Lamp Questions

lxdeptnz said:
Fair enough. I realise that the colour temps are different. What I wanted to know, which I found out from a lamp supply company, was that a MSD 250 lamp is approximately equal to a 1kW parcan. Even though the colour temp of the discharge lamp is higher, so it's whiter and hence appears brighter.

Thanks
David

I’m not your supplier but recognize that the in general balance in some sense between that of a arc source 250w lamp might be similar to that of a 1Kw PAR lamp. This is balance of what light comes out in comparison to what the light looks like only. I in a Leko did not find a similarity, but than of course I have alway rallied behind the fact that a FLK lamp is not a FEL lamp where output and color temperatuer balance. The only balance is that of a FEL lamp in light loss due to a huge filament as to how the FLK becomes similar. How this relates to a 1Kw PAR lamp to a Mac 250, don’t know. I certainly consider them as opposing classes and would not consider them the same to my extent at least. Than of course I would not be attempting to use them for the same intent.

Let’s now take the FFP PAR 64 lamp in comparison to that of a MSD 250/2. The Luminous output of a GE standard FFP Narrow Spot is 12,000 Lumens at 330,000 Candle Power once it hits the reflector. The Mac 250 Krypton states 4,600 Lumens (after the lenses) at a 20.6° beam angle that is roughly similar to that of the FFP at 26x14°. The actual candlepower of this fixture as opposed to the other versions is not stated in my ready reference but should be a lot less. Still it’s possibly similar enough in some assumption of color temperature as balanced against luminous output.

If that’s what the vendor says, perhaps that’s by experience they have found comperable. Than again, perhaps as a last week washing machine sales person, they are blowing smoke up your rear. Test their assertion in seeing what that balance really looks like. It’s going to be different, but in overall effect is it similar? Can you tell the difference between a EHG and FLK or GLA lamp on stage in a 360Q fixture? Nope for the most part. Lots of leeway in lighting effectively.

Answer than is, don’t know. Appears brighter certainly, comprable? That’s for end users not me to say.
 
I just found this post, and have found it very very interesting.

Ship, how is this book you spoke of in post 1 coming along, seems like it could be increadibly useful.
 
When I can take about six months to a year off of work, I'll let you know. Until than, about three years behind schedule in the appendex alone.
 
I'm new to the forum, so I hope this hasn't already been covered. I did a search and didn't see anything quite like my problem.

I just started working at a theatre that has been putting Osram GLA lamps in our Altman 360Qs when the old EHGs burn out... However, we have a large pile of caps that need to have the lamp socket replaced, and more and more caps that have GLA lamps in them are being added to this pile every show. Has anyone else noticed a correlation between these lamps and corrosion in the sockets or is this just the normal amount of wear in old units? It just seems to me that they're breaking faster than I've seen at any other theatre I've worked in, but I might just be crazy.

Any thoughts or comments would be greatly appreciated.
 
It's certainly possible that your GLA lamps to some extent are causing already warn out lamp bases to fail at least in a way you note over that of the stuff that is also wearing out that you have not noted yet.

Long sentence yes. Consider the GLA at 575w but 115v verses that of the EHG at 750w but 120v. I consider this about the same reletive amount of heat on the lamp base.

Given this, it's more likely than not that as you change lamps over to the GLA - much better investment, that the lamp bases were either warn down but not noticed or on their last legs thus blowing now.

Given most of your fixtures were probably bought at about the same time, all thus should wear out also within the same in theory period of time.

Is it the GLA wearing out your bases over that of the theater's standard of a EHG? Possibly in some extent, but most likely the lamp bases are at about the end of their life.

No mention to what extent the bases before the GLA lamps are inspected thus no accurate way to tell if it's the lamp or just an old fixture. You are no doubt noting the wearing out after the fact of the GLA going bye bye. The GLA no doubt will have lasted much longer given the lamp base providing power to it were any good.

A Bone pile of fixtures to work on is a good thing. Once you get high temperature lamp bases in the fixtures - given you don't attempt to use old lamps in re-trashing them the new wired fixture will last a good long time. Just a question of the rotation of the gear I thing in sending it in for service call.

