Bulbs bulbs bulbs

[CSCTech]

Well this upcoming year I going to be the one asking for lamps, as we are going to need a relamp for the beggining of the year. I was wondering what the real differences are between some different lamps as I have just used our supply not paying much attention to the different watts but our supply is out and I am going to need to bring up buying more now.

For our ellipsoidals (Colortran 5/50s), they use two pin 500-1000 tungesten sockets. I believe we use 750w lamps right now, I am wondering if a 500w lamp would make much of a difference or not would be good to say they are more efficient than the old ones, or is there an advantage to the 1000w ones and we should maybe get those? Or should we just stick with the 750s?

For our far cycs (Colortran 3 unit far cyc) I believe they only are supposed to take 1,500w double ended base tungsten tubes, on 120v. I have never had seen a box these came in as whenever one would burn out I always had an extra I just took from another fixture (Useally have some of these fixtures lying around.)

For our Fresnals (Colortran 6'' theatre) the sockets are porcelain insulated ones. I am a little confused about these, do the lamps plug into these procelain mounts or are they seperatee from the fixture and built onto two prong tungsten lamps? Either way they take 500, 750, or 1000 watt lamps I believe we use 750s, and ad/disadvantages to either?
We also have 8'' fresnals too which use 1000, 1500, and 2000 watters. I believe we use 1000, or 1500.

And lastly mini ellipses use single contact, double ended base tungsten halogens, 500, or 1000 I believe we use 500.


Thank you so much for the help I know it's a lot. Trying to make the most cost and energy effective thing to do for our theatre. Also any ideas on best brands etc if you have a favorite.

Thanks!

 

[Les]

Well this upcoming year I going to be the one asking for lamps, as we are going to need a relamp for the beggining of the year. I was wondering what the real differences are between some different lamps as I have just used our supply not paying much attention to the different watts but our supply is out and I am going to need to bring up buying more now.

For our ellipsoidals (Colortran 5/50s), they use two pin 500-1000 tungesten sockets. I believe we use 750w lamps right now, I am wondering if a 500w lamp would make much of a difference or not would be good to say they are more efficient than the old ones, or is there an advantage to the 1000w ones and we should maybe get those? Or should we just stick with the 750s?

Actually, I would split the difference and look in to the GL(X) series of lamps. GLA is moderate output, long life and GLC is higher output, reduced life. These are 575w lamps. The 500 and 750 watt lamps you use probably have a large coil-like filament which is less efficient than the compact filament of the GLX series. The 1,000w lamp (is it an FEL?) is also a large coil lamp. While it will have more punch than the 575 (though not by much), the FEL will burn through sockets, gels and gobos faster. I would get away from them if possible. A GLA 575 would probably fit the bill nicely.

For our far cycs (Colortran 3 unit far cyc) I believe they only are supposed to take 1,500w double ended base tungsten tubes, on 120v. I have never had seen a box these came in as whenever one would burn out I always had an extra I just took from another fixture (Useally have some of these fixtures lying around.)

CYC lamps as follows:
1500 FDB Clear 3200k
1500 FGT Frost 3200k
1000 FFT Clear 3200k
1000 FGV Frost 3200k
Usage will depend on throw and size of CYC. I find 1,000w FFT to be quite common.

For our Fresnals (Colortran 6'' theatre) the sockets are porcelain insulated ones. I am a little confused about these, do the lamps plug into these procelain mounts or are they seperatee from the fixture and built onto two prong tungsten lamps? Either way they take 500, 750, or 1000 watt lamps I believe we use 750s, and ad/disadvantages to either?

You're probably looking at BTN(750), BTL(500) or BTR(1,000) lamps for your fresnels. These have a medium prefocus socket, which has a large base with two fins, one larger than the other. The whole thing goes in the socket and does a quarter turn to lock. The wattage you need will depend on the throw you are dealing with. Seems like ship has come up with a great little 575w alternative, the BTH --You should definitely look in to that. It's made by OSRAM, I believe.

