Old light meter quandary?

[Bolo Kukus]

I can confirm that two 386 plus the adapters fit well in my Gossen Lunasix Three.

I have two of the beasts. Now relegated to inglorious retirement due to batteries (or lack thereof).

You have made my day, if not my entire week with this post. Thanks!!

 

[wrs1145]

Now, if I just could find a YouTube video showing how to use the meter I'd be ecstatic!

 

[Godfrey]

Now, if I just could find a YouTube video showing how to use the meter I'd be ecstatic!

Read the instruction manual, downloadable from Gossen Luna-Pro instruction manual, user manual, camera manual

G

 

[Chriscrawfordphoto]

Now, if I just could find a YouTube video showing how to use the meter I'd be ecstatic!

If you already know how to use a handheld meter, but just need to know how to operate the Luna-Pro, click the link Godfrey gave you. The meter is pretty simple to use.

If you don't have experience using a handheld meter, and want to know the difference between using incident metering and reflected metering, check out my handheld meter tutorial: Introduction to Handheld Exposure Meters.

 

[wrs1145]

Thanks a lot, you both have been a tremendous of help-that's why I belong to RFF.

 

[DeanThoreau]

If you can get the adapter that Gossen made that lowers the voltage of the silver oxide batteries to match that of the 1.35v Mercury batteries the meter was designed for, then use that. Do not use LR44 (Alkaline) batteries; you MUST use SR44 (Silver Oxide. Also S76 or 357 work too) batteries.

Alkalines do not keep a stable voltage; it constantly drops as the batteries are used. The Luna Pro does not have built in voltage compensation, so the batteries must deliver 1.35v each (total of 2.7v) at all times or the meter will not be accurate. For this reason, the EPX625G will not work on this meter. The starting voltage (1.5v) is too high and they will constantly drop as they are used, so the meter will never give consistent readings.

Stupid question I just picked up a gossen lunar pro… it has the adapters for sr44 aka 357 batteries… which direction do they go in? The adapter has a + sign on the solid flat spot… but now what plus down. Plus up??
And the teeny tiny picture above the battery space is way to small for these 72 yr old eyes to see..
So help would be appreciated…
If it works I’ll use it …

 

[Chriscrawfordphoto]

The instructions for the battery adapter I have shows putting the adapter in the meter first, with the open side facing up. Then place the two batteries in the adapter plus side up, then put on the battery cover.

 

[Muggins]

My III, my two IVs, my three Vs and my four EuroMasters all read exactly spot on, that is half a stop under, which it seems is common with those ancient things.

That half-stop error is almost certainly due to film speeds being redefined at some time in the 1960s.

 

[Coldkennels]

That half-stop error is almost certainly due to film speeds being redefined at some time in the 1960s.

Exactly this. Weston also used their own proprietary scale for a good chunk of time, just to confuse things further.

A Weston I or II will need to be two "notches" below modern film speeds - 64 Weston for 100 ISO.
A Weston III, IV, or V will need to be one notch below; 80 Weston on the III or 80 ASA on the IV or V for 100 ISO. I believe the Euromaster is the same.

The V is particularly interesting, as it shows the speed in DIN as well as ASA. DIN has been much more consistent - 21º DIN has been equivalent to the modern 100 ISO much longer than 100 ASA was. Even so, if you set the scale on a Weston V to 21 DIN, it shows 100 ASA - but you're still 1/3 of a stop out from modern meters. You can see this is an issue with the way the scale is designed and not the reading from the meter itself because 15 EV on the dial comes out at 1/125 and f/16 as you'd expect at 100 ISO, but the arrow is pointing one notch below one of the marked numbers:



On the other hand, set it to 80 ASA or 20 DIN and you get perfectly aligned readouts:


I think Weston just rebranded their old Weston Speeds when they moved to ASA-marked dials and forgot to compensate for the difference between the two ratings - and I do wonder how many of the people claiming their Weston meters are inaccurate simply don't know about this slight design "issue".

 

[Muggins]

Weston numbers are a ballache!

 

[Coldkennels]

Weston numbers aren't that bad. They're pretty easily convertible once you consider the two adjustments made (Weston changed their numbers themselves to mirror ASA just before the III came out, only for ASA to then revise their numbers up a tad at some point after that) - and at least Weston meters themselves give you an easy way to get used to the differences. Something like GOST is far more confusing if you tinker with Soviet stuff.

Where things get really confusing is if you're using really old equipment or reading old books and magazines. I've been getting into flashbulbs, and I have boxes of Philips PF1 and PF5 bulbs marked only in ASA and BS - British Schneider! It's hard to know exactly what the guide numbers should be for modern film emulsions. The best bit is I have some that are marked as having or using "new film speeds!", which just leaves me with even more uncertainty and confusion!

 

[Muggins]

Somewhere I have a meter that reads in H&D....