A fixture taken out of a show in placing it in the bone yard with a large NFG tag on it is a bad thing. No time to fix while in prep for the show. Instead the sooner the better in what you make work long before the show opens.
 
Thanks as usual for your in depth explaination!
 
Thanks, ship. That must be what's happening. They're all pretty old and have never been properly maintained. It's just killing me right now because I just started a tech week, I'm literally hanging the inventory for this show (not a big inventory... just a big show...), and I'm designer, ME, and electrics crew all in one, which means I don't have time to fix stuff, but I need everything fixed. I tried to do a maintenance call and fix some instruments last week, but the guy who was in charge of ordering stuff hadn't gotten the parts on time. Oh well, it will all come together... right? :roll:
 
The magic of opening night and time next show to fix the details you note.
 
so i got this cdrom in the mail from orsam. it seems pretty neat. i havent used it yet but it appears that you can select different lamps and compare them side by side. i think people should get a copy of it if they can.
 
Heat Output

Hey Ship,

I was wondering if you knew the heat output at the back of a 360Q with an EHG 1k... we use Ushio & Osram lamps.

Thanks
 
Re: Heat Output

JohhnyK said:
Hey Ship,

I was wondering if you knew the heat output at the back of a 360Q with an EHG 1k... we use Ushio & Osram lamps.

Thanks

EHG lamps are 750w, FEL lamps are 1Kw.

Bought my laser temperature gauge years after I stopped using the 360Q line in general. While I have a bunch of them at work that were found rusting in the back of a semi-trailer to "fix up", they are way down on my to do list. Not much chance I can measure any such thing as temperature at the cap at the moment... why?

On the other hand the temperature gauge - believe it was a Sears Craftsman was fairly cheap, measure it.

On proofreading, not anywhere near that far yet. Started in taking notes - a few Kb worth of them all hand typed. Than something more important came up - the appendix a cross reference of all lamps made that grew from just stage and studio to all lamps in general.

Such a appendix chart grew huge and all inclusive quickly to the point were if the owner needs a new lamp for his headlight on his car, there is a good chance I have te lamp and alternatives to it noted and can get it by way of part number. Anyway, at some point in doing every lamp invented into the chart, I lost the ambition to write up that what's a lamp part of the book and just focused on making that all inclusive chart. This especially since I heavily rely upon it for work even if incomplete.

This was also as of about two years ago. While at times I will update notes, I have catalogs on my desk over the past two years with updated specifications or new companies, even to the point of this week I have a E=Mail waiting for me to open from a company called "Pro Quip." They make compact fluorescent lamps amongst other lamps. I have the link of another source of lamps - including some not otherwise available, but just don't have time in the day or year to sit down these days to get this thing the specifications typed into the chart up to date.

Chart is built and it's simple enough to go line by line thru a new version of a companie's catalog to verify nothings changed, new items installed or things are missing thus either a typo in being missing or discontinued, but it's literally in going line by line, a week per catalog at times. Simple enough at times to also add all lamps into theh specs a new source offers. This given they publish enough specifications about their lamps so including them serves a comparitive difference. Still it takes time to add those lamps. Got notes on EFP lamps that would be a simple correction to my notes on a noted changed specification amongst oter notes dating back to 2/28 that in theory is just a detail to change. Problem is that there is just not time in the day to work a full time job, commute in loosing three hours a day, and get home of a good mood sufficient to spend it on lamp specs.

At the moment I have the tutorial to Auto Cadd LT 2000 minimized on my monitors. Been five years now but I finally installed it on my computer. Just as with lamp specs that is useful at work for me to update, at the moment something where by I need to re-learn 12 years later how to Cadd is more important than getting back to my notes on lamps. Continuing to move into my Condo is more important than lamp specifications at the moment. Three months later and I'm first un-packing a box full of CD's and VCR tapes. Not because they have a home constructed or bought for them yet, but that I need a CD on the CADD system to install it. It and VectorWorks have been sitting around for years now waiting for me to install and re-learn them.