We also have 8'' fresnals too which use 1000, 1500, and 2000 watters. I believe we use 1000, or 1500.

Cool. I would go with the lowest wattage possible while still achieving acceptable illumination. In a high school auditorium, I don't see any need for anything larger than a 1,000w fresnel. BTR should fit, in fact you could probably even lamp them down further with the aforementioned BTL and BTN lamps. This is assuming that your 8" fresnels have a medium prefocus socket and not a mogul (large) prefocus socket. Sorry, I don't work with 8's very often.

And lastly mini ellipses use single contact, double ended base tungsten halogens, 500, or 1000 I believe we use 500.

I'm sorry . I would lamp those at 500 and be done with it. I've heard that you will get horrible output either way. Hold the phone. Single contact, double ended base? I'm not sure what that means. Are you sure it's not a 500w 'mini-can' lamp, such as the EVR? Those only go up to 500w though. You might also be looking at a fixture that uses a linear lamp (T3) (they look like CYC light lamps). Are they old fixtures?

Thank you so much for the help I know it's a lot. Trying to make the most cost and energy effective thing to do for our theatre. Also any ideas on best brands etc if you have a favorite.

Thanks!

For brands, USHIO, OSRAM - SYLVANIA and PHILIPS are all solid.

Google the mentioned lamp's ANSI codes (GLA, BTN, etc) if you want to see what they look like.

 

[CSCTech]

Thanks for the tips! I will definetly looked into the GLAs and the BTHs.

About the minis-
Year they dont do to much. They are bright enough but the light is just kind of weird all around. But I like using them for the only reason that I am going to get gobo holders for them and start using gobos in them as they do have a slot, they are the mini ones though (forgetting the measure).

And the lamps for these confused me a bit too, I have never seen the inside of one of these (Lamps behind the lens and not visable from front) so I do not know what is in them. I got the "single connector double ended" thing from the product info-
Mini Ellipse > Fixtures > Theatrical Equipment > Commercial Lighting > All Leviton Products from Leviton Electrical and Electronic Products (Spec doc.)

Thanks!




Edit-

I didn't know they sold frosted halogens, do these add a different effect?

And is this the GLA lamp you have in mind for our ellipsoidals?
http://www.stagelightingstore.com/s.nl/it.A/id.5057/.f

 

[Sony]

The product manual for those Mini-Ellipse's says it takes a type EVR lamp. Which are common and can be found online here

General Brand EVR Lamp - 500W/120V - B&H Photo Video

or your local supply house can easily order some for you if they don't have any in stock.

 

[Les]

You're welcome!

And the lamps for these confused me a bit too, I have never seen the inside of one of these (Lamps behind the lens and not visable from front) so I do not know what is in them. I got the "single connector double ended" thing from the product info-
Mini Ellipse > Fixtures > Theatrical Equipment > Commercial Lighting > All Leviton Products from Leviton Electrical and Electronic Products (Spec doc.)

AH, the Colortran (now Leviton) Mini-Ellipse. Those take the EVR 500w lamp. They look like a smaller version of a 2-pin ellipsoidal lamp, except with a small screw base instead of 2 pins.

Edit-

I didn't know they sold frosted halogens, do these add a different effect?

And is this the GLA lamp you have in mind for our ellipsoidals?
OSI GLA Lamp 575W 115VHP600/6992P 3100K 1500 HR

The frosted halogens may diffuse the light more, but it could come at the cost of losing a little output. Personally, I would go with the clear lamps and choose diffusion gel (CYC silk)

--And yes, that is the GLA lamp I recommend for you. Of course, every space is different, so you might want to just start out with a few of each type of lamp and see what works best.

 

[CSCTech]

Alrighty, so I will ask our suppliers if they can get us the following,

575w GLA (Ellispodials)
1000w FFT (Cycs)
575w BTH or 750w BTN (6'' Fresnals)
1000w BTR (8'' Fresnals)
500w EVR (Minis)

Googled them all and they seem to be the right form factor, will need to double check the 8''s to see if they are large or small.



