|Working on a Topcon 35-L
by John Shriver
Comments on the camera
Very well built, solid as a tank. Sturdy cocking and film winding mechanism. Nice Seikosha-MXL shutter, speeds from 1/500 to 1, plus B. Double-stroke winding like the early M3, like Leitz they claim this prevents tearing the sprocket holes. It certainly would have been trivial to change the gear ratios for single-stroke winding.
The 1:1 viewfinder is bright, with a good reflected Albada frameline having automatic parallax correction. The rangefinder image isn't super-bright, although my moving mirror is less than pristine. The semi-silvered mirror between the prisms looks as good as new.
The original 35-L cameras have a true Albada viewfinder, where the last units have a modified version. The early ones have the full curved interior surface of the finder semi-silvered. This costs one stop in light, and only reflects the frame line with a half-silvered mirror. These are obvious because the finder looks very reflective from the front (like mirrored sunglasses).
The last 35-L cameras uses a different design where only the edges of the curved interior surface are silvered, but they are fully silvered (100% reflectance, no transmission). This has the benefit of making the overall view one stop brighter, and the reflected frameline brighter as well. But it crimps the field of view of the finder, acting as a front mask, leaving minimal eye relief. This version, at least, is not for eyeglass wearers. You can tell it by a white border around the viewfinder from the front, with no mirrored look.
The shutter is very quiet. Winding the film ends with a "plonk" when the segment gear for cocking the shutter springs back. It lands on a rubber pad, but it's still the loudest noise the camera makes.
The Topcon 35-S is the same camera, but without EV coupling, and thus with a Seikosha-MX shutter. (The MXL version added equally spaced shutter speed detents.) The 35-S could be more convenient to use in many cases. The shutter speed ring is to the front, and the aperture ring behind it. All 35-S's, being earlier, probably have the full reflector for the Albada finder, so the frameline is probably brighter, but the overall viewfinder view is probably one stop dimmer.
Working on the lens and shutter
Start by removing the front group, it unscrews using rubber gloves or a stopper. Behind it is a thin cover ring, lift it out.
That exposes the three screws that hold on the filter ring and exposure value scales. Remove the screws, and lift off the ring. See that it has separate pegs to connect to the aperture and shutter speed settings of the shutter.
Now there is an aluminum cage around the front of the lens, held in by four brass flat-head screws on the sides. Remove them, and pull out the cage.
Now turn to the back of the camera. Remove the rear group using a spanner wrench in the outer slots. Tease it out through the film frame, you'll have to tip it horizontally.
This exposes another larger spanner ring, which holds the shutter onto the camera. Unscrew it, and off comes the shutter, probably with some paper spacing rings under it.
Now you can open the shutter in the conventional way. Turn the small spanner head screw half a turn to unlock the front plate, and turn it CCW until it unlatches. Remove it and the shutter speed ring.
You probably went in here to clean the shutter blades. First, take note of how they are overlapped.
You will need to remove the flash sync contact (two screws), and then you can remove the back of the shutter (three black screws, note that one is a different length).
The shutter blades will fall out when you split the shutter. To put them back, the easiest thing is to set the shutter to hold them open. Easiest way is to remove all the spring tension on the actuating lever on the front. The spring is easy to pop around, you'll have to be very careful lifting the flash contact over the peg.
Quite a few more common cameras use the Seikosha-MXL shutter, so you can cannibalize them for parts. Most of the Aires 35-III cameras use the same shutter, as does the Ricoh 500 and some Mamiya-Sekor cameras.
You probably need to touch up the black paint on the edges of the glass inside the shutter.
Removing the top plate
The tricky part is taking off the collar that holds the exposure counter dial. It's quite tight, and has two very small spanner notches. I doubt that any general-purpose adjustable spanner wrench can remove it without damage. (I started with a spanner made from a hacksaw blade, Thomosy-style, and it was not sufficient.) So I made a special wrench by grinding down the end of a peice of 7/16" stainless steel tubing (K&S brand, from a good hardware store), and loosened it beforehand by dribbling on some Naptha and letting it sit. It unscrews CCW, normal right-hand threads.
