leighmarrin
5-Mar-2010, 22:23
I read a brief comment by an APUG user with the name of "Phitz" that combining the front and rear cells of the 127mm and 203mm Ektars will give bizarre results. So I had to try it: the combo of the rear 203mm and front 127mm Ektars was unfocusable on my 4x5 Pacemaker, but when I tried the 127 rear and 203mm front cells, I was surprised to see the rails of my Speed Graphic.
Dropping the bed, the strange resulting wide-angle lens goes way back in the box of my Pacemaker, but can focus to infinity. The results were terrible by most standards: at f11 a small center of medicore sharpness, but with bad sharpness fall-off and an image circle of about 4.5" inches when focused at 15 feet.
Attached are a couple of the first tests; looks like I gotta center the front standard of my Pacemaker, and use more developer in my hand-agitated Jobo 2502 tank, hence the black bar on the street scene.
After looking at the negatives, the resulting optical problems were even WORSE than I anticipated! But fun... think I'll try this "kluge" of a lens on the local ugly franchise-chain signage.
FWIW, I also tried the front cell of an old Kodak 170mm f7.7 folder lens in the 127mm Supermatic shutter, and got nearly the same results on the GG.
Should anyone else try this, I suggest out of respect to the brillant Rochester optical engineers, that you NOT call it an "Ektar". I suggest "RATke": Ektar spelled backwards. :-D
http://www.rangefinderforum.com/photopost/uploads/13781/4x5_9.jpg
http://www.rangefinderforum.com/photopost/uploads/13781/4x5_6.jpg
Dropping the bed, the strange resulting wide-angle lens goes way back in the box of my Pacemaker, but can focus to infinity. The results were terrible by most standards: at f11 a small center of medicore sharpness, but with bad sharpness fall-off and an image circle of about 4.5" inches when focused at 15 feet.
Attached are a couple of the first tests; looks like I gotta center the front standard of my Pacemaker, and use more developer in my hand-agitated Jobo 2502 tank, hence the black bar on the street scene.
After looking at the negatives, the resulting optical problems were even WORSE than I anticipated! But fun... think I'll try this "kluge" of a lens on the local ugly franchise-chain signage.
FWIW, I also tried the front cell of an old Kodak 170mm f7.7 folder lens in the 127mm Supermatic shutter, and got nearly the same results on the GG.
Should anyone else try this, I suggest out of respect to the brillant Rochester optical engineers, that you NOT call it an "Ektar". I suggest "RATke": Ektar spelled backwards. :-D
http://www.rangefinderforum.com/photopost/uploads/13781/4x5_9.jpg
http://www.rangefinderforum.com/photopost/uploads/13781/4x5_6.jpg