Photocell for Zone VI compensating enlarging timer
I've been away for a long time and I'm still looking at about a year before I get to doing darkroom work again, but I can see this issue coming up soon enough.
Having moved from the 110v society to one that runs on 220v, I will likely be acquiring an enlarger within European confines, which is going to get me a light source not completely compatible with my beloved Zone VI compensating enlarging timer. Have looked around and see no particular reference to the photocell that was installed in Zone VI cold light heads and was also then available as part (called Zone VI L 702 photocell). To get the most out of this timer, I am looking for that photocell so I can install it inside the light source(s) I'll end up getting.
Is there anyone who can help locating the cell itself or at least the specs (these parts are widely available, but I'm guessing it needs to match the original specs to work properly with the timer).
I can still use a US source for such, although I'm sure I can locate it on this side as well, just need to know what to look for. Thanks.
Last edited by superd; 04-04-2013 at 03:48 PM. Click to view previous post history.
You can also get a transformer which steps down 220 to 120, and will allow you to use your familiar equipment.
No, that's not my question. This has nothing to do with how a light source will be powered, the photocell measures the light output INSIDE and communicates with the timer, so it can compensate with light's output changes. It works and that's why I wish to stay with this timer.
Further, I have the timer, but never moved the enlarger with me, so I'm on to a different setup for sure.
Have you tried contacting Calumet parts department? They may have some around.
Thanks ChuckP, but thus far Calumet is silent and I don't expect anything from that end anymore. Still digging into it. While awaiting some input on here, I will post the answer, if I get one from other sources. All I know at this point is that it needs to be matched as original. Since there are plenty to choose from, guess is not an option.
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I had a Metrolux-II with the sensor and now have two RH Designs Stopclock Pro's, one is the compensating type with the sensor. I believe that the two units used basically the same type of sensor, so ordering a sensor from RH Designs through Second Hand Darkroom supplies might get you what you need.
I would also email Richard Ross who is a member here and ask him as he designed all those goodies and might know of the very components you will need or will be able to tell you if you can simply use the RH Designs sensor with a minimum to no adaptation.
Another thing to consider is that although less than ideal in your case, the Zone stuff is no longer made and RH Designs stuff is. I am willing to bet that the Stopclock Vario is every bit as good if not better than the Zone stuff.
It's kind of expensive now but you have to weigh the cost, time, still being made or not benefit factor. I got rid of the Metrolux unit for this reason, opting for current technology that is still being made versus stuff that is getting much harder to find parts for or multiples of for standardization reasons...
Last edited by PKM-25; 04-05-2013 at 07:56 AM. Click to view previous post history.
I agree with you, PKM, on the RH performance, although the "old" style controls on the Zone VI work like a charm and are much more intuitive . There is more in my case that meets the eye. Without going into details, I have a sentiment towards Zone VI and parting with it is really not a consideration, especially since the part I'm now missing will cost little compared to another timer. I have contacted SHD, but so far no response on the sensor. It does seem like it should be the same one, as the RH timer came with just a cord to plug it directly in. Thanks for the other suggestions, I'll continue my search and eventually will get the info.
I believe this may be what you are looking for?
Originally Posted by superd
Excelitas Tech VTB8440BH Photodiode, IR-Filtered
From another member's earlier post, I believe this to be the same sensor used by both the Zone VI Compensating Enlarging Timer and the RH Designs Stop Clock Vario. The part number given is: EG+G Vactec VTB8440BH. Detailed specs are included in the link.
I also own and use the Zone VI unit and the catalog image of the sensor in the above link appears to be a very close—if not perfect—visual match, both in form factor and coloring.
And welcome back to APUG (posting, that is)...
Last edited by Ken Nadvornick; 04-05-2013 at 12:00 PM. Click to view previous post history.
"They are the proof that something was there and no longer is. Like a stain. And the stillness of them is boggling. You can turn away but when you come back they’ll still be there looking at you."
— Diane Arbus, March 15, 1971, in response to a request for a brief statement about photographs
The part number you're mentioning (EG+G Vactec VTB8440BH) is it from RH manual or some other good source? Because if that's the case, then it would make sense. I will say though that the early Zone VI heads head a different looking cell.
I do know at this point that what Zone VI used was a Hamamatsu branded photocell, but am still waiting on a reply with actual part number. At the end of the day it is the specs not the brand that count. Will post here when available, but if anyone can pitch in on what Ken has upstairs would be just as good.
Last edited by superd; 04-05-2013 at 12:10 PM. Click to view previous post history.
I have found a thread and saw your reply as above, also saying that this cell looks like Zone VI probes you have, so that is also quite helpful. Looks I'm getting there. Thanks.