What are the better light meters for very low level light?

Sparky

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Dan Fromm said:
Lunapro = LunaSix 3. And it doesn't have a selenium cell, it has a CdS cell.

There's also a LunaPro SBC, as mentioned by Helen and others, that is not a LunaSix 3. Gossen's names can confuse.
Click to expand...

Thanks Dan - I'm sure that's the one I was thinking of. Cadmium Sulfide. However the LunaPro is NOT the same a the LunaSix. There ARE actually differences. I realize that they look very much the same on the outside. But it's what's INSIDE that matters, don't you think-?
 

Dan Fromm

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Sparky, you are confusing LunaPros with LunaPros.

When the LunaPro was introduced in the US, it replaced the LunaPro II. A meter identical to the LunaPro sold in the US was sold in the rest of the world as the LunaSix III. You can look it up.
 

JBrunner

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well then maybe I'm not as dim as I look.... well, really no chance of that....
 

Sparky

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Dan Fromm said:
Sparky, you are confusing LunaPros with LunaPros.

When the LunaPro was introduced in the US, it replaced the LunaPro II. A meter identical to the LunaPro sold in the US was sold in the rest of the world as the LunaSix III. You can look it up.
Click to expand...

I suppose I COULD be mistaken - though I DO recall being on another forum somewhere - SOME TIME AGO (so don't hold me to it!) where after EXHAUSTIVE conversation it was determined that the Lunasix was a good deal more sensitive than the Lunapro (pre-SBC). I understand that the housing looks very similar. But I think that the six goes down to -8 and the pro only to -4 or -6 (hard to tell - since everyone's piped in with a different value). And I DO understand that just because the dial reads out a certain value - that it's not necessarily indicative of the sensitivity. I'm assuming the 'pro is a 'desensitized' meter for the american market only.
 

Helen B

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Here's a thread on photo.net.

My Profisix SBC has:

a dial that goes down to EV -8,
but at ISO 100 won't go past -5, and
a table of fc equivalences on the back that goes down to EV -5 @ ISO 50 (ie EV -4 @ ISO 100).

Unlike Ben's, mine doesn't have a memory button. The memory function is automatic, and lasts about forty seconds.

In practice it will read down to -8 at ISO 100: ie the dial set to -5 and the needle at -3. I've just tried it. I set it up in illumination at -4, then added one stop of ND. It read -5 with the needle centred (the dial won't go further than that, as I mentioned). Then I added two more stops of ND and the needle read -2 (ie EV -7). Then I added one more stop of ND and the needle read -3 (ie EV -8). That was 'quite dark'.

How about that? I mean, I've only had this meter for about twenty years so how could I be expected to know much about it? Now I love it even more. I have too many meters, and tend to use dedicated spot and incident meters more than the Profisix type.

Best,
Helen
 

Dan Fromm

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Um, Sparky, my LunaPro, s/n 4D06049, reads to EV -8.

Please go to the public or USC or UCLA library and look in back issues of photography magazines -- I suggest Modern Photography for the US market, BJP for the UK. I think you'll find that the LunaPro II was replaced in the US by the LunaPro and in the UK by the LunaSix III at the same time, also that the LunaPro as originally released and the LunaSix III have the same specifications.

You should know better than to trust any information about equipment found on the Internet except, perhaps, on manufacturers' sites. And that especially includes information on BBSs like APUG's forums.
 

Mick Fagan

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The Gossen people were quite proud of their new meter that was capable of metering under moon light.

This was the beginning of the Luna series of meters.

Luna, is the ancient Roman goddess of the moon.

Mick.
 

Dan Fromm

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MIck, the two-button LunaSix begat the rocker-switch with improved or corrected spectral sensitivity LunaSix II which in turn begat the "accepts clip-on accessories, otherwise not much changed" LunaSix III/LunaPro.
 

Early Riser

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I did a bit of research on this a while ago. The calcuflash XP which was previously mentioned here is the lowest light level reading meter. I bought one used about 2 years ago, they are very hard to find now as they are long discontinued. They measure as low as -7 EV.
 

Helen B

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I thought that we'd established that the cheap and readily available Profisix / Lunapro SBC or whatever it's called reads to EV -8 @ ISO 100.

Best,
Helen
 

egdinger

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What are the options for the 1.35 volt models of the lunapro, is it possible to get one recalibrated?
 

Ted Harris

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Another thought, the Gossen Mavolux series of meters for technical lighting engineering work will> I believe give you readings as low or lower thanany of their meters designed for still photography. Of course you hae to convert from lux or footcandle readings. I'v got an old one I used to use for very fine tuning of theatrical and cine lighting that I can dig out and check tomorrow.

