Conventional Fixtures Source 4 jr

[Musicman56]

Hi all,

I have a quick question. In a contest play (basically a play that competes) that I am the LD, we have to preform in the theater of another local high school. When I get time, I'll set up a post to explain and show you the progress of the show.

I'm in a bit of a dilemma, because of a previous, unbreakable engagement I was not able to attend the theater walkthrough, but was able to send my teacher advisors. Unfortunately, they both know very little about lighting. The school has told me that we are allowed two specials to be hung from the first electric. The instruments will be source 4 jrs. Because our theater program is severely underfunded, I have never been able to work with a source 4 jr. So basically my question is this: if I were to use these two specials as highsides (I think thats the term), would I be able to get a decent color wash from them? Also, in the mean time, would a regular source 4 be a similar substitute for the source 4 jr., or is there something closer that would work better? In case you were wondering, I was planning on using a light brown gel in both of these fixtures.

Thanks,
-Musicman

 

[xander]

S4 jr is a fairly generic term. The most important information is missing: the field angle. You need to know the size of the instrument before any real meaningful decisions can be made. But as far as substituting a full size S4, yes, as long as it is the same degree. The photometrics of the jr and full size are for all intents and purposes the same. The jr is just smaller and lacks some features such as a removable lens train and rotating barrel, etc.

-Tim

 

[Musicman56]

But as far as substituting a full size S4, yes, as long as it is the same degree.

Thanks, thats what I figured, but I wasn't sure.

As far as the angle goes, they didn't specify on their paperwork, so I'll have to shoot them an email to check. Something tells me that they will be 50 degrees. Sorry, I should have caught that.

Thanks for the help,
-MusicMan

 

[rochem]

The photometrics of the jr and full size are for all intents and purposes the same. The jr is just smaller and lacks some features such as a removable lens train and rotating barrel, etc.

That's what I thought. I even made a lengthy post which said essentially the same thing you just said. However, after I posted, I decided to check my facts, and I deleted my post after realizing that I was in fact wrong.

Now I'm not the best at math, but according to my calculations, a S4 jr. with an HPL 575/115 has significantly less light output than a regular S4, also with an HPL 575/115. Calculations made using data from S4 and S4 jr 26deg. All data taken from the relevant ETC datasheets.


Source Four 26deg (Lamp: HPL 750/115)

Candela: 176,255
Cd MF for 575/115: 0.78
176,255 * 0.78 = 137,478 Candela

Adjusted Candela: 137,478
Throw Distance (arbitrary): 20 feet
137,478 / (20^2) = 343.7 fc

Source Four jr. 26deg (Lamp: HPL 575/115)

Candela: 91,480
Cd MF for 575/115: 1.00
91,480 * 1.00 = 91,480

Adjusted Candela: 91,480
Throw Distance (arbitrary): 20 feet
91,480 / (20^2) = 228.7 fc


So assuming my math is correct (and it could be wrong - feel free to double check), a S4 actually puts out considerably more light than a S4 jr, even when lamped the same. I've never used a S4 jr, but I've just always assumed that they would perform the same if lamped the same. But according to these figures, the S4 puts out more than 30% more light than the jr.

 

[bishopthomas]

I had the chance to use S4's and S4 Jr's side by side the other day. The S4's were actually brighter, using the same angle and lamp. I had brand new 575's (although the extended life lamp) in my S4 Jrs and the rented S4's had who knows how many hours. The S4's were obviously way brighter, and this is with gobos installed. I don't know enough about the technical aspects to tell you why but it seems that the S4 reflector is larger/longer so maybe that has to do with it.

 

[derekleffew]

...I don't know enough about the technical aspects to tell you why but it seems that the S4 reflector is larger/longer so maybe that has to do with it.

That's exactly right. Smaller reflector plus smaller gate plus smaller lens(es) equals less light collected and transmitted to the stage. Not that the S4jr. is a bad fixture; it just doesn't compare with the "senior".

...In case you were wondering, I was planning on using a light brown gel in both of these fixtures.

A "light brown gel" such as R99, L156, or AP7100? Be sure to test this in your own theatre; the results may not be what you expect. See Chocolate gel?. Since you're already dealing with a fixture of decreased output, you may not desire the neutral density portion of the color media's spectrum.

Also, it's quite likely that the two specials provided are not at the ends of the electric, where they would want to be for high sides. Much more likely that they are 5' or so off center. The theatre hosting the competition should be able to provide you with a light plot and other lighting information (like a channel list and/or magic sheet), so you could precue the show, and possibly even make a disk if you have a compatible console or OLE, saving you precious set-up time.

 

[briancon7]

What are the rules that you need to follow in the competition? Can you move any other fixtures? Also what is the look you are trying to create?

 

[millamber]

Keep in mind, the S4 jr. does not have a barrel rotation, so if you need to make complex cuts it gets difficult. Also if you are hoping for a soft focus rather than the hard edge, I would suggest using a frost, R119 or similar, rather than sliding the lens tube which dramatically effects (reduces) the field angle of the fixture.

 

[xander]

That's what I thought. I even made a lengthy post which said essentially the same thing you just said. However, after I posted, I decided to check my facts, and I deleted my post after realizing that I was in fact wrong.

