Gossen Luna Pro light meter

Discussion in 'Accessories' started by mario_henriquez, Nov 6, 2008.

  1. I just got a Gossen Luna Pro used from KEH. I went to buy batteries, which are not easy to find. I put the batteries in but the meter gives
    no readings. It doesn't appear to be working. In the manuals I've seen, they say to get "Mallory" PX 625 batteries. Mine didn't say
    "Mallory" and, now that I remember, they had a Z at the beginning, as in Z 625 PX, or something like that. The guy at the store saw my
    meter and said that it took a little while for the batteries to kind of "warm up." Did I get the wrong batteries? Can someone help? Does the
    "+" sign go down or on top? Thanks.
     
  2. Get the manual for your meter here: http://www.butkus.org/chinon/flashes_meters/gossen_luna-pro/gossen_luna-pro.htm.

    Be sure to leave a few bucks via PayPal.
     
  3. Yes, got that. It's not the manual that I need. It doesn't really say anything in specific about the batteries. Thanks
    anyway.
     
  4. Mario, hi. Google 'PX625' or '625PX' and you'll find a lot has been written about this. The PX625 was a mercury
    battery widely used in photo equipment up to the early 1980s or so. They have been banned worldwide and are no
    longer manufactured.

    You can get a silver version of the 625, called something like a S625PX. They have the same physical dimensions,
    but are slightly higher voltage than the mercury cells (1.5V instead of 1.35V). You would probably need to get your
    meter recalibrated for the different voltage.

    There are other workarounds-- the Cris adapter, 675 Zn-air hearing aid batteries, and the Wein cell (an expensive
    modified hearing aid battery). You can read about these elsewhere.
     
  5. I forgot to look at my meter last night, but I'm 99% sure the + faces up. You can try it both ways, though... if you haven't already. The comment from the photoshop about the bateries needing to "warm up" sounds like the babbling of a well-intentioned but somewhat ignorant crackpot.

    If your meter works you still have the voltage issue to deal with, as Dave Sims mentioned. I use the adapter made/marketed by Gossen. Bought it from B&H. Not cheap, but it works flawlessly.
     
  6. Ho do I recalibrate? I nee to use it now. Thanks.
     
  7. I don't think it's a D-I-Y job. If you need it NOW, perhaps your best bet would be to guestimate the adjustment using Sunny-16 as a standard.
     
  8. But for a "need it now" solution... the 675 Zn-air hearing aid batteries, and the Wein cell suggestions is what you should be looking at. Depending on where you live you can get these at a local photo shop or even a local drug/variety store.
     
  9. So, Brian, I'm out the $20 I spent for the batteries I have now? Damn, KEH really screwed me on this one. They were really helpful, the guy who took my order was really helpful, but he shouldn't have sold me, a beginner (and he knew it), such a "cumbersome" light meter. Or if he was going to sell it to me, he definitely should've said that these batteries are hard to find, they were discontinued a long time ago and you have to make sure you use XXXX kind of battery, or something. He said absolutely nothing. I never could have gussed how difficult/cumbersome this little process would turn out to be. Now I'm p1ssed.
     
  10. The salesman may not have realized it. If you went on the internet and looked up the batteries for your meter, the battery companies will tell you that modern equivalents will work properly, even though it may not be the case.

    Gossen sells an adapter that supposedly allows you to use modern batteries in the Luna Pro. It's expensive. I haven't tried it so I don't know if it works.

    The best way to deal with your meter, if you don't want to spend more money (and I can't blame you) is to test it against another meter on a variety of different light levels and see how far off it is. Make notes, and then make the corrections as you meter your subjects.

    Example, and I'll just make up numbers to illustrate it: let's say you have a camera meter and your Luna Pro and a gray card (or any object that can be flatly and evenly illuminated across the field of view). You set the camera and meter for ISO 100.

    First subject is a low light level. Camera says f/2 @ 1/15th. Meter says f/2 @ 1/60th. You write down that your meter reads 2 stops high.

    Next subject is a medium light level. Camera says f/8 @ 1/60th. Meter says f/8 @ 1/125th. You write down that your meter is 1 stop high.

