BTL vs HPL lamps on Studio Fresnels

[Thelightinggal]

I am using studio fresnels for a production, I thought that some fresnels could only take BTL lamps, I think HPL's are being used though. Lamps keep getting blown too. I THINK it is because the wrong type of lamp is being used..this is just a hunch, it really might not be the problem. So, which do I use, BTL or HPL's in a studio fresnel? I think just BTL's..or both can be used. THANKS!

 

[mstaylor]

Correct me if I am wrong but isn't BTLs 500w and HPLs 575?

 

[Grog12]

Unless you're using an ETC Fresnel it isn't using an HPL.

@mstaylor HPL's come in 375 575 and 750. The HPL portion isn't actually an ANSI code.

 

[icewolf08]

I am using studio fresnels for a production, I thought that some fresnels could only take BTL lamps, I think HPL's are being used though. Lamps keep getting blown too. I THINK it is because the wrong type of lamp is being used..this is just a hunch, it really might not be the problem. So, which do I use, BTL or HPL's in a studio fresnel? I think just BTL's..or both can be used. THANKS!

There is no way that you could interchange an HPL for a BTL. A BTL lamp has a medium prefocus base while HPLs are medium bi-pin. See the photos below:
BTL:


HPL:


There are probably other medium prefocus base lamps that you could use in your fresnels provided that the fixture is rated for it and the lamp size and LCL are the same.

 

[Thelightinggal]

I am using studio fresnels for a production, I thought that some fresnels could only take BTL lamps, I think HPL's are being used though. Lamps keep getting blown too. I THINK it is because the wrong type of lamp is being used..this is just a hunch, it really might not be the problem. So, which do I use, BTL or HPL's in a studio fresnel? I think just BTL's..or both can be used. THANKS!

Thanks guys, I need to take a better look at these fresnels another time...

 

[derekleffew]

I am using studio fresnels for a production, I thought that some fresnels could only take BTL lamps, I think HPL's are being used though. Lamps keep getting blown too. I THINK it is because the wrong type of lamp is being used..this is just a hunch, it really might not be the problem. So, which do I use, BTL or HPL's in a studio fresnel? I think just BTL's..or both can be used. THANKS!

The HPL issue has been addressed. ETC has never licensed this lamp for use in anything other than a Source Four series, ETC-branded fixture.

As far as "some fresnels could only take BTL lamps," AFAIK, any Fresnel that is UL Listed to use the 500W BTL can also use a 750W BTN. Some, but not all, can also use the 1000W BTR.

Regarding "studio fresnels," many manufacturers (Strand, Colortran, Altman) make/made essentially the same fixture with two different socket types: the MPF P28s (BTL lamp family) for the "theatre" fixture, and the medium bipost G22 (EGT lamp family) for the "studio" series. Fresnels using the G9.5 (TP-22, "EHD" family) socket were never very successful, due to the wrong filament geometry. "Studio Fresnels" can also sometimes be characterized by their higher wattage and smaller lens size (the Altman 2K 7" Fresnel, for example) than their theatre counterparts.

 

[gafftapegreenia]

The HPL issue has been addressed. ETC has never licensed this lamp for use in anything other than a Source Four series, ETC-branded fixture.

Whats this all about then? ARRI Group: ARRILITE Plus 750

 

[avkid]

Whats this all about then? ARRI Group: ARRILITE Plus 750

"HPL lamp invented by and licensed from David Cunningham"

 

[DELO72]

ARRI makes a Fresnel which uses the HPL under a license agreement from Entertec (D. Cunningham)-- HOWEVER, since the patent for the HPL expired in the USA on July 2nd of 2011, any OEM in the USA can use HPLs now in their fixtures. The reason (I am guessing) that ARRI took a license is that they a) could then start development early, and b) in Germany/Europe where ARRI is based, the HPL patent doesn't expire for another year.

To the original question-- I suggest a BTH lamp (575W 115V) as a far closer lamp to an HPL's output than the BTL, which is a much dimmer, longer-life lamp. HPLs are ~15,500 Lumens, 300hrs. (the non-long life ones). BTH is ~15,500 lumens and 300hrs. BTL is 11,000 lumens and 700 hrs. Not apples to apples.

 

[Gern]

Unless you're using an ETC Fresnel it isn't using an HPL.

@mstaylor HPL's come in 375 575 and 750. The HPL portion isn't actually an ANSI code.

Clearly NOT a Fresnel, but, Bardwell & McAlister Lighting Inc. makes a "Mac Tech 6 Space Light", that first was shipping in 2007 with HPL's. Now it ships with SPH globes. They will still use HPL's according to Brian w/ B&M.
B&M is about launch a new LED line...

