Light Integrator/Timer

[vanbergc]

I'm trying to find out if anyone has had any experience with the Metrolux Light Integrator/Timer. I called Redlight (makers of Metrolux) and found that the spectrum for their sensor is quite broad...from approx. 3200K to 7000K?? if memory serves. I'm looking to expose in sunlight (UV) around 52-55K, and was wondering if there might be a UV filter out there that would make the Metrolux sensor more applicable to the UV range. I will also be using the "timer" for a metal-halide lamp when contact printing my PT/PL prints indoors.

Is there any other sensor anyone has had experience with that might be more applicable? Is the Metrolux worth $345? Any other approaches to exposing PT/PL prints that make the exposure repeatable under any conditions?

Thanks!

 

[Jorge]

Cathy I dont know what your experience is but have you read Dick Arentz book? I dont know that you really need a metrolux timer but if you wish to get one you dont need an UV filter. If you wish to use it in the sun you will need a ND filter to lower the sunlight intensity. You can use it on top of the metrolux cell and it will "integrate" the light intensity. For a mercury vapor light I would also recomend a ND filter to attenuate the light. Basically what the "meter" will do is measure the intensity of light, if it goes lower it will "increase" the time, etc etc...color of light has nothing to do with the process although it is related to the amount of UV light.
IOW you wont be measuring amount of UV light, you will be measuring the intensity.
I recommend you first do your standard printing time and distance according to Arentz book and then worry about the "timer". Or you can always do ziatypes...

 

[vanbergc]

Thanks Jorge...I have read Dick Arentz's book, but it seems I need a refresher. The facts about Kelvin Temp as related to the electromagnetic spetrum is as follows:

"UV radiation is light created by processes more energetic than those
that produce visible light. For example, the light one sees from the
Sun is produced at the solar surface, at a temperature of about
10~340 degrees Fahrenheit (6000 degrees Kelvin). The Sun also
produces ultraviolet light, from the much hotter gases that lie above
the surface, at temperatures of 17~540 to 179,540 degrees
Fahrenheit (10,000 to 100,000 degrees Kelvin)."

Now I know I'm not going to find a lamp at 10kKelvin, so I'm shooting for the next best thing, which is the higher end of sunlight. I want to filter out the lower end of the spectrum, which will have a higher percent of the "unwanted" red energy, and get a higher percent of the "blue" light energy, which is where ultraviolet starts to live. I'm just wondering if I can filter out (most) everything lower than blue light (so repeated exposures will be nearly identical no matter what the intensity of the sun is). Will a neutral density filter do that? I want to raise the capture of sunlight intensity, not lower it.

Anyhow, I know that some of the lamps used in the NuArcs are strictly for UV exposure, and they have their own light integrator (can't remember what it is called or how much it costs). I don't think this is the case for the Metrolux. I suspect the Metrolux bandwidth is much wider than the NuArc light integrator bandwith. My question is whether the Metrolux is worth working with, for the price, to adapt to a strictly UV situation...

I'm going to have to reread that Arentz book...don't remember this being discussed?? Thanks again for the push in the right direction...
Cathy

 

[Jorge]

Ok, it is not discussed in the Arentz book but his approach to testing seems to me would negate the need of the "timer". The only reference I have read refering specifically to the metrolux timer is made in the Weese/Sullivan book. Short of an intergrator I think the metrolux is the best thing, but for that kind of money you can get a NuArc 26-1K with integrator and vaccum frame on E bay. Why dont you check the pre press equipment. I had posted one here about a couple of weeks ago, it went for $243. I got mine on E bay, if you are really looking to control your exposure there is no better way than this plate burner.

 

[Jorge]

Ok here is one a bit more expensive but looks in very good condition.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...item=1784285014

 

[vanbergc]

I had no clue you could buy these units so cheaply...How big are these guys, and how much do they weigh? (Shipping costs?) This total unit is nearly less than the Metrolux itself...Hmmmm.....

Thanks so much Jorge!

 

[Jorge]

Cathy, when I bought mine through e bay. Shipping costs was $150 which included crating. I know it is a bit steep, but for $500 or $600 you are getting a great unit, with very presicise and repeateable "times". The unit must weight about 40 pounds when put together, but individually the vacuum frame is maybe 5 punds and the exposure unit is 35 pounds. The only things you must be aware of is that you will need and 20 amp breaker and you will have to have a "dedicated" outlet for the unit, meaning while you are using the unit nothing else can me hooked to the same line and running at the same time. It really is not big deal if you find you are burning the fuse then there are ways to change the set up to prevent this, but the best way is to have a 20 amp breaker and a dedicated line. It is what I did for my darkroom. Inside the vacuum frame you can fit a 20x24 image comfortably and with even illumination from corner to corner.


BTW NuArc has great customer service. I have used them a couple of times, both for parts and advice and never failed to treat me with courtesy and willigness to help me solve the problem.
So the unit I posted is in very good shape, if you are patient you might even get it for $200 or $300. Is up to you.
As I said, my advice is to get it and stop fooling around with FL tubes or the sun. You will notice improved consistency in your print making.