    Next subject is bright. Camera says f/22 @ 1/500th. Meter says f/22 @ 1/750th. You write down that the meter is 1/2-stop high.

    Now you can meter unknown subjects. If you're at a low light level, open up 2 stops. At a medium light level, open 1 stop. At bright light levels, 1/2 or 1/3rd stop, or leave it alone.

    (As I said, I just made that up. You need to do your own tests to get real world results).

    You can do that with any meter, even old seleniums that you wouldn't otherwise trust. You see how they read vs. a known good meter and note how far off it is. If the results are consistant, then you can use the meter (provided you correct). If the results are erratic, then you need another meter.

    BTW: if you end up buying another meter, try to get one that takes a modern battery. The Luna Pro SBC, for example, uses a 9v battery. It's not exactly compact, but you can go almost anywhere and get the proper battery for it (at least you can in the US).
     
  11. The salesman may not have realized it.
    He knew James. I believe my words were (when he asked what kind of meter I was looking for): "I really don't know what I'm looking for" or "I really don't know what I need." Then he suggested the useless one I ended up getting.
    The best way to deal with your meter, if you don't want to spend more money (and I can't blame you) is to test it against another meter on a variety of different light levels and see how far off it is.
    James, that's a nice suggestion, but I get no readings whatsoever. The meter seems dead. The needle just, hardly, barely, almost moves.
    BTW: if you end up buying another meter, try to get one that takes a modern battery.
    You can say that again. That's what the salesman should have suggested from the get-go; especially with someone who, it was obvious, didn't know much about light meters and was just getting started dealing with them.
    The Luna Pro SBC, for example, uses a 9v battery. It's not exactly compact, but you can go almost anywhere and get the proper battery for it (at least you can in the US).
    I will take that one under consideration. The one I have isn't exactly tiny either. I don't think the Pro SBC will be any bigger/bulkier. How much does that one exactly go for? New and used? Do you know? Also, is it digital or old school? The one I have now is old school. Thanks.
     
  12. Bummer. Even though the gray Luna Pro uses out-of-date batteries it is a great meter. And especailly great for the price. I can't explain or defend KEH but the more important issue is that the meter seems inoperative. If you want suggestion, stop being mad and just return it -- because it doesn't work, not because batteries are hard to find. The cost of a "more modern" meter might be the same or slightly more than the cost of a working Luna Pro and Gossen adapter (I seem to recall that it is $50 or 60... but it really works). None of these suggestions really help you out in your immediate need for a meter. Do you have local photo shops (or even local pros) that yuo can ask around to see if htey can loan/rent you something to meet your immediate needs>
     
  13. If you want suggestion, stop being mad and just return it -- because it doesn't work, not because batteries are hard to find.
    Understood Brian. However, don't you think fair warning would've helped? "Hey, this is a great meter, but the batteries may be a little hard to find; moreover, they were discontinued, but there are workarounds ... blah, blah, blah..." I think that wasn't only fair, but required. I can, and will, return this meter, fine, but what about the $20 I spent on those two batteries? You may say that's not a lot of money, true, but the way things are these days, I can't afford to waste cash. Money is a very prized commodity these days, wouldn't you agree? That's what has me angrier than anything else, not the actual returning of the meter and not having one now that I need it. It would be great if KEH reimbursed me for the batteries, but I highly doubt that. Anyone wants to buy two of these suckers from me?
    Do you have local photo shops (or even local pros) that yuo can ask around to see if htey can loan/rent you something to meet your immediate needs?
    I have here (in San Francisco) Adolph Gassers and Calumet. Gassers is closer so I might go there right now to rent one. This really sucks but what can I do now? Since I'm getting one (I mean buying, not renting), what would you suggest I get? Nothinkg tricky to operate or esoteric batteries. Something good, simple, and affordable. What should I look for? I'll try for a good used one.
     
  14. Good that you live in The City... that gives you some options!

    I appreciate your concern about money... I, too share your situation. Just recently I "wasted" $100 because I was
    told by the cable salesman that a rebate would be sent in the mail, but when I never got it and called the rep, who
    said I had to claim it online... and the deadline was last week. I was P-I-S-S-E-D O-F-F and they offered no option
    other than a somewhat insincere apology!

