Canonet QL17 Question

[bobwysiwyg]

-) Wein cells have fewer (and seemingly smaller holes)
-) Wein cells have a different chemistry thus producing only 1.36V nominal.

Source: Popular Photography, March 1995

AgX,

Are you saying using the 375 batt. is not a good idea or good substitute?

 

[AgX]

...so I thought I would try one of those adapters. Bought one from CRIS which "claims" to reduce the voltage. Not true. In the adapter still measures 1.5+v.

To my understanding the CRIS adapter works by means of a voltage reducing diode. That means the cell's initial voltage output will fall down under strain. Metering with high resistance voltmeter probably won't put on that strain.

 

[bobwysiwyg]

Well, not being very knowledgeable about electronics, it doesn't seem like they were very honest then as it is specifically recommended for, among others, the QL17 to reduce the voltage "with no further adjustments necessary."

 

[AgX]

Bob,

I have no experience with zinc-air cells, so I can't comment on that voltage difference. But I don't think that small difference is crucial. The main problem seems to be the rapid exhaustion of regular zink-air cells in stand-by. Wein stated that their cells would "give about three months of service once the seals are removed".

 

[AgX]

Bob,

Concerning that CRIS adapter: There won't be any adjustments necessary. It's the camera that produces that strain.

As a side note:
That is also the reason that there are special (cheap) battery testers on the market, though one could think a standard voltmeter would be sufficient (except for indicating that voltage range to tell for good or bad). But these testers put strain on the battery in a range typical for the devices in which they are used. That is why one has to adjust those tester to the size of battery one is testing. The reason behind that testing under strain is that batteries/cells (especially standard batteries) produce less voltage under strain when their capacity has fallen off.

For that CRIS adapter that strain will even be necessary for a fresh cell as otherwise that diode-voltage-reducing would not work.

 

[AgX]

For all electro-technically minded with interest in battery adaptors:

Dead Link Removed

 

[bobwysiwyg]

AgX,

Thanks for the PDF, interesting reading, I 'think' I understand better. Though I used a fairly decent multi-meter to read the voltage directly, as the document points out, not a good indicator. I guess checking exposure within the camera, either with its meter or film would be better. Thanks again.

 

[dougjgreen]

Bob,

I have no experience with zinc-air cells, so I can't comment on that voltage difference. But I don't think that small difference is crucial. The main problem seems to be the rapid exhaustion of regular zink-air cells in stand-by. Wein stated that their cells would "give about three months of service once the seals are removed".

BTW, I erred in recommending 375 Zinc Air cells. I meant 675 Zinc Air cells, which are the ones that are the same size as the S76 or SR44 silver oxide cells. My experience with them is that the voltage is so close to Wein Cells that it any difference is not significant. Zinc Air cells are nominally 1.4 Volts, and the cameras that I have used them in rather than Mercury cells, all seemed to give the same readings as with Mercury 625 cells, within a half stop. As to whether or not Wein Cells last longer - if they actually do, it's not by much. The cost differential between Wein Cells and standard Zinc Air cells is vast. I generally pay well under $1 for Zinc Air cells - usually paying about $4-5 for a pack of 6, or even less in larger quantities. I've never seen Wein cells for under $5 each, and typically $7-8 each. So it's a tenfold difference, and AT MOST, the Wein cells last maybe 50% longer than the regular Zinc Air cells. In actual use, The voltage seems to be so close as to render any small differences immaterial.

One area where the aforementioned article is clearly useful, is in mentioning that the types of cameras where my rubber O-ring solution won't work is on cameras where one of the contacts is actually made with the side rim of the battery, rather than the two flat surface. If the camera makes contact with the top and bottom of the battery, the O-ring solution works great, and is dirt cheap.

 

[elekm]

I agree it should be unnecessary. I also think the QL17 would have been greatly improved with TTL metering with shutter release activation.

TTL metering would be highly complex and expensive with a leaf shutter.

Think about it. If TTL metering is to work, there are only two options:

1) The cell would need to be placed behind the lens element and in front of the leaf shutter. That would require a wider opening inside the shutter assembly to place the meter cell, as well as the additional wiring for it. Because most camera makers relied on a third party for shutters, it would have translated into a higher cost.

2) If the meter cell is to be at the film plane, then the leaf shutter must be open. That would require a light baffle at the film plane to keep the film from being exposed. When you pressed the shutter release: The leaf shutter would have to close, the aperture would have to stop down, the baffle would have to open, the leaf shutter would then cycle, the baffle would then close and the leaf shutter would have to reopen. At this point, you might as well make it a focal-plane shutter, which would have increased the cost of a camera that was aimed at the amateur market.

Having the meter cell next to the lens was probably the best location. It was a design used by many camera makers -- German and Japanese.

 

[elekm]

I agree that buying Wein cells is foolish. For the cost of single Wein cell, you usually can buy a pack of 10 zinc-air cells. Only a few cameras require the physical shape of the original PX-13 battery. For others, slap a rubber O-ring on it and perhaps toss a washer into the battery chamber, and you're good to go.

