes don't affect focal length - teleconverters do.

If you're referring to Canon-to-Sony adapters for the a7 platform, then all they do is hold the lens at the correct distance from the sensor - that extra space also already exists in Canon cameras in the form of the mirror box. The adapter on the Sony a7 simply accounts for that missing space since the a7 has no mirror. The focal length and field of view with a Canon 50mm is exactly the same on a 5D III (or other FF Canon) as it is on any of the a7 cameras.

You don't lose any stops either....it's all exactly the same.

thank you very much,that explains it.i wondered why the adapters seemed kinda thick,now i know,thanx again,