    What meter to recommend really depends on what you photograph. Minimally I'd suggest something that offers both
    reflective and incident metering. The modern meter that intriques me is the Gossen Lunasix. It's small, digital,
    reported to be accurate...

    The last meter I bought (Sekonic L558R also included flash metering, spot metering, etc, etc on top of incident
    capabilities. It set me back $500. I justified that buy with the "I really, really need spot metering capability."

    Truth be told, though... I use my gray Luna Pro more than any other meter I own.
     
  15. Hey Mario... when at Gasser's check out their used equipment -- they have a Luna Pro for $89 that appears to be a black case... which I think all use a 9v battery. Don't know what your budget is but mgiht be a good option!
     
  16. I can get this sucker:

    http://www.amazon.com/Polaris-SPD100-Digital-Exposure-Meter/dp/B00009X3UA/ref=sr_1_3?
    ie=UTF8&s=photo&qid=1226087407&sr=1-3

    at Amazon for $169 or locally for $180. Or this one:

    http://www.amazon.com/Sekonic-401309-L-308S-Flashmate-Meter/dp/B0009ISRSA/ref=sr_1_2?
    ie=UTF8&s=photo&qid=1226087745&sr=1-2

    at Amazon for $180, locally probably $10 more, I haven't checked. What do you think? Both, I believe, use normal
    batteries. Batteries that can be found at any store.
     
  17. Thanks Brian. I'm leaving now. I will let you know.
     
  18. Update:
    I went to Gassers and they didn't have any used or new meters for sale. I explained to them what my problem was (I had brought the meter with me), and the salesman I was talking to started fussing with the meter. He checked the batteries to see if they were good and, sure enough, the batteries were not the problem. I had also put the batteries right (the positive sign goes up). He also couldn't figure out why it wasn't working. Then he thought that maybe the lid wasn't making contact with the battery, so he got a screwdriver and lifted the, uh, the metal thingy then closed it up and ... voila! It worked!
    This proves to me that KEH doesn't make sure that their equipment—especially since it's used—works before leaving their store. Those are not good retail habits, are they? Which made me wonder, should I still return this? Since, technically speaking, they sold me a deffective item. What should I do? Thanks all for your help.
     
  19. That's a shame GAsser had no meters (I wonder why they ahve on ontheir web site under 'used equipment'?) But it was nice of them to fiddle with it and fix it. Maybe things are finally going your way. Check out an adapter - either the Gossen (at B&H) or a CRIS (you'll have to google it). Once you get it installed you'll have a fantastic meter with a "modern" battery.

    For your immediate need... go outside before the sun sets and see how far off the meter reads with the 1.5v batteries as compared to Sunny-16. It will likely be high by a stop or so. Then you can use the meter and compensate by subtracting that difference. It should be good enough for average type exposures.
     
  20. If you'll tell us what you want to use the meter for, we can make good suggestions on what will fit your needs. Brand new meters are pricey, but they're now aimed at professionals who can afford to pay the price (since it's a business expense).

    I ask because if you just want something simple to use with an old film camera, the suggestions will be very different than if you want something for studio flash photography with memories, light balancing, etc. There's no point in buying an expensive meter if you don't need all the advanced features.

    To go back and answer your earlier question: the Luna Pro SBC is large. It's a big bigger than the Luna Pro (though it's light for its weight). It's old school in that it's analog needle readout and has a big calculator dial which does quite a few things. But--it's a nice meter. It takes a common battery, it's got a lot of features, and it's part of a system that takes attachments so you can do other things. If big and bulky and complicated is NOT your thing, then you don't want it. I haven't priced it in a long time, but I'm guessing they're around $100 for a good used one.
     
  21. Okay. I take it by your suggestions (after my update) that you wouldn't advice me to return the meter. Ok. Now, I have read the manual for the Luna Pro on how to use the meter and ... I still don't know how to use it. Where are the numbers that I need? I point to a subject and then what. Where are the arrows that point me to the numbers that I will need to make correct exposures? I know this sounds elemental, but I have never used one of these suckers, much less analog. Thank you.
     
