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Light meter behaviour on Canon 512XL (and other models too)?


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#1 Harry Alen

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Posted 06 March 2014 - 02:53 PM

Hi! A couple of quick questions:

 

1) Does the light meter show different readings when there's a film cassette inside than it does without a cassette? Is there difference with different cassettes (f.ex. 100D and 200T?)

 

2) When I pan the camera to the sky, the light meters "rolling numbers" seem to become stuck to some value and will not change unless I pan my camera again back to the normal vertical shooting position. If I point down to my toes, the light meter will not be stuck... Does this mean that the indicator is "stuck" but the iris will behave normally or does it mean the iris value is stuck and therefore I wrongly lighted images? Anyway... There's some issues with my 512XL unless this is confirmed as "a feature" :)

 

Thank You! Just filming with 310XL and 512XL with Ektachrome 100D - nothing developed yet... Unfortunately :)


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#2 Zac Fettig

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Posted 06 March 2014 - 03:36 PM

The lightmeter should adjust to the film cartridge that's loaded into the bay. So 100 should adjust the lens' aperture 1 stop wider than 200, for the same light.

 

Is there a lot of variation in the sky? I believe (but I'm not sure) that Canon used an average meter in their super 8 cameras. So, it could be that the sky is all roughly the same exposure, on average.

 

An indoor test would be useful. Does it change when you're pointing at a ceiling light, instead of bare ceiling?


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#3 Harry Alen

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Posted 07 March 2014 - 06:51 AM

Same behaviour indoors. If the camera is panned up, the light meter stucks to the value it has reached until the camera points "too up" and does not change even if I release the trigger and press it again. No change if I select manual - it is at the same value... But... When I return it to "normal" shooting position without tilting it up - everything is normal.


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#4 Joerg Polzfusz

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Posted 07 March 2014 - 12:14 PM

Canon's online museum says:


Exposure Control:

Type: TTL EE with a CdS exposure meter. Automatic aperture setting coupled to loaded film speed and filming speed.

Metering Range: ISO 250, f/1.2, 9 fps - ISO25, f/45, slow motion (36 fps)

Film Speed: Automatic ISO setting by film cartridge
Tungsten type film: ISO 25, 40, 64, 100, 160 and 250
Daylight type film: ISO 16, 25, 40, 64, 100 and 160

CCA Filter: A Color Conversion filter A is built-in to use tungsten type film under daylight. The CCA filter is automatically cancelled with loading of a daylight type film cartridge. Manual cancellation of the CCA filter is possible.

Manual Aperture Control: Manual aperture setting with the EE/Manual aperture control ring. Fade in/out possible with manual aperture control.

 

Not sure what ASA the camera assumes when no cart has been entered. When it's a low value (e.g. 16) or a high value (e.g. 250), then it's very easy to get "stuck" at either f/1.2 or f/45...


Edited by Joerg Polzfusz, 07 March 2014 - 12:17 PM.

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#5 Mark Dunn

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Posted 07 March 2014 - 03:21 PM

The ISO is set by notches in the cartridge pushing in feelers in the camera. So yes, it will read differently.

I would expect the 'cartridge out' setting would be the lowest, 25.


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#6 Greg Morris

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Posted 08 March 2014 - 02:41 AM

Harry, do you have operations manuals for your cameras?  They were designed to use alkaline batteries. Are both of your cameras loaded with alkaline batteries?


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#7 Harry Alen

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Posted 08 March 2014 - 06:39 AM

I use 1.5V high quality GM or Duracell AA-batteries. I have the user manual and I think I (at least should) have the right kind of batteries. I have now set the manual/auto switch on and off for about 200 times if there's some "stickiness" to the non-usage of the camera before I've had it.


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#8 Greg Morris

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Posted 08 March 2014 - 06:01 PM

Were batteries in the cameras during long term storage? Any damage in the battery compartments from leaking batteries?  A compromised ground connection may be causing problems/damage to the CdS photocell.


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#9 Harry Alen

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Posted 09 March 2014 - 01:13 PM

No long term storage/old batteries... I have to test whether it is a stuck exposure indicator (images will be ok) or will the exposure meter stuck (mostly over exposured images if shot camera pointing up)... I will report here after I've processed the film. I've tried to make the meter to go from underexposure to overexposure (without film of course) in seconds and it seems that the meter is slowly getting better - hopefully this is just about the exposure indicator being "stuck" and the exposure being filmed correctly... However... This will not be solved unless I shoot with the camera and see what happens. Thanks to everyone who contributed to this "mystery"! Thank You all!


Edited by Harry Alen, 09 March 2014 - 01:14 PM.

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