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Evidence a PC was a Leko

Discussion in 'Lighting and Electrics' started by ship, Dec 2, 2008.

  1. ship

    ship Senior Team Emeritus Premium Member

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    In the past I posted about a 2Kw Chicago Stage Lighting 6" Plano Convex fixture I got for Christmas one year with it's lamp but without a rear reflector. Thought it possible given a simliar fixture w/o reflector, this one also never had one, now I think differently and it is a third class of Leko as it were.

    Has a lamp base assembly as if some sort of science experiment stand. the base mount in the photo had a post mount closest to the lamp which mounts the socket & accessory bracket behind it. The center post bracket allows the base plate to orientate the lamp left/right and up and down. Thought it curious the second post mount with its slot but not used persay other than perhaps for an accessory reflector assembly.

    Later I worked on a unknown brand of Fresnel and Mole #2046 Fresnel both also with rear access doors and noted the reflectors flipped down and out of the way to access the lamp. I'm thinking now this PC fixture was a 1930's Leko as it were possibly similar to what Kliegl introduced in the 1930's as with Fresnels back than. 3rd photo from p.28 of Rollo Gillespie Williams, F.I.E.S. 1960 text "The Technique of Stage Lighting." This is the type of reflector assembly that will have been mounted on the fixture.

    [[[Next challenge is to install a 1/4" bronze pencil stock rod into the bracket, and more difficult get a ?Fresnel spherical reflector with rod bracket on its rear + possibly a base mount stop that perhaps indexes in a U-Shape to the flat spots on the base for alignment to the lens.]]]

    On Page 55 of the book Gillespie also shows a photo of a classic wide lamp cap Century' brand "Ellipsoidal Reflector Spotlight" in addition to the "Spotlight" I photoed on page 28. He calls the one in the photo a "spotlight" though it looks like a PC or Profile to me. Old term. Both types of fixture were seemingly on the market at the time or publishing or at least still in use. Williams calls photo #3 I posted from page 28 a "Typical Stage Spotlight for use with Class B1 Projector Lamp" (Reproduced by Courtesy of W.J. Furse & Co. Ltd.)

    [[The yoke knobs on the Chicago and Furse fixtures are also very similar - the Chicago has a bit less venting and shaping to it denoting perhaps an earlier fixture plus square nuts and round head screws, plus round head hot rivets which would not be done in the 1960's. This plus a wooden yoke knob extension handle that would be unknown in later deckades. My Major PC fixture fairly certain to be from about 1926 is very similar in also using the same type of manufacturing technique and hardware though not the yoke knob extension handle.]]

    Interesting none the less because later in Frederuck Bentham's "The Art of Stage Lighing" 1968 text, p.77 shows a cut away photo of a "profile spot" and it's in reality a later era of radial Leko as it were. He also cites the year of invention of the Fresnel and "profile spot" (associated with the photo on the next page) to be Kliegl in the early 1930's.

    By modern standards a "Profile Spot" I believe at least more considered to be a plano convex fixture and not a Leko type using a ellipsoidal reflector. Typical defination of a profile would be with spherical reflector or none at all as opposed to ellipsoidal reflector.

    So assuming that an ellipsoidal reflector spotlight (or profile spot) was invented before 1960 but attributed on the page before a photo in the Betham book one can assume a "profile spot" is a ERS or "Leko", and given G-48 lamps often used in the 1920's and 30's plus a few deckades before the intruduction of say the pre-halogen T-20 lamp and mogul screw lamps were replaced somewhere in this time between 1930 and 1960 by the pre-focus base lamp such as the P-28s we have a problem of definition of fixtures.

    Is there perhaps as a given some confusion between books but perhaps three proper classes of spotlights? Euro/American translations/terms asside.

    Is perhaps plano convex or spotlight fixture without a reflector say a Plano Convex fixture, a PC fixture with a spherical reflector say a Profile Spot ( with a sliding lamp socket/reflector assembly) and a PC fixture (single or dual lens sliding lens assembly but not sliding base assembly) a "Leko" or Ellipsoidal Reflector Spotlight as long as it's using a ellipsoidal reflector?

    Also, a ERS as indicated by Bentham certainly could not have been invented in the 1930's. Think about fitting the optical center of a G-48 lamp into a ellipsoidal reflector. The profile spot as a different class than a PC fixture must have been invented back than. The PC fixture was out in the 1920's and perhaps a few years before. Adding that reflector behind the lamp was probably really useful. And as in the case of many early Kliegl 4.5" PC or profile spot fixtures I worked with, the only difference between them and a Fresnel was distance of lamp to lens plus type of lens used, the rest was the same for all intensive purposes. Both fixtures had simlar reflectors.