Diffusion- We have never used any diffusion gels, once when I was just starting our a company had come in to 'inspect' our lights and they left all the foh ellipsoidals with a light orange diffusion gels in them (I didn't know what these were then). They have since wandered off..I will try to find them sometime. I believe they gave a nice warm tint to the usally white stage. Although we removed them because we had to reset the stage to how we had it since we had it set for a musical the next week..

I am planning to work a lot more with gels and gobos in the future. We have such a small lighting inventory that gels arent really to much of a problem, we get a sheet for ~$7 with a student and school discount. And get at least 4-5 cuts out of one for the ellipsoidals, 2 for the large fresnals, (small fresnals use the same frame as our ellipsoidals), like, 8 for the minis (Although we have 4 of them so doesnt matter.) But the bad part is the cycs need a full sheet for one unit so it got a little costy coloring a backdrop with three different colors (Used two cycs with one of each color in both) and we tape on the gels for those since we don't have frames I do not know why, And for ~$30 each, thats 15 of them to have one for every one. Tape works good, it useally shrivals up and hardens and stays in place. Every few days they need to be stuck back but that is much better then spending the money for frames. Yet.

Ah well, things come in little pieces.



OH, our boarder lights, they are very dim. Hardly noticable at all unless all other lights are off. And somewhat noticable through other colors. I believe I had a thread before on what model they are and they are 12 unit 3 channal Altmans. They use par lamps and use colored roundels. I am wondering if gel would work better. I also will need to get the highest wattage lamps for these to get them brighter I beleive.

 

[derekleffew]

RE: your 8" Fresnels. These will have either a mogul prefocus or (less common, sometimes called "TV" version) mogul bi-post socket. I would use either the 1000W BVT, or CYV lamp. I agree you don't need 1500W or 2kW Fresnels unless your throw distances are >40'.


When considering any lamp choice, one must do a balancing act/compromise between light output, lamp life, and color temperature. Lamp cost is negligible as usually all types are within a couple of dollars of each other. Energy usage isn't that big of a factor either, as stage lights are not used at full intensity for hours on end. It is likely to be more cost effective to use a 750W long life lamp over a 575W high output lamp.

One must also take into consideration if you are transitioning from one lamp type to another, it's best not to mix types among one position. If all your Colortran ERSs are currently using 750W EHGs, you'll want to to introduce the GLEs as inobtrusively as possible.

RE: your 6" Fresnels, here is a comparison I did on the various lamps some time ago, when the BTH was announced.
BTL; 500W; 500 hour; 3000K; 11,000 lumens, LPW=22.0,
BTH; 575W; 300 hour; 3250K; 15,500 lumens, LPW=27.0,
BTN; 750W; 500 hour; 3000K; 17,000 lumens, LPW=22.7,
BTR; 1000W; 250 hour; 3200K; 28,500 lumens, LPW=28.5.
Although the BTH has higher efficacy than the BTN, I'd use the BTN, unless power were an issue. I doubt the higher color temperature would make up for the 1500 lumens lost, and would not want to suffer the loss of life, in an educational setting. In the professional world, we normally want the highest output, highest wattage lamp available, and to heck with the life or labor to change it. See http://www.controlbooth.com/forums/...res-long-life-lamps-vs-high-output-lamps.html.

... And get at least 4-5 cuts out of one for the ellipsoidals, 2 for the large fresnals, (small fresnals use the same frame as our ellipsoidals), ...

You should be getting six 7.5"x7.5" cuts, or four 10"x10" cuts, out of each full sheet. If you're taping gel onto cyc lights, I hope you're using Blacktak and not some other type of tape. Re: diffusion gel, see http://www.controlbooth.com/forums/lighting/4865-cyc-lighting.html , http://www.controlbooth.com/forums/lighting/14157-cyc-light-gel.html , and http://www.controlbooth.com/forums/lighting/16801-cyc-color-solutions.html.

