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60's era Klieglight (ERS) Step Lenses

Discussion in 'Lighting and Electrics' started by pianoman, Jun 4, 2007.

  1. pianoman

    pianoman Member

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    I just acquired two 1960's era Klieglight ERS instruments, but they have two different lenses in them. One has a step lens with more steps than the other lens. Both are mounted in the position closest to the edge (which from what I understand is where the step lenses are supposed to be). However, the instrument with the step lens with more steps will not focus, or at least not at about 25 feet, which is all I've been able to try it out at thus far. The other instrument creates a very nice round beam that can be made slightly fuzzy or nice and sharp with the adjustment of the focus, but the one with more steps basically covers a whole wall, and has about as much focus as a fresnel on flood. I can trade out for a matching lens, but my question is what is wrong with this instrument with the higher stepped lens? I tried moving it to the outer position like the other and that didn't help at all. Is it just that the beam angle is much larger than the other? I can't test it on a large wall as of yet; all I have is my basement, so the distance is not so great and the wall height is only about 8 feet or less. I have attached pictures of the lenses and instruments as well in case you're not sure what I'm talking about.

    -Dan
     

    Attached Files:

  2. ship

    ship Senior Team Emeritus Premium Member

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    most likely yep. Different beam spread and wrong for the lens tube if both lens tubes are the same.

    Extract the lenses and look at the OD size. Remember that step lenses are a lens that has the insides cut away, yet the radius of the lens remains the same as if it were a solid lens. Potentially one with more steps is of a larger magnifiction.

    Than of course I have no experience with wrong step lenses in a fixture. Could have been a replacement lens mis-sized. Could be but doubtful that one lens brand to another, one has more steps than another but I seriously doubt this.

    Most likely it's the wrong lens size in the fixture for the focal length of the lens train.

    Also, if you note your photos, there is some dirt and funkeyness going on inside the fixtures. Might want to look into it.
     
  3. pianoman

    pianoman Member

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    Yeah, I need to clean them all out. The two others I just got are covered in sawdust. I don't mind using the non-focused lenses really, and I suppose at the time they kind of made sense, as the concept of stage lighting was still in development, as well as the real place of an ERS fixture in the theatre. So I find it believable that they just had two different lens focus patterns basically. From what I'm told, these instruments could have plano convex or the two different kinds of step lenses in them. The theatre I got them from only had one of the plano convex lenses; the rest were the two kinds of step lenses. I will mess around with the lens position some, since there's actually two lens positions in the lens tube: one up close to the front and another toward the back. But then again, since I don't have any fresnels anyway, these could work out rather nicely.

    -Dan
     
  4. Logos

    Logos Well-Known Member

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    Have you checked the trim (relation of lamp to reflector) on the lantern with more steps in the lens. In these older lamps that can have quite an effect on the beam spread as well.
    I've just acquired two Strand(UK) Patt 23N lanterns which look as though they are related in the design world to your lanterns. I suspect similar period. My lanterns are mid 60's UK manufacture. These however both have ordinary plano convex lenses. I have seen the lantern fitted with both Fresnel and step lenses though and I am currently seeking lens tubs with those lenses to experiment.
    These lanterns were still aroung quite a lot when I started in this busines but I had little opportunity to use them in those days.
     
  5. pianoman

    pianoman Member

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    That is something to check; I doubt it's been really adjusted at all, ever. I'll have to see about doing that; I don't know how it works as I don't have a manual but if it's something fairly obvious then I might be up for it.

    -Dan
     
  6. Logos

    Logos Well-Known Member

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    In European and UK lights it is usually a screw or small knob on the bottom of the rear body of the lantern but be very careful when adjusting with the lantern powered up. I have blown more lamps that way.
     
  7. pianoman

    pianoman Member

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    Update: I decided last night to clean out all the instruments and primarily the lenses. What I discovered was that the paint that lines the sides of the steps on the inside of the lenses had deteriorated and was just powdering on contact. I popped 3 out of 4 lenses out (the last one broke actually) and cleaned them in oxy clean overnight. They're much cleaner now, but most of the paint is gone. Is this something I should be concerned about?

    -Dan
     
  8. Logos

    Logos Well-Known Member

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    I assume that the paint you're talking about was coating the inside of the lens tube? If it has powdered away it may marginally affect the amount of random reflection you get. What colour is the unpainted metal and what colour was the paint that has come off?
    I have resprayed the interior of lens tubes with the sort of paint you use on engine blocks in a matt black but it isn't a cheap proposition. I don't really know the lantern you are working on so I don't know how hot it gets.
    I hope this is helping.
     
  9. pianoman

    pianoman Member

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    Actually the paint I'm referring to is actually on the glass lens. On the inside of the step lens there are ridges at each step, if you will, and on the part of the step that is perpendicular to the fixture, the step was painted black/grey. If you think of this in terms of an actual stairwell that you would walk on, think of each "step" as the part you walk on to go on the stairs, and so then the part that you do not step on, which is the toeboard of each step, is the part that is painted. Does this make sense? It looked like it was a method of masking off the bits of the step that one doesn't want light coming through.

