Canon LTM Enough Is Enough Stop Telling People This Lie

Canon M39 M39 screw mount bodies/lenses
OK. Now that we got the air cleared.... How would I, backward European, toiling under rather strict environmental laws, go about to get my CL working again once the mercury battery dies on me? Anyone near Holland who has experience and can give me a cheap but effective (and longer-lasting than Wein cells) solution? I can buy a px625 cell on eBay but I'm not too keen on polluting the environment with more mercury (call me leftist but I happen to like the outdoors, of which we don't really have too much here :) ). I've seen a few DIY solutions but I'm more likely to solder my fingers to my forehead than anythings else. I like the idea of cheap hearing aid batteries but where will I get an "adapter" for a reasonable price?
 
Buying a mercury cell, if you can find one, does nothing to further pollution. The battery has already been produced and it is going to go somewhere; somewhere may as well be my camera as long as the battery is disposed of properly when I am finished with it.
 
Stu :) said:
On the subject of suitible batteries for a Canonet.

Anyone tried a Ni-MH Rechargealbe battery yet?
1.2v, doesn't have that nasty alkaline 'spike' and discharge rate similar to the old Mercury Oxide.

QL17 #3 has one in at moment as a field test. If all goes well I might have 1960's camera that plugs in the wall for recharging like modern digital camera.

Stu :)
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You can buy Ni-MH button cells? Or are you wiring up a battery holder for an AA battery?

While we're on Mercury cells, someone on pnet (I think, could be somewhere else) once mentioned that they're _rechargeable_.... anyone know more about this?
 
ray_g said:
I'm with Rob. Zinc air hearing aid batteries plus a #9 o-ring - good (and inexpensive) enough for me.


Last night, I nearly started a new thread asking people to re-state their workarounds for 625 mercury batteries so that they could be found in one place. But I decided to wait until this discussion receeded so that there would not be too much "simultaneous redundancy" (I now wonder what was going through my mind - but then so many people do!)

Anyway, Ray, would you mind giving some details for us technophobes. I did a google search on "#9 o-ring" and did not know what I had before me. Also, what size hearing battery?

Thanks

Alan
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Kin Lau said:
You can buy Ni-MH button cells? Or are you wiring up a battery holder for an AA battery?
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I got mine from a motherboard backup battery pack. There where three cells wrapped in green heat-shrink plastic. I went through the various ones for sale and found some with the same diameter as the LR44.

Kin Lau said:
While we're on Mercury cells, someone on pnet (I think, could be somewhere else) once mentioned that they're _rechargeable_.... anyone know more about this?
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Yeah it's also in one of the versions of the anarchists cookbook, under bomb making... :(
...attempting to recharge any kind of non-rechargeable battery is very dangerous.

Stu :)
 
Mark W said:
...

I now know the base level of this group

...
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I really hope you do. Although I was surprised by some of the replies (not all, as some were obviously tongue in cheek), all were indeed much subdued from what you would have gotten in most, if not all, other fora I have been in. Actually, I am surprised you were not just ignored. I think only because you have enough posts to be considered worth talking to and if you can accept it, corrected. Most persons who come in with one or two posts and say things like that are just ignored. Apparently, responders feel you are worth more than that.

You see, your post was indeed quite confrontational, whether you intended it that way or not. If you do not understand why, please feel free to PM me and I will explain why I think so. Of course you can do it here too, but I am thinking my reasons are all that count between you and I. This is the friendliest forum you will find. Please do consider staying here and contributing. You no doubt have information that would be valuable to the other members.

Just understand that your opinions are only that; your opinions. Just like my opinions are mine. If you disagree with mine, feel free to say so and give reasons or not. It is all the same to me. I think I have the same right towards you. I think other members mostly feel the same way.

Also, understand that few people take to being put down, and it is never considered a good teaching technique. The reaction is to the put down, not to the information imparted.

Have a good day sir.
 
One doesn't get to chose what circuit is in one's camera, but I have seen an old design article that said if a light meter uses a bridge circuit, it's the ratio that matters and it's self-compensating for voltage variations.

