Gossen Luna PRO S Battery Replacement Kit

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marke

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I hope someone can help me with two questions. I recently got a Gossen Luna PRO meter. I realize that I can't get the correct batteries for this meter, but I understand that there is a battery replacement kit available.
http://www.adorama.com/GSLPSB.html

My first question is: Is there a difference between the Luna PRO and the Luna PRO S? I don't see anyting on my meter designating it as an "S" model.

My second question is: What exactly does the battery replacement kit do? Is it just an adapter to make a different sized battery fit properly? I'm assuming it's more than that, considering the $37 price tag! :eek:
 
I bought a Gossen Luna Pro sbc in a case for about the cost of the battery adapter and two batteries. I have both versions. Wein cells work fine in the Luna Pro. The Luna Pro sbc is a much much better meter. Runs on 9v battery.
 
I use the adapter kit on my Luna PRO with acceptable results, but I had it CLA'd too by Quality Metric in Hollywood. Thy said it was off one f-stop thru out the whole range.

I think the adapter reduces the two Silver Oxide SR44 1.5V battery voltage to that of the original Mercury batteries.
 
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Thanks, Wayne. I wasn't aware of the two Pro models when I bought this thing. The thing is, I bought two meters: the Luna Pro and the Luna Lux (sbc). I had heard that the Pro is capable of reading in considerably less light that the Lux. But what I liked about the Lux is the instantanious reading and the ability to see the LCDs in very low light. I figured I would try both out, see what works better for me, then resell the other one.

I don't know what size the Pro sbc is like, with the 9v battery. But the Lux, which also uses a 9v, is considerably bulkier/thicker than the Pro, so much that I just would rather not carry around something that big.

Anyway, I'm still trying to find out what the battery adapter actually is!
 
marke said:
Anyway, I'm still trying to find out what the battery adapter actually is!
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Quite simply, the adapter (as shown in the Adorama ad) accepts two SR44 batteries into a module (contains simple circuitry) that allows them to emulate the extinct mercury batteries. Fits perfectly and works very well in mine.
 
Yes, at some point, Mark, Gossen transitioned the Luna Pro to take those common 9v "transistor" batteries. When I started shopping for a Luna Pro on eBay, I wanted the 9v battery and also the null-reading scale. I ended up with a Luna Pro F, which is the Pro SBC with flash-reading ability. I had it looked over and calibrated by Quality Light Metric and use it as the standard for checking accuracy of cameras and other meters.

But, honestly, I prefer to carry and use the Super Pilot SBC, essentially a compact version of the Luna Pro SBC. Found a spare one of those on eBay too... :D
 
I use 675 hearing aid cells, which are the same as the wein cells. They're pretty cheap and readily available. One just needs a spacer to allow them to sit in the battery compartment correctly. I got my spacers from a set of wein cells, though you could pretty easily sort something out at a hardware store.
 
I had high hopes, buying a pair of Wein cells for my LunaSix 3. Unfortunately $20 later the meter is way off. I adjusted the zero point first and everything but it's at least 2 stops too dark in low light.
 
I bought the adapter from CRIS in Phoenix (crisphoto.com), about $5 cheaper than Adorama one. Also bought an adapter for my Yashicamat 124g from them. Cheaper in the long run than the Weins. They have adapters for many light meters.
 
plummerl said:
Actually, the adapter works for both the S and non-S Luna Pro.
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Ditto!

I have both meters. The adapter works in both meters.

The meters look the same on the inside. I calibrated both. The difference is in the dial on the front. You can dial in filter factors and bellow extensions on the "S". You can't on the non "S".

My "S" is slightly less accurate (<1 stop) in the middle of the range than my non"S".
 
capitalK said:
I had high hopes, buying a pair of Wein cells for my LunaSix 3. Unfortunately $20 later the meter is way off. I adjusted the zero point first and everything but it's at least 2 stops too dark in low light.
Click to expand...

That's interesting b/c I had exactly the opposite problem w/ my LunaSix 3. I purchased one of the battery adapters like the one mentioned by the OP. SR44 and LR44 batteries (1.55 volts) fit perfectly, but the meter read about two stops over. I replaced the batteries w/ Energizer 675 zinc air batteries (1.4 volts), and the meter seems to be reading correctly now.

My LunaSix 3 dates from the early 70s, and was calibrated for the lower voltage PX-13 and PX-625 mercury cells (1.35 volts). The voltage on the 675 zinc air cells is close enough, although battery life is not as good. The point, though, is that for older Gossen Luna Pro and LunaSix meters, the battery adapter solves the battery size problem, but not the battery voltage problem. To solve the latter, you've got to use either hearing-aid type batteries or get the meter re-calibrated.
 
One thing to keep in mind with these old meters is that they may need calibration before they can really be relied upon. Like anything else, they can lose their calibration over time. It's also entirely possible that somebody may have had a mercury metre recalibrated to use silver batteries at some point in the past, which would obviously affect your results.
 
Can anyone explain all of this moaning and groaning about making an old meter do what it was never meant to do? All you have to do is buy one generation newer meter. Case closed.

Buy a Luna Pro sbc or newer. Better meter. Reads lower light. I proved that agianst my Luna Pro with real mercury batteries. AND the sbc and newer meters use batteries you can buy in Timbuktu.

Y'all need to give it up.
 
Easy there, Wayne. :) My LunaSix 3 may be almost 40 years old, but if I can get it to work properly for the price of an adapter and a set of zinc air cells, I've saved a bunch of $$$. And, if not, then I'll buy a new one. But surely anyone who hangs around RFF gets the charm of older gear, right? :rolleyes: Like, say, an M5? :eek::D
 
My sbc isn't a lot newer. Cost me $50 with a case and new 9 volt battery and postage. If adapters are $35-$40, plus batteries.............

shakes his head

Y'all have fun.
 
Wayne' right-If I had one my homework before I bought my Luna Pro, I would've bought the SBC version, then got it CLA'd. The cost difference is nil and the 9V makes a lot more sense.
 
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