Experience with RB-SD film back?

[tkamiya]

I've been having so much trouble getting a good back for my RB-SD.

I have one 6x8 power back (SD style) that has zero light leaks. Over in a span of about a year, I bought S back and SD back, non-power variety from a used source and all had some type of a light leak. I was a bit surprised even an SD type had a leak as I heard (and saw) it uses mechanical light trap rather than foam. Upon close inspection, I did see a use of some foam in hinge area though.

Is this a common experience?? I'd like to have a few back but so far, I'm stuck with just one.

 

[Shawn Dougherty]

I have two SD backs that I use on my Pro S and both of them are light tight. I bought them (used) because of the mechanical light traps you mentioned.

Have you ruled out the rotating back? Does the 6x8 power back mount in such a way as to cover a possible problem with the rotating mechanism that the smaller film backs do not? (Just a thought as I have no experience with the 6x8 back.)

Good luck getting it figured out!
Shawn

 

[tkamiya]

Yup, I ruled out everything else.

1) Each leaking back had different pattern of leaks
2) Power back is leak free

As far as attachment goes, power backs are identical to all other backs.

 

[Shawn Dougherty]

Yup, I ruled out everything else.

1) Each leaking back had different pattern of leaks
2) Power back is leak free

As far as attachment goes, power backs are identical to all other backs.

That sucks. I replaced the seals in a Pro S Back before realizing it had been dented and leaked light anyway... Both my SD backs have been golden. I bought one in Ex+ condition from KEH and one from an APUG member that was really clean.

Hope you find some answers here... and a good back!

Best
Shawn

 

[Buje]

I had a Pro-S back that leaked until I tightened the 11 very tiny screws on the aperture plate (facing the camera body).