 

[bobwysiwyg]

BTW, I erred in recommending 375 Zinc Air cells. I meant 675 Zinc Air cells, which are the ones that are the same size as the S76 or SR44 silver oxide cells. My experience with them is that the voltage is so close to Wein Cells that it any difference is not significant. Zinc Air cells are nominally 1.4 Volts, and the cameras that I have used them in rather than Mercury cells, all seemed to give the same readings as with Mercury 625 cells, within a half stop. As to whether or not Wein Cells last longer - if they actually do, it's not by much. The cost differential between Wein Cells and standard Zinc Air cells is vast. I generally pay well under $1 for Zinc Air cells - usually paying about $4-5 for a pack of 6, or even less in larger quantities. I've never seen Wein cells for under $5 each, and typically $7-8 each. So it's a tenfold difference, and AT MOST, the Wein cells last maybe 50% longer than the regular Zinc Air cells. In actual use, The voltage seems to be so close as to render any small differences immaterial.

One area where the aforementioned article is clearly useful, is in mentioning that the types of cameras where my rubber O-ring solution won't work is on cameras where one of the contacts is actually made with the side rim of the battery, rather than the two flat surface. If the camera makes contact with the top and bottom of the battery, the O-ring solution works great, and is dirt cheap.

Doug,

Thanks for the correction on the batt. designation. I made note of it.

 

[bobwysiwyg]

Put a new Wein cell in the QL17, measures 1.35v as it should, meter and check light work fine. I know they don't last long, are hard to get and a bit pricey so I thought I would try one of those adapters. Bought one from CRIS which "claims" to reduce the voltage. Not true. In the adapter still measures 1.5+v.

My apologies to CRIS, their claim appears to be correct and the description of the 'load' provided by the camera, as AgX explained, seems to be the answer. Sorry for my electronic ignorance.

I did to a quick in-camera comparison, not very scientific, but I was careful to duplicate scene/target and lighting. With the Wein cell, and cam. set to auto, it called for f2.8 at ISO 100. With the CRIS adapter and the included SR43W batt. same reading. For the heck of it, removed the battery from the adapter and used the SR43W directly with some foil padding to make fit and make contact. It was a full 1/2 stop off.

 

[bobwysiwyg]

OK, light seals replaced, battery problem solved.. ready to try a roll.

I am assuming the only means by which one can turn off the meter on these is to put a lens cap on, correct?

 

[Andy K]

OK, light seals replaced, battery problem solved.. ready to try a roll.

I am assuming the only means by which one can turn off the meter on these is to put a lens cap on, correct?

Yup. That is why I believe it would have been better to design the camera with a shutter release activated meter.

 

[bobwysiwyg]

Thanks Andy. I guess it won't be too much of a problem. I tend to have always been the kind to put the lens cap back on all my cameras right a way, but I just wanted to make sure I wasn't overlooking something, or had a defective advance lever switch or something.

 

[Russ - SVP]

I had mine convereted to 1.5v Silver Oxide. Works great. Stable and batt's last much longer.

Kiron Kid

 

[bobwysiwyg]

I just finished my first roll in the QL17 and plan to develop it shortly. I have one last question on these. I take it there is no "advance lock" and you have to pay attention to that tiny indicator to tell you you have advanced and are ready for the next shot? In other words, there's nothing to stop you from double advancing the lever and skipping a frame accidently.

 

[Clovis]

I take it there is no "advance lock" and you have to pay attention to that tiny indicator to tell you you have advanced and are ready for the next shot? In other words, there's nothing to stop you from double advancing the lever and skipping a frame accidently.

There must be something wrong with yours. My canonet won't advance if the shutter is already cocked (indicator showing red). The lever will refuse to turn past the standoff position.

 

[bobwysiwyg]

Hmm, that was my other possibility. It did seem odd there would be no lock to prevent double advancing. I guess I better be careful. I'm sure I will find two blank frames... or worse if it isn't functioning very well period.

 

[Clovis]

Rick Oleson has a good overview of how to fix the winder lock issue here:

http://rick_oleson.tripod.com/index-30.html

(second and third pictures)

 

[bobwysiwyg]

Thanks much for the link, I may give it a try. I just finished developing my first roll out of the camera and they look pretty good. Can't do any real close inspection until they are dry though. The cam meter and my Sekonic agree and the "auto" setting seems pretty good as well under most conditions. Free cameras are especially fun.

 

[bobwysiwyg]

Well, I can see why folks like the QL17, nice little camera. I noticed some uneven spacing between frames, but I think that might be me not completely advancing the lever firmly. At first the shutter bothered me, a bit long-ish stroke compared, say to Nikons, but came to like it, silky smooth than a very quiet release. Advance lock not working as mentioned earlier, looked at the instructions for fixing it but I wonder if the risk of going into the camera, which I've never done before, and messing things up is greater than original problem. I can avoid double advances.. I think.

 

[EdColorado]

Congrats on the camera, looks to me like it works fine. I'd agree that the advance lock is a problem I could probably live with and I dont think I'd open the camera to try a fix. I love my QL17!