Bronica SQ-A Extension Tubes

[mkiernan]

I have purchased a S-36 Extension tube for an SQ-A on E-Bay. I have used 2 rolls of film with little success. The first was grossly over-exposed (developed as black). The second was exposed normally, but the focus was well out. I focused as normally using the view-finder surround image (the split screen center was just black). I am hoping that there is some trick to focusing that I am just not yet aware of. Being an E-Bay purchase I don't have access to a manual. Is someone able to direct me to some information so that I can sort out these problems without wasting too much film?

Much appreciated.

 

[glbeas]

You need to figure in your bellows factor for the increased extension which for an 80mm is about a stop if you are metering handheld. You should be focusing wide open, if the lens is not doing that there may be a problem with the mechanical coupling. The overexposure may be due to a bad coupler too, not shutting down for the exposure. Get it checked by a competent repairman.