Orbit lens question

[jpreston]

Anyone know what is the longest lens I can use on an Orbit 4x5? I think John said it has a 22" rail.

 

[shutterfinger]

http://www.cameraeccentric.com/html/info/bj_1.html
see page 9

 

[jpreston]

Thanks!

 

[markbarendt]

Depends on how close you want to focus.

For normal (non-telephoto) LF lenses the focal length, say 250mm (roughly 10"), is also roughly the distance from the film plane to the lens board when focused at infinity. If you want to focus on something closer than infinity then the distance between film and lens board has to get longer.

To focus on something 20" (500mm) from the lens board with a 250mm lens the distance from lens board to film needs to be 20" (500mm) so your 22" (550mm) rail should work very nicely with a 250mm lens. A 300mm lens will probably work for most situations but the close focus point is going to be out a bit farther, a 500mm lens will just focus on considerably more distant subjects and be useless for close subjects, a 600mm lens would probably never find focus on your camera.

 

[jpreston]

Depends on how close you want to focus.

For normal (non-telephoto) LF lenses the focal length, say 250mm (roughly 10"), is also roughly the distance from the film plane to the lens board when focused at infinity. If you want to focus on something closer than infinity then the distance between film and lens board has to get longer.

To focus on something 20" (500mm) from the lens board with a 250mm lens the distance from lens board to film needs to be 20" (500mm) so your 22" (550mm) rail should work very nicely with a 250mm lens. A 300mm lens will probably work for most situations but the close focus point is going to be out a bit farther, a 500mm lens will just focus on considerably more distant subjects and be useless for close subjects, a 600mm lens would probably never find focus on your camera.

So much to learn about this large format stuff! Thanks for the info.

Jeff

 

[shutterfinger]

Specs in the link above says bellows draw is 16 inch.
Large format press cameras with rangefinders have a maximum of 1 1/8 inches/28mm of movement from infinity to end of travel/closest focus distance.
Applying that to the specs a lens that will infinity focus at 14 7/8 inches from the film plane is usable. 1 1/8=1.125; 16-1.125=14.875; 1 inch = 25.4mm; 14.875*25.4= 377.825mm.
A 350-360mm lens will focus to 10 to 15 feet on a 16 inch bellows for standard photography.
For 1:1 a 8 inch/203mm lens is the longest that can be used.
Telephoto lens are another subject for someone else to discuss.

 

[markbarendt]

So much to learn about this large format stuff! Thanks for the info.

Jeff

Yep, lots to learn.

Lots of info here:

http://www.largeformatphotography.info/

 

[jpreston]

Yep, lots to learn.

Lots of info here:

http://www.largeformatphotography.info/

I've been doing some reading there. Lots to learn...

 

[jpreston]

Specs in the link above says bellows draw is 16 inch.
Large format press cameras with rangefinders have a maximum of 1 1/8 inches/28mm of movement from infinity to end of travel/closest focus distance.
Applying that to the specs a lens that will infinity focus at 14 7/8 inches from the film plane is usable. 1 1/8=1.125; 16-1.125=14.875; 1 inch = 25.4mm; 14.875*25.4= 377.825mm.
A 350-360mm lens will focus to 10 to 15 feet on a 16 inch bellows for standard photography.
For 1:1 a 8 inch/203mm lens is the longest that can be used.
Telephoto lens are another subject for someone else to discuss.

Great! So a 360mm lens would work for a longish lens, then. I've read that true telephoto lenses don't need as much draw as non-tele types.

Thanks,

Jeff

 

[Jim Jones]

I believe my 5x7 Orbit has the long rail, maybe 22", but I can't check on it at the moment. Some of its details differ from the 1968 catalog. It makes a great studio camera with a 4x5 back.

 

[jpreston]

Pretty sure John Kroehrer said it has a 22" rail. I should find out when it arrives in the next few days. I probably won't be doing much super close work with it anyway. Long lens land/cityscapes are what I'm interested in. Already looking for a long lens to put on it. Probably going to take my 40D to Columbus Camera Group or Midwest Photo Exchange and trade it for the longest lens I can afford.

 

[Jon Shiu]

Due to the construction of the camera, it can have a 22" long rail, but only 16" of bellows extension from lens board to ground glass surface.

Jon

 

[markbarendt]

What Jon is getting at is that the shape of the sliders on the rail limit extension to less than 22". See the photo.

(there was a url link here which no longer exists)

The other limit is the bellows.

I have essentially the same camera, just has the Calumet name on it instead.

My camera has a 20" rail, a long bellows that can get to 20", and the adjusters on the rail can also be removed, turned 180 and reinstalled to allow the full 20" reach. Turning the sliders makes the camera tough to use with shorter lenses, may not be able to focus.

 

[jpreston]

Just received the camera and I must say it is V E R Y nice! John included some extra items that were not discussed and it got here SUPER fast! As much as I was disappointed with the Graphic View that I bought from the evil place, I am doubly happy with this purchase from John Koehrer! The rail is actually 26" long and it appears that there's a solid 22" from the back of the lens board to the film plane. Seems like a great camera for long lens work. Now, if I could only figure out how to open the preview on the 12cm f6.8 G. Leitmeyr Weitwinkel Anastigmat lens...

 

[shutterfinger]

What shutter is it in? name will be on the shutter itself, not the lens barrels.
Not all shutters have a press to focus feature.
Open on T, focus, close shutter and set speed.
B 0nly, lock shutter open with a locking shutter release cable.

 

[jpreston]

What shutter is it in? name will be on the shutter itself, not the lens barrels.
Not all shutters have a press to focus feature.
Open on T, focus, close shutter and set speed.
B 0nly, lock shutter open with a locking shutter release cable.

Shutter is a Seikosha-S that goes to 1/500th (Copal 0, I think) and has B, but no T. I locked it open on B like you said. Thanks for the info.

 

[shutterfinger]

No its a Seiko Seikosha S. Search engine Seiko shutter or Seikosha shutter. It may have a preview lever but the shutter will have to be set before it will move or work. Seiko shutters are used on Mamiya cameras and a few large format lens. been a while since I owned one.