ADB Europe DW/DVW burning gels

[k.alexiou]

We are having a great deal of trouble with our inventory of ADB Europe DW's & DVW's burning out gels in seconds. It seems the light is getting focused onto the gel exactly at the cross over point of the beam.

Is this normal? Could there be some error in assembly? What other solutions have worked?

[ramdram]

In seconds? Generic answer:

 

Duff gels? Is the problem new or have you have changed your gel supplier? Has someone been at the lanterns as in fiddled about with different lamps?

 

Probably best to check those issues first before looking at the lenses, position of etc, etc.

[k.alexiou]

We have been open for 11 months now mostly using Lee filters, I have seen the DVW's burn gels in the past at full wide zoom, and we backed off the zoom a bit & it was OK on Lee202. Now we are using Rosco E-colour 200+ 257 & 117+257 on DW's, again at quite a wide lens setting.

[ramdram]

Assuming too you have attempted to use high temp gels where/if possible(?) then perhaps where the lanterns are situated has a high ambient temperature?

 

Your first question asked "is this normal". What does the manual state about the working temperature range? Can you try firing up the lanterns in a cooler place to see if the gels last any longer? Your profile says you work in Athens...and as I recall Athens is not known for being even remotely cold...even by the sea.

 

Then, to address your second question of "error in assembly". Does this imply you have had them apart? Presume, if they have been apart, you used the manual?

 

Presume also you have replaced any duff lamps with exact same spec?

[ajh51]

We've got a pair of these which were acquired 2nd hand - and we had very similar issues.

 

When I looked into this I found that I couldn't fully flatten the beam. When the adjustment knob/screw was at it's "flattest" position the beam was still quite peaky. It was an issue for us as we got them specifically for gobo projection.

 

I've still no idea why this should be - I puzzled over it for ages, assuming they'd been reassembled incorrectly at some time in their past - in the end I modified the lamp carrier slightly to allow a little more movement on the screw thread. That solved the problem and now I can get a lovely flat beam.

 

Not too sure I can remember what I did - a little judicious filing of the end stop I think.

 

I really like them though - We have a mixed rig containing these ADBs, Selecon Pacifics and a few SIL turbos and the ADBs hold up much better against the Pacifics than the SILs, and I think I like them best of all our lanterns for gobo work.

 

Andy.

[gyro_gearloose]

Has your lamp still got its condenser optics inside the lamphouse? I only ask because on one of our ADBs the lens closest to the lamp broke so we tried running it without either of the two lenses in the lamphouse, just the two in the lens tube. Needless to say the beam wasn't great.

[k.alexiou]

Well guys I have news.

 

 

As chance would have it I bumped into the president & the business development manager of ADB Belgium while they were being shown around our theatre yesterday, and I asked them about this issue.

 

Their answer was 'yes they do burn the filter if you are not using the "cross"...' which leads us on to what is the "cross"? Apparently ADB produces a device which as I understand it is a gel frame with a vertical & a horizontal wire which at the cross point in the centre has a piece of metal or metal gauze which acts as a heatsink transmitting the heat of the focused beam outwards to the frame thus saving the gel from burning, there is a 'slight' loss of light output I am told.

 

I have looked for other references to this contraption as yet found nothing - not even on ADB's site

 

Anyway, am now awaiting a sample of "the cross" to see if it solves the problem.

 

Thanks for your input.

 

[adam2]

Sounds a bit odd, I would not expect a relatively thin wire to conduct much heat away from the gel.

Any such heat removal would only be from perhaps the 1mm of gel nearest the wire.

 

Larger gel frames often have cross wires, but these are primarily to limit any bending, warping or buckling of the gel, not to assist in heat disipation.

[ocfe]

I think some of the later Cantata Fresnels had something like this, they had a honeycomb lens guard and in the centre was a solid piece with a perforations.

[Ashley R]

Sounds a bit odd, I would not expect a relatively thin wire to conduct much heat away from the gel.

Any such heat removal would only be from perhaps the 1mm of gel nearest the wire.

 

Larger gel frames often have cross wires, but these are primarily to limit any bending, warping or buckling of the gel, not to assist in heat disipation.

 

The way I read it was as how ocfe below has described it. 4 small pieces of wire to hold a more meaty plate of metal in the center, this plate of metal would then take the full blow of the focal point, and disperse the heat to its surroundings, would also serve the purpose of holding the Gels in there.

 

I think some of the later Cantata Fresnels had something like this, they had a honeycomb lens guard and in the centre was a solid piece with a perforations.