Now I'm not the best at math, but according to my calculations, a S4 jr. with an HPL 575/115 has significantly less light output than a regular S4, also with an HPL 575/115. Calculations made using data from S4 and S4 jr 26deg. All data taken from the relevant ETC datasheets.


Source Four 26deg (Lamp: HPL 750/115)

Candela: 176,255
Cd MF for 575/115: 0.78
176,255 * 0.78 = 137,478 Candela

Adjusted Candela: 137,478
Throw Distance (arbitrary): 20 feet
137,478 / (20^2) = 343.7 fc

Source Four jr. 26deg (Lamp: HPL 575/115)

Candela: 91,480
Cd MF for 575/115: 1.00
91,480 * 1.00 = 91,480

Adjusted Candela: 91,480
Throw Distance (arbitrary): 20 feet
91,480 / (20^2) = 228.7 fc


So assuming my math is correct (and that could very well be - feel free to double check), a S4 actually puts out considerably more light than a S4 jr, even when lamped the same. I've never used a S4 jr, but I've just always assumed that they would perform the same if lamped the same. But according to these figures, the S4 puts out more than 30% more light than the jr.

Well, darn, son. You are right and I should have checked my info first. I knew the Jr would be a little bit less powerful, but not by that much. I retract the statement in my initial post.

That also changes my opinion on the S4 Jr quite a bit....

Thanks,
-Tim

 

[bishopthomas]

Anyone want a pair of 36 degree S4 Jrs? I guess I'm going to be stepping up to the big daddies.

 

[chris325]

What are the rules that you need to follow in the competition? Can you move any other fixtures? Also what is the look you are trying to create?

Assuming that this is an IHSA Contest Play/Group Interpretation sectional (I did tech for our school's entry last year, and I am acting this year) you will have a total of twenty minutes to set up and take down your entire set and lighting equipment (i.e. 10 minutes setting up, ten minutes striking.) That is the only time that you have to hang and focus, so you're going to have to be quick.

Here's a complete listing of terms and conditions.

 

[Musicman56]

First of all, thanks for all of the great advice. If anyone is interested, I'm hoping to set up a blog right after this post.

Quote de Musicman56
...In case you were wondering, I was planning on using a light brown gel in both of these fixtures.
A "light brown gel" such as R99, L156, or AP7100? Be sure to test this in your own theatre; the results may not be what you expect. See Chocolate gel?. Since you're already dealing with a fixture of decreased output, you may not desire the neutral density portion of the color media's spectrum.

I'm not sure why I said light brown, brown in general would do. Actually I was just looking at chocolate the other day, I think its R99. I'm afraid, like you said, that it may be too dim, but I'll check. After seeing how very little brown gel there actually is, I might decide to change it to a dark green. I'm trying to get a dingy, dirty type of feel. This is all going to have to be a learning experience for me, and I'm looking forward to it.

Also, it's quite likely that the two specials provided are not at the ends of the electric, where they would want to be for high sides. Much more likely that they are 5' or so off center. The theatre hosting the competition should be able to provide you with a light plot and other lighting information (like a channel list and/or magic sheet), so you could precue the show, and possibly even make a disk if you have a compatible console or OLE, saving you precious set-up time.

Fortunately, the advisor who went reported that they are on the ends of the pipe, which works very well for me. So it looks like I have that going for me. I'm also visiting the space on Friday and they just got their new board yesterday, so I'll have a look, thanks for the tip.

What are the rules that you need to follow in the competition? Can you move any other fixtures? Also what is the look you are trying to create?

I am not allowed to move fixtures. The only thing that I can do with the non-special lights are shuttering them. For this use, I'm trying to create a dingy, dirty feeling, with the use of a wash from the two source 4 jrs. Any fixtures that we bring would have to be hung on our own trees (which we don't have). So I basically am at the mercy of their theater.

Assuming that this is an IHSA Contest Play/Group Interpretation sectional (I did tech for our school's entry last year, and I am acting this year) you will have a total of twenty minutes to set up and take down your entire set and lighting equipment (i.e. 10 minutes setting up, ten minutes striking.) That is the only time that you have to hang and focus, so you're going to have to be quick.

Here's a complete listing of terms and conditions.

Yep, that's right, we are in IHSA. Unfortunately, I have already taken a look at the rules, and they don't offer much in the form of the technical side, but the high school (which happens to be hosting conference and sectionals this year) has been really helpful as far as to the rules.

 

[Musicman56]

UPDATE: We were able to arrange a special theater tour for myself, the stage managers and a few of the senior crew(in experience, that is) members for this friday. Hopefully I'll be abel to get a better grasp of what I'm dealing with then, not only for the S4 jrs, but for the whole theater as well. Once again, thanks for everyone's help, I keep saying this, but hopefully I'll post my progress soon.

-Musicman

 

[mrb]

Anyone want a pair of 36 degree S4 Jrs? I guess I'm going to be stepping up to the big daddies.

want to trade anything for them?

 

[bishopthomas]

want to trade anything for them?

Yeah, two of them for a new Papa Bear S4. Seriously, though, PM me if you're serious and we can discuss.