Ever since I got into photography in the late 1970s I’ve wanted a medium format film camera. More specifically, I wanted a Hasselblad, the iconic studio camera of the era. I really knew little about medium format, but was intrigued. Well, over thirty years later, I now own a medium format camera.
At first, inspired by my friend’s vintage Pentax 6×7, I was looking for a either a Pentax 67 or Mamiya RZ67 camera. Then this 6 x 4.5 medium format Mamiya 645 Pro TL came into my radar. I liked the bang-for-buck I was hearing about, particularly the sharpness of the lenses that are very affordable. I liked the idea of a prism with built in metering without emptying the wallet. The more I looked, the more I was convinced that a Mamiya 645 would satisfy the craving.
I found this on eBay, a package deal consisting of Mamiya 645 Pro TL with power winder, one 120 back, a 220 cassette, and the ‘kit’ lens, a reasonably fast f2.8 80mm lens. The camera is in superb condition and everything functions correctly.. well almost everything. The achilles heel of this camera is its mirror stop. And in this case, the mirror stop arrived broken. The spring was floating around inside the camera, and the heel of the mirror stop was missing, an indication that it was broken before it was shipped. The seller was apologetic and I set out googling what I could on the topic.
I stumbled upon a thread on Flickr about this very issue and how common it was. One enterprising Mamiya owner took matters into his own hands and built a replacement part out of metal. I tried to find the part for sale online at at our local camera repair center, but no luck. So, following the lead of the handy Mamiya owner on Flickr, I fashioned a replacement mirror stop out of modeller’s brass sheets and tubes and used a soldering iron and solder to ‘glue’ the parts together. My Dremel tool did the filing and riffling to arrive at a satisfactory replica. The problem was the factory spring would not sit in place on my new part. the problem was my adjustment screw fashioned from tiny bolts and nuts from the modelling store was too big. So, again, following the lead of the handy Flickr member, I used a portion of a tubular spring from a pen. It worked.
The next task was to ensure the mirror was adjusted correctly. To achieve this, again, the Internet pointed me to a process I could handle. I first sanded a pane of glass from a 3×5 picture frame using fine emery cloth. This created a focus screen of sorts. And I’d place this at the focal plane of the camera. Then, using a tripod and a focus test poster, I used a magnifying glass to view the finder prism while focussing the lens. With it sharp looking, I compared the sharpness to the fashioned focus screen taped onto the back of the camera at a measured distance off the back to sit at the focal plane. There is no markings on the film back to know where this is, so I used verniers to measure. After a few adjustments of my mirror stop screw I had arrived at reasonable looking sharpness on both the makeshift focus screen and the primary focus screen (viewed with the prism removed).
Shortly after purchasing the camera, I tracked down the 150mm f3.5 portrait lens and a second film back. I now have a roll of FujiPro 400 film in one back, and a roll of Ilford HP5+ 400 ISO in the other. I’ll develop the rolls myself, the colour being my first venture into DIY colour developing using the Unicolor kit.
I have taken a single roll of film since the repair and the results seem encouraging. I am in the midst of another roll and will see how focus is with it, before considering success. The home made mirror stop is working flawlessly, and so at least that problem seems solved.