Thanks Brian. Trial and error in finding what works for you can be quite expensive at times. It should be called the "iterative process tax" and not the "newbie tax" because it is a never ending process. It is really nice that people are so generous with their time and insights on this blog. I love hearing about what works for different people.
Hay Brian can you clarify what you mean by "memory effect” of the CdS cells". I just reread everybody's response. Did I miss something?
CdS cells, if pointed at a very bright light will register that light level correctly . If quickly pointed at a lower level light source, the CdS cell may not read accurately. That is the memory effect. It only lasts a matter of a few seconds before the light readings to read correctly again. Some people say “minutes” but that has never been my experience. Maybe if metering a welding torch, though.
This is one of the improvements when Luna Pro switched to silicon blue cell in the Luna Pro SBC meters. SBC does not exhibit that memory effect.
I am currently working on two Luna Pro (the original).
One has factory battery conversion and came to life after I repaired the obvious battery chamber issue (Corrosion ruined the tip of the battery contact which fell off covered in blue gunk. So I cleaned and resoldered it).
That one has calibration that I originally considered so good compared to my Sekonic L-758DR that I used it as my backup reference meter while working on Weston meters. (I believe it had been calibrated and left in a drawer for the battery to die)
Then I did battery conversion on the second one, using a 2.7 volt regulator circuit from Filip Dee. This conversion requires a switch, but the Luna Pro activates the battery via three different connections (battery check, high and low are independent).
I solved this by epoxying a surface mount "latch detect" switch from a spare old ZIP drive, positioned where the needle lock spring reaches when either the battery check or meter switch is activated. Consider it a weird workaround but it's effective.
On that meter the dates on the calibration sticker and the date the meter was marked NG are so close that I think it had been calibrated then dropped causing the needle to touch the glass.
Now that I have two identical meters, the differences in calibration are apparent. So far I haven't touched any of the variable resistors because both are so close. But I am considering calibrating them.
I've been using the same original Luna-Pro since 1979. I supplemented it with various flat meters (currently a Minolta IVF) and spot meters (Z-VI modified Pentax Digital that I lost somewhere out in the field). The Luna-Pro has been mostly a backup in recent times, but with a recent calibration by Richard Ritter, I use it with confidence.
The old gray LunaPro meters will not be accurate or usable if you attempt to use alkaline or silver oxide batteries in them, as their voltage is too high. The meter's accuracy depends crucially on the voltage staying at exactly 1.35 volts for each of the two cells required. You can't just adjust the ISO rating, as the reading will go off at one end of the other. Zinc air hearing aid batteries will work, but the best solution is the battery conversion approach mentioned previously. On the other hand, a LunaPro F meter is bulky but accurate, takes a nine volt battery, and I have used one for years.
… and the good news is that the Gossen battery converter recently became available again!
I bought my Gossen Profi Six light meter in 1985 when on a visit to Germany.Originally Posted by Andy F
Tremendous value and it has been with me on motorcycles, hikes, trucks, and various trips to quite a few countries where it has been transported in not really good circumstances. I really love this meter.
That said, late last year I thought I noticed something not quite right, I couldn't quite put my finger on it, but there was just something not 100%.
In June this year on a cold and wet winter trip, it really started playing up. Mainly the needle started to do a jig, or the meter wouldn't wake up. Working on the basis that it had served me well and really done a lot of work over the last 38 years, I decided to get something to replace it.
At my stage of life, any light meter I would be buying, should see me out. My parameters were smaller and lighter than my Gossen, which eventually steered me towards Sekonic. I picked up a Sekonic L-308X light meter which is slightly restrictive compared to the Gossen it is replacing, but so much better in many aspects.
It has aperture priority reading, which was one of my requirements as I select the aperture first, then decide on the shutter speed. It measures in full or half stops, 1/3 stops or 1/10 stops. At least I think they are the measurement parameters. Regardless, I used the meter in various settings and have finally settled on 1/10 aperture stop readout as what I like best.
Essentially I use incident readings with the Sekonic, and generally did so with the Gossen since 1985.
My thoughts as to whether I should get my Gossen serviced/repaired, or purchase a new light meter, favoured purchasing something new, as the cost of doing either, would be roughly the same.
I'm glad I did purchase this small Sekonic L-308X light meter; it does everything I need and there is more I could do with it but I don't need. In short, it should see me out.
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