 

[Les]

Thanks Derek, I didn't really consider lamp life. In an educational setting Long Life > High Output in most cases. I also didn't realize the relatively short life of the BTH.

Thanks for the clarification on the 8" Fresnels as well.

Re, Border Lights. You might try gels, since they are thinner than roundels, thus have higher transmission ratings. Don't throw out those roundels though - they might be needed again some day and they are becoming quite rare --- and expensive at about $23 a pop!
Altman recommended lamping the R40 borderlights to a maximum of 300w R40 lamps, but they are (or were) expensive, and probably no longer available. IF they are available, they won't be for much longer. You might be able to throw some 150w PAR 38 lamps in, which will give more punch, but it will be an expensive endeavor. Incandescent borderlights are inherently dim in comparison to quartz halogen lamps.

Good note also in phasing lamps in. Try to phase them in little by little, such as Alcove/Box Boom ellipsoidals, FOH Ellipsoidals, Top Light Fresnels, etc.

Hard to tell what gels the lighting company used, but it was probably some light bastard amber. Not sure if they make such a light amber in a diffused version though. Are you sure they didn't use a standard gel with a diffusion gel behind it? In general, you won't use open white lighting. In area front lighting you will typically use one warm (light bastard amber) and one cool (no color blue) per area if going with a Mc.Candless plot. Of course, these colors are not set in stone, and most designers will choose the gel colors based on the show.

 

[CSCTech]

Derek, Thanks I will look over the different lamps. And I will check all the fixtures when I am in, I am not sure if they are all using the same lamps, as I said I have no clue what my preassesors did.

Les, that is good to know, because we have been using all open white light for a long time...I do not think they ever considered gels.
We useally just change everything based on the show, but I am wondering if for anytime I have a white light, to gel it with a light amber?

I will probably ask similar questions in a few months when we start getting into the season and for specific shows, so right now it isnt a huge deal.

Thanks!

 

[ship]

I’ll ignore the bulb’ description as opposed to the more proper lamp’ description of a lamp.

For the ellipsoidals. the energy efficiency and same output isn’t much in converting 750w/120v lamps to other older technology 500w/120v lamps, it’s more in converting to high output 575w/115v lamps that can approximate that output of a 750w lamp or do better, or in going with long life 575w/115v lamps that could approximate the output and color temperature for you situation but also last about as long as your current lamps - only for less wattage. Means at times four of them per dimmer in being different also.

As above, a question about efficiency of the lamp and it’s filament for why it’s better.

For the cyc’s, there is the FCM/HIR lamp from GE as still made I think. Best lamp on the market - only wish they were frosted. Still though at 625w/120v, and similar output to a 1Kw lamp... easy choice. Otherwise there is other lamps to choose from.

On the 6" Fresnels, there is the BTH at 575w/115v but it’s high output and less life. The BTL/BTN lamps for them are the norm. If you have budget the BTH might pay off in cost over that of the 750w BTN for energy savings.

On 8" Fresnels, the above info is incorrect. 8" Fresnels take a different type of lamp. There is no upgrade to them at this point. The EGE is a bit weak, the EGG if possible use, otherwise the 1Kw EGM is the normal lamp to use. (If I don’t mention voltage, it’s 120v.)

Such fixtures are mostly obsolete - by way of lamp technology thus dead end in getting better lamps for them. Not persay obsolete in use, just not getting better in lamps. A BTH for a 8" Fresnel would be cool especially if based off the GLC lamp, but I doubt there is enough market out there for such a lamp or more properly it’s 750w/115v version. 8" Fresnels are a useful but dying breed for a fixture.

Really have some “And lastly mini ellipses use single contact, double ended base tungsten halogens, 500, or 1000 I believe we use 500.” No such thing as a dual ended 500w version with that 2.3/8" LL length, it was 400w. Major and Kliegl made them in me dating them to 1972. Got two now and know of others, and they are brilliant fixtures but are very dated. If you bench focus them efficiently they are good fixtures, just not very efficient given a linear filament in them.

