Colorimeter... PM1

So I've lurked this site a bit in the past and it's been really helpful. Sooo... Thanks guys. I have a specific question though though, the answer to which I haven't been able to find by searching here or on google.

Anyways, I have a Beseler PM1 color analyzer. I have no idea what it is telling me when I use it. Could somebody please explain to me the concept behind color analyzers and how one could practically employ one in RA-4 printing specifically? Thanks a lot.

First off - I'm a real novice at colour printing so my responses need to be taken in that context.
That said I bought a Dorst colorimeter last year and my colour prints come out first time 90% of the time using this. Basically you need to find a negative which you know gives a good print-the Durst has a reference negative and print. If you don't have a reference I suggest that you get a colour reference card (auction sites often have old kodak colour printing manuals which are good for this) or even a print in a book and take a shot of that. Get the film developed and a print made commercially then do test prints until you get one that suitably matches your reference. Then you set up your enlarger etc. with the reference neg in it with the settings you used for that print. There will be some way to adjust your PM1 so that you have a 'null' reading or maybe you have to note the readings for that set up (others may give greater help on this- a search on goolgle for Beseler PM1 gave several sites selling thee manual). Once you have the analyser set up then next time you want to print a neg ON THE SAME PAPER FROM THE SAME FILM you put the analyser under the enlarger and once you replicate the settings then you can print. Each new film/paper combo needs a new calibration.
Hope that explanation starts things moving - Good luck

Thanks, Digiconvert. Don't you think that this is kind of redundant though? If you are using the same film and paper, couldn't you just note the CMY combination on the color head and reuse those settings?

Exactly! If you can calibrate a color analyzer to good effect, then you don't need one.

A diffuser is good to have to integrate the colors for an average reading on a print. I use mine to get very close when using a different film on the same paper. It's also handy if the color balance of the image is different, like a shot under tungsten or open shade when you have a good color for normal conditions.
Assuming you have found a filter set for a good print:
In actual use I hold the diffuser under the lens with the probe head switched to cyan and set a null on the meter, do the same with the other colors and the white light setting. This sets the meter for your paper.
Going to a different image, hold the diffuser under the lens, set to cyan and null the meter with the aperture, since the cyan should be at zero. The other two colors set the null with the filter dials. By the time you get to the white light setting it should be close to a null, adjust with the aperture.

An analyser is actually a comparitor. It compares the unknown negative to the known settings. To use one successfully you need negatives that are similar (all fleshtone or all similar landscapes for example) You choose either a spot reading (such as a normal flesh tone) that you can match in all your negatives or intigrate to grey( Gary gives a good outine of that so I won't repeat it). Once your paper batch changes you must re test. If your negatives are all different then you are right keeping a filtration log works just as well. Film as in film type must be the same as well.

The other trick to it is you must make the first print exactly correct to be able to program the analyser the first time. Having a good representative negative is key. A neg of your own like what you will be printing is usually better than a standard neg because there will be less differance between the standard and the unknowns.