Use a gobo or shutters?

[len]

I need to get a very narrow beam out of a S4 ellipsoidal. Focus isn't the issue, just need a very narrow box. Do I shutter it in, or use a variation of Apollo Design | Rectangle (even that one might be too wide). It'll be gelled to a very dark color, like a primary red, blue, etc.

 

[icewolf08]

Shutters with give you much more flexibility, and they don't cost anything extra. Also, if you pick the smallest angle unit you have that will give you the right size then you don't have to cut out as much light.

 

[Grog12]

I'd use the gobo so I didn't damage the shutters if it were going to be on for a long time.

 

[seanandkate]

Isn't the gate for gobos before the shutters on an S4 (don't make fun -- I'm tired)? If so, how about using both? A rectangle gobo a little wider than you think you need to act as a heat sink, then make the exact cuts with the shutters.

 

[Sony]

Just use the shutters, that is what they are there for...also do as icewolf08 says, use the smallest angle lens possible.

 

[gafftapegreenia]

If it must be an absurdly small square, I'd just cut one out of a pie tin.

 

[derekleffew]

Isn't the gate for gobos before the shutters on an S4 (don't make fun -- I'm tired)? ...

I can't recall ever seeing any ERS where the template slot is not farther from the lamp than the shutters. In the olden days (360Q) we would bring in shutters until they were almost seen to help protect the gobo.

It would take YEARS (if ever) to burn a shutter in a SourceFour, even with an HPL750/115. Running with a severely reduced gate could shorten lamp life and lead to reflector degradation, however.

Pictured below is a shutter taken from a Strand LEKO with an FEL lamp.

 

[Grog12]

Burn through yes, warp no. More so on juniors than full size, but I've seen a fair share of warped full size as well.

Its easier to replace a gobo than a shutter. (well on a S4 at least 360q is a whole different ball of wax).

 

[rochem]

I really don't see any reason to use a gobo over shutters, especially considering how well the shutters in a Source Four can stand up to heat. And if it's that big of a show that it could run for a number of years, the savings gained by saving the shutters on one unit would be insignificant.

What if for some reason you couldn't hang the unit directly over the focus point, but instead maybe a foot or two off center? With a gobo, your square would start to look more like a diamond or a rectangle, but if you used your shutters, you can still adjust the beam to make a perfect square even if the angle isn't perfectly on. And if nothing else, you can save yourself a few bucks by not needing to buy a new gobo (and spares).

 

[soundman]

Using a gobo will give you a sharper square. Because shutters are not all in the same plain it is impossible to get a sharp focus on all sides of the box. Granted once the gobo warps all bets are off but its a start. This seems like a gobo that could easly be made by hand.

 

[shiben]

I feel like the easiest method would be to shutter in something like a 10* or 14* Source 4, maybe even a 5* depending on trim height. You can get a decently sharp focus on them, and i doubt youll have shutter life problems.