    Must have been a fascinating time between 1930 and 1960 for lighting fixture design. At some point in that period - most likely the early 1930's, the Fresnel came out. Also the Profile came out. Than following lamp technology, lamp globes were able to get smaller and bases more indexed accurate so one could than bring out the ellipsoidal reflector spotlight for much better control of the light beam and especially its stray light.

    Still though, overall thought, is there three class of fixture based on the two books cited? Going to have a look at a few more from the period but I think during that period such a concept was not defined yet, and since than been washed over.

    Following this, when did each of the three classes of Leko as it were come out?
     

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    Last edited: Dec 2, 2008
  2. gafftapegreenia

    gafftapegreenia CBMod CB Mods

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    Ship this sounds interestingly similar to something I remember reading in the Fuch's book.

    Since I don't have the book with me I can't cite page number, but it was certainly in the lighting section. I believe he called them something like "tormentor and teaser spots". Take a look.
     
  3. ship

    ship Senior Team Emeritus Premium Member

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    In further reading, in this case "Lighting the Stage: Art and Practice" by Willard F. Bellman 1967 (all books I read years ago in college and am ever so glad I later bought), he goes into further detail. Kliegl might just have had a ERS proper in the 1930's though it's not defined in a definate way on pages 16-18. Says in the 1930's the industry was asking for a more efficient spotlight, also mentions 1910 - 1920 for the spotlight starting with the 100-250w baby spot followed by up to 2Kw spotlights proper.

    Anyway, mentions about the tube shaped lamp and even pre-focus bases somewhere around the 1930's coming out which would than lead to a ERS proper once especially the smaller globe was developed. Good book, goes into a lot of detail as with Fuch's and the other two of the period I know of. "Theatrical Lighting Practice" by Joel E. Rubin 1968 is only of limited use on this type of detailed tech.

    So, I'm still thinking for the most part given Beilman was fairly vauge about when the T-shaped lamp really came out which most likely will have been necessary for a realistic ERS fixture, that the reflector behind the lamp was still added first and it's a Profile Spot. Than somewhere after that the lamp caught up and the proper ERS was introduced. Side note however was his noting of the Fresnel fixture in needing to get the lamp closer to the lens. Helps date my round 400G30SP lamped Fresnel at least, but he implies that the Fresnel was in part because of the T-shaped lamps in parallel or even before in importance to a proper Leko coming out due to this need. Interesting chapter.

    Still could have been as with the above Fresnel and the Leko/Profile in question that a Profile Spot in reality was what came out in the 1930's and at some point say after WWII the T-20 lamps came to market and soon afterwards the modern both Fresnel and Leko came to market.

    Searching for info on this for me black hole in history as with defining a clear devision of three different fixture types here with the Fresnel fixture dragged along in having two different types.

    In reality, there is four types of Fresnel - Globe lamp version, incandescent version, RSC version (didn't last long but I have one. Unfortunately I upgraded it to 65Q standards but I do still have it's origional socket and reflector but not its bracket,) and halogen version which just went back for all intensive purposes to the incandescent version. (Perhaps a bit more shallow of a reflector.)

    Than for Lekos' much similar. First the spotlight or PC, than the Profile Spot, than the Incandescent Radial Lekolight type, than the RSC double ended halogen axial Leko (also limited in life but I am very familiar with at least the 3.5Q version) and the modern axial Leko.

    Specific years for each of the earlier versions and confirmation that when texts say ellipsoidal was a ellipsoidal and not a profile however is still a bit foggy for me. Keeping reading on.

    Further research, 1967 Bellman cites both the advent of the single sided (non-RSC) based halogen lamp back than and also the dual lens Leko so more modern concept in Lekos of that era could date at least to that year.

    Beyond that I checked "A Syllabus of Stage Lighting" by Stanley McCandless c.1931 (no not "A Method of Lighting the Stage" or "Glossary of Stage Lighting" by the same author) in a 1964 reprint and it clearly on page 30 notes the advent of both the T-shaped lamp and the Ellipsoidal Spotlight fixture.

    I stand corrected (McCandless is god, especially in this book w/o photos) on dates and perhaps beyond that move the Spherical reflector versions of the PC's or as I might call them Profile Spots to the 1920's, thus the in general reflector or non-reflector versions a mud between 1910 and 1931.

