Topcon Super RE - Light Meter Help

Update: I've brought the camera to a repair shop. It had the Zeiss lens attached, they told me that they cannot test the functions of the light meter without a Topcon RE lens. That seems puzzling to me, since the light meter should be reacting regardless of which, if any, lens is attached! Can anyone shed any light on that situation? Specifically those of you who have Topcon Super REs or Super Ds...

I have a Zeiss Jena Pancolar "double zebra" very similar to your Tessar, and I put it on my Super D and then just to be sure tested it again on my RE-2. The results are:

 

- The meter would not react to changes in aperture in the TTL mode, because there is no linkage to tell it what aperture you have selected.

 

- The meter would however react, and provide credible results to changes in speed - with the aperture "fixed" at max. value.

 

- The meter would react to changes in aperture in the stop-down mode (when practicable).

Ooooops... The above should read, "the meter would not react to changes in aperture in the TTL full- aperture mode, because..."

 

It thus would seem to me that it is possible to repair/adjust the meter even with your Zeiss lens.

What do you mean by "TLL full-aperature mode" and also "stop-down mode" (in specific relation to the Super RE)? I know of these terms but I want to make sure we're on the same page.

 

And yes, I thought that it should be no problem to test the light meter with any exakta lens! Unless someone can prove otherwise.

Edited December 14, 2017 by stevenenglund

Full aperture metering means, that where you turn the aperture ring on the lens, the iris will not open or close corresponding to the values you have selected; this will only happen when pressing the shutter, and until that moment the lens will remain at full aperture. However a link between the lens and the camera will tell the meter the selected aperture, and it will calculate the appropriate speed accordingly. This is possible with a Topcor lens but not for other Lenses in Exacta mount, because these have no link to the meter.

 

You can meter in stop down mode with you camera in two ways:

 

- by metering while depressing the DOF button, which will close the Iris at the selected value;

 

- or, by using the button on your lens that will block the preset function, function, so that the Iris will open or close following the ring.

...and the saga continues...

 

I brought my Topcon to a shop in reputable Portland, "Blue Moon Camera & Machine." However the said they would decline attempting to fix the light-meter and couldn't recommend a local shop who could help. I did buy the Topcor 50mm f1.8 even though my body still isn't fully functional. It's a smooth lens and I'm looking forward to snapping with it. Then I was able to play with a Super D they had for sale that did have a working light-meter, and it was fun to see the needle actually react to changes in light or settings.

 

At this point (after the holidays) I might try to disassemble the body based on the service manual, and see if there are any obvious reasons why my needle won't budge. Then I'll go from there. Happy Holidays everyone!

 

Oh and @bonsignore_ezio thanks for the info about the metering modes. It should be noted though that the camera can in fact be tested for a light-meter's reaction to light regardless of what lens is on the body. If there's a working battery, and a working light-meter, the Topcon needle should move as you point the camera around at various lighting situations.

You can make the retaining screw for the shutter speed dial out of any reasonably long metric M1.4 screw, after filing the tip to conical shape.

 

A lens spanner will help remove the ring around the PC terminal. You will need some 1/16" (or thicker) sheet brass or aluminum and a jeweler's saw to make a ring wrench to remove the disc on top of the film wind lever. You could also make a custom spanner wrench for the PC terminal from the sheet brass.

 

A set of small JIS cross-point screwdrivers are recommended for the screws.

 

A Topcor lens is not required to calibrate the meter, since it works perfectly fine with non-meter-coupled lenses. All you really need to do is prove that the aperture coupler for the lens properly moves the chains.

Thank you for the tips John. How in depth does the camera dismantling have to get, in order to see if the aperture coupler is moving the chains? Or... to see if the black bland is blocking the exposure needle?

 

From what I can research, I'll have to remove the top left cover plate and the top right cover plate. It looks like I won't have to remove the bottom cover plate.

Steven, here's what I found under the covers of my "doner" body which turned out to have a non-working meter. "Brace yourself", as they say here in Australia ;-)

Regards,

Rif

 

It should not be necessary to remove the top right or front cover plate to work on the meter. The top left, as in the picture above, should be enough. I think that's also enough to check every wire, resistor, and the CdS cell with an ohmmeter. (You really want to have an ohmmeter.)

 

If the wires to the CdS cell in the mirror have broken, it's a huge teardown, and no parts available anyway.

 

In the picture above, the chain that goes to the aperture feeler and the shutter speed/ASA dial "computes" the EV. The chain that is dangling normally has a pulley on the end, which the "computing" chain loops around. That chain is the one that rotates the meter body.

 

The chains are very durable, highly unlikely to fail.

 

Since the meter has to rotate, the two electrical connections to it are one possible problem area. (One is to the camera body, which is "common".) But the most fragile thing on the meter is the windings, and their soldered connections at the end.

