theoretical lens stacking combination

[airdima]

i was just wondering, has anyone tried stacking a UWA lens like a 10-20 on top of a long tele lens somewhere around 300+mm? i mean that would give a 15-30:1 magnification, but would it be anywhere near practical? even with a focusing rail and an uber stable setup?

[LordV]

Fraid not- I suspect you would end up with impossibly close focus distances (possibly inside the front element of the reversed lens). Have heard of people using a 50mm on a 200mm lens ok.
Brian V.

[gasrocks]

You can use a normal lens (50mm) backwards on the front of a telephoto (say 100-200mm) and get something like 3x life size. Subject will be mm from the front of the glass - not practical for field work but ok for studio.