For this, I say that I need about a year off work to get back to writing the book and get anywhere with it.

Help for me would be someone able to just type in lamp data. Much less I'm thinking that having gotten distracted from the subject of this book on lamps more than once, someone else to write the book I provide notes to or something like that. Too much else comes up that gets into the way of sitting down to get much work done on this book as it were.

Beyond all of this is the fact that in my writing style, I perhaps could give the information but am not very adapt in wiriting a short attention span version of anything. A book on lamps for me would thus no doubt run into hundreds upon hundreds of pages thus at very least price itself out of the market of anyone that it would be designed for in affording the price to read it. I'm probably not up to writing it thus in the end.
 
I have 2 words for you ship:

"Intern and .pdf"

Ok - three is you include "and" but then again, I'm not sure that .pdf is a word
 
Thanks Phil - so I was correct in saying two words then! ("Intern", "and").

Still - it sounds better than saying that I have 2 words and an acronym!
 
Yea... while that all falls into my lap - 1-800-My Assistant.

Once life settles down again - as If I will get back into lamp specs. Lots of notes and new catalogs to add.

After that, it's ownly what another 30 or 40 years until I retire and have lots of time on my hands.
 
You think there will be lamps in 30-40 years?
 
Back in the 1920's commuting to work was supposted to be by now done in personal air planes. Think what was it monorails in the 30's, jet space cars in the 1950's, cars tat run on water in te 70's.

Water might be still on the way but it's taking a lot longer than I remember the estimate to be. Took how long to convert houses wired for gas lighting fixtures over to electric? Ok, that's probably a bad example because it did not take that long.

I'm thinking that while heater lamps are grosely inefficient as compared to other sources and more and more these days it is a Star Trek technology world - (Scott doesn't have to change light bulbs) it's going to be a long time before the incandescent lamp goes away. More efficient yes, goes away no.

One will also note on Star Trek a certain amount of lack of task lighting such as Little Ligts on the control consules for controlling the ship. Much less from Next Generation, when they do plays there is no need for stage managers, light or sound board operators. They just say, computer... more light.

Led's and Fiber Optics still have a long way to go before they are a suitable alternative in other than being either a in general bank of them making up a wash light, or point source making up task lighting.

At this point, a single LED installed at the focal point of a Leko won't even begin to be bright enough. A single LED with reflector assembly that replaces a reflector/lamp assembly in a Leko still won't be bright enough. Takes a lot of assemblies of LEDs to make enough intensity which quickly gets away from the point source of light concept. Lumens per watt of a LED might be high, there is still a threshold as to maximum light output.

Here is a thought or wonder, when manned space fligt started, what type of lamps were in use? Given the G-forces and rocking about as part of blasting off from the Earth, one would think a filament lamp would have trouble surviving and there would not be a lot of room for spares.
 
Been playing with the new Coemar LED par of late a lot. (Don't think it's even on the market yet.) Takes the same size gel frame as a PAR 46 but is not as bright in my opinion as even a incandescent 200w PAR lamp. Nor as even a beam where it comes to projecting light.

As above where popping one's ultra high intensity flash light lamp inside a Leko and looking at the beam of light verses a incandescent beam of light, one should compare a LED PAR fixture next to what it's supposted to replace. The LED changes color but in my opinion is nowhere near as intense or controlled a beam.

LED's have a long way to go yet. While the technology might be right around the corner, it's still a long way off where it comes to replacing a wash of 1Kw PAR cans, 750w Lekos or any size of Fresnel. Just not point source enough in luminous output.

Though a Color Kenetics MR-16 LED is a fairly good replacement for a MR-16 lamp and such things are coming along in replacing Juno Light type assemblies for architecture. Such might also be good for short distance stage lighting.
 
I figure that this should go here instead of starting a new thread: What are the lamps that work in the Altman 3.5Q ellipsoidals? What is the highest wattage (they say 500 watts, can you use a 575W lamp)? Which lamps are available in long life (1000 or 2000 hour) models? Thanks in advance!
 

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