 

Your hope is that something is just mechanically stuck in the meter area, like the pointer being snagged on one of the stops.

Hello everybody,

sorry for necroing this thread... I'm a bit Topcon lover myself.

 

I got a very well preserved Super D with somehow misbehaving light meter. It underexposes the image by 2+EV (when comparing to a A7 or other Topcon bodies). First I thought it would be the battery - 1.35V vs 1.5V. Other bodies work fine with it. So this is not an issue.

 

Mechanically the exposimeter subsystem is perfect - chain links, default ranges, etc. Alignment tests results are OK according the repair guide.

 

In other words - the light meter needle suggests 1/125sec, f/2.8 with 100 ASA indoors. That's not correct.

 

My last suspect is the electronic part of the light meter. Connection wires seems to be soldered OK. So maybe when a 'serial' resistor loses its rated resistance it could lead to excessive current and thus resulting in greater than expected needle deviation. Thus it might worth a try to check resistance of the resistors.

 

Thanks

Some of the resistors were selected. I would be surprised if a resistor chaned value I'd suspect characteristic of CdS cell changed. Broken wire would be total failure.

 

But just follow the procedures in the service manual. Calibrate light source with another Super D, then follow instructions.

Some of the resistors were selected. I would be surprised if a resistor chaned value I'd suspect characteristic of CdS cell changed. Broken wire would be total failure.

 

But just follow the procedures in the service manual. Calibrate light source with another Super D, then follow instructions.

John, could you, please, elaborate on the "follow the procedures in the service manual" part?

 

The service manual contains a whole section called 'Exposure meter adjustments'. It also features a troubleshooting procedures and more. Which procedure described there you recommend as the easiest one?

 

Currently, that particular Super D body has top and front parts removed as per the service manual.

 

Thanks a lot

For future consideration, since you are handy enough to get inside your camera, once you solve your meter issues, see where you can mount a diode in series with the positive battery terminal to step the voltage of a standard 675 (1.5v) battery down to 1.37v. There is lots on the web about this. I modified my Nikon F's this way and the meter is fine with it.

For future consideration, since you are handy enough to get inside your camera, once you solve your meter issues, see where you can mount a diode in series with the positive battery terminal to step the voltage of a standard 675 (1.5v) battery down to 1.37v. There is lots on the web about this. I modified my Nikon F's this way and the meter is fine with it.

Thanks for the suggestion. I might do this if the meter gets fixed. By the way, any suggestions how to proceed on that matter?

^ Sorry I don't but I will say the chain managed meter function in your Topcon reminds me of the Zeiss Contarex system. They used cables and yes, even tough the meters were shot, just moving the shutter speed dial caused the meter to move - giving the erroneous indication the meter had life left in it. Wish I could help but I have no experience with your camera.

^ Sorry I don't but I will say the chain managed meter function in your Topcon reminds me of the Zeiss Contarex system. They used cables and yes, even tough the meters were shot, just moving the shutter speed dial caused the meter to move - giving the erroneous indication the meter had life left in it. Wish I could help but I have no experience with your camera.

Nice, I've never seen a real Contarex. I know they were known as mechanic marvels, but a nightmare to repair.

I've finally figured out how to adjust the light meter (in a very croase way). The light meter itself is rotated by a pulley chain gear which is rotated by the chain link subsystem. So you have to adjust the "gearing meshing" - rotate the meter a bit without rotating the gear.

 

Description in the service manual is a bit vague (section Exposure Meter Adjustments 2a and Fig. 3), so I made a schematic picture for anybody interested:

 

A first roll of film has been shot today using this particular Super D body. I'm eager to see whether the repair was successful.

Update: I've brought the camera to a repair shop. It had the Zeiss lens attached, they told me that they cannot test the functions of the light meter without a Topcon RE lens. That seems puzzling to me, since the light meter should be reacting regardless of which, if any, lens is attached! Can anyone shed any light on that situation? Specifically those of you who have Topcon Super REs or Super Ds...

You are correct, if the light meter works, it works without a lens attached. Make DARN sure the on -off switch is ON! if it still doesnt work removed the base3plate (easy) and remove the battery compartment, check the wiring under that (50%) certain the problem is there. The D'Arsonval meter on that RE Super is built like a tank, not likely the its bad. Dont forget the ASA wheel on the speed dial. Theres a carbon resistor pad under there and thats where I would go next for possible dirt, corosin, etc. Clen there, Regards, Don

I've finally figured out how to adjust the light meter (in a very croase way). The light meter itself is rotated by a pulley chain gear which is rotated by the chain link subsystem. So you have to adjust the "gearing meshing" - rotate the meter a bit without rotating the gear.

Description in the service manual is a bit vague (section Exposure Meter Adjustments 2a and Fig. 3), so I made a schematic picture for anybody interested:

A first roll of film has been shot today using this particular Super D body. I'm eager to see whether the repair was successful.

