depth of field in Xenar 500 mm. f.5.5greenspun.com : LUSENET : Large format photography : One Thread
I just bought such lens and won't be able to use it for a while. In the meantime i am torturing myself , since i am always looking for very shallow depth of field in a lens and i don't know if this lens is going to do the trick...
I know it isn't an f. 4.5 or less , but being 500 mm. the focal length the max. aperture seems to me wide enough to achieve a nice effect on my 8 x 10.. It also has a 19 blades iris which should help.
My question is : has anybody tried this lens? What should i expect?
-- domenico (firstname.lastname@example.org), April 28, 2002
The depth of field can easily be calculated given the distance to the subject. At 25 meter subject distance wide open you would have a depth of field about 2.8 mm. This depends on the circle of confusion you calculate with and such but you get the idea, there is very little depth of field. How little depth of field are you looking for and what is the application?
-- Dave Schneider (email@example.com), April 28, 2002.
your view camera is not limited to DOF for sharpness control. You can have selective sharpness even with a stopped down short lens, if you make use of your tilt- and swing controls. Try some "inverse" adjustments, like upwards tilt or opposite swing. Using a LF lens wide open is usually not a good idea, because the parts of your picutre that are supposed to be sharp should come out real sharp. if you like to take soft pictures, think of using an Imagon, Softar Filters or just breathe on the lens.
-- Thilo Schmid (firstname.lastname@example.org), April 28, 2002.
To ans wer to Dave , my main application will be poirtrature, but i will be using it for other applications like " moody details" i find in nature and architecture.
Thilo ,thank you for your input . I have used already tilt of the lens and camera back, but i find it too limited in effect variety and if you have noticed it everybody is doing it. I also have tried to do it in print session by tilting the lens.
I am not really looking for soft focus as much as a gradual access from the sharp and self evident world to an uncertain realm expressed by the out of focus areas. Thank you guys, it is always a pleasure to have exchanges of informations, ideas and opinions.
-- domenico (email@example.com), April 28, 2002.
At normal portrait distances (say, 1.5-3 meters), it is pretty easy to create short DOF in 8x10" with any lens longer than about 300mm. In this example, for instance, with a 305mm lens, f:14, and a subject distance of about 2 meters, the zone of critical focus is maybe 6 cm (computed with the standard value for circle of confusion on 8x10", it should be about 30 cm, but to my eye, that's an exaggeration):
For a really narrow zone, I could go to f:8 with that lens or I could decrease the subject distance for an even tighter portrait.
Bear in mind that relatively tight portraits on an 8x10" camera are effectively macro shots (magnification will be on the order of 1:4 to 1:1), so a longer lens will get you more working room, but for the same composition with any lens, DOF will not be substantially different.
-- David Goldfarb (firstname.lastname@example.org), April 28, 2002.