  22. First set your film's ASA on the dial.

    For averaged reflected light readings:

    With the white dome pushed to the side, point your meter at a scene.

    Press and hold the lever on the side - down for bright light; up for dim light (I think. You'll know if it is the opposite)

    When the needle settles (about 1 second) release the lever and it will lock the needle in place.

    The number that the needle points at should be transferred to the dial - at the yellow diamond mark.

    (The red and green markers are for when using the Gossen 7/15 degree spot attachment)

    Now read either EV from the EV window or any of the equivelent shutter speed + aperture combinations.

    Set your camera to the EV (if your camera allows that) or to your desired shutter speed + aperture combination.
     
  23. For incident light readings...

    Do everything above, except center the white dome over the meter sensor.

    From the postion of the SUBJECT, point the meter toward the camera and take a reading.

    Transfer the meter reading to the dial and set your cammera acccordingly.
     
  24. Mario, it's like riding a bike... takes a bit to get used to it but then you'll have the skill for a lifetime!
     
  25. Why don't you just go to a Batteries Plus store and buy either the Kodak or Duracell direct replacements for the Z625PX?
    They sell two for $9.00. I bought mine in one somewhere in Arizona as I was driving through.
     
  26. Why don't you just go to a Batteries Plus store and buy either the Kodak or Duracell direct replacements for the Z625PX? They sell two for $9.00. I bought mine in one somewhere in Arizona as I was driving through.
    I already got them. They're working now.
    Thanks all for your help.
     
  27. I've had a Gossen Luna Pro for years. Mine was made in 79 if I remember right. It's a terrific meter. I really need to get a flash meter with a PC port, but I've always resisted because I love my LP so much. You got a terrific meter.
     
  28. Ok, one sideways question: why do you need a lightmeter, or put another way: what kind of camera are you using?

    And secondly, will you not also need a flash capable meter, given that you use a non metering camera?

    Just a few thoughts. Mess around with them and see what you can make of them to whom KEH "shouldn't have sold
    me, a beginner (and he knew it), such a "cumbersome" light meter." (quoted from your post) A self-pronounced
    beginner with a professional lightmeter, what gives, Mario? Sorry, be mad if you need be, but be good as well,
    please.
     
  29. The simple answer is to return it. Having a hard time gettting batteries, or having to buy an adapter you didn't know
    about, are both legitimate reasons to return it.


    The adapter that Gossen (sold at both Adorama and B&H) makes for the batteries actually is cheaper than buying
    two CRIS adapters, which you would have to do if you went the CRIS route

    I still haven't found a definitive answer on whether the Gossen adapter actually steps down the 1.5-volt batteries to
    1.35 volts. If anyone has a definitive answer on this -- i.e., some kind of literature from Gossen, or maybe you're
    handy enough to know how to measure the voltage through the adapter, or even if you have measured the adapted
    meter against another meter you know to be accurate -- I'd like to hear from you. Otherwise, please don't quote what
    you've seen on other posts (they're definitively contradictory) or suggest I look on the Bogen site (there's nothing
    there about the adapter).
     
  30. I saw someone on ebay recently who had a bunch of the old (now illegal) mercury batteries for sale for around $3 each. I don't know where he got them from but that would be the easiest solution and they should last for years. I'm not sure if it's illegal to buy them, but I do think hes not supposed to sell them, but hey, we need them, so get um while you can!
     
  31. Ok, one sideways question: why do you need a lightmeter, or put another way: what kind of camera are you using?
    Mamiya RB67.
    I found the batteries. The suckers are about $9.95 each. I'm still mad at KEH, but I'm going to keep the meter. I don't want to deal with returning it. I got it for about $39. Hopefully it won't break down. I'm testing my Mamiya, that's why I got it. I have to figure out how to use it now.
     
