Lycian SuperArc 400 dimness

[agcraig]

I'm at a venue at the moment that has two Lycian SuperArc 400 - Short throw follow spots. One spot is perfectly bright when it's on low-range and the lowest setting. The other spot is significantly dimmer when it's on High-range on setting 6. We've changed the lamp again and again and it is still very dim. Any suggestions on how to remedy this?

 

[Thetechmanmac]

The first thing that comes to mind would be an issue with the ballast. Have you checked the ballast for any burn marks or anything of the sort? Scuffed cable? Next, I would get a voltage tester and meter the voltage coming out of the ballast to make sure your lamp is getting the correct amount of power. Check the reading on the functional spot to see what the reading should be for the other spot.

 

[FMEng]

I'd start by verifying the voltage at the AC receptacle, under load. Then, based upon the few metal halide ballasts I've worked on, I would look for a big capacitor in the ballast. Those tend to fail from heat exposure.

 

[JD]

Don't forget that adjustments in the reflector and lens train can drastically effect the output.
Iris both spots wide open:
A) Is the diameter of the circle of light the same? It should be.
B) Is the field of the light even? It should be.
Even with these two things checked, there are still a number of things that can kill the optical efficiency on a spot.

 

[PeteEngel]

The lamp in the Lycian 400 is integrated into the reflector so no lamp/reflector adjustment. If the lamp is installed correctly, you probably have a power supply issue. you might want to check that the lenses are clean.

 

[JD]

The lamp in the Lycian 400 is integrated into the reflector so no lamp/reflector adjustment. If the lamp is installed correctly, you probably have a power supply issue. you might want to check that the lenses are clean.

In the early days of the Altman Satellite I the lamps used to come that way, mounted in the reflector with no adjustments. Got one in that was dim once, and when I did an A/B with a known good unit, the lamp was deeper in the reflector on the one. Still, the op has stated he changed the lamp assembly so I am sure that's not the case. Swapping lamps between spots would eliminate that. Yes, the PF cap in the ballast is a likely suspect, but you first want to make sure the optics are racked correctly. They are designed to give up brightness if you need more spread. Seen many a case where the optics were racked for a wide spread and Iris'ed down. That's why I suggested opening up the irises all the way on both spots and see if the beam spread is the same. No point in getting the tool kit out before it's needed.

 

[PeteEngel]

If I recall correctly, there is no real iris in the SuperArc400. The fixture irises by moving the first lens closer or farther away from the lamp. A cute way of doing things but screws any real ability to iris without massively changing the output of the pool of light from wide to zoom. swapping the lamp between fixtures is a good idea.

 

[JD]

Despite the single handle approach, it still actually uses an Iris in there and you can see the variance in foot-candles depending on how it is set up:
Here is the parts list: https://www.google.com/url?sa=i&rct...V2TRBj3QjkQVgYZA&ust=1459909904283801&cad=rjt
The Iris is part # 126661 The cap is also listed

 

[PeteEngel]

Not sure about that link you pasted. here is the link to the Lycian diagram. agreed, it isn't as complete as one would hope but still not finding an iris here. http://www.lycian.com/lycian_partslist_1266.pdf
and changes in output based upon iris size only back up the change in optics as one irises down. I could be wrong about the lack of iris...

 

[JD]

Not sure about that link you pasted. here is the link to the Lycian diagram. agreed, it isn't as complete as one would hope but still not finding an iris here. http://www.lycian.com/lycian_partslist_1266.pdf
and changes in output based upon iris size only back up the change in optics as one irises down. I could be wrong about the lack of iris...

If you go to that document, look at the list at the bottom of the page (right hand side) it is listed. In the picture, it would be on the back side of the plate so it is not visible. Part # 126661 - Iris. As with most spots, it can be configured for width vs brightness. Unfortunately, Lycian doesn't give the nice visual breakdowns like Strong used to.

 

[Mac Hosehead]

The Lycian SuperArc 400 certainly has an iris but there is something I have only seen in this spot. That is, when the iris handle is engaged the iris closes and the lamp is moved toward the iris. Opening the iris moves the lamp away. The output appears to get brighter as you iris in.

 

[PeteEngel]

Ah yes, there it is, in the list of parts not shown... sigh. I haven't pulled one of those apart for over 15 years.
and back to the point of the OP, any word on the low output?

 

[Mac Hosehead]

The OP mentions the output knob on level 6 and the switch set to high. This is the max output setting and normally a new lamp run in this way would make the current meter run into the red zone. If the meter does not get into the red zone with a new lamp at this setting then the ballast needs to be serviced.