Yes, I had that tidbit about spectral sensitivity stuffed way back in my
head somewhere but it hasn't needed to be accessed for a long, long
time. But these days I like my histograms a lot more. ;-)
Chuck Norcutt
Tim Hughes wrote:
> Chuck, You are right I did not check link.
>
> The nice thing about the selenium PV cells, is the they have very
> aproximately the right spectral
> sensitivity for photography.
> Silicon is way off, even the so called blue enhanced need an IR filter and
> more.
> In the US the Quantum Calculite(?) and Calcuflash range of electronic
> lighmeters which use 1mm^2
> Silicon cells as sensors, have very careful spectral correction filters, so
> that the meters can be
> used for industrial as well as regular photographic use. Normaly most
> photographic meters have
> very low absolute accuracy requirements. A few other photographic,meters
> have industrial specs
> like the Minolta spot meters which are widely used for measuring lcd sceen
> brightness etc.
>
> Tim Hughes
>
>
> --- Chuck Norcutt <chucknorcutt@xxxxxxxxxxxxxxxx> wrote:
>
>> You neglected to click on the link. Megatron *is* the manufacturer.
>> They produce both standard and custom size selenium cells.
>>
>> Chuck Norcutt
>>
>> Tim Hughes wrote:
>>> Interesting that you think they have selenium cells still?
>>> I do not know of any vendors who still make them.
>>> You could substitute silicon if you had something the right size (or cut a
>>> larger cell with a
>>> diamond blade saw) and then recalibrate, but the spectral sensitivity of
>>> Silicon is such that
>> it
>>> has high sensitivity in the infra-red, so they would need to put a
>>> sprectral correction filter
>>> (infrared and light green) to get the correct spectral response.
>>> Tim Hughes
>>>
>>>
>>> --- Robert McFetridge <rmcfet@xxxxxxxxxx> wrote:
>>>
>>>> I have a couple of Weston IVs and both work although there is almost
>>>> a stop of difference between them now. Yes indeed they are repairable
>>>> but it may not be worth the cost. There is an outfit in California
>>>> that can do it that I know of and I will try and find their address a
>>>> bit later and post it unless someone else has it readily. As well
>>>> there is a company in the UK, < http://www.megatron.co.uk/ > that
>>>> sells the selenium cells and can also do repairs.
>>>> Bob
>>>> On 6-Apr-08, at 9:49 AM, John Hudson wrote:
>>>>
>>>>> I have a Weston Master V, model S461.5, meter. It is totally dead.
>>>>>
>>>>> Are these meters repairable?
>>>>>
>>>>> If so, does anyone know who could do the necessary service and
>>>>> repair work?
>>>>>
>>>>> jh
>>>>>
>>>>>
>>>>>
>>>>> ----- Original Message -----
>>>>> From: "Martyn Smoothy" <photo@xxxxxxxxxxxxxxx>
>>>>> To: <olympus@xxxxxxxxxx>
>>>>> Sent: Friday, April 04, 2008 6:29 PM
>>>>> Subject: [OM] Re: Selenium light meters (Was: OM 2N vs OM4T(i) -
>>>>> Relative
>>>>> reliability/repairability)
>>>>>
>>>>>
>>>>>> Still have a Weston Euro Master which is over 20 years old & in
>>>>>> working
>>>>>> order, regularly use it with my Mamiya RB67.
>>>>>> It will come in useful when the meter in the OM-3 finally packs up.
>>>>>>
>>>>>> Martyn
>>>>>>
>>>>>>
>>>>>>
>>>>>> Leandro DUTRA wrote:
>>>>>>> 2008/4/4, John Hermanson <omtech1@xxxxxxxxxxx>:
>>>>>>>
>>>>>>>> I recently stumbled upon my and my wifes old Gossen Pilot selenium
>>>>>>>> meters, and it made me feel good that they both work AND are both
>>>>>>>> accurate. My sample goes back to the 60's.
>>>>>>>>
>>>>>>> So is that a good buy? That should be good for the environment.
>>>>>>>
>>>>>>> Or is there some must-have in newer, battery-powered meters?
>>>>>>>
>>>>>>> Sorry for the stupid questions, I am just trying to figure it out.
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