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01-23-2016, 08:07 PM   #1
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Film Folks: External Spot Metering

Im looking to step up my film game and exploring buying an external spot meter. Currently I just use spot metering on my 645n and take a few readings from around the scene, determine the exposure I want, compose the scene and go. This has been working well, I still tend to bracket just to be safe, but I feel it would be a lot smoother if I could compose (so I know exactly whats in the scene), then meter and set exposure. My issue is that current meters that have built-in spot metering are really expensive and the one Im looking that has an add-on module is a 5 degree spot (as opposed to 1 degree for dedicated meters).

Effectively Im looking at 3 options:
Option 1:
Sekonic L-758 (various models) with built-in spot meter

Option 2:
Use Pentax digital spot meter (as available)
Some other meter for flash and still life scenes

Option 3:
Sekonic L478 w/ 5-degree add-on spot meter

My shooting involves almost exclusively landscape work with a small, but growing, percentage of still life work. Thoughts?

**Admin, I'm cross-posting this in the Photography Technique forum in case folks aren't tracking both. Feel free to adjust as necessary.

01-23-2016, 08:42 PM   #2
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You really can't go wrong with a Sekonic and your first option would be an excellent choice. I've owned Sekonic analog and digital incident and flash meters since 1979 and (knock on wood) they've never needed repair. The main advantage of Sekonic is that they are still in business in case you needed a repair.

Pentax digital spot meters may be your least expensive option but I am only familiar with their older analog spot meter which works well, but is a bit more cumbersome.

My bread and butter spot meter that I still own and it still works is the Minolta Spotmeter F. I paid around $400 for mine 30 years ago as it was the default spot meter on film sets. Here's a link for two in excellent condition at KEH for $238.

https://www.keh.com/shop/light-meters-minolta-spotmeter-f-ambi-flash-711002.html
01-23-2016, 08:54 PM   #3
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I own several one-degree spot meters and I also have a Sekonic with a 5 spot attachment. Plus I've been using a one-degree for my sole source of light metering on film for a long time. With my choices there is no question I'd grab my Pentax "digital" one-degree first. But I have a choice.

The darn thing is expensive but it's pretty compact compared to the Pentax Spotmeter V and the 1 circle is way more useful for picking out specific areas than a 5 a lot of the time. One thing very import about the the Pentax Spotmeter V and the "Digital" is they use an analog scale for finding all your combinations of exposures once you set the middle gray EV at a glance.

I like that interface that WAY more than a LED screen read out of your values and paging through different modes. If you do long exposures with say a 9 or 10 stop ND filter and perhaps stack that with say a orange filter (BW film) it is way easer to count stops with that scale than on something like that Sekonic. And you can even extrapolate past its scale to get a long exposure time. But that is my preference. Your milage may vary.
01-23-2016, 11:16 PM   #4
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I have become a bit interested in why there are photographers still preferring the old time external hand held light meters.
I am mainly interested in the meters with the cadmium sulphide sensors (called CdS or LDR) .

A while ago, I restored a dead Honeywell Pentax 3/21 spotmeter ( about 1963 vintage I think) by replacing its corroded, obsolete dual battery,
and crude scaling resistors with an elementary active circuit.
Here is a link to my apug thread about the conversion in 2013 ( with some photos of it)
Vintage Spot Meter Refurbish

That one is working OK, and I must say, there is some "feel good" about being able to scan around a scene for spot EV indication on that Pentax meter.

The present restoration I am doing is more elaborate.
The light meter being resurrected is a Gossen LunaSix, obtained for mostly shipping cost.
This one looks like it was "murdered" by someone cracking open its nice case.
These old meters were more or less designed for no intrusion to unauthorized service,
by covering the cover screws with glued on thin, soft aluminum silkscreened plate

The other problems with these old light meters:

:The mercuric oxide batteries of old were chemically configured to hold excellent voltage regulation over their life and temperature.
There is currently no replacement, and ( I conclude, my opinion) the voltage reducing adaptors with Shottky diodes are not nearly as accurate.

:There was no compensation in these meters for ambient temperature drift of the LDR sensors.

: It is likely that the factory set screwdriver variable resistors would have been tampered with over the life of these old units.

:The d'arsonval needle meters suffered from impacts, old age, and operation at other than horizontal.
https://en.wikipedia.org/wiki/Galvanometer

:These meters provided the logarithm conversion to EV by a combination of a reciprocal math approximation which is further tuned by
non linear graduations on the meter scales.
"Company" specific scales were needed as the meters were not quite capable of scaling EV directly.

Anyway I have a prototype for a printed circuit board ( analog of course !) on my electronics bench
that will use the optical parts and the circular scaler from the old Gossen,
and hopefully reduce tha above problems. It uses FET op amps in logarithmic mode and a constant temperature controller for the critical parts.

If i get it working I will put a thread on apug.
(ps I have the "Light Meter Tools-Trial" on my HTC Android, and it looks rather good by my eye in the wintry sun here. )

May the whimsical light meter live on !