    -Dan
     
  10. Logos

    Logos Well-Known Member

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    Fascinating. I haven't seen that but I guess it makes sense. I have no idea what effect it's absence will have. Maybe Ship or one of the other guys who knows american fixtures better than I do can help.
     
  11. ship

    ship Senior Team Emeritus Premium Member

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    Paint gone is probably something the end user applied. I have not cleaned any step lenses with paint recently but would think the paint would be perminant. It's demise shouldn't effect the light output given it was not designed I would think to be on the lens. Beyond that. Jet Dry and the dish washer... mmm, good stuff for cleaning lenses.


    On the other hand, if these were painted step lenses, while you probably won't notice the baffle as it were gone in light blocking, it's possible that the OxiWash got rid of what was origional to the fixture lens. Should you wish to re-apply it, should be fairly simple to mask off the lens than find a paint that sticks to glass well say some creamic paint that's a flat paint and go for it....

    Interesting the brand in if it is the case that it removed the old paint - have to try it in the future as opposed to ignoring the sales add. How efficiently did it remove the paint from the lens? Did it just kind of allow some to chip off, the rest fall off, or completely remove it? By way of description what did this product do to the lenses in removing the paint? For me from Manson blood to some stray paint on a lens I'm curious.
     
    Last edited: Jun 12, 2007
  12. pianoman

    pianoman Member

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    I was wondering about that. Beyond the somewhat shady background of the paint on the step lenses, I'm wondering if I really want to use the step lenses anyway. Since I have them all out now, instead of reinstalling them (which is a PITA), I'm looking into getting modern plano-convex lenses for these fixtures. I'll keep the step lenses just in case, and I might actually end up with a spare lens tube or two to put a couple step lenses in if I feel nostalgic or something, but I did find one tube with an old, somewhat scratched/chipped plano-convex lens that I tried out today, and the light was so much more even, so I think I'd rather go that route in the end.

    -Dan
     
  13. ship

    ship Senior Team Emeritus Premium Member

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    A step lens verses a PC lens on a medium to long throw fixture shouldn't be detectable in my minds eye at least. Check your bench focuses etc. Concept of a step lens is that it's a PC lens, just that the extra glass that dimishes light output and effects color temperature is removed. This for wide angle lenses at least that such things would most be effected. Given less refined lenses in many older fixtures, the step lens also with less refined glass - green or amber, the step lens would have less of it showing up on stage to color correct for. Modern lenses are better than most older lenses - not all, your concept is correct but would be a shame to do. In long throw, shouldn't be much a difference I would think.

    I'm personally not much a fan of removing a lens that's origional and works as per the fixture design, and replacing it with something else that is different. A 6x16 step lens should be a 6x16 PC lens unless I'm wrong. Time for the much more experienced - old timers or better yet in calling them Grand Old Men Of the Theater (A term I hope to earn) to chime in given they lived thru such concepts I would think.

    Me nope, wouldn't do it in a similar situation.
     
  14. pianoman

    pianoman Member

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    Well, I've put the lenses back in, and with or without paint, there's no visible rings in the light. What I do notice is that the wide angle lens (more steps than the others) has a sort of halo around it; i.e. there's the main part of the light, which is about 3/4 as bright as the narrow angle light, and then there's this second 1/2 light ring around the main focus of the fixture. I haven't messed with the lamp trim yet (that sort of intimidates me simply because I don't want to blow lamps), but it is sort of annoying, because even if you shutter the light, the halo remains on the shuttered side; only the bright part is shuttered. Any suggestions on how to remedy this? The lens is in the correct position according to the Kliegl spec sheets I have seen; they show the wide angle lens further into the lens tube, closer to the shutters than the other lenses.

    -Dan
     
  15. ship

    ship Senior Team Emeritus Premium Member

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    I’m looking at a 8" step lens at the moment - forget where I got it from. Has the very flat ceramic paint on it’s steps. Likely this would peel up potentially if the cleaning solution were left on for a while. I’m noting that the paint is not just on the inside of the steps but also wrapping the corner by about 1/16". (Kopp #FF-5088, 8 DIA x 11f - wish all lenses were as well marked.)

    Paint or no paint shouldn’t effect anything but it’s feasible and very possible that it does.

    Your not noting any visible rings of light is good in the main field angle but these would be more of a stray light nature.

    A halo effect is typically used to describe the hard edge of the beam. Your double image sounds like it is from an out of focus fixture by way of the lenses and most likely not the lamp. Try running the lens train, that inner beam should grow larger almost to the extent of the two beams converging. If you cannot by running the lens train get them to converge, you probably have the wrong lens train in the fixture - going back to your wide verses narrow angle lens. Theoretically a shuttered fixture that’s far out of focus would have two separate rings to it shuttered or not.

    In other words, the lens is not at the focal point of the beam right now. A wider angle lens might need to be closer to the lamp thus a shorter lens train barrel. If you have some Altman 360Q fixtures about, you will note for instance that a 6x9 is a bit shorter than a 6x12 in this way. Going to be the same with any other radial or axial Leko of those generations.

