How long should my bellow really be with a 11x14 ?

[tim k]

I am in the early stages of building/designing a 11x14 flat bed. I have some specs from the builders on-line, but in the real world, how long are you guys really stretching out.

I'm a stick and stone landscape guy. Don't think I'd ever want to chase bugs or flowers up close. I don't have any lens yet, but in my 4x5 I have a 90, 150, and a 210, and I feel pretty happy with them, and don't feel the need for more. Most of the time its either the 150 or the 210 so I guess I'm usually pretty close to normal.

So, what do you guys think? Is 3 feet going to be enough.

[RalphLambrecht]

Tim

Do the calculations yourself. The bellows extension 'v' is calculated as:

v = (u*f)/(u-f)

where 'u' is the focusing distance, and 'f' is the focal length of your lens.

[frednewman]

Hi tim k - The Canham 11x14 camera has 48" of bellows. It all depends upon your longest lens. If you are using even a 600mm lens like the Fuji, 36" of bellows should be fine.

Fred Newman

[tim k]

Ralph, is this one of those "teach them to fish" answers?

I came out with something over 400 feet, is that too long?

Then I did it right and came up with 40".

Thanks

[tim k]

Fred, sounds like if I do 40 inches I'd be safe.

Thanks

[RalphLambrecht]

Ralph, is this one of those "teach them to fish" answers?

I came out with something over 400 feet, is that too long?

Then I did it right and came up with 40".

Thanks

Yes, but apparently, you've mastered it!

[rrankin]

If you plan on ever selling it, then I'd say most 11x14 users are going to expect a meter or more of bellows on that size camera.
Cheers,
Richard

[keithwms]

For 1:1 macro images (with non-tele lenses) you need bellows length twice the focal length. That is a pretty good estimate of maximum bellows length you'll need (although I think there is a lot of good work to be done in LF/ULF beyond 1:1 and we shouldn't automatically cede that territory to smaller formats).

http://www.apug.org/forums/forum44/5...extension.html

[tim k]

So, thinking out loud. With a 480mm I'm good for 1:1 with 40 inches. With a 600mm I'd need closer to 4 ft for 1:1.
40 Inches is starting to sound about right.

[Jim Fitzgerald]

So, thinking out loud. With a 480mm I'm good for 1:1 with 40 inches. With a 600mm I'd need closer to 4 ft for 1:1.
40 Inches is starting to sound about right.

Tim, I've done quite fine with 36" of bellows. Remember the lens coverage increases as you get closer and extend your bellows. I've done some nice 1:1 with my 12" Gerogon.

Now for my 14x17 I'm thinking 48".

Jim