canonet 17ql qIII questions

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alkos

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Hi!

I've received a Canonet 17QL III camera yesterday, changed light seals and cleared a bit hazy RF/VF with window cleaner and cotton buds - even the gold beamsplitter (yes, I've done it once on Yashica GX before 🙂.

1. Now I can see - on the whole VF area - double or even triple images of all bright light sources (bulbs, strong reflections, etc). In all other aspects the VF/RF is fine: bright and contrasty. The focusing spot is allright too.

Is it normal? I didn't notice it before...

2. Have anyone calibrated the lightmeter to 1,5V with the 2 variable resistors inside? When using 1,5V cells is the meter linear? I use "two dots towards ISO800" setting for iso400 film in the daylight and the negative looks fine. What about worse lighting conditions and/or lower iso settings?

cheers

alkos
--
"the humanity of the moment of the magic of the coincidence"
24x36 at op pl
http://pad.go.pl
 
Hi,
The exposure difference when using 1.35 and 1.5v cells is not linear so adjusting the ASA doesn't work across the board. I have had good results adjusting the trim pot behind the film moving flag and this seems to give reasonable results across the range. It might not be perfect but it is within the normal accuracy limits of the meter.

Kim
 
Is it hard to do? (is the screw very sensitive?) Any tips&tricks? 🙂

Is it possible to adjust the meter to i.e. iso1600 instead of 800, maintaining the linearity?


cheers

alkos
--
"the humanity of the moment of the magic of the coincidence"
24x36 at op pl
http://pad.go.pl
 
alkos said:
That's more than I've paid for the camera, in excellent condition 🙂
Click to expand...


Maybe, but you don't have to take the chance of ruining the meter if you use an adapter. I have one in my QL17 GIII and also in my Olympus OM-1, they work perfectly and I no longer have to remember to compensate the exposure. These adapters work in any camera or light meter which was designed to use the PX625 cell.
Obviously it isn't the only solution, but for me I figured it was the simplest and best.
 
If you have taken the top off allready, it is not too bad. It is not that sensitive but can be awkward to get to because of the flag. I use a small jeweller's screwdriver to lever it rounds. Do it on a brightly lit day against a known meter for the best results. I would be very wary oif trying to adjust it to 1600ASA. Not only are you starting to go outside the meter range but it could lead to problems when you use a slower film.

Kim

alkos said:
Is it hard to do? (is the screw very sensitive?) Any tips&tricks? 🙂

Is it possible to adjust the meter to i.e. iso1600 instead of 800, maintaining the linearity?


cheers

alkos
--
"the humanity of the moment of the magic of the coincidence"
24x36 at op pl
http://pad.go.pl
Click to expand...
 
Hi,
These are very expensive and they do not work in all cameras. The diode they use is quite low powered and some of the high drain cameras could blow it. Another member of the Forum, John Neal, makes an adapter that wil suit more cameras including the high drain ones and is a fraction of the cost.

Kim

Andy K said:
Maybe, but you don't have to take the chance of ruining the meter if you use an adapter. I have one in my QL17 GIII and also in my Olympus OM-1, they work perfectly and I no longer have to remember to compensate the exposure. These adapters work in any camera or light meter which was designed to use the PX625 cell.
Obviously it isn't the only solution, but for me I figured it was the simplest and best.
Click to expand...
 
Andy K said:
A simple and permanent solution to the voltage problem is this. Not cheap but you only have to buy it once.
Click to expand...

This was the solution I chose. I bought my adapter from B&H. The meter now reads pretty much as expected and appears to be linear. The battery check light won't work using this adapter. I don't particulary like this camera but at least I know it will properly expose film when I choose to use it.
 
Kim Coxon said:
Not only are you starting to go outside the meter range but it could lead to problems when you use a slower film. Kim
Click to expand...

Well, actually I don't use slower films 🙂

I'm going to give it a try - first with adjusting to nominal values (up to iso 800) - then more. Battery adaptors have a dark side - they cost and take time to be shipped ;-)

cheers,

alkos
--
"the humanity of the moment of the magic of the coincidence"
24x36 at op pl
http://pad.go.pl
 
alkos said:
Is it possible to adjust the meter to i.e. iso1600 instead of 800, maintaining the linearity?
Click to expand...

This is something I want to try, and I've been studying it, but so far I lack the initiative and the nerve to actually do it.

I've mentioned doing this before here a few times, and nobody seems to be cheering me on to try it, but nobody seems to have come up with any real reasons why it won't work, either.

On one hand "it ain't broke, it don't need fixed" but on the other hand, if I did this I would be able to shoot 1600 film in even lower light and I would be able to shoot 800 film at 1600, similar to how I've been shooting 400 film at 800 and getting good results on brightly lit night scenes. I'm very sure that the lowest film speed I will ever want to shoot is 64 (Kodachrome) so I don't worry about losing the lower film speeds.

What I want to try is the equivalent of what laboratory people would call a two-point calibration on lab instrumentation, one point at the low end of the scale, another at the high end. I've talked to some friends of mine who work with this stuff and they agree that it's do-able.

The GIII only has one calibration adjustment, electrically speaking, which appears to be what a lab person would call the span adjustment, or the high point.

It does, however, have a mechanical adjustment on the meter itself, and this would be similar to what a lab person would call the zero adjustment in lab equipment. This is the one I'm most afraid to touch, or rather uneasy doing so.

I'm hoping that the zero adjustment, the low end, the mechanical one, is close enough so it does not have to be adjusted.

Anyway, what I'm planning to do is to first re-calibrate the high end of the scale, or rather intentionally mis-calibrate it so it's off by one stop. In other words, I want to change it so that a 1/250 and f16 exposure at iso 800 now reads 1/500 and f16. This would be done with the electrical adjustment.

Then, adjust the low end of the scale, checking so see that what used to show as something like 1/15 at f1.7 now reads close to 1/30 at f1.7 and adjust the mechanical zero to make that read right. Then go back and check and maybe adjust the high end, then the low end again, rinse, repeat, until it needs no significant re-adjustment.

Those are my plans for a maybe-recalibration, anyway ...

If and when I actually try this, I'll sure report on the results. 🙂
 
thanx DMR!

I'm gonna try it exactly the same way as soon as the second canonet (old 17QL) reaches me - I'm on the slr detox now ;-) and don't want to stay without at least one so-so working RF 🙂 (my zorki & yashica gx don't count - they're almost dead 🙁(( )
 
There's a description somewhere on RFF about soldering a diode into the circuit. I tried it, and was mostly successful--except the battery contact tab I soldered it to was a very effective heat sink, and it heated the plastic to the point of shattering when I tried to put it all back together 🙁 But I can keep the battery stable and it meters fine, best I can tell from the couple rolls I've put through it.
 
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