RB67 Pro-S Darkslide Exposure Prevention

[joey]

I've lost quite a few shots on my RB67 (Pro-S model) because of

leaving the darkslide in the back. Supposedly, the RB isn't supposed

to fire unless the darkslide has been removed--hence the little pin

mechanism in the rotating back. However, on my camera, the piece

doesn't come all the way out of the body to push the pin when the

shutter is pressed (those with RB's will know what I am referring to;

it's on the rear bottom right corner). On the back (I am using

original RB 120 backs, not Pro-S), the pin won't push in when the

darkslide is in the back, but it moves without resistance when the

darkslide is removed.

 

So, the body can't tell when the darkslide is in, and the shutter can

be pressed anytime. Has anybody else had this problem? And if

something is broken or mechanically wrong, how much do you think it

would cost to fix?

 

Thanks for your responses.

[skygzr]

Hi Joey -

 

All the RB backs and cameras are interchangable, but you sometimes give up function when you mix-n-match. Is it possible that the original 120 backs don't enable double-exposure prevention on the Pro-S body? Seems like I used to have a document that discussed this very issue. I'll take a look.

[joey]

Hi Kevin,

Thanks for your response. Actually, I'm talking about accidentally pressing the shutter with the darkslide in, not double-exposure (you're right that only Pro-S and above backs support double exposure prevention). The Pro-S body shouldn't let you release the shutter with the darkslide in the camera, regardless of the model of the back (somebody please correct me if I'm wrong).

[bill_dewberry]

You're wrong, its a feature of a pro s BACK.

[hkbmac]

You need a Pro-S back in order to prevent this from happening. I have one original back that drives me insane... The extra functionality of the newer models are totally worth the extra price.

<BR><BR>Brian<BR>

<a href="http://bmacphoto.com">http://bmacphoto.com</a>

[jonathan_ratzlaff]

The darkslide should have a tab that engages the stop when it is all the way in. I have an original RB and this feature does work even in the original back, so it would seem that there is something wrong with the camera, back or your dark slide.

[joey]

I don't think the problem is the back. When the darkslide is in, the pin on the rotating back is held in place just like it would be in any other back. (In fact, you can try this out for yourself. Take off the rotating back, and look for the the pin in the front bottom right corner. With no back or a back without a darkslide, this pin can be pushed freely--which is what the body is supposed to do. However, when the darkslide is in, a little tab is pushed on the rotating back which prevents the pin from moving [you can press this tab with your finger if you don't have a back attached]. Everything there is working properly, so that's why I think the body is the culprit.)

 

It would be a great help if somebody could check how the body is supposed to work with this pin. Thanks!

[ed farmer - mount laurel,]

The <A HREF="http://www.mamiya.com">Mamiya</A> website has a its own user forum. This is monitored by Mamiya personel and is a great source of information such as this.

[joey]

Hi Everybody,

Here's a follow-up post for anybody that's interested. As I suspected, the problem wasn't the film back. I just replaced my RB body (the mirror cracked), and the new Pro-S came with a Pro-S rotating back adapter. My old RB67 Pro-S had the original rotating adapter on it, which didn't support the darkslide exposure prevention system. Now that I've got the newer body, the 120 backs (original) work fine with the lock system.

 

Thanks!