Bag bellows DIY material for compact 8x10 pinhole camera

[blee1996]

Hi, do you have any recommendation on soft and light tight material for bag bellows?

My purpose: build a very compact and lightweight 8x10 pinhole camera. My design goal is that the entire camera will be 9x12x3 inches folded, and 9x12x6 inches in use. I intend to have just one focal length of 6" (150mm) paired with 0.5mm diameter pinhole. The body and back standard will be adapted from a shadow (deep) picture frame, while the front standard will be just some 6x6 wooden lens board. I will use either wooden or metal pieces as struts to keep the front standard solidly in place.

So far during my research I found the following candidates:

1) Shutter curtain material (SILK) 20 x 30cm repair parts t0.18mm (eBay NobbySparrow)
2) A film changing bag
3) Lights-out curtain material
4) Pseudo leather short skirts
5) Thick black industrial trash bags

If you had experience making your own bag bellows of that size, please kindly share your wisdom in terms of material and fabrication. Thank you!

P.S. I got a Metrogon 6" f/6.8 lens from a camera show for coffee money, and can potentially use it as a point'n shoot lens for the 8x10 as well.

 

[Dan Fromm]

http://www.galerie-photo.com/bag-bellows.html

 

[ivan35mm]

Currently fabricating my own bag bellows for my Plaubel Peco Junior.

I decided to use genuine leather (very thin, roughly ~0.75mm), backed with a polyester "blackout" fabric I was able to locally source. When I purchased the blackout fabric, I noticed it was a 3-layer material. It has a sort of vulcanized rubber material sandwiched between two layers of polyester. It is absolutely light-proof.

Maybe you have already seen these, but I will leave these two links that have been very helpful for me..

Grossformat-Zubehör: Eigenbau

Bag Bellows – Darkshop

 

[blee1996]

Thank you both for sharing the useful links and personal experience.

I felt that those material might be a bit too thick or stiff for my purpose. I'm now leaning towards using the film change bag as foundation for the bag bellows. Some family member can help me with sewing machine.

 

[Dan Fromm]

Thank you both for sharing the useful links and personal experience.

I felt that those material might be a bit too thick or stiff for my purpose. I'm now leaning towards using the film change bag as foundation for the bag bellows. Some family member can help me with sewing machine.

Before you cut fabric, play around with it. If I tried to make a bag bellows starting from my changing bag, the bellows would collapse. You want the bellows to keep the dark in without preventing wanted light (from lens to film) in. That's why I used wet suit material.

 

[ivan35mm]

Thank you both for sharing the useful links and personal experience.

I felt that those material might be a bit too thick or stiff for my purpose. I'm now leaning towards using the film change bag as foundation for the bag bellows. Some family member can help me with sewing machine.

I would recommend two more things in that case:

1 - Maybe glue two layers of film changing bag fabric together using contact adhesive webbing spray, just so its not too flimsy. If you go too thin, you risk lots of movement in the bag (ie: the bag falling during long exposures, blocking the lens, etc)

2 - Try and avoid sewing. It can be done with good results, but with graffers tape, & contact adhesive for the seams, you can achieve a very long lasting & good set of bellow

Regardless, looking forward to seeing how your product turns out