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michael franc
13-Jan-2002, 21:37
I am in the market for a tele lens. Does anyone know what is the longest lens i can use on a 4 x 5 Calumet with rail about 490mm long? Thank You

Fred De Van
13-Jan-2002, 21:57
It depends on how close you need to focus, and that depends on what kind if work you intend to do.

michael franc
13-Jan-2002, 22:04
Mainly studio work from face close-up to full body. (Oh yes--a very small studio). I like about 135 in 35mm so I assume the same would be about 400mm in 4 x 5. Sorry I wasn't more specific in the first place.

Jennifer Waak
14-Jan-2002, 01:32
You need to consider both your maximum bellows draw and rail length. Both need to be sufficiently long. But, assuming a 400mm lens and a 490mm rail I came up with a minimum focusing distance of about 7 feet, or about 2.25 meters (so your subject will have to be at least 7' from the camera lens to be in focus).

Technically, the longest lens you can use is 490mm, but that is only focused at infinity -- no close-ups allowed. If you want to focus between infinity and 1:1 reproduction you will need rail and bellows that extend between the length of your lens and 2x the length of your lens. In other words, there is an inverse relationship between how close to your camera you want to focus and how much bellows/rail you need. The closer to the camera the subject is, the more bellows and rail.

I don't know about the Calumet, but with many monorail cameras you can get rail extensions and long bellows for this sort of thing.

michael franc
14-Jan-2002, 10:07
I don't think there is a longer rail available (nor are the bellows removable) o n old Calumets. Nonetheless, thank you for the info.

Wayne_6692
14-Jan-2002, 14:46
Some people didn't read the question. You will be limited to about 7' with a 400mm long-focus lens (~1:5 I:S ratio). If you use a TELEPHOTO as you had asked, a 360 - 400mm telephoto will have a short enough back focus to allow you to get to about 1:2 - with a correspondingly short lens to subject distance.

michael franc
14-Jan-2002, 15:04
That's what I needed to know. Thank you very much.

Jennifer Waak
14-Jan-2002, 15:34
My bad. I did read the question but didn't realize there was a difference in focusing distance between a tele lens and a regular lens. I knew if I screwed up someone would show up to correct me.

Wayne_6692
14-Jan-2002, 17:47
Wish I knew how to paste these things correctly. Anyway, the Schneider site lists the backfocus for their 400mm tele at 265mm - much better than the ~400mm of a "long-focus" lens. Other "tele" lenses should have similarly short back focus distances.

Wayne

http://www.schneideroptics.com/photography/large_format_lenses/apo- tele-xenar_hm/56_400/apo-txr5,6-400p1.htm

Ed Balko
15-Jan-2002, 09:18
One possible way to use a long focus lens such as a 480 Ronar with this bellows might be to mount the lens in a short extension tube to gain the additional distance between the film plane and the lens. This would be more useful for distant subjects rather than closeup work.

There will be a modest loss in the front movements possible but these shouldn't be too restrictive with a relatively short (say 6") tube.

Wayne_6692
15-Jan-2002, 18:07
Ed - With the 480 Ronar on the end of an extension you'll have one hell of a lever, I wouldn't trust most cameras front standards with that stress. A 450 Fuji would make a much lighter load.

Ed Balko
15-Jan-2002, 20:34
Wayne is correct that the Ronar is a heavy lens.

I've just completed a 5 1/2" extension tube for a 480 mm Ronar; the tube has its own lensboard to mate with the front standard of the camera and the lens is mounted in a second, removable board at the opposite end of the tube. I've tried it, with the Ronar, on a Calumet CC-400 without any apparent problems. The front standard seems to be able to handle the weight and with the standard tightening knob good and snug, the front standard remains vertical with no creeping.

If this hadn't proved to be the case and the front standard alone were not able to accomodate the weight, I'd add a short extension bar to the rail and support the tube at both ends.

The lens will focus down to about 12 feet with this tube. I built the tube as a low cost means to permit use of the Ronar on this camera (22" rail) for landscape photography and it should be just fine for that purpose. One issue to keep in mind is that with this lens and tube mounted, there is a lot of weight at the top of the tripod and one need be careful that things are balanced.

michael franc
15-Jan-2002, 21:49
Thanks for all the advice. The tube sounds interesting. My rail is only 19" long.