Vintage Lighting Quartz Klieglights!

[JChenault]

Also consider filament geometry. There's a good amount of tungsten material in the filament for a given wattage, and optically it's best to contain it in as small an area as possible, thus the CC or coiled coil. If a lamp is burned upside down, supports intended to hang are worthless, parts of the filament sag, touch another, and boom, burnout.

Eric. I respectfully disagree and ask you to consider the BBD T20 CC lamps used in a fresnel. I believe You can design filament supports for BBD just as easily as BBU.

 

[derekleffew]

I meant one shouldn't burn a BBU lamp base down, and vice versa.

 

[Scenemaster60]

While I agree with everything said in the last few posts about lamp physics, as a "young 'en" (relatively speaking), in practice I have always benched radial ellipsoidals to favor brightness towards towards the top of the beam as opposed the to bottom

 

[venuetech]

I recall the radial BBU units that had been miss hung base down, the lamp envelope could distort so much that the only way to remove it would be to take the lens barrel out and break the lamp.

 

[SteveB]

My recollection of BBU design was the tungsten filament in non halogen glass lamps, would blacken the interior of the glass, with most of the used tungsten ejected from the filament coating the inside of the cooler glass envelope.

With a BBU design, that blackening would occur near the base, thus leaving the middle of the glass envelope clear of burned filament, which allowed more light to pass out of the lamp. Same thing would happen with a BBD design, where the very top of the glass envelope would blacken, leaving a somewhat clear glass at the filament area.

 

[Ancient Engineer]

Those Kleig Lekos were pigs. Heavy and a major PITA. I worked a studio that had a few on pantographs and they were a misery not yet displaced in my memory... (although I have tried)

However...the 3508 and 3525 Fresnels were LOVELY. I am wispy-eyed thinking about the quality of that light. Sumthin' about those lenses made them super-amazingly even. The worm-drive lamp carriers were occasionally wonky, but some application of persuasion would get them moving. I was always impressed with the "gas-gauge" indicator on the carrier, it made tuning a scene pretty intuitive once you figured out the way it worked. You could tell - at a distance - what an instrument was focused to.

The same space had some quartz Kleig focusable scoops. By focusable, they meant you could generate a pretty severe hot spot almost instantly. Then, you would turn the knob back and wonder why they went to all that expense...

 

[ship]

While I agree with everything said in the last few posts about lamp physics, as a "young 'en" (relatively speaking), in practice I have always benched radial ellipsoidals to favor brightness towards towards the top of the beam as opposed the to bottom

Why on earth would you out of bench focus to favor the higher side? Splaining please in asking by someone that works on old fixtures normally with damage to the gate mechanism often out of focus.. Possible not a lack of bothering to bench focus, at times by intent or learned? What is this theory and where did you get it from?