not sure I made the right decision

[rdzmzda]

the canon 50mm 1.8f 52mm filter size

 

[Josh66]

Do you also have another lens (you will need one to use a macro coupler)?

...Preferably something long - 100mm or longer. You get the most magnification with macro couplers when you combine a long lens with a short one.

 

[rdzmzda]

hmmm i have a few old school minolta film lens's and a canon 75-300

 

[Josh66]

Even if you do get a macro coupler, an actuall macro lens would still be very nice to have too...

 

[Josh66]

With the macro couplers, you want the lens with the larger maximum aperture to be mounted to the camera. The other lens gets mounted on front of the lens on the camera.

Mixing manufactures/mounts would be fine too, as long as the one that doesn't fit your camera is on the end.

edit
Oops - typo. You want the lens with the smaller aperture to be on the camera. Sorry.

Why? You will have two lenses on your camera. Your camera can only control the one that is mounted to it directly. The one with the smaller aperture is the limiting one, so put it on the camera. If you had an f/1.4 and an f/2.8 stacked, it would be f/2.8 (no matter what the camera was set to) until you stopped down beyond that.

(That may not be 100% technically accurate, but it's close enough - I think. I'm sure someone will correct me if I'm wrong.)