Foam Light Seals necessary?

PGraham3 · Mar 17, 2018

Howdy, APUG!
The other day I picked up a Nikon FG to give to one of my students. The light seals were pretty gumy and falling apart, so I scraped off a good portion of it all. I have never worried about the foam seals much when giving cameras like this to students until a friend mentioned the importance of them. I had new ones installed in my Nikon F3 some years ago, and was told by several folks that they were not necessary, Anyway, the FG’s film door locks in very tight and snug, and I suppose the best the way ascertain if I need to install foam light seals is to run a test roll.
However, do you think they are necessary for Nikons like this?

shutterfinger · Mar 17, 2018

Light will pipe around turns and curves in camera backs. Certain angles of light to the camera will get through to the film while others will not. The light that does get through may not be noticed unless using ISO 400 or faster film.

PGraham3 · Mar 17, 2018

Thanks, @shutterfinger
My students mostly use ISO 100/200 color film. So essentially, not really a problem if film door closes nice and snug?

-Paul

faberryman · Mar 17, 2018

My feeling is that the manufacturer installed the foam seals for a reason, and if you want to assure yourself against light leaks, you should replace them. They are inexpensive and easy to install.

WilmarcoImaging · Mar 17, 2018

Answer: it depends. Some cameras are sensitive to light seal presence/quality and others aren't. The decision is made by experience and your/the students' judgment.

shutterfinger · Mar 17, 2018

PGraham3 said:
My students mostly use ISO 100/200 color film. So essentially, not really a problem if film door closes nice and snug?

Depends totally on the intensity of the light source and its angle to the camera back.
How are you going to determine if its the missing light seals or light entering the eyepiece that fogged the film, guess?

mdarnton · Mar 17, 2018

I have replaced FG seals with soft adhesive felt (they also have a hard type that doesn't compress well) from Dick Blick. The one seal that doesn't work well for this is the one next to the hinge (maybe a narrower strip than what they used, farther from the hinge would be a good idea). For the channels, the felt was fine, though. I remember someone mentioning black yarn would also work, but you'd need some small amount of some adhesive.

I don't know if they're necessary, but Nikon seemed to think so. Certainly my Leicas seem to have a lot less light trapping than the FG.

Sirius Glass · Mar 17, 2018

faberryman said:
My feeling is that the manufacturer installed the foam seals for a reason, and if you want to assure yourself against light leaks, you should replace them. They are inexpensive and easy to install.

+1

jtk · Mar 17, 2018

mdarnton said:
I have replaced FG seals with soft adhesive felt (they also have a hard type that doesn't compress well) from Dick Blick. The one seal that doesn't work well for this is the one next to the hinge (maybe a narrower strip than what they used, farther from the hinge would be a good idea). For the channels, the felt was fine, though. I remember someone mentioning black yarn would also work, but you'd need some small amount of some adhesive.

I don't know if they're necessary, but Nikon seemed to think so. Certainly my Leicas seem to have a lot less light trapping than the FG.

You probably don't want felt or yarn (!) unless you like lint from wear accumulating on your film. Probably.

Svenedin · Mar 17, 2018

I don't know about your Nikon but they are definitely essential to my Olympus OM cameras. I had deteriorating light seals and intermittent light leaks until I replaced the seals. Good frames and bad frames. The most critical in the case of my OM cameras is near the hinge.

shutterfinger · Mar 17, 2018

Black velvet and yarn were the go to seals until foam came along. Do not use the fuzzy yarn. Velvet is getting difficult to acquire.

The film door closing nice and snug means the hinge and latch are not worn or out of alignment.
For the door to be light tight without any type of extra seal the lip of the door must be the same as the depth of the recess in the body so that there is zero clearance when the door is closed with pressure being put on the door or body.
I doubt any camera mentioned in this thread meets that requirement.

John Koehrer · Mar 17, 2018

velvet ribbon is stocked at JoAnn fabrics.
Use the foam or you're going to post a "why is my film fogged" thread sooner rather than later.

shutterfinger · Mar 17, 2018

John Koehrer said:
velvet ribbon is stocked at JoAnn fabrics.

According to the web site but I could not find any at the store closest to me that showed to have it in stock.

Scott Micciche · Mar 24, 2018

Foam also prevents excess dust from entering the camera.

E. von Hoegh · Mar 24, 2018

jtk said:
You probably don't want felt or yarn (!) unless you like lint from wear accumulating on your film. Probably.

Felt and yarn were used before foam was available. I replace foam light seals with yarn and velvet, and foam mirror buffers with felt. I have no problems with lint, the oldest is a Nikon F done in '98.

E. von Hoegh · Mar 24, 2018

Scott Micciche said:
Foam also prevents excess dust from entering the camera.

Yes. Sover Wong states that an F2 is light tight without foam, but not dustproof.

jim10219 · Mar 24, 2018

I bought some adhesive backed sheets of closed cell foam, open cell foam, and velvet in various thicknesses from eBay a while back. I use a paper cutter to cut them down to the appropriate widths. With a little bit of naphtha and some toothpicks, it doesn’t take too long to replace the seals on a camera. Plus, all of the stuff cost me probably $40. So far, I’ve done probably 30 cameras and film backs and have enough left over to do another 50. That makes it a very economical way to deal with that problem. So no matter if the light seal is needed or not, I’ll replace it because it only costs me an hour after dinner to do one. It’s really the way to go if you buy a lot of used cameras.

Kodachromeguy · Mar 24, 2018

Temporary repair: If you do not have time to replace the foam and felt (and you really should do it!), tape the hinge and seams with electrical tape after you load film. That will keep out light and dust. A roll of black electrical tape is cheap. Use the 3M brand and it will come off clean. I once nursed a beater Nikkormat all through Costa Rica that way and it was fine, not a hint of a light leak.

Alan Gales · Mar 25, 2018

I used to own an original Mamiya RZ67. It's film back had light seals. The later backs for the RZ67 pro ll and pro llD were designed differently and did not require light seals. All backs worked on my camera so I added a couple later film backs.

Your camera was designed to use light seals. They are there for a reason so I'd replace them.

Foam Light Seals necessary?

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