MSD250/2 Lamps

[amillar]

Guys,

 

I have 4 fixtures as part of my rig, all of which take Phillips MSD 250/2 lamps. I know the expected lamp life for these and also know that as they near the end of their life, they will get noticably dimmer.

 

I do know that there is potential for these lamps to explode (although I'm told it is rare) - but how likely is it that they will fail prior to the time when they get noticably dimmer?

 

I do carry spares for all my Pars and Fresnels but due to the cost of the MSD lamps, I haven't yet purchased spares. I'm trying to decide whether or not it is worth my while carrying these with me and that depends on how likely you folk think they are to fail.

 

Any views/experiences greatly received.

 

Thanks,

Andrew.

 

May follow this up with a poll depending on your responses.

[Locksmith]

I think it depends on how crucial the fixtures are to your show. I don't think it's likely that they will all fail at once, unless there is a major catastrophe. We have four fixtures which use them and they are not in the main rig, This means they are always being moved around and this will increase the chances of failure. (Especially when one of our 'helpers' dropped one from the trolley when taking them out to the van one night.) We had two spare lamps and used one that night. I now have to convince the boss to replace the spare, but I think it's unlikely as they are 'extra' fixtures and not essential. If they are essential to your show, I'd have at least one spare. It can be hard to get one at short notice/night.

[Jivemaster]

Never sure about discharge lamp spares as they change colour with age and a replacement lamp will look odd. Still depends on your choice, Replace them all together at listed life hours and have a matched set, or replace individually and risk mismatching colour and intensity.

[amillar]

I guess I'm really after information about how likely it would be for one to fail?

 

Although I have four, they are 2 pairs of different fixtures so I guess holding 2 spare is an option and swap a pair if I have a failure - still an outlay of almost £150.

 

Ta.

Andrew.

[Brian Ship]

A 10% fixture count to spare lamps would be about the norm. Moving lights are expensive, just as doing shows is. If you can't afford to lamp them, you should not depend upon the necessity of using them.

 

This similar to the point of how badly should it go out did you need it?

 

Moving light lamps do have something about what won't work in one fixture but will work in another that you can at times take advantage of both for going dim and for not striking. Ballasts and lamps one might say have signatures about the power they give out or what they need. While not perfect and only at time is works (especially if the lamp is less than it's service life and other than snow balled,) the lamp that won't work in one fixture or will seem dim in it at times will work or be brighter in another fixture.

 

Should you not have cash for spares, and if you have time. If the lamp seems like it should work, try it in aother fixture before you write it off. It's possible you will have just solved your problem.

 

Philips and Osram have just upgraded their MSD 250/2 and HSD lamps to 3,000 hour versions. In addition to this, Philips is about to come out with a 4,000 hour MSA 300 lamp - or something if they follow thru that will be similar but with different code to it. Luminous output is less but life is more.