    As for bench focus, get a hard edge (or as near to one as you can) first than you bench focus. Hard to tell where the filament is in reference to the reflector until you have a image that can show it and what the now hot spot and even beam of light looks like. At that point you are also looking at the edge of the hard edge beam for what the halo effect looks like - should be hard edge and the same color all the way around it. Something out of axis will show hot spots, dark spots and often two-colored halo effects. If it helps, if you have gotten this far, your initial focus should be fine for now and is most likely near where it needs to be.

    I note that your description does not note what the more narrow lens did with the fixture - no doubt it was fine?

    Finally, don’t be afraid of bench focusing - one should more be afraid of what a pain in the rear it is than of stuff blowing up - really really rare and contained within the fixture should it. Did a bench focus on a 360Q type fixture not long ago and cranked the lamp against a reflector until it blew. All that happened was the lamp suddenly went out. That’s it no bang, no spark just went out and I knew that it was like $20.00 down the hole.

    In other posts I and others have described procedures for bench focusing both radial and axial fixtures. Have a read. Starts with opening the fixture up and eyeballing it centered on the reflector, than closing it and adjusting some, than opening it again re-centering or inspecting, than re-adjusting until you do find the optical center. If that’s too near the optical center, could be that the reflector has a bit of warp to it or something. Possible in which case you would never be able to get the correct beam and your halo on the hard edge most likely would be say brown on top and blue on the bottom. Good luck, it’s not that bad but seek trained help in doing so - lots of little details or things that only eyes on site can convey in teaching.
     
  16. dhorn

    dhorn Member

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    I just found this thread today.

    If you are still attempting to use these fixtures, they are Kliegl Bros Model 1355 fixtures. From your photos, it looks like the first photo has the original step lens installed, smooth curved face towards the Gel and fairly flat steps on the lamp side. The flat black paint on the edges of each step are incredibly important. Without the paint, all of the light striking that edge is bent at more severe angles than the curved surface, resulting in a beam of light that can't be sharpened, and lots of flare. The paint is a special hi-temp Ceramic paint in flat black. I have had limited luck in past repainting the the steps with black barbecue/stove paint. This will last a few hundred hours of use in 500 to 750 watt fixtures. Painting the steps is incredibly tedious and difficult. The second photo looks like a lens with steps on the outside, perhaps it is a double convex lens with steps on both the inside and outside surfaces. This is not the correct lens for the fixture. The model 1355 came in 2 beam spread options: A 30° field angle - 1355W and an 18° field angle - 1355N. Until 2000, I was responsible for maintaining almost 200 1960's era Klieglight ERS in active inventory here at CTC.

    I hope this has been helpful.
     
  17. derekleffew

    derekleffew Resident Curmudgeon Senior Team Premium Member

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    (Realizing that this thread is two years old.)
    I always referred to them as 6 x 3 3/4 and 6 x 8. IIRC, the narrow lens goes nearest the color frame and the wide lens goes toward the lamp. I heard, but never saw, that there was an xtra-wide version as well. I still have nightmares...
     
  18. ship

    ship Senior Team Emeritus Premium Member

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    Old post but always good with more expert help for future help with and knowledge about. Thanks for the post and education to us all in doing so. Chug away at old posts and initial posts and if your own questions, welcome to the forum in none of us persay experts just a quarm of pooled thoughts.

    Me, Myself and I, I constantly have old fixture questions such as this from last night on a E-Bay box spot:
    Vintage Capitol Stage Lighting Spotlight Cast Base WORK - eBay (item 320348043900 end time Mar-15-09 121652 PDT).htm

    Told me in seeing the photo and matching cooling vents and style up to my own, the brand of five out of seven of my box spots, given I think I know another band or two, but there was still the question of - that's seeming like a pinspot lamp inside a box spot fixture. When whas a SBL lamp developed in relation to a box spot, what is it doing with a slider plate if a narrow focus lamp. Thinking A-Modified = #1415 lamp based antique fixture. Thinking this is an antique with a bad idea for a retrofit. On the other hand, could use some extra gel frames and given I could also use a fifth MR-16 modified box spot fixture for my garage (keeping one of each brand origional in original but currently wired condition) - this would be the perfect thing assuming I would have to buy another lens but Altman still sells box spot lenses.

    This as opposed to the other box spot they are currently offering that seems very home made and JB welded up in not being worth buying.

    Thoughts on someone attaching the asbestos whip to a pinspot transformer and somehow rigged a PAR 36 pinspot lamp to it's lens?

     
  19. gordonmcleod

    gordonmcleod Active Member

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    I believe that they reffered to the painted steps as a colourvered stepped lens
    Capitol did the same with some of there fresnels as well
     
  20. derekleffew

    derekleffew Resident Curmudgeon Senior Team Premium Member

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    ERSs using step lenses had "black ceramic-painted risers" (not steps). Not needed so much on a Fresnel lens, as halation was not so much a problem. In fact, almost all Fresnel lenses have a texture or pattern embossed on the flat side to further soften and homogenize the beam.

    [​IMG]

    [​IMG]

    Above from 1978 Kliegl Bros. catalog.
     

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