Question about Kiev 4 meter

[ruben]

Hi,

I am investigating now what use can I have for the meter at the Kiev 4. And here I have a very important question, at least for me.

You may have noticed that if you select for example the film sensibility of 250 roct (something slightly over ISO 200), then the meter speed dial will stop at a point showing 1/1250 at f1.5. This means that the other equivalent combinations at the scales, for the same film sensibility, will be something like 1/50 at f4, or 1/25 at f/5.6.

But I "need" the meter to read, with the same film sensibility, lower light levels like 1/25 at f/2, and the speed dial refuses to move.

So my question is if this is a design shortcomming of the dials, or the real limit of sensibility the metering cell was designed for. I cannot check it since my cell is not new (but a new one is under way).
Cheers,
Ruben

 

[dexdog]

More than likely an issue with the sensitivity of the selenium cell in the meter. In general, selenium cells are known not to be especially effective in low light conditions. The meter on my Contax IIIa (replaced by Henry S.) is usually pretty worthless in lower light conditions, such as heavy shade on a moderately bright sunny day (I don't know the corresponding EV numbers off-hand).

Just my two cents

 

[outfitter]

More than likely an issue with the sensitivity of the selenium cell in the meter. In general, selenium cells are known not to be especially effective in low light conditions. The meter on my Contax IIIa (replaced by Henry S.) is usually pretty worthless in lower light conditions, such as heavy shade on a moderately bright sunny day (I don't know the corresponding EV numbers off-hand).

Just my two cents

Henry S did the same for my Contax IIIa and I can easily get readings for ASA400 indoors illuminated by table lamps - something is not right if you can't measure in shade on a sunny day. I suggest you email Henry

Michael

 

[outfitter]

Hi,

I am investigating now what use can I have for the meter at the Kiev 4. And here I have a very important question, at least for me.

You may have noticed that if you select for example the film sensibility of 250 roct (something slightly over ISO 200), then the meter speed dial will stop at a point showing 1/1250 at f1.5. This means that the other equivalent combinations at the scales, for the same film sensibility, will be something like 1/50 at f4, or 1/25 at f/5.6.

But I "need" the meter to read, with the same film sensibility, lower light levels like 1/25 at f/2, and the speed dial refuses to move.

So my question is if this is a design shortcomming of the dials, or the real limit of sensibility the metering cell was designed for. I cannot check it since my cell is not new (but a new one is under way).

Cheers,
Ruben

250 gost is ISO320 - a perfect setting for Kodak BW400CN. ISO 200 is gost 180 and ISO 400 is gost 350.

Michael

 

[ruben]

Thank you folks for your good will and interesting commentaries, yet still not a hint about my question.

cheers,
Ruben

Now on bold yellow.

 

[Xmas]

The calculator does indeed limit at 1.5 and 1250 (from memory), and dependent on the cell and galavomener you may be able to take a reading just about at that level.

If you want a meter for dusk you need to think about a FSU CdS meter.

The Selenium cell is not big, there is a damping resistor in parrallel and the galvo is not terrible sensitive a Weston will be a more sensitive.

Noel
P.S. (edit) but you also have two stops below the calculator limit?

 

[ruben]

Thank you Noel. So I understand from you the mechanical limit of the dials, matches the light sensibility of the cell in its best original shape.. And including the 2 additional points below the needle, for further reading of 2 additional lower light stops.

Cheers,
Ruben

 

[Xmas]

Ruben

That is my appreciation I was comparing three Kievs, after fixing one and the 'fixed' one was a stop less sensitive, than the other two at the end of the calculator scale. It was not that dark either. The two working ones at 400 asa had a zero at 1250 and f/2 the fixed one zeroed at close to f/1.5.

This would get you to 250 and f/2 with 400 asa, using the x4. The contax III/Kiev III had a more complicated scale calculator then the x4 of the Kiev to allow 'darker' light.

I have to lift the dial and adjust the position of the arm that rides on the variable resistor track next.

I stopped and instead applied PTFE to the collection of wind on clutches, as part of keep Ruben happy on 4am wind on clutches thread.

I'll try it again this evening to confirm but wont be on line again until Monday next sorry. But the meter was for colour film in day light, not for dusk, before CdS cells you had to bracket. People did not use meters in '36.

Noel

 

[Xmas]

Ruben

Tried my collection on dim light source, only two of eight were within half a stop, but seven were ok on sunny day levels.

So the calibration may be more difficult at low levels. The circuit is as below.

http://www.rangefinderforum.com/forums/showthread.php?t=34021&highlight=circuit

Noel

 

[ruben]

Ruben

Tried my collection on dim light source, only two of eight were within half a stop, but seven were ok on sunny day levels.

So the calibration may be more difficult at low levels. The circuit is as below.

http://www.rangefinderforum.com/forums/showthread.php?t=34021&highlight=circuit

Noel

Hi Noel,

Four questions. What am I supposed to learn from the link you refer me?

b) Given the existance of digital meters, can we use them to calibrate the meter instead of the black point provided at the scale ?

c) The screw provided by the camera for calibration. Does it work in an infinetely circular movement like the ones provided by Gossen, in which at a full rotation you arrive to the same point you started, or is the calibration limited by the screwing depht ?

d) Can I use the metal arm below the speed dial for the calibration ? Will it give me anything ?

Cheers,
Ruben

 

[Xmas]

Ruben

Information and teaching are quite independent, I merely did not want you to complain that I had not told you something.

The meter is like the rangefinder ideally you need to calibrate

in sunlight bright
overcast dull and
near dusk.

The 'zero' adjust merely moves the scale to suit the galvo movement relaxed position, if you cannot get a zero you need to rotate the meter movement, but you needs to handle the galvo like Ming vase (-eggs).

The finger that rides on the variable resistor track may be enough to calibrate a new cell, use a 2nd known resonable meter, to tell you what the reading should be, set the calculator dial to same and if the meter is not at the null point... Note what way and how much you had to turn (degrees) the calculator for a zero, strip calculator rotate the finger to suit, reassemble, confirm OK, find a different light level confirm meter is same as reference meter. (Make a paper protractor for this angle record.)

You should use three levels if you want to use the meter in dusk conditions, & my living room lights are 'dusk' as far as my Kiev's are concerned.

There is a risk that a new cell may be a lot more efficient than the origional was when it was new and you might need to adjust the fixed resistor. You would need to substitute a high quality variable resistor, unless you are really good, and understand the circuit Fidget(Dave) provided.

As only two of mine work well at the bottom of the range it may be a difficult calibration and dusk may be way too difficult.

Noel