    So where is it that the PC fixture came about with the internal reflector and is that what made for a Profile Spot? Given it at times takes a long time for industry to catch up with current technology thru history, what's the real dates of the various I think three classes of PC or Leko fixture?
     
  4. church

    church Active Member

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    I remember the Furse fixture you show in the photograph, Strand also had fixtures that are almost identical - the Furse instruments are probably based on the Strand items - remember that Furse was and is a lightning conductor and engineering company who dabbled in stage lighting. The stage lighting part of Furse is now part of CCT.

    Strand had these in both 500W and 1000W versions called the Patt 44 and Patt 43 respectively. These were all rendered obsolete by the Patt 23 when it came out in 1953. I remember looking at Patt 43s under the stage in the theatre I worked as a teenager and we still had two patt 44s at the school I attended in the 70s. The patt 23 put out more better controlled light than the patt 43 and the patt 44 was very dim in comparison to a patt 23. The patt 23 also allowed the use of an iris, gobos and shutters.

    If this all sounds like the Source 4 versus the other ERs debate of today then it - it should because it was. Check out the following link to the Strand Archive.

    [media]http://www.strandarchive.co.uk/lanterns/images/patt23_apr1953.jpg[/media]


    You are correct Ship the early fixtures are basically an unrefined version of the PC fixture of today, using a fixed lens; and a lamp and reflector that move relative to the lens. The patt 23s and the profiles that came after these use a spherical reflector, usually a front reflector, have a base down lamp: the lens moves relative to the lamp. I believe these are really a greatly improved stage in the development between the modern ERS and the older PC fixtures which were called in the UK - Focus Lanterns.

    Check out the Strand Archive you will see many examples. The Strand Patt 264 was a radial Leko which is why it ooutperformed the older and strangely newer Strand designs.

    I have used all the fixtures I mention above on stage side by side because when I started doing lighting as a kid in the 70s with the UK deep in recession and no money for anything the professional theatres and schools used what they had, even getting replacement lamps was almost impossible. The lamps for the Patt 23 cost 5 pounds each in 1974 and I was paid 1-15 pounds per show to run a follow spot.

    To summarise from my own personal hands on experience I know of the following:

    1) Focus spots became the PC fixtures used frequently in Europe and seldom seen in North America
    2) Profile spots represent a major performance improvement due to new lamps and better optic design examples include the Patt 23s and similar from other manufacturers ( also seen in follow spots i.e. Altman Dyna spot)
    3) Radial ERS Lekos Patt 264 and similar from other manufacturers
    4) Axial ERS first generation
    5) Axial ERS second generation with enhanced lamp and optic technology of which the S4 is considered the state of the art
     
  5. ship

    ship Senior Team Emeritus Premium Member

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    Indeed, much to study, thanks.

    Made a reflector today. Bent a 1/4" bronze rod to a 3/4" offset flair which matched the bracket on the base. Went to Menards, bought a Abco/Westinghouse ceiling canopy kit and buy way of MAAS polishing compound and Dremmel buffing wheel removed all the coating from the reflector like inside of the part and polished it to a reflector like mirror finish. Followed up by denatured alcohol to remove impurities or left overs in the finish, it reflects really well as per a reflector even if the inside of a arch. housing - though not a persay true known Parabolic or Spherical reflector type. Will know once I attempt to bench focus the thing - later how well that as it were prop reflector assembly worked. Still for now it's within the concept and should it work last a long time.

    Mounting to the pencil stock was from amongst my spare lamp parts bin and pneumatic lamp parts bin. First a zinc plated brass fitting that was key but unusual in working once thru drilled and or tapped in a few places. Pneumatic 3/8" NPT to 1/4" hose fitting on the bottom that's set screw mounted and a 3/8" lamp fitting thread to mount the mirror once I ground off the rest of the fitting. Plus a buffed belleville washer to keep it honest and a brass thumb screw.

    Anyway, I think so far it looks good in reproducing a reflector in its relation to the origional G-48 2Kw lamp. Will see how well the reflector helps to focus the light given it's just a store bought ceiling canopy cap.

    Also never ceases to amaze me how narrow and long these fixtures often were in comparison to what was going on in them. Fascinating to me.

    Side note, once installed into the fixture it seemed to me that the lamp axis was slightly higher than that of the axis of the lens. All specifications should be the same in not really changing anything. Slight adjustment of the seat height of the lamp socket base assembly on it's own rod and all should be solved. Again fascinating fixture and should be much easier to bench focus such a thing than an Altman 360Q given only two thumb screws to adjust once the rear of the fixture door is open.
     

