Canonet 28 battery

[blacknoise]

hey

Got a canonet 28 off of the second hand market the other day. I know that it needs a no longer produced mercury battery, but will using a silver oxide battery have much effect on the metering? Ive tried loading an SR44 (silver oxide), it seems to power the meter up (shutter fires, meter needle moves), but im unsure as of to how it will affect accuracy, as it is impossible to check without wasting film.

Any ideas? I plan to shoot mostly print film.

Rob

[Kim Coxon]

If you are using print film, the latitude of the film should take care os any exposure inaccuracy. I would be wary of using E6 unless you use an adapter.

Kim

PS. Are you aware they may be a Northern UK RFF meet soon?
http://www.rangefinderforum.com/foru...threadid=60338

Originally Posted by blacknoise

hey

Got a canonet 28 off of the second hand market the other day. I know that it needs a no longer produced mercury battery, but will using a silver oxide battery have much effect on the metering? Ive tried loading an SR44 (silver oxide), it seems to power the meter up (shutter fires, meter needle moves), but im unsure as of to how it will affect accuracy, as it is impossible to check without wasting film.

Any ideas? I plan to shoot mostly print film.

Rob

[blacknoise]

nice one!

Ill fire it up tomorrow and run a film through it

Thanks for letting me know about that, if I'm available and it isn't too much of a trek I'll be there

Rob

[john neal]

Rob,

The SR44 will probably under expose by around 1 stop, as Kim said that is well within the range of most print films.

I'm still trying to find a solder that will allow me to make the 625 and 640 adapters again, but every one that I have tried in the last year has needed so much heat that it fries the electronics

[blacknoise]

thanks for that advice

Ill try setting it to overexpose a stop then!

P.s. Have you tried using some sort of tool (locking tweezers work well) to clip to the leads of the component your soldering to sink some of the heat away from it?

[januaryman]

Originally Posted by john neal

Rob,
I'm still trying to find a solder that will allow me to make the 625 and 640 adapters again, but every one that I have tried in the last year has needed so much heat that it fries the electronics

John -- I used to use a type of liquid solder that was sold in a tube like plastic cement, but had all the characteristics of real solder. This was 30+ yrs back, so maybe it's no longer available. Thought I'd mention it.

[micromontenegro]

In my experience the 28, unlike the 17, exposes properly with alkaline 1.5 volt batteries. I did extensive tests several years ago. I read somewhere that its circutry has built in voltage compensation, but I can't recall where. Will try to find the reference and post it here.

[blacknoise]

oh,

Well ive shot about half of the roll with the meter at 200 (im using Delta 400 pulled to 200) and a bit more today shot with the meter at ISO 100, well see what happens when I develop it :P

[gordonb]

Originally Posted by john neal

...
I'm still trying to find a solder that will allow me to make the 625 and 640 adapters again, but every one that I have tried in the last year has needed so much heat that it fries the electronics

Ditto on using a heat sink to remove the excess heat. Kester makes some funky Tin/Lead/Gold or Bismuth solders with a low melting point.

A good iron with low temperature tips will go a long way.

[payasam]

A Dutch fibre optics engineer named Frans de Gruijter used to make adaptors with a hollowed out 625 shell and a Schottky diode soldered around the rim. Brought 1.55V down to 1.35V. If you can't find him on the Net, tell me at uthappam[at]gmail[dot]com and I'll send you his PDF guide to making the thing.

[kuzano]

I get months of useful life out of Wein Cells.
They are the correct 1.35 volts as the 625 mercury batteries.
Unlike Alkalines, they have a flat discharge curve for their life.
They are the right size without an adaptor
They can be widely purchase at two for about $15 incl ship.
I get a year of life from single wein cells by putting tape over the holes on the battery when not in use. They do not discharge when taped shut.
I get 6 months easily without taping them.
No adaptors
No faking out the batteries with adjusted ISO settings.
My last two cost about $15 w-shipping and took 4 days to get from the User ID aperture-frequency or the eBay store My Old Camera.

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I would never consider off voltage, silver oxide, lithium or alkaline unless I was using an adaptor for silver oxides that corrected the voltage to 1.35.

[emilyyyk]

when you put the batteries in ?
I'm sending my mom tomorrow to a battery store to get a suitable replacement, but I need something to tell her so that she will know it's working. Any hints?
Help would be greatly appreciated. =]

[Carterofmars]

http://www.criscam.com/newsite/mercu..._adapters.php#

[vidgamer]

I used an idea I saw online... I put a #9 rubber washer around a #675 hearing-aid battery.

Cheap and effective. Although, it would be good to know if the alkaline was an alternative, unless I'm sure that the camera has a special circuit for it, the zinc-air should work well. The only problem I see is that I'll have to replace them often, but for the cost of these adaptors, I can buy enough zinc-air batteries to last years! :-)