7x17 Back and Bellows Weight?

[Kerry L. Thalmann]

Here's a rather odd request...

I am in the middle of designing and assembling (I say assembling because I'm leaving the building of key components to those more skilled than me) a 7x17 camera. It will be similar to the 4x10 camera I currently used that was assembled using parts from ARCA-SWISS and Lotus. The design work is done and I have created a spreadsheet with the weights of the individual pieces/assemblies. However, the two pieces of data I lack are the weight of the bellows and back. At this point, I just have place holders for those two values and would like to get a more refined estimate of what my finished camera will weigh.

So, I seek the assistance of all you 7x17 shooters out there. If you have a 7x17 camera with an easily removable back and bellows, could you weigh those items (bellows including mounting frames and camera back - just the back, not the entire rear standard) and post the weights here I'd appreciate it. Also, please state which brand of camera you have and your maximum bellows length. I suspect different brands will vary a bit in weight and, of course, bellows weight is a function of length.

Also, while you have the back off of your camera, if you could measure the width and height, that would also be helpful. I'm currently using 20"x11" for the width and height of the back (based on a 7x17 Korona), but if there are any back designs out there that are more compact, I'd be interested in the details.

At this point, I suspect I'm in the 12 lb. plus/minus 1 lb. range. It's gotten a little heavier than originally planned, but I've added self-arresting geared rise and axis tilt to the front standard, as well as rear base tilt and swing to my original concept and I've beefed up the rear format frame to make it more rigid.

Thanks in advance for any data you can provide.

Kerry

[Ken Osthimer]

Mr.Thalman
Your question has many variables in it. The wt. would depend the materials used for the bellows and the wood and metal components in the back itself. Also whether a "thin" piece of glass is used for the ground glass or not. I built my 7x17 from an old Agfa Ancso 5x7 chasis and had the bellows made at Westeren Bellows, they provide 35 inches of draw and are very "light" wt. I would guess that my whole set up weights around 10lbs. (bathroom scales). Hope this helps.

[Kerry L. Thalmann]

Ken,

Thanks for your response. Yes, the exact weight will vary depending on the materials used for the back and bellows. I should have been a more clear in my request. I already have all the other parts and materials on hand for the rest of the camera - except the back and bellows, which I will have made for me to my specifications. So, I have a very good idea what everything else weighs and a rough idea what a 7x17 back and bellows will weigh. What I would like to do is solicit input from those who have 7x17 cameras to further refine my rough estimates for the weight of the back and bellows.

The type of wood I use will have very little impact on the weight of the camera. The back and rear frame will be the only parts of the camera made from wood. As I already know the approximate dimensions of the rear frame, I can accurately estimate its weight. That just leaves the back and bellows. I have narrowed my choices of wood to the traditional cherry, mahogany and walnut - the three most common choices for makers of 7x17 cameras. Wisner uses both cherry and mahogany, Lotus uses cherry and Canham uses walnut. Even the older classic 7x17 banquet cameras are mostly made from cherry or mahogany. The densities of these woods are all very similar. Cherry and mahogany are almost identical in density (the exact weight will be more influenced by the grade of the wood and the moisture content). Walnut typically weighs about 10% more than the other two. So, at the most the difference due to the choice of wood will be a few ounces. That is also one reason I asked people to specify the brand of their camera when posting their weights.

Bellows weight will also be a function of materials (leather typically being heavier than synthetic), and especially length.

So, if 7x17 owners would post the weights of their backs and bellows, as well as the camera brand and maximum bellows lengths, I can get a better idea of about how much the back and bellows for my camera will weigh - or at least get a practical upper and lower bound.

Thanks,
Kerry

[Pete Roody]

Kerry,

Glenn Evans makes format change kits for Sinar rail cameras and lists the following for an 8x20 back, format frame, p-mount and bellows:

8X20 format change kit, with new 36" bellows, horizontal format only, you'll have to turn the camera on it's side to do a vertical, made of black lacquered lightweight Mahogany, weighs only 7# 3oz.,

Since 7x17 is approximately 75% the area of 8x20, this would give a minimum weight of 5# 6oz. This is an oversimplication but maybe you can estimate somewhere between these two figures.

I wonder if you could share some additional information regarding the camera you are building.

Are you using the Arca rail & function carrier system for the camera? If so, what function carrier are you planning to use? I would also like to hear your thoughts on what you consider as the 'largest format' you would think practicable on an Arca based camera. I know this is a difficult question to answer because you have to deal with more than weight (stability for wind, etc.) when you have a ULF system.

My final question would be where you are getting your custom fabrication work from. Is it a camera maker or craftsperson?

Thanks,

Peter