 

Yesterday I tried to take apart my Topcon yet again. I almost got to where you have yours in the image. However, there was a small plate above the gear, and it had a wire intricately threaded through it. Didn't seem easy to remove so I didn't mess with it.

 

I can confirm that my light meter works and reacts to a flash light through the lens, but the meter is not sensitive enough to react during normal light changes, such as pointing towards a window and then pointing towards a dark shadow. I'm thinking that it will work correctly if I can adjust the gear you mentioned.

 

How did your first roll ever turn out?

Can someone with a Topcon Super RE with a *VERIFIED & WORKING* light meter help me solve this problem... I'm more interested in fact than opinion.

 

The question to answer: When you remove the battery from your Super RE, does your light meter change if you adjust the shutter, ISO, and or aperture?

 

I purchased a Super RE and am trying the "hearing aid battery fix." But I've tried a couple different batteries now so I'm curious if my light-meter is simply broken. I turn the camera to On and nothing changes. The light meter does not move when I adjust anything. If I can verify the light meter does absolutely nothing without a battery, then I'll move on and try purchasing a Wein MRB625 1.35V Zinc-air.

 

Attached is an image of what my (in viewfinder) light-meter reading looks like. I've read page 16 of the manual and know that something is is not being displayed correctly.

 

[ATTACH=full]1222637[/ATTACH]

Don @ Eastwestphoto here-------------------------- A balanced bridge circuit works by equal current flow in the legs of the bridge, with a galvanometer from one side of the bridge to the other. At balance the galvanometer will null at Zero. Thus, The Topcon RE meter will be dead center. One response I read was correct, the Topcon RE Super circuit can accept from 1.6v~1.2v range in batteries. The meter will then be dead center in the two points viewed in the eyelevel prism. so here's the PROBLEM. Battery corrosion puts a resistance in the circuit. IF the battery compartment is clean, no bluish tint, its UNDER the battery compartment the fault. Remove base plate. Be careful of the on - off switch. I use two tiny brads with fine point held by a plier, screw counter clock-wise (easy). take the other screws off, but arrange in order as they are NOT the same length! Take the tripod one of also above the base-plate. set aside. Remove the 3 screws holding the battery compartment. Lift is out from under the back door release lever. Flip over, is it greenish? TROUBLE ahead. The back compartment needs to be very clean, and the center contact if greenish will be a resistance and needs to be re-soldered. Make sure the wire is not corroded. I use solder paste (SMD) and soldering iron, low wattage.. The on off switch is contact driven so make sure they are clean, congrats thats phase 1. Use a DVOM to test for Continuity or voltage around 1.35v, PASS ?, Put the assembly back together and TEST your meter. Works Great, FAILS, Phase 2

Phase 2= DANGER= ASA speed dial is a mechanical gearing , a chain and gears, dont mess with this as you need special tool to hold the spring tension of the chain. Left side top, view, remove rewind two screws in its cover below the rewind knob, Philips screw in back of cover, X-synch screw is a spanner type use those tiny brads again, and pry gently up till its free. From TOP left side is the meter, remember its a Galvanometer and can be tested by a diode test mode of your DVOM meter. Since its 0.7v output it will move the meter movement and you will see it and heard it. If the spring is broken, your dead! Then canalization required from another broken camera. Rutt Roe, Don

The skipping gear teeth on the meter is the coarse adjust. The fine adjust is that one of the bearings for those pullies on the far right of the picture is eccentric. Loosen set-screw on side, turn bearing in via slot.

A nasty to repair failure mode of the Super D meter circuit is for one of the wires connecting to the meter cell in the mirror breaking from metal fatigue.

The full service manual is online.

If there's no battery in the battery box, the needle will not move, regardless of  shutter speed or f stop changes. If the switch is moved to on,  and needle does not move the following is possible:

1. Corrosion under the battery box, dead short

2. Corrosion inside the wires under base plate

3. Bad chain drive to the balance bridge circuit variable resistor.

4. Bad ASA speed dial resistance. 

5. #1, #2  the most common,  it's been 50+ years.

The Super D has no variable resistors, not on the ASA dial, nor reading out aperture. The setting of the shutter speed and ASA mechanically controls one end of the chain, the other end of the chain is controlled by the relative stop-down of the lens. The chain does "math" by rotating the case of the meter. The fine calibration of the meter is done by adjusting one of the chain pulleys that's on an eccentric stud.

Given how unreliable variable resistors have been in camera exposure meters over the long run, this is very wise design by Topcon. They also patented it. Of course, the rotating meter takes a lot of space.

The variable resistor in the Nikon Photomic finders for the F and F2 is their Achilles Heel!

Follow the instructions in the service manual very carefully for disassembling the top of the camera, or you will spin the meter and fatally bend the needle. You will need to create some tooling (a pointed M1.4 screw) to hold parts in the shutter/ASA assembly.