360Q is burning gels

[lighttech11]

So I have this Altman 360Q 6x9 that is burning gels like crazy. The gel happens to be R99. Within seconds of putting the gel on the instrument, it begins to warp and burn the color out of the gel. What can I do about this? Do I need to change the lamp, or do I need to align the lamp and the base? Any tips out there on how to avoid gel burning?

Thanks

 

[icewolf08]

6x9s and 36˚ Source fours seem to be the most notorious for making gel go Bonanza. The quick, simple and fast solutions are to run the barrel all the way out, or to use a color extender/top-hat putting the gel farther away from the lens. Sometimes doing this won't help you at all, which is when I would look into other potential issues. First, you should check to make sure that you have the proper lamp in the fixture. Some people lamp the 360Qs up to the 1000W FEL, and this could be your problem. Usually it is OK (though I don't believe it is recommended), but you may have issues with dark colors. Next up is bench focus, make sure that you have a flat, even field and not one with a hotspot that stands out. If none of this works then I would suggest picking a different color or springing for some gel shield.

 

[Clifford]

Wow, I've never had any trouble with our 6x9 360Q's or our 36 degree Source4's. And none have ever been bench focused! That said, we lamp at 575W, not 750 or 1000. I've also never tried a really dark (saturated?) gel in them.

 

[gafftaper]

As for the original post has someone taken the lenses out and cleaned them? If you didn't put the lenses back in correctly it could cause this.

Wow, I've never had any trouble with our 6x9 360Q's or our 36 degree Source4's. And none have ever been bench focused! That said, we lamp at 575W, not 750 or 1000. I've also never tried a really dark (saturated?) gel in them.

Yes saturation is the correct term to describe how dark or light a gel is.

If you lamp at 575 your gel will last a lot longer (except if you have S4 zooms they burn gel fairly quickly no matter what you do).

 

[icewolf08]

Wow, I've never had any trouble with our 6x9 360Q's or our 36 degree Source4's. And none have ever been bench focused! That said, we lamp at 575W, not 750 or 1000. I've also never tried a really dark (saturated?) gel in them.

Try putting a L119 in a 36˚ with the barrel all the way in. I have seen more gel go Bonanza in one focus call on our current show than ever. It isn't because our lights are poorly benched, just combination of lens and color. It all has to do with the optics and where the focal points of the lenses are. We burn more color in 36˚s and 6x9s than almost any other fixture. We also lamp all our 50˚-19˚ source fours at 575W.

 

[dhorn]

Here are some suggestions to try after you have confirmed that the fixtures are correctly lensed and have been properly Bench Focused.

1) If you have Gel extender/Top hats available, put your framed color in the far end of the Gel extender or tape the gel over the end of the Tophat. If the color still doesn't last long enough try the next suggestion.

2) If you have Gel extender/Top hats available, get some sheets of Roscolux #101-01991 "Super Heat Shield" OR GAM #GC99 "Heat Shield" and place a frame of the Heat shield in the gel slot of the 6x9 along with the Gel extender. Then put the frame of your Roscolux Chocolate out at the far end of the Gel extender.

3) If you don't have the Gel extenders, you can make some with metal gel frames and some #8x1.5" machine screws and lots of #8 nuts. You will also need some of the Heat Shield mentioned above.

Step #1 Drill a 3/16" hole thru both bottom corners of a pair of 7.5" metal Gel Frames for each Gel extender. The holes should be 1/2" from the folded edge and side edge of the frames.

Step #2 Load one frame with the Heat Shield, this is now the "Rear" frame. Use an Awl or large pin or nail to make a hole in all four corners of the Heat shield, lined up with the holes in the "Rear" frame.

Step #3 Take your empty "Front" frame and insert a #8 machine screw through one of the bottom corner holes. Thread a #8 nut all the way down the screw and tighten. Stack on more nuts to total about 1". Repeat with the other bottom corner of the "Front" frame. For the existing holes in the top corners of the frame, Insert the #8 screws through the rear hole only! This will allow you to easily insert your gels for each production, just cut off a 1" triangle from 2 corners of your gel to fit the bottom of the "Front" frame. Repeat the #8 nuts for the 2 top screws.

Step #4 Now line up the four screws with the "Rear" frame and push through. Attach one #8 nut on each screw and tighten securely. On your first extender, test your bolt length/ stack of nuts and adjust the quantity of nuts to ensure the last nut on the back of the "Rear" frame is flush with the end of the Screw.

I also like to thread a short loop of 1/16" steel safety cable through an extra hole in the top corner of both frames. I use a Nicopress sleeve to secure the 2" loop permanently. Then you clip the the end of the fixture's safety cable to the loop on the gel frames. I also use the 1/2" size "Binder Clip" to hold the "Front" frame closed to keep the gel color from falling out.

Dave Horn
Children's Theatre Company

 

[FatherMurphy]

I've noticed a tendency for wide angle ellipsoidals to be more likely to burn saturate gel than narrower beams, especially 4.5x6 360Qs. IIRC, putting the instrument slightly into a hot spot bench focus can help. It's counterintuitive, but it has to do with how the light is concentrated as it passes through the plane of the gel. If I'm remembering my college lighting lab correctly, when you look at the beam with fog, the conical X in front of the light is a lot closer to a wide lensed instrument than for a narrow lensed unit, so the same amount of energy is passing through a smaller diameter of gel, since it's closer to the cross point of the X.

Mention was made of the possibility of the lenses being in wrong - a 360Q uses two plano-convex lenses, and they should have the flats out, curves facing each other, like so - |) (| . Any other orientation will give very odd results. Interesting, but odd.

Otherwise, if everything else fails, and you simply must have that color from that position, is another type of instrument an option?

 

[lazor]

I had a similar problem a couple of years back with S4 36degs. It seemed like there was nothing I could do and the gel would burn through in the first 15-30 minutes of the show. Heat shielding worked a little but next time I need to try what FatherMurphy suggested about putting the light into a slightly hot spot bench focus. I had tried to flatten the field before and it just seems to make the problem worse.

Though I have noticed that it does not happen with all 36 deg we had. And they were all bench focused the same. Strange.

 

[icewolf08]

The newer revisions of the 36˚ lens tubes are much better, but they are still prone to burning gel.

 

[chris325]

Colortran has always been the worst for me with "gel bonanzas". Every gel brand except for Apollo gets fried almost immediatly.

 

[Kelite]

So I have this Altman 360Q 6x9 that is burning gels like crazy. The gel happens to be R99. Within seconds of putting the gel on the instrument, it begins to warp and burn the color out of the gel. What can I do about this? Do I need to change the lamp, or do I need to align the lamp and the base? Any tips out there on how to avoid gel burning?

Thanks

Sorry to chime in so late, but here is a solution for hard-to-reach ellipsoidal and PAR positions that contain deeply saturated gel transmissions-

Apollo Design | Gel Miser

The average gel lifespan has increased 700% when the Apollo Gel Miser was used within 360Q and S4 PAR fixtures...

 

[RTDesigns]

I haven't had this problem since I quit using RX, and started using nothing but Lee. The deeper saturated colors always last longer with Lee gels. It seems to me that in the past year of so, roscolux has just been getting crapier than ever. Not sure if they changed their formulas or what, but Lee is far superior in my opinion.