Barrel Lensesgreenspun.com : LUSENET : Large format photography : One Thread
If a barrel lens has no shutter, how do you keep light out of it before and after exposure? How do you time the exposure? And I assume it has a diaphragm?
Unbelievably naive, I know, I've just been too embarrased to ask at a camera shop where I have to look someone who knows me in the face.
-- Chris Tolson (email@example.com), May 02, 2002
An old timer would keep his fedora over the lens when the dark slide was withdrawn from the film holder. I'm old enough to have seem a old timer actually doing this taking available light photographs of a weding inside a church (come to think of it, since he was inside a church, the hat was in his hand, not on his head. The couple, the photographer, and the church were 100% Italian, BTW) These days I suppose one would use a baseball cap or, in extremity, an actual lens cap.
There are a number of shutters which are intended to be mounted on the front of a barrel lens and act in a functionally equivalent way to an internal leaf shutter. These exist as both "rollerblind" type (close relative of the cloth focal plane shutter common in 35 mm cameras) and the leaf shutter variety, such as the "Luc". The Packard shutter, a leaf shutter variant, can be mounted at the front of a barrel lens but is probably more commonly found at the reverse side of the lensboard.
A Speed Graphic really shines in this aspect. With its rear focal plane shutter, one can use anything that one can mount on a Speed Graphic lensboard and which will focus with the available bellows extension; barrel lenses, enlarger lenses, process lenses, or pinholes. The only lenses I have not yet been able to fit to a Speed Graphic are some of the the larger diameter Aero Ektars whose diameter exceeds the diagonal of the Pacemaker lensboard.
-- Ed Balko (firstname.lastname@example.org), May 02, 2002.
Hi Chris, I'm actually only ½ Italian but I use the lens cap to keep the light out until exposure. Obviously you'd have to have a quick and accurate hand to take the place of a shutter's normal function, or some slow film in less than robust light. I photographed some baby owls inside an old mine mill here where I live last weekend and the exposure with reciprocity failure on Ilford FP-4 was 19 seconds. Owls are incredibly cooperative. Out of 4 shots only one had movement. Some people can get reasonably good with ½ and 1 second exposures by removing and replacing a lens cap. That's how you do it.
-- Jim Galli (email@example.com), May 02, 2002.
Packard shutters are a great solution for using barrel lenses. I picked up a 24" APO Artar about three months ago and while I would love to have it mounted into shutter, fact of the matter is it's just a little too costly at the time being. So I found a great deal on a Packard shutter, used an exacto knife, empty film box, and about six feet of gaff tape to mount it on the front of the lens, and voila, a nicely usable setup. Sure, there are situations in which it would be nice to have a speed other than instantaneous or bulb, but you'd be surprised how easily one can adapt to most situations with this setup. Besides, it makes everything all the more fun when you're in a busy area with a big old camera on a big wooden tripod with 2 feet of bellows extension and an air operated shutter.....
-- David Munson (firstname.lastname@example.org), May 02, 2002.
Depends on the barrel lens. Check S.K.Grimes' site (www.skgrimes.com) for info on mounting barrel lenses in front of shutters.
Used Ilex #3s and #5s are not that expensive to get and have overhauled. Also Copal #1 Press shutters, as from Polaroid MP-4 cameras, are available used at very attractive prices.
Mr. Grimes makes adapters to hold lenses in front of shutters, and his prices aren't that high.
To give an idea of his prices, he charged me $75 for an adapter to hold a 210/9 Hexanon in front of a Copal #1. I use it for 2x3 and, believe it or not, 35 mm. I knew before I bought that the combo wouldn't cover 4x5, so please no one tell me that I'm an idiot for getting it. If you must tell me I'm an idiot, find another reason why.
-- Dan Fromm (email@example.com), May 03, 2002.
Hi Chris I have a couple of barrel lenses I use and what works for me is the bottom half of a hard lens case for, oh say, a 100 mm lens. Its insides are lined with black felt, which is really black, and the shape fits like a glove over the lens' front until I want to take it off. Good Luck
-- Gary Meader (firstname.lastname@example.org), May 03, 2002.
Continuing Dan's discussion on front mounting lenses -
It isn't too difficult to fabricate a front mounting for a barrel lens. The adaptor which you make looks rather like a big filterholder (or a normal holder for big filters, I suppose). With Elgeet, Ilex, or Alphax shutters and a Wollensak or Artar lens all threads are English and can be cut on lathes which are common in North America. FWIW, the last Ilex #3 I worked on had 52 tpi x 1.75" internal threads to which I fitted a 12 inch Artar which had 36 tpi pitch threads. Wollensak seemed to be partial to 30 tpi threads on both lenses and Alphax shutters.
Steve Grimes has a nice discussion of the limitations inherent in a front lens mount (may take a minute or two to find since he shuffled his website). The potential disadvantage of some loss of movement due to vignetting within the shutter body becomes much less important as the focal length of the lens increases, I presume due to the larger projection distance between lens and film plane. I've front mounted several process lenses in the range of 300-400 mm focal length recently and have had no vignetting at maximum rise and shift on my 4x5 CC400 Calumet. This is of some practical interest since its process lenses in this focal length range that seem to be most common, and correspondingly inexpensive, now.
The front mount has the slight additional advantage of acting like a short extension tube squeezing in a bit more focussing extension. Nice to have if you're attempting to use a 325 mm lens on a camera with a 330 mm bellows.
-- Ed Balko (email@example.com), May 03, 2002.