Cadenza Fresnel

[cmccabe]

Hi,

 

We have two strand cadenza fresnels,

 

One of them insists on burning through gels at an amazing rate. We have tried different focuses, using a heat shield, and many different gels including high temp ones.

 

Are there any suggestions, or advice related to this particular lantern? Any fine lamp adjustments to be made? Its brother seems to cope much better even under the same focus and with the same lamp.

 

 

Or is it the case that...they are old and I should expect bad things to happen.

 

Any advice or help please!

 

Thanks

[smalljoshua]

Are the lenses in the faulty unit the same way around as the decent one?

 

Josh

[indyld]

It seems to me that if you are using the same / correct lamp type (and have swapped them over) and the correct lens fitted the right way etc. then something else is making them not the same. This could be the cooling provision being impaired or the reflector alignment or maybe even the focus control endstop (setting one lamp nearer the lens than the other.) Or is it they are different marks? I don't remember there being many iterations of the Cadenza but you never know.

 

Something is making them different to behave like this regarding gel burnout with what seems to the casual user as being exactly the same treatment. The question is: What...?

[Nicktaylor]

I am quite surprised gel is burning through on a large fresnel. Minuettes seem to with 650w in but they are much more compact. It will be interesting to hear the conclusion!

[Chris Wilcox]

Having used Cadenza Fresnel over a number of years. I found the actual lamp holder would fall forward and produce this problem. A small tweak backwards would A.produce a better uniform light output. B. stop the gel burn thru. A longer lasting solution was to provide a small brace from the rear of the lamp holder to keep it upright.

 

[the kid]

Having used Cadenza Fresnel over a number of years. I found the actual lamp holder would fall forward and produce this problem. A small tweak backwards would A.produce a better uniform light output. B. stop the gel burn thru. A longer lasting solution was to provide a small brace from the rear of the lamp holder to keep it upright.

While not EXACTLY the same lanterns I have to do this with my harmonys, it does work very well though.

[paulears]

Having still got loads of 2K 243s in service, gel burn is just a fact of life. If when focussing, you need to have the thing on it's widest setting, then gel replacement goes up. One show I do quite often uses 126 and 181 in upwards facing PAR64s. They burn through in one show. Moving the gel to simply sit on the top gets you maybe 20mins extra and the chance of somebody kicking them off, so I don't bother. Just stick fresh in each show! I've never understood those who put up with colours lightening, show by show, eeking the last minute out of a piece of filter.

 

If you can't afford the gel, then maybe the lighting design that used it was faulty? Dear Mr Designer, can we have no gel replacements please. A nice lavender, straw and pale blue design will result - no problem with gels then!

[LXbydesign]

Having still got loads of 2K 243s in service, gel burn is just a fact of life. If when focussing, you need to have the thing on it's widest setting, then gel replacement goes up. One show I do quite often uses 126 and 181 in upwards facing PAR64s. They burn through in one show. Moving the gel to simply sit on the top gets you maybe 20mins extra and the chance of somebody kicking them off, so I don't bother. Just stick fresh in each show! I've never understood those who put up with colours lightening, show by show, eeking the last minute out of a piece of filter.

 

If you can't afford the gel, then maybe the lighting design that used it was faulty? Dear Mr Designer, can we have no gel replacements please. A nice lavender, straw and pale blue design will result - no problem with gels then!

 

-or just be creative with o/w and colour correction! hehe

[J Pearce]

On a long run show it can work out more economic to buy the glass filters from LEE, but they are pricey and far easier to break than a floppy bit of gel.

[gibbothegreat]

Long time ago, possibly even in the days of cinemoid, I read something (and I think it might have been from Strand themselves) to the effec that they recommended punching a lot of very small holes in a filter: apparently, this was sufficent to let a significant portion of the heat escape, but not to affect the colour. Anybody any memory/experience of this or anything like it?

[the kid]

Long time ago, possibly even in the days of cinemoid, I read something (and I think it might have been from Strand themselves) to the effec that they recommended punching a lot of very small holes in a filter: apparently, this was sufficent to let a significant portion of the heat escape, but not to affect the colour. Anybody any memory/experience of this or anything like it?

I vaguely remember ( and I hope it is a memory and not a dream ) someone at plasa (maybe Apollo as Gam are never there) were making "perforated" gel reason 1 - no more blades just rip to fit 2 - less meltyness.

[indyld]

Long time ago, possibly even in the days of cinemoid, I read something (and I think it might have been from Strand themselves) to the effec that they recommended punching a lot of very small holes in a filter: apparently, this was sufficent to let a significant portion of the heat escape, but not to affect the colour. Anybody any memory/experience of this or anything like it?

 

Yes, this came to me years ago while attending the Made-Up Rock and Rock School Of Lighting (For Boys and Girls of all ages on the road).

 

Saturated colour filters would get a peppering of dots stabbed all around to supposedly let the heat out. However, I was never quite sure if the physics of this actually stacked up and didn't just encourage hot spots and compromise the structure of the filter. It was so long ago that I can't remember any A/B or multi-variate testing that confirmed or denied the effectiveness of having a bash at the gel with the point of a Stanley blade.

 

Don't remember perforated gel although I'm sure others remember instructions to "go find a PAR frame and make sure it's a sharp one" in the days when gel (particularly Supergel, less so with Lee) you could rip up colour with a flick of the wrist and have it preloaded in the frame without the use of a knife. Of course, if you weren't very good with a "sharp" gel frame you wasted colour and looked a bit of a numpty as it ripped in a random and jaggedy style across the sheet.

 

Do remember a fashion for perforated business cards/flyers though, but that was for entirely different reasons.

[Don Allen]

See if you can accurately measure the distance from the front face of the lamp to the inside rear of the lens to see if a spacer has been left off the lamp carrier rail.

 

If you are using Lee filters, make sure you have the colour surface facing out, so the clear surface acts as a heat shield or use some heat shield in a seperate colout frame so there is an air gap between the heat shield and the gel in the outer colout frame runner. Rosco gel colour is difused through the plastic so it does not matter which way around it goes.

 

Depending on your budget, do the sums on gel replacement costs, labout to change gels, running cost of lamp etc and see if you can go to led's for the saturated colours.

 

My rule of thumb is at least sixty watts of a led colour to match a 1K fresnel with saturated colours. My first led par's were 12R, 12G, 12B, 12A 5W leds.

[Ashley R]

If you are using Lee filters, make sure you have the colour surface facing out, so the clear surface acts as a heat shield

 

My rule of thumb is at least sixty watts of a led colour to match a 1K fresnel with saturated colours. My first led par's were 12R, 12G, 12B, 12A 5W leds.

 

Don how can you tell, which side is which with LEE?

 

Hmmm Just picked up some 120w RGBW LED Fixtures (12x10w) Unfortunately to bloody noisy to use in theater, But its a half decent rule of thumb at the moment!

[Don Allen]

I used to tell the colour side by looking at the surface, the colour side was less shiny or reflective. However I have just tried a piece of Lee gel and could not pick which side was less reflective, so I scratched the surfaces of the Lee gel in a corner to see which side had the coating and both sides were coated ! Back to the drawing board on that technique. Currently waiting for a reply from Lee which might take a while in this season.

 

Seasons greatings to everyone.