Which brand do you have in I have never seen a Major version of them. They do work as small Lekos’s once bench focused, and are fairly efficient and good in design. But are as described as also as c. 1972 branch to stage lighting history that went in another direction - the Altman 3.5Qx series of light and as later as the more crappy mini-can version of them that are no more efficient than the dual ended versions you have. Your fixtures are mostly just as efficient as what’s currently sold on the market given this Altman change in lamp type on their mini-fixtures. Less in wattage, and keep them at 400w, but for all intensive purposes, there is currently no replacement for them other than the ETC mini-ellipse that has it’s own problems. For a small fixture, if they currently work for you (and I would be suspect of their wiring,) keep using them. Takes work to re-convert a Altman 3.5Q fixture back to a normal lampholder and the ETC mini Leko is very expensive. 400w high output lamp such as the (really more of a 3.1/8" lamp) the EHR lamp is the best lamp for such a fixture in balancing lamp life for luminous output. Other lamps out there but not as lasting in lamp life.

If you really have a EVR type mini-Ellipse... you teater is cursed by that person that bought them and you now unless you get rid of them. These are architectural display fixtures with green lenses and I know about them in depth in my first main theater had some of them. If you have them, get rid of them in passing them onto someone else in doing no favor other than for illumination. These fixtures are first on your inventory to remove. Trust me - these are some of the worst designed fixtures ever invente and in fact not done so for theater - they were for display purposes.

You cannot passs on the curse by recycling... you now in having them have to pass them onto someone else for their own edification. Tag you are it. These really are some of the least efficient fixtures ever deigned. Them I call boat anchors even if lugging about a Altman 360 6x9 as heavy but useful once bench focused properly.

 

[CSCTech]

Thanks for the help ship. Our mini ellipse's are again Colortran, sorry for not saying. I am sorry for the way I stated the lamp socket, I simply read that straight from the product description. I do not believe I have these really bad ones as you say because we use them regulary, yet they have never burned out, We havent done much special with them besides washing the stage from above, but I will be using them for gobos soon, so maybe I should look into the least heat output? I know our ellipsoidals burn gobos to hell. Never had a gel melting problem.


We have never bench focused, I do not even know if a Colortran ellipsoidal can be, can they?

 

[Les]

I do not believe I have these really bad ones as you say because we use them regulary, yet they have never burned out, We havent done much special with them besides washing the stage from above, but I will be using them for gobos soon, so maybe I should look into the least heat output? I know our ellipsoidals burn gobos to hell. Never had a gel melting problem.

Use a Source Four, and then use one of these. You will change your tune . You just haven't been 'spoiled' yet. haha. I think these lights can be okay as long as you don't move them much or expect too much out of them. I know I always had problems with the tilt handles breaking off. Nothing like focusing with a pair of vise-grips!!

The heat out of the front will probably be the same no matter what lamp you use, as long as you stay at 500w. [You can get lamps that fit as low as about 50w, but 500 is where you will most likely need to keep them]. There may be marginal differences, but for all practical purposes, they will throw significant heat due to the aluminum reflectors. The fact that they have never burned out says more about the care you take in handling your lamps and fixtures rather than the quality of the fixture itself. So good job in not banging your lights around!

We have never bench focused, I do not even know if a Colortran ellipsoidal can be, can they?

They can be. In fact, the 5/50's and the Mini's may be pretty similar in concept. I know that on the mini's there is a knob on each side of the lamp cap. It's the same knob that you use to remove the cap to change the lamp. When the fixture is on, try loosening these knobs and backing out the housing a little. This will pull the lamp towards the reflector and you may or may not find that the light output improves. There should also be a small black knob in the center of the back housing (near where the cord exits). This should center the lamp in the reflector. Play with that a little also. Again, these instructions are for the Mini Ellipses, but I believe the 5/50's are close in comparison.

