JChenault
Well-Known Member
In
Er -- the photometrics on the ETC site do not indicate the S4J Zoom are more efficient except at 36 degrees. From the etc website.
Quick table. S4 Jr Zoom SR Jr Fixed lens
At 26 degree. 91,480
At 25 degree 77,085
At 36 degree 48,010 42,490
At 50 degree 21,495 23.420
Zooms do have their place - but for the OP I would suggest using regular S4's not the S4 Jr. Several reasons.
1 - They are substantially more efficient. A 50 degree S4 gives you 34,150 candella with a 575 watt 300 hour lamp as opposed to 23,420 for the SFjr. Thats almost a 50 % increase in efficiency.
2 - You have the ability to put in higher wattage. The S4 can take a 750 watt lamp, the Jr only up to 575 watts. At a 750 watt, 300 hour lamp, the 50 degree S4 puts out 45,650 candella. IE twice what the Jr will put out.
3 - You can have 70 and 90 degree lens tubes. This is much wider than the Jr can go.
To the OP, your stage is 65 feet wide and 30 feet deep. This is a big stage. You need all the punch you can get. If you go with S4 Jr's I don't believe you will be happy.
As others have suggested, consider using two or three fixtures per boom. The lower fixture ( Say 6 to 10 feet off the ground) will light the near side of the stage. Since it is lighting actors that are closer to the light, you want a relatively wide beam spread. Above the first fixture you want to have another unit to light the far side of the stage. It will be focused to light actors farther away. By making this a narrower spread, you can keep the intensity, and the size of the beam, consistent with the near fixture ( A god thing).
With a 60 foot throw, I would want three or four units - - but budget may not allow.
The upper fixtures will not light the actors closest to the boom - only the bottom fixture. This reduces ( but does not eliminate) the issue with too much light as the actor exits the wing. IE only one fixture is lighting an actor standing just onstage - not two.
As for beam spread - it depends on a number of factors such as how far offstage the fixtures will be - and how high you will be hanging them. In my space ( with a 30 foot proscenium ) I use more of a pipe end for side lights - and use 70, 50, and 36 degree fixture for each side light position. To figure out your answer, you need to determine how high the fixtures are, and graph it out.
Gut feel - one 50 degree and a 36 degree from each side - or maybe a 50 and 26 degree.
Er -- the photometrics on the ETC site do not indicate the S4J Zoom are more efficient except at 36 degrees. From the etc website.
Quick table. S4 Jr Zoom SR Jr Fixed lens
At 26 degree. 91,480
At 25 degree 77,085
At 36 degree 48,010 42,490
At 50 degree 21,495 23.420
Zooms do have their place - but for the OP I would suggest using regular S4's not the S4 Jr. Several reasons.
1 - They are substantially more efficient. A 50 degree S4 gives you 34,150 candella with a 575 watt 300 hour lamp as opposed to 23,420 for the SFjr. Thats almost a 50 % increase in efficiency.
2 - You have the ability to put in higher wattage. The S4 can take a 750 watt lamp, the Jr only up to 575 watts. At a 750 watt, 300 hour lamp, the 50 degree S4 puts out 45,650 candella. IE twice what the Jr will put out.
3 - You can have 70 and 90 degree lens tubes. This is much wider than the Jr can go.
To the OP, your stage is 65 feet wide and 30 feet deep. This is a big stage. You need all the punch you can get. If you go with S4 Jr's I don't believe you will be happy.
As others have suggested, consider using two or three fixtures per boom. The lower fixture ( Say 6 to 10 feet off the ground) will light the near side of the stage. Since it is lighting actors that are closer to the light, you want a relatively wide beam spread. Above the first fixture you want to have another unit to light the far side of the stage. It will be focused to light actors farther away. By making this a narrower spread, you can keep the intensity, and the size of the beam, consistent with the near fixture ( A god thing).
With a 60 foot throw, I would want three or four units - - but budget may not allow.
The upper fixtures will not light the actors closest to the boom - only the bottom fixture. This reduces ( but does not eliminate) the issue with too much light as the actor exits the wing. IE only one fixture is lighting an actor standing just onstage - not two.
As for beam spread - it depends on a number of factors such as how far offstage the fixtures will be - and how high you will be hanging them. In my space ( with a 30 foot proscenium ) I use more of a pipe end for side lights - and use 70, 50, and 36 degree fixture for each side light position. To figure out your answer, you need to determine how high the fixtures are, and graph it out.
Gut feel - one 50 degree and a 36 degree from each side - or maybe a 50 and 26 degree.
