sinar norma felt light trap

[steve barry]

i just took receipt of my new 5x7 sinar norma last night. there is a felt material in the dados of all the metal grooves (where lens boards/bellows/etc. connect). the felt is very old and disintegrating.

my questions:
A)was this from the factory or put there by old owner and
B)is the felt redundant? as sinar uses metal channels for light traps (i thought).
C)would you replace it?

thank you

steve barry

[Stan. L-B]

Hello Steve.

I have a number of Sinar cameras but not the Norma.
None of my Sinars use felt a light traps, as you mention it is the metal channels alone that trap the light on all surfaces.
My models range from the Original P1 5X4 and 8X10 to the P2s and the F1 and F2.
Never had any problem with light proof ingegrity. Hope this inspires your confidence,
congratulations on your choice of camera.

[steve barry]

thanks Stan - I was thinking maybe a previous owner was paranoid about light leaks and put the felt there....or sinar put them there due to irregularities in the machining of the channels. everything seems to fit together nicely, nothing bent no warps, etc. so im not sure, i just ran into a brick wall searching here and the internet for felt light traps on a sinar and/or sinar norma.

[Struan Gray]

My 5x7 Norma also has a compliant black material in the light traps. In my case it looks like blackened string. Bits of mine are missing and I've not had any problems (the reentrant design of the light trap should be sufficient), but I've not used the 5x7 conversion enough to be sure.

Micro-Tools sell self-adhesive sealing foam strips that would be easy enough to bed down into the grooves. Were I using my camera a lot, I'd probably re-line the light traps just to be on the safe side.

[Mark Woods]

Yes, I just checked my 5x7 (and I just rehabed my 8x10 Back) and they both have what appears as a rubber gasket that the Graflok style back mates with. Struan's suggestion is a good one. My gaskets are in good shape. ;-)