 

[CSCTech]

Haha yeah, my next order of business will be trying to get some new fixtures, maybe replacing a few of the 5/50s with source 4s.

haha, well, matter of fact, on one of our 8'' Fresnals one of the fins on the iris (Well not really, it moves the lense to make the output larger or smaller..) is broken and one of the tilt knobs is missing.

Oh so that is what the knob on the back of the ellipsoidals is, yeah, I asked someone to replace a lamp for me once and they unscrewed the knob completely, took us a while to get it back together, heh. After that I printed out all the spec sheets for our lights which have instructions on lamp replacment.

 

[Les]

Haha yeah, my next order of business will be trying to get some new fixtures, maybe replacing a few of the 5/50s with source 4s.

I'd replace the Mini's first, honestly. The 5/50's aren't really too bad a fixture, given proper cleaning and regular maintenance. They can perform about the same as a 360Q and for all intensive purposes are more or less the same thing.

haha, well, matter of fact, on one of our 8'' Fresnals one of the fins on the iris (Well not really, it moves the lense to make the output larger or smaller..) is broken and one of the tilt knobs is missing.

I'm not sure how the Colortran FresnEls are set up, but it sounds like an ordinary focus knob or wing nut. Take a picture of it and post it here and we'll tell you what it's called and where you can get it. Same for the tilt knob. It might be a part common enough that the local hardware store may carry it. Definitely not an iris, but it does sort of "iris in" the beam; I can see where you'd come up with that comparison. We just call it 'focusing' the fre'nel.

Oh so that is what the knob on the back of the ellipsoidals is, yeah, I asked someone to replace a lamp for me once and they unscrewed the knob completely, took us a while to get it back together, heh. After that I printed out all the spec sheets for our lights which have instructions on lamp replacment.

Yeah that's a common mistake when someone doesn't know much about the piece of equipment they're working on. That knob can be a pain with its washers and parts to lose. Definitely want to keep it all in there unless you don't mind having an unpredictable bench focus every time you bump it .
I've seen people completely remove lenses and shutter gates to try and get to an ellipsoidal lamp before. Makes me wonder about their lamp handling abilities once they finally get access to it. Heh.
>I never had problems with ellipsoidals, but I had a fight with an old brown 65Q fresnel once. Ended up taking the whole socket apart just to get the lamp out. Turns out, the socket was bad and the arcing had welded the lamp base to the center pin of the socket.

 

[ship]

"on one of our 8'' Fresnals one of the fins on the iris"

Realizing it's not helpful to the duscussion but really wrong in so many ways. Buying and reading stage lighting text books at your stage of wondering and development would be relly useful to you. That's where you get education. Posted instead of PM'd because many look to the web, instead of reading and understanding the books. You are at a point of development in asking these questions where stage lighting books would be useful. Gotta buy and read them now. That's where in getting to the point we ask questions, many of us have no doubt found education into our fields. No skipping that step.

On the Mini-Ellipse, good point about if you are not used to better that they are fine. For me... I'll always curse them.. sorry and possibly unfair but realistic in having to use them early on.

On the other hand... I think they can be easily upgraded to GLC lamp type in making them more efficient. That would help.

 

[CSCTech]

Due to our very limited inventory I think I am going to keep what I can, I definetly want to add to it though. And I will be needing the minis to do the gobos I am thinking of doing next year. It was killing me this last year we did some palace them I wanted to do something nice with a window gobo but didn't happen.

As for the fresnal, I guess it is the focus knob, I just thought of it as something different, because on our other lights, when focusing them it doesnt make the beam smaller or largerby much just sharpens and dulls the edges, but on these it dramaticly differs the size of the beam but doesnt really sharpen it. Comes in handy sometimes since it can cover a large area if needed.
Although the fin is broken the wheel is there so I can still turn it.

Now that I know about bench focusing I really need to check our ellipsoidals, because that is our problem half the time, a face or legs are dark, although the light is clealy right on them. Very good thing to know.

