Bronica SQ shutter issue

Hello everyone,

First post from a fairly new member here! After a first foray into 35mm film this year, I've recently taken the plunge into medium format. I now have an SQ which seems to function just fine except for one issue (I haven't run film through yet so let's hope it's the ONLY issue.)

I've tested the speeds with the battery in and they all work accurately except for 1/500. From what I understand, the shutter is mechanically controlled at that speed which can be an emergency function in case the battery dies. When I fire the shutter at 1/500, the shutter sometimes has a 1 sec delay in closing or is stuck open altogether (this happens with and without the battery in.) When I do have the battery in and I fire at 1/500, the mirror flips up and the battery light comes on indicating that the shutter has not closed. This doesn't go away until I cock the winding lever and reset the mirror.

My question is whether or not this is an issue with the lens or the body. The fact that all other speeds (electronically-controlled) operate correctly makes me assume there is nothing wrong with the contacts between the lens and the body; but I could be wrong. Could this be a sticky shutter issue?

Any help is greatly appreciated!

There is a complex series of interactions between the mechanical works within the body (interlocks, the reflex mirror, the lever connecting to the lens) and the lens (the shutter, the lever).
I strongly urge that your find another Bronica S or PS lens to mount on the body, and try the 1/500 shutter with it.

1. If the shutter acts up on the borrowed lens, too, I would send your body with your lens to a shop for adjustment
2. If the shutter does not act up with the borrowed lens, you know your body is OK and you need to send the lens only to a shop

In fact, two decades ago I have seen an interaction between body and film magazine (purchased used) which cause the lens to not fire properly with film loaded (no film multiexposure was OK!)...I had to send them both in -- without lens -- for adjustment of the back!

Those were my thoughts as well.

Unfortunately, Bronica anything is hard to come by in brick and mortar stores so I've just had to buy another lens from eBay to run the test. I did try firing the 1/500 shutter without the back attached and it did the same thing (I never would expect the problem you just described!) Hopefully the different lens will act accordingly.

The interaction including the back, which I experienced in the days before Tamron purchased Bronica, was that a loaded film magazine had the 'film advanced' interlock pin intrude just a bit too far into the body. That result in -- sometimes -- the reflex mirror would flip upward when the shutter button was pressed, but it would not flip upward all the way to allow the lens lever to actuate the lens shutter (so no shutter open/close LED in the viewfinder). The camera looked like it fired, but you had to focus your attention of the shutter firing LED in the viewfinder to see if the shutter actually opened and closed again. The fix was for Bronica service to merely file the interlock pin shorter by a bit, in the used back which I had purchased.

It took me a while to figure out which back was responsible for the intermittent shutter operation and blank shots on certain rolls, as I had a number of different backs for quick reload during wedding coverage. Fortunately I discovered the blank shots while on holiday, so I never lost any wedding photos due to the malfunction of a back.