Not very useful info to apply specifically, but just interesting anyway...might matter for some meters, and not others, depending on the details.

I put an alkaline 625? in my Pentax 1 degree spot meter because that's what was abailable. I took another rotted one apart to fix (someday) apart, drew a schematic, then analyzed (watch out for those first four letters!) the circuit with 1.35 and 1.55 V and was puzzled why it would make much difference at all based on the change in current I calculated. But that's not the same as shooting slides with two different voltages and SEEing if it made a difference.

Murray
 
All of photography is compromise, improvise, approximate. No amount of measuring and ranting will change that. Absolutes don't exist anywhere in the world of measurement.
 
i want to sell my canon 7 rf....

i want to sell my canon 7 rf....

i have a canon 7 rf, very minty and no wrinkled curtain.
with a beautiful canon rf 50mm f1.2 minty like new, gorgeous-only one mark on the knurle that doesn't even bother. and a voigtlander 35mm f2.5 c lens black new with box.
the entire outfit would make a fine collector quality edition, everything is silky smoth and meter works fine. all for the very low price of $950.00

please only serious inqueries. :D
 
street-fighter said:
i have a canon 7 rf, very minty and no wrinkled curtain.
with a beautiful canon rf 50mm f1.2 minty like new, gorgeous-only one mark on the knurle that doesn't even bother. and a voigtlander 35mm f2.5 c lens black new with box.
the entire outfit would make a fine collector quality edition, everything is silky smoth and meter works fine. all for the very low price of $950.00

please only serious inqueries. :D
Click to expand...


you might be better served with this in the classifieds section...
 
Very interesting. Me thinks the creator of this thread should just stick to the 'Sunny 16 Rule' :D
Oh, and regarding the comment about shooting 100 ASA slide film, even with my limited photographic skills, my Auto S2 with the wrong darn battery took an amazing roll of Velvia 100. Guess I got lucky.

JP
 
Hi,
Pentax was one of the few manufacturers to use a bridge circuit. You are quite right , it is the balance between the 2 sides that gives the "null" or correct exposure so the voltage doesn't really matter. The meter will be a bit more sensitive away from the null position. Unfortunately, I am not aware of many, or indeed, any RF's that use bridge ccts.

Kim

murrayatuptown said:
One doesn't get to chose what circuit is in one's camera, but I have seen an old design article that said if a light meter uses a bridge circuit, it's the ratio that matters and it's self-compensating for voltage variations.

Not very useful info to apply specifically, but just interesting anyway...might matter for some meters, and not others, depending on the details.

I put an alkaline 625? in my Pentax 1 degree spot meter because that's what was abailable. I took another rotted one apart to fix (someday) apart, drew a schematic, then analyzed (watch out for those first four letters!) the circuit with 1.35 and 1.55 V and was puzzled why it would make much difference at all based on the change in current I calculated. But that's not the same as shooting slides with two different voltages and SEEing if it made a difference.

Murray
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Hi,
John Neal, another forum member, makes a very good adapter which uses cheap SR44 cells. He charges about a 1/3 the price of the commercial ones and I think his are better. I either adapt the camera or use these. I don't like using hearing aid batteries as there is a higher risk of leakage due to the air holes.

Regards
Kim


RML said:
OK. Now that we got the air cleared.... How would I, backward European, toiling under rather strict environmental laws, go about to get my CL working again once the mercury battery dies on me? Anyone near Holland who has experience and can give me a cheap but effective (and longer-lasting than Wein cells) solution? I can buy a px625 cell on eBay but I'm not too keen on polluting the environment with more mercury (call me leftist but I happen to like the outdoors, of which we don't really have too much here :) ). I've seen a few DIY solutions but I'm more likely to solder my fingers to my forehead than anythings else. I like the idea of cheap hearing aid batteries but where will I get an "adapter" for a reasonable price?
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Hi,
I would disagree slightly with this. The relationship between the resitances in the meter circuitis not quite linear. From my research on the GIII and others, I have found the following:

