Yes, as mentioned that info comes from another APUG poster. But I do not know his source. Might you be able to PM that poster directly to see if the chain leads back to a hard-copy reference somewhere?
Right before Calumet dropped most Zone VI products I did a "distress" purchase of items I thought might disappear. A replacement light sensor was one of those items. That sensor also matches the appearance of the factory-installed one in my original Zone VI single-tube head, as well as the one pictured in the link.
I have it currently installed in my Aristo VCL4500 dual-tube VC head. That setup is not fully functional in terms of the range of adjustments available at the timer, but it's close enough that I can procedurally work around the constraints.
Last edited by Ken Nadvornick; 04-05-2013 at 01:10 PM. Click to view previous post history.
"There is very limited audience for the arty stuff, and it is largely comprised of other arty types, most of whom have no money to spend because no one is buying their stuff either. More people bring their emotions to an image than bring their intellect. The former are the folks who have checkbooks because they are engineers, accountants, and bankers—and generally they are engineers, accountants and bankers because they are not artists."
— Amanda Tomlin, Looking Glass Magazine, 2014
Thanks again, and I'm still waiting for the Hamamatsu reference. They have a number of cells that look the same as this one, but all have different specs and none matches it. So I'll wait and see if the actual original part can be referenced with certainty. Will update it here too.
Ok guys, I have received the specs for the original photocell that Zone VI used. It was a Hamamatsu S1133 photodiode with a blue filter on top (called visual compensation filter). This part appears to have been discontinued according to some on line suppliers, but the photocell linked by Ken above is indeed a very close match. So I am now convinced that it will work as advertised. As you can see the price is next to nothing.
Have just come across the original cell listed on Ebay from Taiwanese supplier HERE Well, just realized this is not exactly the one as it has -14 at the end and differs somewhat.
Last edited by superd; 04-05-2013 at 06:20 PM. Click to view previous post history.
I use an RH Designs StopClock Vario. I had this email exchange with Richard Ross on the subject of the light sensor. I don't know if it's exactly the same as the Zone VI model (models?). There is a post at APUG in which I describe the wiring on my original Zone VI single tube light sensor. I'll find a link to it later.
At 02:19 01/12/2010, you wrote:
>I've been using my Stop Clock Vario for several years now and it's a
>delight to use.
>Would you be able to tell me the specification/name/model of the
>photodiode that you supply for the Vario? Mine's working perfectly, but
>I'm interested in getting a couple of old enlargers going for use with
We sell sensor assemblies for exactly this reason - you can have more than one enlarger. However if you prefer to make your own you'll need a EG+G Vactec VTB8440BH photodiode with IR filtering.
More info at
Wire it so that the pin with the polarity dot goes to the outer pole of the jack plug.
Thanks john_s, this just confirms what I've received from the man who designed the Zone VI timer. Parts match, and with the Hamamatsu being out, EG+G remains on the table.
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I have found some notes that describe how the sensor is wired for RH Designs units on one hand, and for the Zone VI units as well.
For do it yourself types, the sensor is
EG+G Vactec VTB8440BH photodiode with IR filtering.
More info at
Wire it so that the pin with the polarity dot goes to the outer pole of the jack plug (for RH Designs fitting).
The Zone VI cold light head probe was supplied wired to a three-pin DIN socket, as used in old audio equipment. The socket was mounted on the surface of the head. The Zone VI compensating timer and the older stabilizer had captive cable with DIN plugs if I remember correctly. The wiring of the sensor is as follows, using two core (black and red) with shielding:
Photodiode end: black wire to the cathode, which is identified by a small reference hole through the base- see the pdf spec sheet, and
red wire to the other pin. The shield is not connected.
DIN socket end: Black wire to pin 1, red wire to pin 2, shield to pin 3 and linked to the metal case of the socket.
Thanks John, I got the same from PH who's been extremely helpful and responsive to all of my questions.
For anyone who ever thought (or not) of it, I also have a confirmation that sensor can be installed in ANY light source (like a dichro), although (naturally) cold lights have the real output stability issues, but any lamp can fluctuate to some degree.
That link results in a "403 Your Request Was Denied" page here. Any way to share the information? Thanks in advance.
Originally Posted by john_s
John's earlier link goes to same place, must have been some bug on the second one to alter it;
Originally Posted by Sal Santamaura
Here it is http://uk.farnell.com/eg-g-vactec/vt...0?Ntt=118-2340
You may have to take a black marker and cover half the photo cell to get a good range on the timer.
Almost any visible light photo diode will work. The Hamamatsu S1133 photodiode was the one we used in the meters and worked in the cold lights.