Reading a UNITTIC Light Meter

[Raffay]

Hello,

I have a UNITTIC light meter, and before I move on to a one with reflective reading capability I need to learn how to use it perfectly. I would appreciate if anyone with experience could guide me, I assume that with these it is not possible to use the zone system, am I right?

The front picture shows all the dials and the reading scale, the second picture shows the back, the reason I have included the back picture is that there is a little screw that is not aligned with 0, is this exposure compensation or just a screw. If it is compensation then it seems to be a stopped down a few stops.

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Cheers
Raffay

[Ian Gordon Bilson]

The screw is used to zero the needle. Typically you should have the meter horizontal,exclude all light from the photocell,and adjust the screw until it aligns neatly with the O mark on the scale.
Your meter is reflective reading only,unless you have the white translucent incident diffuser.
It also has a flip-up cover over the cell to use in low light.
Note the 2 arrows at either side of the ASA window -use the black arrow with the cover open,and the red arrow with the cover closed.

[John Koehrer]

The meter can be used with the Zone system, you may have to approach your subject to get a meaningful reading.
Additionally,
1)set the ASA in the window
2)Point the meter at your subject
3)take the value pointed at by the meter and set one of the arrows(high or low light. Black for low, red for high) mentioned above to a matching value on the dial.
4)The dial(s) then read all combinations for that ASA

[Raffay]

The meter can be used with the Zone system, you may have to approach your subject to get a meaningful reading.
Additionally,
1)set the ASA in the window
2)Point the meter at your subject
3)take the value pointed at by the meter and set one of the arrows(high or low light. Black for low, red for high) mentioned above to a matching value on the dial.
4)The dial(s) then read all combinations for that ASA

Hello John

I need some clarifications:

1. when you say point the meter at your subject, do I need to open the flap (what are the flaps for) and use the meter or use it with the flap closed.

2. Does this meter take a reflective reading so if I want to meter a human face I should go close to the face (how close) point the meter to the face and take the reading, is this correct?

3. When you say set the meter for high or low light black or red arrow, what exactly do you mean?

Any idea about the screw at the back, I tested by putting my hand on the meter to block the light the reading goes down to zero, so do I need to do anything to the screw, it's not pointing at 0 does this affect the reading I take.

Cheers
Raffay

[Raffay]

I just noticed, the red arrow is marked with a 0 and the blue arrow is marked with a c. Any ideas?

[Raffay]

Hello All

Take a look at this picture, I took the reading using my UNITTIC meter, by close the the areas marked in shutter speeds, all the readings are at f16 and asa set to 200. My questions:

1. Now if I want to meter right then I should increase exposure by two stops for the left pillar and make is 1/15 from 1/60 to put in the zone VII and hope that everything else will fall in place, right?

2. When I took the reading of the floor of the kitchen it came to 1.5" when I aligned the red arrow which is marked with a zero under it with the light reading that was 1. Now if I align the blue arrow with c marking under it to it the reading comes to 1/10 that is I think four stops faster that's almost zone I. So does this mean that these arrows are for zone system and only to be used if one needs to make an area fall into the zone I.

Cheers
Raffay

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[Sevo]

So does this mean that these arrows are for zone system and only to be used if one needs to make an area fall into the zone I.


No, these arrows are for measuring with open ("o") respectively closed ("c") flap - the latter obviously with a five stop attenuation. This dual range setup is standard on selenium meters, as they did not have enough of a range to handle both sunlight and indoor situations off the same cell area. If the meter calibration is off, these might happen to point to two meaningful zones, but by design, the one matching the current flap setting should be (roughly) Zone V, i.e. a mid tone, and the other is five stops off from that.

[Raffay]

How do I calibrate? The screw at the back is nit aligned with the zero mark, does that have anything to do with calibration? Also, so if I understood you correctly, if the light is too harsh that the needle is going beyond 16 on the light scale then I should close the flap and align the dials with the blue arrow which has a c marking?

[Raffay]

I tested it, but it is getting confusing, with the flap on I took a reading and it was showing 11, so I aligned the dial, so that the red arrow with "o" marking aligns with 11. At this moment the blue arrow is aligned with 2.8, and now when i closed the flap the meter showed 2.8. So I did had to move the dial as the blue arrow was already aligned with 2.8.... So what is the different, I am surely missing something here...sorry for my ignorance

[Sevo]

Do ignore the fact that the values on the needle meter and upper scale show numbers resembling a aperture scale! There was one shutter speed at one film speed (perhaps Kodachrome amateur silent cine film, 1/30@64ASA, if I interpret it right) where the needle meter could be used for direct readout. For all other applications (in particular photography) these are just arbitrary numbers you have to match up between scale and calculator - the apertures you have to use are down below, paired with the exposure times.

[Raffay]

Do ignore the fact that the values on the needle meter and upper scale show numbers resembling a aperture scale! There was one shutter speed at one film speed (perhaps Kodachrome amateur silent cine film, 1/30@64ASA, if I interpret it right) where the needle meter could be used for direct readout. For all other applications (in particular photography) these are just arbitrary numbers you have to match up between scale and calculator - the apertures you have to use are down below, paired with the exposure times.

I understand what you are saying, take a look at these two pictures showing what I am saying.

Flap open:

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Flap close:

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In both pictures the only thing that differed is that the flap is open and closed in the second one. Otherwise the alignment or the number below do not change. Any thoughts?

Cheers
Raffay

[Sevo]

In both pictures the only thing that differed is that the flap is open and closed in the second one. Otherwise the alignment or the number below do not change. Any thoughts?


This is the expected behaviour, you should get the same reading (using the different reference marks for "o" and "c") when measuring with flap open and closed. Wherever that is possible - only a part of the meter range intersects.

[Ian Gordon Bilson]

The readings you obtain are more likely to be accurate if the needle is not at the extreme end of the scale,Flap up or down.
But old,Selenium meters like this have a mixed record for reliability.
The zero by the screw adjuster is just an identifier for the screws function- there is no index mark to which you set it-this is done by viewing the needle as you adjust.
Sekonic.com has some useful tutorials on metering practice for reflected/incident techniques.