At very low light levels ie 1/15 at F4, there is very little or no difference in the readings when using a 1.35 or 1.55v battery. At high light levels, ie 1/500 F11, there is about 1 stop difference. As a result, offsettng the meter by a 1/2 stop will work in the middle of the range but will be out at either end. The latitude of most film will probably cover this. Off the top of my head (as I don't have access to my data at work) the resistance of the CdS cell used is about 2Kohm in the dark and 200 ohms in bright light. This is in series with the trim pot and another resister to reduce the current. The CdS resistance will vary according to the light level but the other 2 won't. It follows that the effect of the current flow caused by the different battery voltage over the whole circuit will change as the proportion of these resistances changes. I have found a better solution is the alter the trim pot. This corrects for the voltage difference but has only a very small effect on the proportions. However, because of the very small difference at low light levels, this MUST be done in bright light. I have found it best to to do it on a very bright sunny day. Having done this, I found that the meter is within 0.2 of a stop right across the board which is fine for even pro slide film and about as accurate as you can get with reflected light metering. If you want a more accurate result, even a mercury cell won't help and you need incident metering.

Regards
Kim

Pherdinand said:
Sockeyed - yes. It seemed to me that the "half-stop" (more or less) underexposure tendency is quite consistent through the range of the canonet meter.
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People with more interested in equipment and factoids than in photography may not be fully aware that metering is a game of compromises and best efforts.
 
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Kin Lau said:
You can buy Ni-MH button cells? Or are you wiring up a battery holder for an AA battery?
Click to expand...

Mouser Electronics list Varta Rechargeable NiMH batteries in two sizes of interest, both 1.2v :
Mouser Part No
672-55604 .45" dia x .21" high, 43 mAH $1.60/ea
672-55608 .61" dia x .23" high, 80 mAH $1.82/ea

I just measured an SR44 at .455" dia x .205" high, and a PX625 at .612" dia x .231" high. .05" should be more than taken up by the spring contacts, so I think you can get the 43mAH in a SR44 spot, if not there is a 16mAH of that diameter that's only .12" high. I've not tried them, but they should be very close fits, or be good candidates for adapters. I've also not looked into recharging them, since NiMH's are charged on a rate based on capacity, and your average AA charger is expecting to charge 1800-2200 mAH cells.
 
Hi,
NiMh batteries should be charged at 1/10 of their capacity for 14 hours. At this rate they can be left on "continuous charge" with no danger but prolonged charging may reduce their life. They can be charged at a higher rate but this would need more complicated circuitry that either has a timing device or a sensing circuit to switch them off or reduce the charge once the cycle is complete.

However, these will still give a problem. Mercury batteries are 1.35v nad the nominal voltage of NiMh cells is 1.2v. Therefore, the voltage is still about 10% out which will cause inaccuracies in the meter circuit unless it is adapted.

Kim

XAos said:
Mouser Electronics list Varta Rechargeable NiMH batteries in two sizes of interest, both 1.2v :
Mouser Part No
672-55604 .45" dia x .21" high, 43 mAH $1.60/ea
672-55608 .61" dia x .23" high, 80 mAH $1.82/ea

I just measured an SR44 at .455" dia x .205" high, and a PX625 at .612" dia x .231" high. .05" should be more than taken up by the spring contacts, so I think you can get the 43mAH in a SR44 spot, if not there is a 16mAH of that diameter that's only .12" high. I've not tried them, but they should be very close fits, or be good candidates for adapters. I've also not looked into recharging them, since NiMH's are charged on a rate based on capacity, and your average AA charger is expecting to charge 1800-2200 mAH cells.
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Ain't it great, this thread is ending with members actually quoting specs and pointing to things that shouldn't work, but do, and sometimes better.

All because someone was looking for an opportunity to slam/vent.

Mark W, Hope you had a good read.

By the way- Ronsonol works and if you are pouring it in then you missed some important steps. Besides, we aren't operating on family heirlooms. These are mainly finds and bargains that have good lenses.

Tell the camera repairman we said hello.

Bob H
 
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