Eastman Empire State back hinged flap thingy?

[Scott --]

Hi, all -

Picked up a whole plate Eastman Empire State #2 recently. Just noticed it's got this elaborate little hinged flap thing integral to the back. I've never seen one - anyone know what it is? Here's a video of it (http://www.youtube.com/watch?v=7pTss0xScXI).

Scott

[Steven Tribe]

Nice short video!
The only thing I can think of is a format changing (reducing) mask release system. You need hard cardboard cutouts. There may be a slot on the opposing side. A patentable alternative to making ugly and less effective ink marks on the GG.

[Louis Pacilla]

Some type of light seal as you insert a holder? That seems to make the most sense . At least to me.

[Scott --]

Louis, it seems like a light seal, as it's on the holder-insertion end, and flips down when the holder is inserted. It does mask off a small part of the frame, but not enough to be a mask. If it is a light trap device, I'm just wondering why - I can't see any purpose for it... :confused:

Steven, I'll check and see if there're any other slots milled in the holder. It's upstairs right now, and after shoveling the drive five times in the last 24 hours, and just getting back from sledding, well, I just don't feel like going up the stairs right now... :p

[Steven Tribe]

At last we have a break in our snowfall - I saw that the worst cold area had moved to N.America!

[Scott --]

Okay, looked again and there are no other slots or any other mask-holding accoutrement milled in the back. Looks just to be a light seal, but in use you lose about 3/8" of the frame. Makes no sense to me... :confused:

[Scott --]

May've figured this out...

There's no groove in the back for the riblock on a holder. The flap thingy acts as a light trap and catches the riblock. You have to keep a finger on the film holder when withdrawing a darkslide since there's no locking action with the riblock, but even with a bright flashlight in a dark room, I can't find any light leaking around the holder anywhere...

[Michael Carter]

I have a whole plate sized back with a device like you described on it. It has a date of 1902. No camera, just the back.

[Jim Graves]

Is the flap just on one side ... if so, which side?

[Michael Carter]

It must be the insert side, it is just on one side; it is the side that has a groove for the thumb to pull it out so a holder may be inserted. Therefore it flaps inwards. If a holder were to be inserted from the other side it would hit a flat wall.