Cold Light Enlarger Heads

[Peter Rockstroh]

Cold Light Heads

I have been printing for many years with a standard Cold Light. My negatives are mainly 120 PMK Pyro HP5 and 8x10 HP5 in HC110 contact prints. Although my first choice are always graded papers, I will occasionally use VC paper. Basic exposure times generally run between 20-30 seconds, which I would consider "normal."
Are VC Cold Light Heads that much slower ? I´ve never used one.

 

[Loose Gravel]

I'd say my Aristo VC was about 3+ stops slower than my Aristo V54. My typical exposure ran 30 seconds or more at 1 stop down with the VC. I like 10 - 15 sec exposures and several stop down. I print mostly 45 and 57 negs and mostly 810 and 1114 prints. Film is HP5+ in PMK.

 

[hortense]

About 6-months ago, I had a problem with my Zone VI head and associated timer. I recieved very good service from a tech named Jeff. However, I suspect you are correct about part shortages.

 

[Peter Rockstroh]

Metrolux Timer and Zone VI Cold Light

I ended up ordering a Metrolux II Timer Kit for a Zone VI Cold Light at Calumet, since I did not get an answer from Metered Light. The Zone VI Cold Light for my Beseler 23 has a Preheater/Stabilizer unit. I understand that is no longer needed with the Metrolux II ?
I guess the next step should be considering a new Cold Light Head, in case mine should fail. What would be your suggestion ? It seems the Aristo equivalent would be my best/only choice ?
Thanks.

 

[Loose Gravel]

I ended up ordering a Metrolux II Timer Kit for a Zone VI Cold Light at Calumet, since I did not get an answer from Metered Light. The Zone VI Cold Light for my Beseler 23 has a Preheater/Stabilizer unit. I understand that is no longer needed with the Metrolux II ?
I guess the next step should be considering a new Cold Light Head, in case mine should fail. What would be your suggestion ? It seems the Aristo equivalent would be my best/only choice ?
Thanks.

Peter, Although the preheater or 'thermo' is not required, you may find it helpful. It preheats the tube to a temperature that will give you high light output and thus make your exposure times shorter. I find this handy in the winter time. As my darkroom gets warmer and I switch over to AC from heat in my darkroom, I no longer use the preheater.

If your Z6 coldlight is working, why switch? If you're going to switch, then I think Aristo is the way to go. You will have to install a photo sensor in the Aristo coldlight, as they do not come pre installed as do the Z6. If you are going for an Aristo because you want V54, then ask Aristo about just changing the tube from Z6 to Aristo. Maybe. I don't know, but worth the question.

 

[Peter Rockstroh]

I always had the idea that the "preheater" was more of fancy name for a voltage regulator, than an actual heat source. This sounds as if it works like a thyristor in a flash light.
My question regarding the Z6 coldlight was basically because the cold light and the timer were bought at the same time, and I´d like to be prepared for the moment it stops working and know what my alternatives are (I´ve had them for 12 years). Living in a third world country where I have to mail-order everything (except for a few films and chemicals) I like to have the necessary information that allows me to solve emergencies within a reasonable time. (I have 200 new negatives and no enlarger - that´s an emergency; the timer should arrive on friday thanks to your suggestion - that´s a reasonable time)
Muchas Gracias.

 

[Loose Gravel]

I've never used a Z6, but the 'thermo' on an Aristo is a heater, plain and simple. It is a bank of resistors and a thermostat that heats the chamber that the tube is in to 105F.

 

[Neil Poulsen]

"The Early Zone VI enlarger was a piece of junk. Picker rushed it to market with an unstable negative carrier and other problems. The light source was, however, very effective in drawing out the full responsiveness of VC paper. Its only problem (this light source - I can't speak to others) was excruciatingly long exposure times with 4X5 negs."

I have one of these enlargers and get good performance from it. I use it for 4x5 and smaller negatives. It has the following idiosynchriasies:

> Contrary to early claims, it doesn't support 5x7. It was designed as an oversized 4X5 enlarger. It's vague as to why Fred Picker gave it the 5x7 label.

> The lens boards are a bit small for 8x10 enlarging, as is the rectangular opening in the negative stage. It will work for 8x10 with a 240mm Componon that I have. (Also with a Rodenstock 270 Apo Geronar.) It has no problem working with a 150mm Componon-S, but of course, not for 8x10.

> Using the VC head for this enlarger with a compensating developing timer, one must expose the two colors consecutively versus simultaneously to obtain consistent results. (First green, then blue, or vice versa. There's only one sensor, versus a sensor dedicated to each color.)

As to being slow with 4x5 film, the opposite is the case. I use mine at low "B" and "C" settings and successfully print in just a few seconds. (10 or so.) I have no problem printing 35mm negatives with it. The head's quite a bit brighter than the later Type II heads, because the power sources for each color were located in the heavy, huge control panel that goes along with Type I VC head.

With the purchase of three, small, inexpensive screws at a hardware store, the Type I works with a Type II 8x10 head. The chassis has no problem supporting this head.

By using the Beseler adaptor, I was able to adapt a D2V condensor head to this enlarger. This should also be true for the Type II. It was trivial and only involved gluing a 1/2" strip of rubber around the metal cylinder that holds the condensors. So, I can easily switch back and forth. These Beseler adaptors are no longer made and are hard to find for the Type I like mine, but they're available for the Type II.

Contrary to being "a piece of junk", I find the Type I enlarger to be quite useful and relatively well-built. It's as well built as either an Omega or Beseler enlarger. (Not up to Durst standards, though.)

To the point of this thread, using the Beseler adaptor, either the Type I or II can be used for either condensor or diffusion enlarging.