 

[JD]

All other issues aside, the real question is that of LCL? Whatever lamp is used it must have the same LCL as what is spec'ed for the fixture. Otherwise, the output will stink, and the inefficiency will raise the temperature inside the fixture.

 

[avkid]

Unless you're using an ETC Fresnel it isn't using an HPL.

On a related note: Port Lighting Systems of Seabrook, NH just took delivery of the first ETC Fresnels in the US.

 

[ship]

All other issues aside, the real question is that of LCL? Whatever lamp is used it must have the same LCL as what is spec'ed for the fixture. Otherwise, the output will stink, and the inefficiency will raise the temperature inside the fixture.

LCL between a G-9.5 with or without heat sink is the same - just a question of the heat sink and entirly possible I think in fitting a HPl into what was not designed for it. Have not tried it though. Same basic lamp only one with a heat sink.

Never mind the above - base of a normal G-9.5 socket lamp grips the lamp on it's base in a by far different way than the HPL. LCL is the same but different animal.

This until as reported by Mark above, Philips or someone else comes back to market with the removable heat sink. Hmm. HPL lamps and remove the heat sink for the 360Q, or etc...

Mark, what's now the status of the HPL/R lamp with removable heat sink??? You know I would ask? Don't say anything if top secret or it's coming with the liquid filled halogen reflector lamp. (Private concept perhaps) Saw the new LED Robert Juliat Leko and Fresnel this week, filament sources still have a few more years. Good but not there yet the LED versions.

 

[DELO72]

Yeah, I personally was really impressed by the light out of the Robert Juliat LED Fresnel. Far better than I was expecting from an LED light source in terms of color and appearance. Not sure how it plays with gel though.... (in terms of what the color ends up being vs. a Halogen source.)

HPL without a heatsink is called a GLC. (more or less.) The HPL has the filaments very tightly defined and in a square pattern or sextagon, vs. the GLC which is a C-13D with the filaments offset and not equally spaced out. I don't think you'll see much of a performance difference though if you aren't using the Source Four reflector, which was designed for that tightly defined filament design. The HPL lamp was specifically designed in concert with and for the Source Four Reflector, so the full performance is achieved when you use them both together. I can't speak for the performance of a GLC in that reflector. Ship- you like to experiment- find out and let us know your thoughts! ;-)

HPL/R with removable heat-sink... you crack me up. That's on the development list alongside the Liquid Nitrogen filled FEL with Ceramic Coil and clear Saphire envelope.

 

[ship]

Yeah, I personally was really impressed by the light out of the Robert Juliat LED Fresnel. Far better than I was expecting from an LED light source in terms of color and appearance. Not sure how it plays with gel though.... (in terms of what the color ends up being vs. a Halogen source.)

HPL without a heatsink is called a GLC. (more or less.) The HPL has the filaments very tightly defined and in a square pattern or sextagon, vs. the GLC which is a C-13D with the filaments offset and not equally spaced out. I don't think you'll see much of a performance difference though if you aren't using the Source Four reflector, which was designed for that tightly defined filament design. The HPL lamp was specifically designed in concert with and for the Source Four Reflector, so the full performance is achieved when you use them both together. I can't speak for the performance of a GLC in that reflector. Ship- you like to experiment- find out and let us know your thoughts! ;-)

HPL/R with removable heat-sink... you crack me up. That's on the development list alongside the Liquid Nitrogen filled FEL with Ceramic Coil and clear Saphire envelope.

On the R&J Fresnel - simple concept, wish I were given the chance in I could have done that type of thing. I was just doing them in fitting fixtures into studio Frenels over the years, taking it apart and fitting the source of the light for bench focus... Simple and easy concept - why hadn't anyone done it before now? Expext the LED Fresnel will now become more simple and cheaper soon as a concept.

Ah' glad it's all on the list or under consideration. OK Fresnel and Leko will be LED but years before viable in a cost effective way I think thus overall the concept that filament lamps still have a few years to go and anything extra for output you can eeek out of them would be useful in this or beyond while the change over goes for later years.

No HPL/R lamp ha? Probably not optically useful due to the tight grid perpendicular to the reflector. No removable heat sinks for the HPL... that's a shame in again standardizing lighting systems. When's the next visit? Would love the museum.

 

[gafftapegreenia]

I have seen such an animal as an "HPL" heat sink existing naked without a lamp envelope. I believe the intent was to allow one to use a non HPL lamp in a Source 4. (What could possibly go wrong.......)

(Pic borrowed from a friend's facebook)