Noritsu DM-1 Densitometer Calibration

[Neil Miller]

Hi,

I have recently bought a used Noritsu DM-1 transmission/reflection densitometer without instructions and wondered whether any of you out there have used this or a similar machine and know how to use/calibrate it.

I have tried websearches on Noritsu, both UK and USA and I cant find anything ab out densitometers, only mini-labs and other stuff.

The densitometer appears to work OK. If I set it on "V" (dont know what this is , I only know the other three settings are colour channels) and use the "transmi ssion" setting (this is the setting I'm interested in) it displays values that a gree nr enough with the steps on my uncalibrated Agfa step tablet, i.e.: 0.15 st eps.

I know that for comparative purposes I only have to subtract the a film-base + f og reading from other readings to find the range of a neg, but I would like to b e able to calibrate it. It comes with a sort of calibration device cocnsisting of a wafer with one opal and one dark round lens and someone has recorded values against each - any ideas what this means?

Thanks for your time.

Regrads,

Neil

[Kevin Crisp]

I assume that the two filter device you have is for calibration, and the numbers written on it are for calibration purposes. I picked up a densitometer (made by Nuclear Associates, for x-ray machine calibration, runs on batteries) and wrote the manufacturer. For a hefty price I got a calibrated wedge. It is normal for the factory calibration to be hand written. Turned out it device was right on the money but at least now I know that. I suggest you zero it out, then test the two filters you have and see if what you get it close or the same as what is written on them. Make adjustments to get there. If you do this, when you zero out B+F and then measure you should be accurate. If one of the known values on the calibration is the 0.10 you're looking for on a film speed test, that would, of course, be the value to adjust to as close as you can get so you're reading right in the middle of the most accurate calibrated range. Note the measurement of B+F (slightly different for different film and developer combinations) before you zero that out for an actual test of the exposed film density. Going from memory, if it's not something like 0.06 to 0.10 for B+F before you zero out the clear processed film then something is wrong.

[Bill C]

Neil, there's a good liklihood that it's an X-Rite 810 or very similar. A post at the following location may be helpful. Someone had also put a link to download a manual.

http://hv.greenspun.com/bboard/q-and-a-fetch-msg.tcl?msg_id=007oMH

PS: the 'V' probably means "visual" density. It has a much wider spectral span and is generally considered to be the best one to use for general B&W work.

[James Phillips]

Hi Neil,

I have a manual for an XRite-810 model. If you think that is what you have or could send me a picture of yours I may be able to help you.

Regards,

[brad_knight]

Hi Neil

The Noritsu DM1 Densitometer was made by Noritsu back in the 80's. It is not at all similar to the X-rite series. I am in possetion of both the operating manual and the technical manual for this equipment. I will be in the UK in September for Photokina and will be happy to give you a copy or alternativley I can scan and mail you these manuals

Hope this is of use to you

Regards

Brad

[Kirk Keyes]

I have the manual for the DM-201 online. You can find a link to the manual on the bottom of this page:

http://www.keyesphoto.com/Kdktech.html

I know they somewhat different machines... If you have any questions, or problems downloading it, let me know.

[Marko]

Neil,

I'm in a very similar situation, except that I acquired a different brand of densitometer. Mine also came with no manuals and no calibration "chips", but at a great price.

I obtained the manuals, and right now I am looking for the appropriate calibration standard. I have an option of buying it from the OEM for some $35 (transmission only) or I can acquire a calibrated 4x5 Stouffer Step Wedge in the similar price range.

I would think that the original wedge must be better, but then again, a calibrated step wedge from a reputed source should be equally good AND it could have more uses.

Stouffer Photographic Scales (http://www.stouffer.net/Photo.htm)

List of models and prices (http://www.stouffer.net/Productlist.htm)

Specifically, I am looking at TP4x5-21C, which is a calibrated 1/2-stop model and TP4x5-31C, a calibrated 1/3-stop model. Also note that these cost half of what most stores that carry them charge...

Locating missing pieces for something like this can be challenging, but it is also great fun because it makes you learn things along the way you would never bother to notice otherwise.

It'd be even greater if someone experienced with densitometers could comment on this approach with pros and cons. I am sure that there are others reading this board who could benefit from the advice beside Neil and me.

[luxikon]

Hi Brad,

I came to your message because I also bought a Noritsu DM 1 without instruction manuals and searched the net for it. Can you do me the favor and send me the manuals too, as you suggested to Neil?

Regards

Klaus