 

[CSCTech]

"on one of our 8'' Fresnals one of the fins on the iris"

Realizing it's not helpful to the duscussion but really wrong in so many ways. Buying and reading stage lighting text books at your stage of wondering and development would be relly useful to you. That's where you get education. Posted instead of PM'd because many look to the web, instead of reading and understanding the books. You are at a point of development in asking these questions where stage lighting books would be useful. Gotta buy and read them now. That's where in getting to the point we ask questions, many of us have no doubt found education into our fields. No skipping that step.

On the Mini-Ellipse, good point about if you are not used to better that they are fine. For me... I'll always curse them.. sorry and possibly unfair but realistic in having to use them early on.

On the other hand... I think they can be easily upgraded to GLC lamp type in making them more efficient. That would help.

I know I have lots of questions, but I do know what an iris is, and I do believe I said-
iris (Well not really, it moves the lense to make the output larger or smaller..) , I said this particularily because I knew someone would mention that it is not an iris. I just said iris because it acts a lot like one because it dramaticly increases the beam size.

 

[derekleffew]

... Realizing it's not helpful to the duscussion but really wrong in so many ways. Buying and reading stage lighting text books at your stage of wondering and development would be relly useful to you. That's where you get education. Posted instead of PM'd because many look to the web, instead of reading and understanding the books. You are at a point of development in asking these questions where stage lighting books would be useful. Gotta buy and read them now. That's where in getting to the point we ask questions, many of us have no doubt found education into our fields. No skipping that step. ...

Well, okay, in that vein, I believe the following to be erroneous information.

... On 8" Fresnels, the above info is incorrect. 8" Fresnels take a different type of lamp. There is no upgrade to them at this point. The EGE is a bit weak, the EGG if possible use, otherwise the 1Kw EGM is the normal lamp to use. (If I don’t mention voltage, it’s 120v.) ...

I've never seen, in person or on a spec sheet, an 8" Fresnel or any Fresnel, that takes an EGE/EGG/EGJ/EGM lamp. These lamps are most often used in radial ERSs, with the exception of the axial EC Parellipshere and I believe some axial Century or Century-Strand Lekolights. Although most 6" Fresnels have a medium prefocus socket that accepts the EGE/EGG/EGJ/EGM lamps, the LCL is longer than that of the BTL/BTH/BTN/BTM family, and results would not be satisfactory. As I said, most 8" Fresnels use a mogul prefocus socket, but some 8" and larger use the mogul bi-post socket. (Used in this context, mogul=larger than medium.)

 

[CSCTech]

Due to the confusion I have re-read the spec sheet and I believe this is where I got confused-


"Mechanical
• Optical Train consists of a mogul prefocus tungsten
halogen lamp , an etched super pure aluminum clad
reflector, 8” x 5” low expansion borosilicate fresnel lens mounted in a hinged door for easy lamp replacement.
• Socket shall be medium prefocus porcelain insulated:
UL recognized for 250 volts, 1200 watts, 200˚C
continuous operation. Rated lamp seal temperatures
shall not be exceeded.
• Performance with catalog number 176-194 (ANSI code BVW) lamp in a 15.3˚ field with 358,000 beam candlepower, in spot focus, and in flood focus a 63.5˚ field with 37,000 beam candlepower.
• Mounting heavy steel yoke, with painted malleable iron C-clamp for pipe up to 2” I.D., with a tapped and threaded steel hanger pin. Stand mounting requires combo stud.
• Electrical 36” cable, 3 wire leads covered with black
sleeving with connector as specified by option number"

Also I guess the recommended lamp is a BVW 1200w.

 

[ship]

Yep, got me, was thinking elsewise. #75Q 8"Fresn: BVT, BVV, BVW, CWZ. Really been thinking about that all day and checked to see if I was corrected without anything so far before you in further forgetting to re-check it. Yep, you are absolutely correct in me not checking notes before posting. Got myself confused on Studio Fresnel lamps in also not accurate, verses the stock 75Q. My bad, and thanks for the correction.