1.5 Volt

[Sparky]

PX-1A = alkaline = 1.5V when new, so if they're fresh you would need to compensate.

Mark

[clivetobin]

Since the 1.3 volt akaline mercury batteries are no longer aval, and the 1.5 V is the replacement how much off will the metering be ? ...

The metering can be off a lot.

Old meters reply completely on the stability of voltage of a mercury cell. It holds its voltage within a few hundredths of a volt until it dies completely.

If the voltage is 1.55 like a new alkaline or silver cell, the exposure could be bang-on the same in dim light, but a couple of stops underexposed in bright light. It will not track correctly over the expected brightness range.

I doubt very much if any substitute chemistry is going to have the required stability for old metering systems.

Newer meter types however may have a voltage regulated or Wheatstone bridge type circuit that is independent of voltage shifts.

[marc]

There's a potential synergy occurring between the new exposure meter batteries and the new film stocks. On my Nikon R8, the 625 battery replacing the original 1.35v battery in the exposure meter causes the meter to be about, oh, 2/3 stop oversensitive, thus forcing the iris to close up. The Kodachrome 40 replacement, EPY 64T, is also 2/3 stop more sensitive, so according to my figuring the two error sources should cancel each other out (unless the Nikon actually reads E64T as ASA 64, in which case I'll have to use exposure compensation anyway).

What about if the 625 (1.5 v) causes the tester button to read barely in the black? Does that mean that it should work like the old merc. 1.35 v batteries?

[Shanec8mm]

I did a test with my Bolex S-1 camera outside today under cloudy skies, without film and watched the metering through the viewfinder and it seemed to react to different lighting fairly well. I used the auto feature, and first pointed the camera at a black car it read something like 5.6, then on my white car and it went up to 8. I stood at about 10 to 15ft away, this may or may not mean anything but atleast I got something.
From what some of you have been telling me, setting the camera at 20 ASA down from 25 using tungsten cinechrome 40 I should be ok. I'm not worried about to much perfection, as it's only going to be a homemovie, but getting it close is what I would like to achieve. So I guess I will find out if changing the settings with a 1.5 battery in there will work.

[vidwerk]

I went to Henry's in Toronto to buy replacements for my Gossen Luna Pro.
The guy gave me 1.5v batteries. I told him they needed to be 1.35v. He insisted that the 1.5's would be fine. WAY OFF!! I tested it against several meters and the Gossen was very high in its reading. I ended up going to Vistek.ca Not the cheapest things around but worth it.

vidwerk[/i]

[Juno]

I went to Henry's in Toronto to buy replacements for my Gossen Luna Pro.
The guy gave me 1.5v batteries. I told him they needed to be 1.35v. He insisted that the 1.5's would be fine. WAY OFF!! I tested it against several meters and the Gossen was very high in its reading. I ended up going to Vistek.ca Not the cheapest things around but worth it.

vidwerk[/i]

How high ( or how much of a stop was it off)-over or or under?

[vidwerk]

I went to Henry's in Toronto to buy replacements for my Gossen Luna Pro.
The guy gave me 1.5v batteries. I told him they needed to be 1.35v. He insisted that the 1.5's would be fine. WAY OFF!! I tested it against several meters and the Gossen was very high in its reading. I ended up going to Vistek.ca Not the cheapest things around but worth it.

vidwerk[/i]

How high ( or how much of a stop was it off)-over or or under?

It was over buy a stop and a half. At let's say 1/30 shutter at f/8 being the correct reading. The meter would tell me to expose between f/11 and f/16.

[Juno]

So it will render your scenes underexposed due to the higher voltage.

[Andreas Wideroe]

Do a search for "Wein Cells". They are good replacements for 1.35v batteries.

[vidwerk]

So it will render your scenes underexposed due to the higher voltage.

Yes.

Do a search for "Wein Cells". They are good replacements for 1.35v batteries.

This is what I ended up getting. Exposure it bang on every time.

vidwerk

[Norseman]

Do you have a manual for your Bolex S-1? I have a Bolex P1 that uses a 1.35v battery also. My owners manual says:

"The Bolex photo-electric cell (battery) compensates for the light lost through filters automatically. To determine the exposure you should therefore use the figure for the true film speed (16 ASA for type A Kodachrome, for example) and NOT the film speed corrected for the filter in use (10 ASA, for example, for type A Kodachrome with a conversion filter)."

I am new to this too, but I am taking this to mean that I (and maybe you) should film outside, with the #85 filter, with the ASA set at 40 (and not at 25). If I am understanding this wrong, someone please let me know.

[super8man]

The R8 and R10 (Nikon) read 64 film just fine...you will still need to compensate for the voltage...or just apply a load until the voltage drops to about 1.4 and you should be good to go (a load like a small 3volt bulb wired across the battery terminals).

m

[super8man]

http://rick_oleson.tripod.com/index-111.html

[Shanec8mm]

Norseman
Yes I do have a owner's manual for my Bolex S-1. Here's what my manual states when using filters "When using filters the exposure is alterned and must be corrected. For this, you must first know the filter factor of your filter. Divide the ASA sensitivity number of the film being used by the filter factor and set this figure on the sensitivity knob opposite the index mark." This is the example the manual gives.
:Conversion filter: factor = 1.6
film sensitivity = 40 ASA
set 40 divided 1.6 = 25 on sensitivity knob.
Automatic diaphragm setting: Your camera enables you to film without bothering about the diaphragm, for it ensures that the film will be correctly exposed, regardless of the variations of light in the scene or of the speed at which you are filming.
and lastly from the manual:
Photo-resistance batteries:
The automatic diaphragm setting device is controlled by a photo-resistance which is fed by two long-life batteries (ref. Mallory PX-1).
That's really all I could find in the manual pertaining to this subject.
So Norseman, from what you are saying, instead of setting the ASA to 20
outside with a #85 filter (which I plan on using), I should set it to 40 ASA. Won't that effect the metering, with those 1.5's I have in it. So basically the higher the number the more sensitive the reading, or is it opposite that ? very confusing. What I gather from the manual is film of ASA 40 should be set to ASA 25 outdoors when using a filter, so I am assuming that if this is true turning the knob to ASA 20 (considering the 1.5's in my camera) would give a close exposure. I very well might be wrong here, but I am quoting other's here too.
Sincerley
Shane ...

[Norseman]

Shane, it sounds like my P1 automaticlly compensates for the use of filters, but your S1 does not. You'll need to follow your manual's instructions (and the advice of the experts here in this forum), and compensate for your filter AND 1.5 battery. Someone said to set the ASA at 20, so I'd go with that.

I recently shot some film with my P1, outside with the #85 filter. I shot the same scene with the ASA at 40, and then shot it again at 25. When I get the film back from processing, I'll take a look and see what looks better.
Norseman