This is anEnsign Autorange 20 by Houghton-Butcher. A folding medium format roll film camera from the 1930's. It is equipped with a 100mm F1:4.5 Ensar Anastigmat in a 'Mulchro' shutter. Serial no. H23908, probably from the late 1930's

When I bought it, the shutter was sticking and the lens was cloudy. Also the rangefinder was filthy and the door wouldnt close properly.

The lens cleaned up easily - someone had squirted light oil into the shutter and this had got onto the lenses. The glass is now clear and showing only a few light cleaning marks.

The self cocking "mulchro" shutter was another story. Its a crude design and relies on the rather soft brass parts to keep their shape with some accuracy. There are several pawls which run up ramps to catch and they are quite worn. Also the B/T mechanism requires undue precision from some of the levers and wear and tear has made this unreliable. Worst of all the main pinion that engages the segment arm of the timing mechanism is well worn and didn't always stay engaged with the segment arm.

Basically the shutter is worn out. In the past some of the arms have been bent with pliers to make up for worn out pawls. In doing so the slow times got shortened and this had to be sorted out by very careful bending of some of the internal levers to return them to their intended travel. There is no gear train mechanism like a compur just a rather odd star wheel escapement and a lever with a gear segment.

I managed to sort out most of its trobles, but the B/T mechanism is beyond help. B is OK but T is unreliable and sometimes the shutter closes immediately. After using B or T you must turn the shutter to 1/100th and back to release the timing mechanism. Still it works well enough for me to put a film in this weekend.

One odd thing with this camera is that it has rise and cross slide movements (about 12mm each - see right..). This is puzzling as the lens - a triplet, like a cooke lens - ought to only barely cover the 6x9 film format. Also because this is a roll film camera, there is no way to see what the effect of the rise/slide is. Both the 'brilliant' finder and the main finder on the body are unaffected by the movements.

The focussing is by the chrome lever visible at the front left of the bed in the photos. This swings out to slide the lens bed along - no front cell focussing! There is a lever arm that couples the bed to the rangefinder. Inside the rangefinder there are two adjustments to control the near/far points. Unfortunately the rangefinder is a seperate window to the viewfinder so you have to focus; then move over to frame. The viewfinder has a lever for a 6x4.5 mask - but of course the film plate mask is missing so I am stuck with 6x9.

Now that its ready for some film, maybe I will find out if the somewhat excessive efforts on the shutter were worth the trouble....