Actually, Ron... I asked because I don't think he is right. I am a user of the Gossen Luna Pro (gray) with Gossen adapter and silver cells. Mine never needed "recalibration" to be "accurate". It works just as good as the meter worked with mercury cells.
May be. Even if, what cost that adapter? How long is the life expectancy (both on the shelf as in use) of a silver cell?
The part I can agree with is that non-silver batteries have a discharge curve that is inconsistent with usage in a light meter. I can also agree that the air cells have a life-expectancy that makes carrying spares essential.
Here we agree.
Plus the price question.
The statement I quoted is just too excessively absolute and all-inclusive... and appears to be coming from the perspective of a salesman selling old-technology batteries that were banned for environmental purposes. "(happly selling fresh mercuries to anyone contacts him)" says he.
I am very sorry you got this impression.
It just happened that looking for a viable solution for my cameras needing a fixed reference voltage (aka mercury oxide batteries) I came across the information GP/Silva still produces mercury cells and "imported" (= a friend travelling there bought them for me) two boxes of these from Asia. The hapilly meant I will be happy helping people using the same cameras as I do and be assured it covers not the intention to get rich out of this "big buck" business. Maybe this would be nice, but it surely will not happen.
As about old tehnology: Isn't this a bit contradictory, especially when stated in the same posting you tell us you use a gray Luna Pro?
Environmental purposes: 1. Used in a lightmeter or camera (even when it also supplies the shutter magnet) a mercury lasts about 10 years. How many Zn-Air cells will you consume in these years? Ofcourse they have no heavy metal, but they need to be produced. 2. How many mercury oxyde batteries could you produce from the mercury contained in a single neon tube? (Yes they intend to forbid tungsten bulbs until 2012 completly in favor of neon, veeeery environmental friendly.) 3. Returning rates of mercuries were indeed very low (this even worse with used neon tubes), but the main buyers of them were not photographers, they were extensively used in hearing aids where they get rapidly consumed (weeks and not a decade).
So if you will tell me they were forbidden out of environmental reasons I can only answer you that this is a big lie and in my opinion they were forbidden as it was in the interest of the industry. From the tehnological point of wiev it may be old (so what?) but it was a simple and working solution. A Wheatstone brigde don't need too much components but a pair of diodes and condensators (these also can contain heavy metals, especially if they need to be miniaturised - you don't want to have a bulky camera, do you?), some resistors also need to be produced and silicon production is also not the most environmental friendly.
Oh.. as about "excessively absolute": I have not found any solution that would be equivalent to mercuries in all these 3 aspects: 1. tehnologically (voltage sufficently constant to serve as a reference), 2. commoditiy (a. drop it in the camera and forget about it for the next 10 years, b. no modification to the camera), 3. pricewise (a. Zn-Air or even more expensive Wein cells every 2 weeks, b. expensive adapters). The different solutions replacing mercuries fulfill one or two of the 3 aspects, but noone do for all of them.
Well... this said, who is interested will contact me, who not... nobody forces him.
🙂 I just don't like to be suspected by folks I would make a fortune when I am not, especially not if these persons talk without even asking what I would ask for a battery.
Eugen