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    Last edited: Dec 4, 2008
  6. church

    church Active Member

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    Hi Ship

    I am always fascinated to experiment like this with fixtures and see how well they work and if they can be improved with modern lamps etc. I have polished a number of fresnel reflectors and I find that the polishing compound used for the plastic lens on car headlights works really well as the finishing polishing compound. I use the one made by Meguire's.

    If you have one in your shop you could also try the reflector from a fresnel or an Altman followspot of the Altspot or Dynaspot vintage.

    As you say the bench focus shouldn't be too difficult. I was a teenager the last time I benched a fixture of this type - a Strand Patt 44 and in truth adjusting the distance of the reflector from the lamp and the reflector height did not make much difference.

    Out of interest it would be interesting once you have it working just to pop in a BTH lamp and a P28 base and see what it does.

    Have fun I eagerly await what happens
     
  7. tjrobb

    tjrobb Active Member

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    Wow, such a necro-post. And a pseudo-hijack.

    Found this and had to mention the instruments I found in my theatre.
    Somehow the fixtures from 1928 made their way under the house. What I found was a PC spot with a screw base; the style with reflector (IIRC, it is in storage at the moment), lamp, and single plano-convex lens. Turns out the P28 base wasn't around until the '30's. The fixture I found ran a G40 1kw incandescent lamp with a mogul screw base (which was still in it!?).

    Thusly, I could say that PC's were around ~1928?

    Also found was a Fresnel, but it is much harder to date as it has a G22 lamp base. The closest I found was a 1938 patent (US2,177,639, Motion Picture Electric Products) for a fixture that is really close to what it looks like.
    As for RSC leko's, I found a lamp for one (it is too small for anything in our inventory, and dang old), but so far haven't found the fixture for it (ANSI EHR).

    Ship: When did lamps start having ceramic bases? I also found a lamp (now broken due to transit/flood issues) that was all glass and metal, no ceramic base. IIRC, it was a G22 base incandescent.
     
    Last edited: Jul 14, 2009
  8. ship

    ship Senior Team Emeritus Premium Member

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    No hijack, more carrying on of such studies.

    Photos would help as with more descriptions.

    Screw base first of course in development though not always the case. All in science. Present what you got, study into it and present the questions further in depth.
     
  9. tjrobb

    tjrobb Active Member

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    Thomas Robb's Photos - Really old lighting | Facebook

    The above has two parts, the first relates to this thread, the other is part of a quest I have and will be it's own thread.

    Shown is the PC spot in question, with a few views of the mogul screw base lamps.
     
  10. ship

    ship Senior Team Emeritus Premium Member

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    I want it!
    That’s a really cool almost even Art Deco design of a light. Eeek! The asbestos. Beliving you are showing more than one fixture here. G-22 half lock base with the screw type. G-22 is odd and probably Euro but still mostly I would think Euro from about the 60's.

    Of photo six, I don’t have a reference point but would guess Times Square for brand. Of Photo Ten... all I can say is I want one, really really think it very special in type and style. Could be if found in the same place they are of the same brand also. This G-22 base, which fixture was the base found in photo ten? If the second one as leading in the photos it is truly a curious fixture.

    First fixture, typical I would say 20's thru 40's PC fixture, any idea of brand often found on the front face aluminum casting or as a sticker on the yoke? Second fixture, never seen anything like it before in design. 50's thru early 60's I would guess and way cool. Perhaps Euro given its base. Have at work a Mole Richardson Fresnel from about the 30's that while globe type also uses a similar bi-pin lamp base but it’s not twist to lock and the keying of your base is much different than this fixture’s base thus me thinking Euro. Fascinating fixture.
     
  11. tjrobb

    tjrobb Active Member

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    Ship-
    The album is a bit confusing (sorry). There are three fixtures here, roughly grouped. The first set is the ~1928 PC spot, the next two photos(with the G22 base) are a second fixture and it's lamp, and the last group is a mystery ERS (which has it's own thread on CB).
    Indeed, the first fixture, the PC, is from 1928-ish, and is a Kliegl (it can be found in one of their old catalogs from that era) if I'm not mistaken. EDIT I have recently found an old Altman (#10) that appears very similar, as well. I have two of them, if you may be interested I can ask around...
    Near as I can tell the second, the G22, is from the 30's or 40's. I found a similar fixture in the patent archives (see earlier post in this thread), but the one I have appears to have mild tweaks.
    The G22 base was not for the ERS, the ERS has the P28s base. I'm just trying to figure out what it is. So as not to hijack, it has it's own thread.
     
    Last edited: Jul 20, 2009

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