Canon LTM Assistance with Lightmeter on canon 7S

Canon M39 M39 screw mount bodies/lenses

Austrokiwi

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I recently became a Canon 7sz owner. My experience with Film Cameras was never good. I recently became a Canon 7sz owner. This was by default as the camera came with a lens I had purchased. Having looked hard at the Camera I decided to give it a try out. I have worked all the controls out (except one), obtained a battery( and adapter), and mistakenly took shop advice and got 400 ISO film (the lens is the F0.95). The light meter works fine but I am intrigued with the switch for the light meter. It has "C", "Off", and "On". Would someone please enlighten me what in the world is the "C" for. I noticed when I turn the switch to "C" the meter swings fully to the right of the meter dial. As is usual in such forums as I write my question I suddenly think of an answer; does the "C" stand for "check" as in checking the power level of the battery.
 
C is for battery check. If the battery is good, then the needle should swing all the way into the blue section of the meter readout.

The lens meter has a High and Low sensitivity setting. This is adjusted by turning the bezel around the light meter port.
Use the High (marked "H") setting for low light.
CdS cells may take some time to stabilize in low light settings, so give it time if it is very dark. Remember this is technology from the 1960s. Later Gallium Arsenide or Silicon blue cells have instantaneous response.

The Low sensitivity setting ("L") puts an aperture plate physically in front of the cell to reduce its sensitivity. Use this setting for typical daylight exposure measurement. The Leicameters also use the same trick to adjust their sensitivity ratios. CdS cells are also subject to temporary blindness after exposure to excessive light. So, if you aim the camera at the sun, not only could you burn the shutter (stainless steel, but it has been reported that a hole could burn through), but you may blind the meter. That is, it could take several minutes before it can respond accurately to light level changes.

Film is not complicated, but it does require understanding of what is going on. These old cameras expect you to do the thinking. There is no "AUTO" function.

Stephen Gandy has a great writeup on the Canon 7 series of cameras here: https://cameraquest.com/canon7sz.htm
 
Thanks for the pointers Robert. I suspect a challenging learning curve. At least my most used setting on my modern camera is "M". I expect the Range finder will teach me a few things that I can use on the modern beast.
 
I used to be confused about the "H" and "L" settings for the light meter on my 7S. Did I use the "L" setting for Low light and the "H" setting for High light? WRONG! It's "H" for High sensitivity in Low light and "L" for Low sensitivity in High light. Confusion reigned supreme. Be confused no more. Spavinaw to the rescue! If the light is low like from an orange candle flame or the orange setting sun use the orange letter "H" setting. If the light is white and bright like the midday sun use the white "L" setting. Logic reigns supreme. You're welcome.
 
canon 7sz dead meter

canon 7sz dead meter

I recently ordered a canon 7sz in fine condition except when it arrived and I checked the meter with a new Wein 1.35 volt cell the meter did not respond and the needle remained fixed in place even when the C, On switch was activated. Needless to say switching the Hi/low switch up front did nothing.

Given the situation is it worth having the meter fixed ? If so who can fix it?
Otherwise I would just get a hand held meter.
 
Is it worth getting the light meter fixed? Probably not. It is an external CdS cell of questionable accuracy (depends on where your camera is pointing). If you do want to get it fixed, maybe try Cameraquest or KEH. You might even try Ken Oikawa, who specializes in Canon FL and FD gear.

Personally, I just use a handheld meter or get a good light metering app for your phone.

Jim B.
 
It's probably not dead, only having poor electrical contact with the battery. Try getting a little tube of de-oxit red. Swab it on the contacts, AND the screw thread of the battery cover AND the mating screw thread on the camera. While you're at it, get some tweezers and gently lift up on the springs in the battery chamber and the battery cover. After many years of use, the spring on the battery chamber lid may have flattened out, so that the battery is no longer making secure contact with the opposite pole's contact inside the chamber. The spring on the lid pushes the battery upwards to make contact with the upper contact in the camera.


The old mercury batteries are quite corrosive if they leak (and so are Wein cells). If you find corrosion on the contacts, there may have been a leak in the past. Thus, the wire to the contact may actually have been eaten away for an open circuit. Thus, if just cleaning the battery contacts does the trick, then you may want to buy a pratedthai adapter and use a silver oxide cell instead.



You may also have contact issues at the meter switch (though I have not found this to be a problem), and the last possible issue may be a dead CdS cell. These last two issues are highly unlikely. I had a problem with my 7s, and it turned out that the battery contacts were just too compressed, and needed a cleaning.



The 7sz is a rare camera, and worth having repaired. The usual suspects such as Gus Lazzari, and Don Goldberg work on them.
 
Thanks for the pointers Robert. I suspect a challenging learning curve. At least my most used setting on my modern camera is "M". I expect the Range finder will teach me a few things that I can use on the modern beast.
The learning curve is worth it. Nothing from olde beast, is exactly on new beastie (as new beastie is le automatique). I drive an Automatique with le power steering, le power brakes. As the left leg and hip no workee well. I use le hand controls, le spinner knob to drive with le adaptique interfacee (ROFL). Feet le optionale. My cameras are le Manuel! Le Mechanical. I use le Gossen Luna-Pro F for le metering. Enjoy the learning curve. I use "M" all the time, all day long! I cherish "M" on cameras and love it.
 
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