  32. I have two of the Luna Pro meters for use with my many old Pentax screwthread cameras. I have a small stock of
    mercury cells that I mainly use in old Canons. I also have two of the Gossen battery adapters. They are exactly the
    same as the mercury cells when I use them in my camera with the cheap, easily found SR44 batts. Two CRIS
    adapters may not fit in the battery chamber. I also have a Gossen Super Pilot, a great meter that uses only one of
    the old mercury cells. My preference is the Gossen adapter for the Luna Pro.
     
  33. I have a old Gossen Lunasix 3. Similar to your meter. It takes two PX625 batteries.

    The silver version of the PX625 battery is available from different sources on the net. MD battery seemed like a
    fair place, and I received a pack of 6 PX625s for 16.95 plus shipping. (DO NOT USE THE ALKALINE VERSION OF THIS
    BATTERY.)

    I opened the case of the meter and installed a 1n914 diode in the + lead coming from the battery compartment.
    There are two ways to do this, one is wrong, so experiment. Being able to solder is important. This operation
    took less than 15 minutes. When the battery test button thingy is pushed the needle of the meter hits the "OK"
    mark.

    There is nothing special about the diode other than it is plentiful and has the right characteristics. I
    purchased a package of them and I may have been ripped off a bit by paying about 95 cents for 50. Try Radio Shack.

    The whole effort cost somewhere around $3.00 and 15 minutes.

    I was so pleased that this worked so well I then did the same to my crusty old Weston Ranger 9 meter and a
    Olympus OM1.

    Yes, the meters are accurate and when the batteries go dead in a few years I'll simply replace with another
    silver battery.

    Paying all that money for an adaptor or adaptors seems a little expensive, as well, the batteries can be very
    expensive if purchased from the local drug store!
     
  34. I have a Gossen Lunasix. Same problem.

    I got a homemade adapter for it (two actually), that will take SR44 silver oxide batteries (DO NOT use the LR44 alkaline variant). Works perfectly.

    Look also at this link: http://www.buhla.de/Foto/eQuecksilber.html

    There are several sources where you can get them if you don't trust your DIY skills. I can't find where I got mine though... but they were 15 euros each. Makes 25 for the meter + 30 = still only 55 euros for an excellent meter.

    Please be aware that using 'equivalent' alkaline batteries in your meter, you will get readings, but they will be inaccurate. You MUST use silver oxide batteries.
     
  35. Look, unless your film and processing are free, sideline the relic and get something newer that swallows AA batteries.The "adapters" outside the CRIS products just sleeve the smaller silver cells into the old PX625's home. The Sekonic 318-328-308 meters are all over the big auction site and usually don't fetch huge $. Just do it and get shooting, OK?
     
  36. The Sarah Fox fix requires another meter to calibrate the Luna with. That could be a problem.
    The Gossen battery kit costs $40 at Adorama. http://www.adorama.com/GSLPSB.html
    Is that for an adapter and two batteries? Once that is purchased, can just batteries be purchased as required later, or is that kit required whenever new batteries are needed?
     
  37. Paul's suggestion of adding a diode in series with the + lead is definitely the way to go. Although I would make one small change: the 1N914 has a rated voltage drop of 0.6V to 1.0V. That's a bit more than we want (3V - 2.7V); we'd be better off using a Schottky diode with a forward voltage drop of 0.4V, like an SD-101 or 1N6263. Pretty much any Schottky small signal diode that will fit, will do the job. Less than a buck at Digikey.
     
  38. The "adapters" outside the CRIS products just sleeve the smaller silver cells into the old PX625's home.
    No, they contain a diode that produces a constant 0.4V drop, reducing the effective voltage of two 1.55V batteries to what you would get with two 1.35V mercury batteries.
    As for the "warm-up" period of the other batteries, this is completely true. Virtually all batteries work by an oxidation-reduction chemical reaction. Zinc air batteries, which have a potential of 1.4V, work by using actual oxygen in the air to oxidize the zinc. It takes from 5-30 minutes for the air to react enough with the zinc for the battery to get up to the correct voltage. It's this reaction that reduces their lifespan, since they keep reacting with air whether or not you're using them (unlike regular batteries, where the oxidizer and reducer only react when there's a complete circuit, with electrons flowing through, give or take a small trickle charge that can deplete some batteries during storage).
     

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