Remove the counter dial and spring. Now remove the three screws that hold the top ring in place. It will come off, along with a wavy spring ring, and the cocking lever.
The film reminder is held in place by a spanner-head screw, right-handed. Remove the screw, disk, and spring disk.
The rewind knob is threaded onto the levitating aluminum shaft. Block the fork in the camera, and turn CCW. Careful, both are aluminum.
Remove the eyepeice -- two screws.
Now remove the RF adjustment cover on the front of the camera, using smooth jaw pliers. Remove the two screws on the end of the camera. Lift off the top cover.
The RF mirror pivots on a pair of about 3mm steel balls, very elegant, low friction. Rough vertical rangefinder alignment is done by loosening the screws that hold the top spring steel plate. You probably want to just leave this alone.
Fine vertical alignment is done by loosening the two screws holding the rangefinder window, and rotating it using the knurling at the edge.
Horizontal alignment is done in the standard way through the hole next to the viewfinder window.
The sliding glass with the frameline is held by the two screws with glue on the back. Note the present position before removing them. It is also caught under a strong spring on the right. You can loosen the pivot of that spring without removing it, that helps.
I was extremely gentle cleaning the frameline side of that glass. Don't want to erase it.
The viewfinder is one cemented block of two prisms, two lenses, and a side port for the rangefinder path.
Not much need to go in here. The solid brass gears run dry. Unscrew the rewind button CCW. Remove four screws, and lift off plate. Be aware that the tripod socket is loose, as is a brass ring around the rewind button shaft.
Note that the gear around the sprocket shaft (where the rewind button was) can slide away from the camera, disengage from the other gears, and get out of sync. The bottom part of this gear has a cam that releases the segment gear that cocks the shutter.
The only place I saw any need for lube was a little grease on the peg of the cocking ring pushed by the segment gear. I suppose the pivots of the gears deserve the tiniest bit of light oil, but clearly the gear teeth run dry.
I don't know which way the gear on the bottom of the wind shaft unscrews. Intuition tells me that it should be left-handed, otherwise every swing of the wind lever would try and loosen it. None of the threads are exposed to see.
The only reason you would need to do this is to lubricate the focusing helical, or to adjust the infinity stop. Nominally, the infinity stop is adjusted by rotating the outer focusing collar with relation to the focusing mechanism within. If you remove the focusing knob (two screws), you will see that is on top of an oblong slot over threads. The problem is that these threads may be frozen. You'll have to tear things down pretty far to get to those threads and soak them loose.
Remove the two screws holding the focusing knob.
Unhook the spring for the shutter actuating lever from it's stationary post. Remove the four brass screws. Lift off this unit, which holds the depth of focus scale and shutter speeds, along with the shutter actuating lever.
Loosen the three set-screws holding the aluminum collar to the brass focusing tube. Make reference marks. Unscrew the aluminum collar.
Four brass screws are now visible that hold the focusing ring to the moving threads of the helical. Make reference marks, and remove those screws. Lift off the focusing ring.
Now you can use naptha soak that tan goo that was once lube (or maybe glue?) in the threads between the inner and outer rings of the focusing collar. Take note of how far in the inner ring is screwed. (The two screw holes for the focusing knob serve as your index mark.) When they come loose, unscrew the inner ring out the back. Clean out the gunk. Put on a bit of grease, else the threads will seize up. Reassemble except for the focusing knob.
To collimate, mount the focusing knob loosely. Set the focusing scale on infinity, arrange your favorite collimator, and use the focusing knob to focus for infinity. Tighten the two screws on the focusing knob securely.
If there isn't enough range for collimation, you'll have to change the orientation of the four screws that hold the inner focusing ring to the moving part of the helical. That's a lot of disassembly, sorry.