Kodak 5x7 Enlarger and an Aristo EK-SP

**false_Aesthetic** · 27-Nov-2011, 21:40

Hey,

I was just given a Kodak 5x7 enlarger (looks like one of those Elwood? enlargers. The orig. lamp housing looks like a hair salon dryer from the 60s) and an Aristo cold light lamp.

The lamp says Aristo EK-SP but a google search (and forum search) offers me nothing. Looking inside I see that the lamp says W-55.

From what I've read, cold light heads produce more light as the exposure gets longer (to a certain point). This makes me think that there's a specific timer that I should obtain to compensate for that issue. But I'm not exactly sure where to look or what to look for.

Also, I seem to remember someting about needing to put a filter of some sort in front of the light source before I use a standard (ilford) filter set. Is this the case?

Thanks
T

**John Kasaian** · 27-Nov-2011, 21:45

Have you contacted Aristo?

**false_Aesthetic** · 27-Nov-2011, 21:54

Nope. Just got the head earlier today.

Been looking for info on the internets since they're probably closed today

**nolindan** · 28-Nov-2011, 12:28

Cold lights get brighter as they warm up. Some Aristo heads have heaters in them in an attempt to keep the lamp warm - the heater is kept plugged in throughout the darkroom session.

A 'compensating timer' can help with the warm-up issue.

An alternative is to leave the enlarger on for as long as possible, turning it off only to load or develop paper. Modern cold-light enlargers use a shutter to control exposure and leave the lamp on.

Older Aristo lamps produced a bluish 'actinic' light. Without filtration this can produce #3 - #4 grade contrast. Figure on using a #0 - #1 filter for normal printing. Some users just leave a yellow filter - 40Y CC has been mentioned - in the light path.

**false_Aesthetic** · 28-Nov-2011, 13:49

Originally Posted by nolindan

Cold lights get brighter as they warm up. Some Aristo heads have heaters in them in an attempt to keep the lamp warm - the heater is kept plugged in throughout the darkroom session.

A 'compensating timer' can help with the warm-up issue.

An alternative is to leave the enlarger on for as long as possible, turning it off only to load or develop paper. Modern cold-light enlargers use a shutter to control exposure and leave the lamp on.

Older Aristo lamps produced a bluish 'actinic' light. Without filtration this can produce #3 - #4 grade contrast. Figure on using a #0 - #1 filter for normal printing. Some users just leave a yellow filter - 40Y CC has been mentioned - in the light path.

Hey thanks for your response.

1) My aristo head has 2 plugs coming out of it. Does this mean that it has a heater built in?
1.1) If I do have a heater in the head, does this mean that I don't need to purchase something like a metrolux and probe?

2) From what I can tell, this head has a daylight 5500k bulb. Does this = 'actinic' ?

**Jim Noel** · 29-Nov-2011, 15:39

Originally Posted by false_Aesthetic

Hey thanks for your response.

1) My aristo head has 2 plugs coming out of it. Does this mean that it has a heater built in?
1.1) If I do have a heater in the head, does this mean that I don't need to purchase something like a metrolux and probe?

2) From what I can tell, this head has a daylight 5500k bulb. Does this = 'actinic' ?

1. Yes,the second cord is the heater. I plug mine in about an hour prior to use. The second one goes to the timer. You shouldn't need a Metrolux, at least I have never seen the need on this enlarger. I did use one on a different cold light.
2. It is not actinic.

**tedw6** · 29-Nov-2011, 18:33

I have a beseler mx with blue green aristo 810 cold light. I run it with a metrolux unit with a probe in the head. I have home made voltage stabilizers for the tubes. Basically A big Zener diode with a fan for cooling. I do split grade printing with it. Oh yeah, I have modified zone 6 controllers, one for each tube.

This is the best enlarger ever. Get the metrolux and set it up right. Good luck.

Ted

**false_Aesthetic** · 29-Nov-2011, 19:47

Metrolux (orig version) ordered. Sent an email to the dude(s) that sell em to see if I can get a probe from them.

I sent Aristo an email. The lady that responded said that the only way I can tell if I need to drop a filter in front of the head is by testing. Isn't there another way? The light emitted looks very "white."

**ic-racer** · 29-Nov-2011, 21:16

Once you get the lamp heated up with the heater, it will get dimmer when you turn it on as it gets hotter.

**dsphotog** · 29-Nov-2011, 21:37

Originally Posted by Jim Noel

1. Yes,the second cord is the heater. I plug mine in about an hour prior to use. The second one goes to the timer. You shouldn't need a Metrolux, at least I have never seen the need on this enlarger. I did use one on a different cold light.
2. It is not actinic.

...and don't forget to unplug the heater when your printing session is done.