Manual for Beseler PM4L/PM2M Color Analyzer Wanted

I know khbphotografix.com has manuals for sale, but its a rather small transaction for the complication of international shipping (CAN->US).

Does anyone have a PDF copy of the Beseler PM4L/PM2M manual? I have a PM4L that I'd like to do some experiments with. I do have the PM2L manual PDF mentioned in another thread, but it doesn't cover all the features available on the PM4L/PM2M units.

Thanks,
-- David

Mine is in storage, and not easily found! You can buy a copy here http://www.khbphotografix.com/Beseler/BeselerManuals.htm

Is it a question of how to use this analyser, or just this is your first analyser, and you are not sure how thay work overall?

Besalar made/marketted a slew of analysers, and the more sophisticated ones allowed more than one 'personality' to be stored. Some times electronically, and sometiems just as multple gangs of potentiometers that could be bank switched in and out of the bridge balance circuit.

Are you interested in using this for color negative to print RA-4 process work, or as a general b&w darkroom tool?

Mike Wilde said:

Is it a question of how to use this analyser, or just this is your first analyser, and you are not sure how thay work overall?

Besalar made/marketted a slew of analysers, and the more sophisticated ones allowed more than one 'personality' to be stored. Some times electronically, and sometiems just as multple gangs of potentiometers that could be bank switched in and out of the bridge balance circuit.

Are you interested in using this for color negative to print RA-4 process work, or as a general b&w darkroom tool?

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I don't have the manual for the PM4L but I have one for the PM2M which is similar in everything except that the display for the 2M is analog and when in white channel it has scale for both time and density, The 4L display only time value in the white channel. Color channels are display in densities.
The response of the PMT (Photomultiplier Tube) is linear its output is routed thru a bunch of diode and turn to logarithmic response. I don't exactly know how they did it. This signal is then display on the meter. On the 4L the output once again converted back to linear when in the white channel via a Log to Linear IC.

Hey I'd also be interested in a copy of the manual for the PM4. I have been using it but have no idea what the results actually mean in real world values.

I use it to set my VC filtering for B&W. I've compared my gels n noted the valuse so I can now set my head to any filter in just seconds.

It would be nice to know what the potential n values of the display of the meter actually represent.


Thanks Chan, she's working just fine BTW.

paul ron said:

Hey I'd also be interested in a copy of the manual for the PM4. I have been using it but have no idea what the results actually mean in real world values.

I use it to set my VC filtering for B&W. I've compared my gels n noted the valuse so I can now set my head to any filter in just seconds.

It would be nice to know what the potential n values of the display of the meter actually represent.


Thanks Chan, she's working just fine BTW.

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The meter readout is in density for C,Y, and M. But let me do some more reading before answering your question.

Manual for the Beseler PM4L color analyzer

I could not find the manual for this model but I have used it for a long time and familiar with its operation. I know quite well how it works so I would like to post some information on this unit so some of us here can make use of the information. I won’t mention the way one should use the analyzer as I have heard and read many people’s opinion on whether the color analyzer would really work. Many don’t think it would work so I wish not to explain on how to use it but rather on how it works. Knowing how it works each of us can devise ways to make it works for us even though some of the applications weren’t intended by Beseler.
1. It seems that Beseler used the same PMT (photo multiplier tube) to sense light for all models of their analyzer. On lesser models the PMT is housed in a box with the color selector and is used as the probe. On the PM2M and PM4L this box is housed inside the cabinet right behind the color selector knob. Light is fed into this box via a fiber optic cable and the probe is made so that it can be turned toward the lens for cosine correction. When measuring a spot that is not directly under the lens, position the probe so that the arrow pointing toward the lens and then slowly turn the probe toward the lens until you have the most light coming into the probe. When you have more light into the probe the reading would be more toward the negative side as the meter is indicating filtration or lack of light. The color selector will position the corresponding filter in front of the PMT to read light of only one color channel. Red filter for cyan, green filter for magenta and blue filter for yellow. The output of the PMT is very much proportional to the amount of light striking it.
2. The output of the PMT is then routed thru a bunch of circuit that has diodes in them. I still not yet understand how these circuit works but they make this signal becomes approximately proportional to the logarithm of the light intensity. This signal is then fed into a comparator circuit that compares it with the voltage set by the programming knobs on front of the analyzer or in the program cube is if the selector is set to module. When you switch the filter selector the unit also switches in the corresponding resistor for the color channel. The front panel setting resistor is the combination of the coarse and fine adjustment.
3. The output from the comparator circuit is then fed into the meter for readout. This readout is calibrated so that to show density or CC unit. On the PM2M and the unit is set for white light it can be used to measure the negative density. To do this first set the programming knob so that the meter reads zero without the negative. Then put in the negative and position the probe where you want to measure density. Till the probe toward the lens so that you have the lowest density. This is supposed to be the density of the negative at that spot. I have found that the reading is a bit lower than what I read from an X-rite densitometer. It’s about 90%. The PM2M meter also is marked in seconds and normally you would program for the meter to read the the time it takes to correctly expose the known negative. On the PM4L when you switch to white channel the signal is fed thru a converter to make it once again directly proportional to the light intensity and the meter would readout in seconds. I sometimes bypass this circuit so that I have the meter readout in density because it’s more useful to me.
I hope it would help some of us here. If any of you have any more questions I would gladly answer.

Thanks for the tutorial on the electronics n workings of the meters. Firtst thing I did when I got her was open it up n clean everything inside n out top to bottom. It is facinating the sensor has 3 color gels CYM n when you turn the dial to each channel it moves the window to that particular gel over the sensor diode tube.. white has no gel of course... such an elegant n simple solution.

What I'd like to know; what are the real world values of say the Y chanel when set to G then null tuned to 20 on the second dial? G-20 has no transaltion to anything I am familiar with in terms of density or CC values. Does the manual deal with that at all?

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I picked up a copy of the PM4L manual on the 'bay cheaper than the above mentioned site sells them for. When it arrives I'll scan it for everyone.

paul ron said:

Thanks for the tutorial on the electronics n workings of the meters. Firtst thing I did when I got her was open it up n clean everything inside n out top to bottom. It is facinating the sensor has 3 color gels CYM n when you turn the dial to each channel it moves the window to that particular gel over the sensor diode tube.. white has no gel of course... such an elegant n simple solution.

What I'd like to know; what are the real world values of say the Y chanel when set to G then null tuned to 20 on the second dial? G-20 has no transaltion to anything I am familiar with in terms of density or CC values. Does the manual deal with that at all?

.

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If you set the coarce dial to say G and the fine dial to 20 it doesn't really mean any thing. It's just there so that you could remember to return to the same setting. Beseler made the module and in the module are 4 multiturn potentiometer and there is no such marking. Basically you would null each channel for each kind of analyzing mode. For example skin tone, gray card, or diffuse with a diffuser and everaging the entire negative. You could use each module per program or you can jot down the setting on the coarce and fine adjustment knobs. My newer Omega SCA 400 would automatically null when you push a button and store the setting in digital memories.
The color analyzer measures light in relative term and not absolute. It only tells you the difference in light level in relative to the null.

As promised, here's a quick scan of the PM4L manual.

Dead Link Removed

kerne said:

As promised, here's a quick scan of the PM4L manual.

Dead Link Removed

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Thank you so much. I'll read it tonight after printing it all out.