On Tue, 11 Oct 2005, Godfrey DiGiorgi wrote:
On Oct 11, 2005, at 6:33 PM, Rob Studdert wrote:
On 13 Jan 2004 at 6:58, Christian Skofteland wrote:
OK I performed some practical tests with various combinations of
lens TC and tubes. In all cases I used the full 57mm 3 tube set
with the lens set wide open and set at its minimum focus distance,
the AF TC was set at its infinity focus position. The exposure
factor quoted below is relative to 200mm at minimum focus distance.
The 200 alone gave me 1:1 (23.5x15.7) on the sensor.
The 200 +1.7AF gave me 1.75:1 (13.4x9mm), exposure -1.58 stops
The 200 +1.7AF+tubes gave me 2.85:1 (8.2x5.5mm), exposure -2.74 stops
The 200 +tubes +1.7AF gave me 2.42:1 (9.7x6.5mm), exposure -1.77 stops
My quick test with the 50mm seems to indicate the same thing.
Camera->tubes->converter->lens
nets greater magnification than
camera->converter->tubes->lens.
Would reversing the lens make any diffrence?
Kostas