01-24-2016, 12:38 AM   #5
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QuoteOriginally posted by wombat2go Quote
The light meter being resurrected is a Gossen LunaSix, obtained for mostly shipping cost.
QuoteOriginally posted by wombat2go Quote
The other problems with these old light meters: :The mercuric oxide batteries of old were chemically configured to hold excellent voltage regulation over their life and temperature.
QuoteOriginally posted by wombat2go Quote
I am mainly interested in the meters with the cadmium sulphide sensors (called CdS or LDR) .
The Gossen Lunasix also known as LunaPro was released in its earlier versions with a Cadmium Sulphide sensor and its later versions with a Silicon Blue Cell, the earlier versions also used mercury cell batteries and the later ones used a simple common 9 volt battery. Gossens website still has user and service manuals for their old meters, you possibly could compare the schematics for the earlier and later models and make changes to your meter to convert it to 9v or find a non working later donor for the resurrection.
I have one of the later LunaSix F meters with a silicone blue cell and its accuracy and sensitivity are amazing ( -6 to +22 EV ), the analogue scale is even better than the one on my Pentax spotmeter and is a joy to use. Just like Tuco I much prefer an anologue scale it feels more intuitive.

Glenn
01-24-2016, 12:57 AM   #6
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QuoteOriginally posted by wombat2go Quote
I have become a bit interested in why there are photographers still preferring the old time external hand held light meters.
Probably because they come in handy at times. TTL metering is nice, particularly when using filters, but when you need to know the range of light in the scene and where particular values lie, that is pretty hard to do with an in-camera meter. I always have a hand-held in the bag.


Steve
01-24-2016, 01:23 AM   #7
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Hi G&T and Steve
Yes absolute brightness makes sense to me and I am giving my meter a direct EV output, (with the dome on the sensor.)
The LunaSix I am dissecting ( I have the circuit of it ) had a range of approximately EV minus 4.4 to plus 17.
That is range 0.17 Lux to 350,000 Lux ( EV ~ Lux cast in stone by ISO since 1950's , as I read)

Actually the original LunaSix LDR sensor exceeds this range at low light and at high light,
but the design was limited by scales on the 40 microAmp meter
and the crude passive transfer function. ( it used 2 ranges to get there)

The LDRs are still available at very low cost, I expect at similar sensitivity, but i have not yet tested the samples here.
The circuit I am designing has a 9V 6LF22 battery to give a split +/- 3.6V supply for the light meter op amps,
plus another 6LF22 for the ambient compensating heater.
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01-24-2016, 07:24 AM   #8
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QuoteOriginally posted by wombat2go Quote
I have become a bit interested in why there are photographers still preferring the old time external hand held light meters.
I
Because with a one-degree meter, YOU get to select what tone in the scene is the middle gray. Use an incident or reflective average meter then ask yourself how many stops of light are in the scene and how many stops above/below the middle gray exposure are the shadows/highlights and will they reproduce on the film to support your vision of what you want. You won't know that very well if at all with the other meters or perhaps don't care.

But armed with that information and experience placing your values you will know what the exposure looks like before you even develop the film with a one-degree meter. That can be especially useful in high/low contrast scenes.

And if you shoot BW film and used a one-degree spot meter long enough, soon you will rarely need a meter at all anymore outdoors in the daylight. You will soon discover something about the EV of shadows and then can place your low values pretty easy without one most of the time.

01-24-2016, 11:33 AM   #9
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QuoteOriginally posted by tuco Quote
Because with a one-degree meter, YOU get to select what tone in the scene is the middle gray. Use an incident or reflective average meter then ask yourself how many stops of light are in the scene and how many stops above/below the middle gray exposure are the shadows/highlights and will they reproduce on the film to support your vision of what you want. You won't know that very well if at all with the other meters or perhaps don't care.

But armed with that information and experience placing your values you will know what the exposure looks like before you even develop the film with a one-degree meter. That can be especially useful in high/low contrast scenes.

And if you shoot BW film and used a one-degree spot meter long enough, soon you will rarely need a meter at all anymore outdoors in the daylight. You will soon discover something about the EV of shadows and then can place your low values pretty easy without one most of the time.
And, with the modern multi meters, you get flash and incident light thrown in for the bargain, exposure and flash compensations, all sorts of convenient things displayed in a way that is often easier to read than in the camera---and allows for switching back and forth easily. You also get Zone System, at least with the Gossen.
01-24-2016, 10:32 PM   #10
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+1 for the older analog handheld meters.

I use a Pentax Spotmeter V and a GOSSEN LUNA-PRO SBC when shooting with my 6x7 bodies.

Phil.
01-25-2016, 12:16 AM   #11
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Spot and multispot metering is very straightforward, assuming you have the aptitude and an analytical approach to the process. It cannot be rushed and you must first examine the scene with your own eyes and make informed judgement as to what the meter will be reading, and what the meter will be doing with that reading in the end (most users average multi-readings; some will make do with just one or two with no averaging). Whether you use an analogue or a digital meter is secondary to the skills you possess that will make the most effective (and correct) use of either meter type. Everybody has their own choice; mine is a Sekonic L758D and I swear by it for all multispot metering instead of my Pentax 67's TTL meter (used only if I need to in a scene where there isn't the time to multispot). There are many, many different processes that can be customised with digital meters, less so with analogue meters; whether this is important to you is not known, but to professionals with experience they can tailor the meter's response and readings to one or more customisations. A 1 spot meter has far more discernable accuracy than a 5 meter which will have overlap (some Gossen digital meters have both, selectable), but having said that, either type will deliver the results the photographer envisions if he knows his stuff. The emphasis thus is on the photographer, not on the meter.

Last edited by Silent Street; 01-25-2016 at 01:15 AM.
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