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

tim k · Sep 14, 2010

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 · Sep 14, 2010

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 · Sep 14, 2010

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 · Sep 14, 2010

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 · Sep 14, 2010

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

Thanks

RalphLambrecht · Sep 14, 2010

tim k said:
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 · Sep 14, 2010

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 · Sep 14, 2010

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).

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

tim k · Sep 14, 2010

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 · Sep 14, 2010

tim k said:
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

Ian Grant · Sep 15, 2010

The bellows extension has less to do with the lens choice and is more to do with the actual design of the camera. You need to decide whether the camera is to be double or triple extension, that's compared to a standard lens for the format. Double extension allows 1:1 focus with a standard lens.

Typically a 10x8 camera with a 300mm/12" lens has an extension of approx 24"-27" and a triple extension version around 36". Scale that up for your 14x11 camera and 36" may well be practical without the hassle of adding an additional extension rail.

Ian

John Jarosz · Sep 15, 2010

What will you be doing with the camera? A 600mm lens on my camera (extends to 36") won't focus to give a head & shoulders photograph. Sure, you can get head & shoulders with a shorter FL lens, but you have to decide if that's what you want.

John

Michael Kadillak · Sep 15, 2010

When you contemplate how long your bellows should be on your 11x14 please consider how heavy your longest lens would be at this focal length and make sure that you design your support members to handle and "balance" this weight properly. This includes materials deflection properties and insuring that your tripod screw is sufficiently sturdy. A bit of research as to the range of weight of the optics that you could utilize would be well advised. The numbers could surprise you.

Personally I would make sure that my rail proportions for the front standard were at least as stout as the Deardorff V11. If you need some dimensions for the V11 I would be more than willing to provide you with some data.

tim k · Sep 15, 2010

Michael, I would love to know the width and height of your front rails. The bed design that I have in mind is similar to your v11, but a little more like an Ebony. As long as you got your tape out, it would be interesting to know the back width, and the bed length. Thanks for the offer.

tim k · Sep 15, 2010

Ian, its going to be triple (the bed plus front and rear sliding rails). Three is only one more set of rails, doesn't seem like much more work. Its the same design as the 4x5 that I built.

John, I have no Idea what I'm going to use the camera for. I'm not into people. Most everybody I know runs from me when they see a camera. I just want to not be limited by design.

tim k · Sep 15, 2010

Jim, thats reassuring, if I understand it right, with your 12" lens focused 1:1 with 36" bellows you still have an extra unused foot of extension.

Michael Kadillak · Sep 15, 2010

Tim:

The Deardorff V11 front rails are 1 9/16" wide and have a metal side plate affixed to it that has the drive gears along the bottom of the wooden rail for forward and rearward motion. This metal plate has flush mount screw driven into the side plate and adds structural stability to the rail. This front rail is 3/4" thick. The real rails are the same proportions. Let me know if you needs pics or have other questions. I use a 35" Red Dot in Ilex #5 with the V11 and it handles it with ease.

Jim Fitzgerald · Sep 15, 2010

tim k said:
Jim, thats reassuring, if I understand it right, with your 12" lens focused 1:1 with 36" bellows you still have an extra unused foot of extension.

Tim, that is right. I just use a lens that will give me what I need as far as close ups go. I love shooting close up with ULF.

Jim

Ian Grant · Sep 16, 2010

tim k said:
Ian, its going to be triple (the bed plus front and rear sliding rails). Three is only one more set of rails, doesn't seem like much more work. Its the same design as the 4x5 that I built.

Makes sense to use an extension rail. The issue then is making bellows that don't sag, and 2 or 3 ring tabs can help enormously.

I'm about to make a set of large bellows for a De Vere Monorail and looked how the originals were made, as well as those on my two Agfa Ansco 10x8's as all have very minimal sag. While the stiffeners on the original De Vere bellows are quite thin it uses three cloth layers this seems to give the additional stiffness preventing sag, the original bellows would have been made by Camera Bellows - now Custom Bellows in Birmingham, UK.

Ian

tim k · Sep 16, 2010

Michael, thanks for the sizes. I'm a little surprised, in the pictures I've seen they don't look that big. In my design they were going to be quite a bit smaller than that. I think I'm going to do a little upgrading, based on your suggestion.

tim k · Sep 16, 2010

Ian, off the top of your head can you say what the thickness was of the three layers of material and stiffeners all added up? With all that in there it sounds quite heavy duty. I'd be worried about them compressing in to a small enough space. Obviously they made it work, but with every set of bellows I've made they are always happier extended rather than folded.

Ian Grant · Sep 16, 2010

The original De Vere bellows seemed thicker than they are, and they aren't heavy. They are back in the UK so I can't give a better uea or photograph a cross section.

The rigidity seems to come from the way the three layers and stiffeners are glued together. They were tatty and leaked when I bought the camera in 1976, and I had some bag bellows made by Camera Bellows who had made the originals so had the patterns. The camera is a whole plate monorail with half [late & 5x4 backs and the bellows were only just usable with the 5x4 back.

The cloth I'm using will make the thickness slightly less, and lighter, but still as rigid so I'd expect the bellows to compress more than the old ones. That's based on the two other sets I've made so far.

I guess I could glue up some off-cuts tomorrow & measure the thickness, 2& 3 layers of cloth.

Ian

tim k · Sep 16, 2010

Ian, don't go out of your way, I'm moving pretty slow on this project, and the bellows are near the end.
Thanks

Ian Grant · Sep 16, 2010

tim k said:
Ian, don't go out of your way, I'm moving pretty slow on this project, and the bellows are near the end.
Thanks

I need to do this anyway, I brought the material here to Turkey in early June to make new bellows for the De Vere, so I can sell it when I return to the UK in about 5 weeks

It's a 5-10 minute task to cut some fabric & stiffeners & glue them up to test the two thickness and rigidity, I need to finally decide whether to go double or treble thickness before I start printing out the pattern & making the stiffeners.

It'll take longer for the glue to dry

Ian

tim k · Sep 16, 2010

Sounds great, it will be interesting to see what you come up with.

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

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