Sven Schroder
17-Jun-2006, 07:14
Hi
Having found the Ross/petzval I need for some portraits of Glacial Erratics (yes big Limestone ones) with Swirly bokeh. Typically it was found without any waterhouse stops so speed is a problem f3 wide open, I like what I see wide open but how much do petzval users stop down f8 ? also how low with the film speed as I want shallow DOF?
So the lens I have is a Ross petzval "for cartes de visite" in focal lenght of approx 6", I intend to shoot on 5x7/halfplate the swirl shows up well on this size. There is little info on vademecum to help determine the speed of the lens just "Quick acting for cartes de visite" which of course is not insribed on the lens, so is my estimation of f3.7 correct?
As for exposures I will have a look at front mounting a packard as I don't have much room inside the camera ( a Gandolfi ) I am used shooting with barrels at f32 or so but not F3.7 or so.
Thanks and Regards
Sven
Well not for cartes de visite, unless the Glacial Erratics need to introduce themselves.
Having found the Ross/petzval I need for some portraits of Glacial Erratics (yes big Limestone ones) with Swirly bokeh. Typically it was found without any waterhouse stops so speed is a problem f3 wide open, I like what I see wide open but how much do petzval users stop down f8 ? also how low with the film speed as I want shallow DOF?
So the lens I have is a Ross petzval "for cartes de visite" in focal lenght of approx 6", I intend to shoot on 5x7/halfplate the swirl shows up well on this size. There is little info on vademecum to help determine the speed of the lens just "Quick acting for cartes de visite" which of course is not insribed on the lens, so is my estimation of f3.7 correct?
As for exposures I will have a look at front mounting a packard as I don't have much room inside the camera ( a Gandolfi ) I am used shooting with barrels at f32 or so but not F3.7 or so.
Thanks and Regards
Sven
Well not for cartes de visite, unless the Glacial Erratics need to introduce themselves.