Is stacking TN's the same as moving just one TN further from the camera mount ?
I was thinking about all that glass being added to get 3.5x
SW 120mm f5 ST @ 600mm
All @ ISO 200
All @ 1/750
Slavonian Grebe
SW 120mm f5 ST + Prinzflex 100-200mm TN ( 1.5x )
900mm FL
All @ ISO 200
1 + 2 @ 1/250
3 + 4 @ 1/500
Wild Pheasant