Replacing Light Trap in old Century Plate Holders?

[leighmarrin]

I recently picked up a "whole plate" 6.5x8.5" Century No. 2 view camera in very good condition. It has a working Compound shutter and a Goerz 9.5" Celor lens. The bellows are in good shape and are light-tight.

Included were three Century double-sided wooden plate holders. They are in very good shape and are light-tight EXCEPT for the dark-slide light traps.

I took out one of the light traps: it is held in place with three tiny wood screws. The black felt is frayed-looking. The felt is held in place under a spring assembly, which looks something like a double-sided brass comb; the comb teeth act as springs. The felt/comb-spring assembly is held to a small strip of wood with tiny finish nails. I'm afraid to pull the nails out of the ancient wood strip, as it is so fragile-looking.

I tried gingerly expanding the spring-comb assembly to put more pressure on the black felt, and reassembling it, but it still leaks light... A new piece of black felt the correct thickness would probably fix the problem, but I'm uneasy about more dis-assembly...

If I can fix the light traps, I'm going to try to take a 5x7" film sheath and attach it to a 6.5x8.5" insert, and hopefully use 5x7" sheet film in them.

Anyone have suggestions for rebuilding or replacing the old Century light traps? (Yes, I know custom "whole plate" film holders are now being made, but they cost more than the $270 I paid for my whole Century No. 2 outfit.) While the Century view does not have a lot of movements and is lightly constructed, I'd still like to get a little light use out of this old well-made beauty.

Thanks from Leigh in Santa Barbara, Calif.

[Michael Carter]

How did you figure out they were not light tight? I guess a print was fogged? I also have one of those cameras, but have not used it yet. Glass plates is what I intend to use. The glue is most likely water soluable; why not wet an end for a while and see if it comes loose?

[leighmarrin]

Michael, I've not run any film through the whole-plate Century view camera yet. I found that all three holders leak light by removing the lens, putting a holder without dark-slide in the spring-back, turning out the lights, and then put a small penlight stuck inside the camera and found all three holders leak at the light trap. The bellows, back, and other parts of the plate holders are otherwise light-tight, as far as I can tell. All three holders appear in good shape.

You mention glue: the light-traps are not glued in place. Instead the brass spring-comb and black felt strip are nailed with two tiny nails to a thin wooden strip. The tiny finish nails have small heads, and thus far I've not been brave enough to risk breaking the narrow/thin wooden strip by trying to pull them out.

--Leigh.

[Michael Carter]

That is a cleaver way to check for light leaks; I never thought to do that. Like you I put a flash light inside the bellows to look for leaks, while in my dark room. Now I must put the film holder on and try again.

I thought the felt was glued somewhere. Don't worry about the thin strip of wood. It often comes off of its own. The glue is so old and crystalized that it doesn't hold very well. They pop right off. Replacement glue to use is hyde glue or Rabbit Skin glue as for wood shops or artists canvas.

[RJ-]

Anyone have suggestions for rebuilding or replacing the old Century light traps? (Yes, I know custom "whole plate" film holders are now being made, but they cost more than the $270 I paid for my whole Century No. 2 outfit.) While the Century view does not have a lot of movements and is lightly constructed, I'd still like to get a little light use out of this old well-made beauty.
I took out one of the light traps: it is held in place with three tiny wood screws. The black felt is frayed-looking. The felt is held in place under a spring assembly, which looks something like a double-sided brass comb; the comb teeth act as springs. The felt/comb-spring assembly is held to a small strip of wood with tiny finish nails. I'm afraid to pull the nails out of the ancient wood strip, as it is so fragile-looking.

Hi Leigh,

Congratulations on joining the whole plate renaissance.

The construction of the Century whole plate holders are not very different from the Kodak Eastman types. If the whole plate holder is orientated in the vertical portrait format with the darkslide end at the top, here is one way to work through the restoration.

Image A: bilateral wood nailscrews which need to be retained on removing the upper plinth. The plinth is easier to pull apart with a Stanley knife slipped in between.

Image A1: Exposed Black Felt
Image A2: Black felt lifted with metal rod, exposing black card/paper light trap
Image A3: Reed bed system enclosed within black card/paper light trap exposed. This is clearly broken across the reed bed system
Image A4: Reed bed system, with individual fins moved. In the Kodak Eastman system, these fins are securely locked down into the septum. If you can avoid removing this and restore around the system, the repair is more likely to be successful.

Looking at the system as a whole, there is a black felt light trap (obvious) and a black paper baffle which encloses the reed bed of metal fins. This needs to be replaced for a more light proof trap. It may be possible to rely solely on the black felt light trap (this is the case with many 1930's smaller German plate type cameras). With the Kodak system, replacement of both the black felt and the black paper baffle is required to make a robust light seal. If you check the length of the metal reeds, and how far the paper baffle extends beyond the black felt trap, it should be evident that this function was important for the patency of the light trap.

Both materials are not difficult to source. The restoration of a vintage whole plate camera and its holders is a completely different path than working on imaging with a whole plate camera. I guess both can be rewarding, even if the former can be more frustrating compared to a contemporary whole plate format system.


Kind regards,

RJ

Whole Plate Column

[leighmarrin]

RJ, thanks very much for the info. My vertical Century holders look similar to the Kodak, but not quite identical. (And no black paper; just black felt and the metal comb/reed assembly.)

So if I understand right, I should not attempt to detach the metal comb/reed assembly, but instead cut off the exposed felt and glue on a new section of felt?

I admit to being very uneasy about removing the "plinth"... on mine each plinth also is held in place by two tiny finish nails; so I leave the nails in place but use a Stanley knife to remove the wooden plinth? I'd suspect that the 100 year-old glued wooden plinth is gonna break.. it's not very thick. Did you use steam or some weak solvent to loosen the old glue on yours?

--Leigh.

[RJ-]

So if I understand right, I should not attempt to detach the metal comb/reed assembly, but instead cut off the exposed felt and glue on a new section of felt?

Hi Leigh,

Yes, I think so. I'm more inclined to do minimal, rather than a more comprehensive, restoration. If there is a displacement of the metal bed from the flat septum, this will not introduce a light leak if there is a double baffle system; just less pressure against the black card.

Given that your Century whole plate holders have no black card baffle, it may be best to bend the metal reeds out for greater pressure against the new felt strip. The thickness of the felt will be more critical in preventing light leaks then - you may need to experiment to find a thickness which enables the darkslide to move in and out without forcing the plinth to come loose after resealing the assembly.

I'm afraid steam will probably warp the century old holders too much. If you can source Three Bond Acetyl Nitrite (Harris Performance stock the Three Bond range in the UK; in the USA you may need to check out a craft or tool stockist) which is effectively a glue remover, it is easier to use this to prime the plinth before lift-off. The small set screws will come out smooth if the plinth is then gently eased off with a flat metal screw driver

Kind regards,

RJ

Whole Plate Column