Caveatthat these are ot easy to use meters. They are two piece with a separate probe.

Michael, can you add anything here?
 

Early Riser

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Helen B said:
I thought that we'd established that the cheap and readily available Profisix / Lunapro SBC or whatever it's called reads to EV -8 @ ISO 100.

Best,
Helen
Click to expand...


Helen, the meter dial has markings as low as -8 EV on that meter, however I understand that the meter itself only has sensitivity down to -4 EV.
 

Dan Fromm

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Early Riser said:
Helen, the meter dial has markings as low as -8 EV on that meter, however I understand that the meter itself only has sensitivity down to -4 EV.
Click to expand...
Please give a source for that.
 

Helen B

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Early Riser said:
Helen, the meter dial has markings as low as -8 EV on that meter, however I understand that the meter itself only has sensitivity down to -4 EV.
Click to expand...

Well, as I explained in an earlier post, as a result of this thread I tested mine down to an EV of -8 @ ISO 100 and it was surprisingly linear down to -8, so I'm satisfied that it works down there.

Best,
Helen
 

Helen B

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Ted,

I think that you will find that industrial light meters like the Mavolux are significantly less sensitive than photo ones: those guys just don't need to measure down to the levels we are interested in - certainly not down to the 0.001 fc that the Profisix will measure.

If you are happy with a two-part instrument, the Minolta Booster II is probably the most sensitive photographic lightmeter around. They work with some Sekonic meters (like the 508) as well as some of the Minolta range. Though I have one, I don't think that it is a significant enough improvement over the Profisix based on its low light performance alone. Its versatility is another matter.

Best,
Helen
 
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Ted Harris

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I checked and actually the Mavolux measures down to the same 0.001 fc that theProfisix mesures .... but as I noted it is a harder meter to use and also costs more.

One more question here .... how important is this actually? Considering that a light meter is a reference tool only and when we are talking extremely long exposures a light meter goes from being a reference point to a broad guideline. Extremem low light exposure may jsut be oneof those areas where experience counts for as much as all the technology we can muster.
 

Michael Mutmansky

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Ted,

The biggest problem with scientific meters is that they are geared towards eye sensitivity curves, not film. That can introduce some errors along the way. Interestingly, the human visual system is not linear (big surprise), and the meters are all geared toward photopic vision (normal vision conditions), not scotopic vision (night vision), or mesopic vision (a transition band between the two).

So, I would probably avoid using a scientific meter unless it is specifically made for film sensitivity, or unless you are willing to do a little testing.

Scotopic and mesopic vision are the resaon we can be out at night an think there is something worth photographing when the light levels are so excessively low. Scotopic vision is 'rod' vision, and is mostly color blind, but highly sensitivitve to blue wavelengths. This should come as no suprise as the reflected light of the moon has a good bit of blue in it, and it is what we evolved to see under at night.

FYI full moonlight is often about 0.03fc, and once fully dark adapted, it feels like you could perform brain surgery under that level of illumination.


---Michael
 

naturephoto1

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As I stated on the first page of this thread and because light meters only become a guide in such low light, a guide such as the Black Cat may prove very useful under these conditions.

Rich
 

Lee L

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Early Riser said:
Helen, the meter dial has markings as low as -8 EV on that meter, however I understand that the meter itself only has sensitivity down to -4 EV.
Click to expand...
As I stated in earlier post to this thread, the instructions for the LunaPro F (a variant of the SBC with flash metering added) specify -8 EV. That's a manufacturer's spec, verified by Helen on an equivalent model. Good enough for me. I'll be meeting John, this thread's originator, with my LunaPro F at the site he wishes to meter tomorrow.

Lee

P.S. Manuals for older Gossen meters (English sections) are at: http://www.gossen-photo.de/english/...icts/navi_foto_sammler_sub_01_anleitungen.gif
German language manuals are on another part of that site.
 
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jp80874

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Thanks Lee. I was just about to send an email to confirm that. Coco my Labrador and I were just hiking there this morning. Thanks for coming and bringing the meter. Thank you all for your help on this thread and the Rocks and Roots thread from which this started.

John Powers
 

jd callow

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I suspect Helen may be a bit more forthright than many manufacturers.

Reciprocity failure is a real issue. I've never used anyone's charts and have found many manufacturers either don't give extensive information (stoping at 30 seconds or a minute) or are somewhat optimistic. Doing your own testing is easy enough. Using someone elses test results would be a good starting point, but nothing can anticipate variances in meters and metering styles. There is much to be gained above and beyond reciprocity attributes by doing it yourself.
 
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