Glass Gobos

[mstaylor]

Although I was a theatre guy to start, I am now a concert/industrial show guy for the most part. Even the theatre I do is adapting national touring companies into arenas.
I am doing a show this week-end that is using 6 glass gobos. The is new to me so I need a little help. The instruments are 26 degree S4 knockoffs that the lighting company calls Leos. I can't get the image to completely sharpen up, one edge or the other is blurry. Is this the result of poor bench focusing or the knockoff being just not as good? The gobos are Bs.

 

[Footer]

Optics probably are not the best, however using a donut will help sharpen it up a big. It will cut the intensity down a bit. If you don't want to buy one, once can be made out of some blackwrap. Apollo Design | ThinLine Donut: Source 4 Par

 

[Les]

A donut will help tremendously. I would also check the bench focus to make sure the lamp is aligned in the reflector properly.

The Leo is a relatively new instrument made by Leviton (formerly Colortran).

 

[derekleffew]

... The instruments are 26 degree S4 knockoffs that the lighting company calls Leos. ...

LEO? > Fixtures > Theatrical Equipment > Commercial Lighting > All Leviton Products from Leviton Electrical and Electronic Products

 

[JD]

If it is a left to right issue, and you are projecting on a surface that is flat relative to the front lens, then something is not right. As long as the gobo and lens are flat relative to each other, and the target/subject is flat relative to the fixture then that should not happen.

I suspect it is more of a problem where the light is aimed at an angle and therefore one side is closer to the target/subject then the other.

 

[Syphilis]

I'm with JD. The most overwhelmingly frequent cause of the problem you're talking about is the beam angle. If it isn't dead on perpendicular it'll look wonky on one side or the other, especially with high definition glass gobos. I've used an HD glass gobo of the moon in a few productions, and encountered this problem. If it's not that, I can't think of anything other than what's been suggested by these other fine gentlemen.

 

[mstaylor]

I think part of the problem is the accessary slot that the Leo has. You slide it back, install the gobo holder and then slide the slot cover back against it. I suspect it is creating the out of plane that you are talking about. Glass gobos are new to me so I am learning.

 

[SteveB]

I think part of the problem is the accessary slot that the Leo has. You slide it back, install the gobo holder and then slide the slot cover back against it. I suspect it is creating the out of plane that you are talking about. Glass gobos are new to me so I am learning.

Manufacturer dependent, but glass gobo's use a holder that has a spacer between the sandwich plates, so as to account for and support the thicker glass. On an S4 I can insert this type of holder in the regular gobo slot, but on a Altman Shakespeare and I suspect a Colortran, you may have to use the accessory slot. The accessory slot allows for a lot more play as the gobo holder isn't sized correctly for the slot tracks, which may be why the gobo holder is not parallel to the gate, resulting in poor imaging.

Once you solve that issue, you can then play with lamp alignment to get the best image.

 

[Kelite]

Although I was a theatre guy to start, I am now a concert/industrial show guy for the most part. Even the theatre I do is adapting national touring companies into arenas.
I am doing a show this week-end that is using 6 glass gobos. The is new to me so I need a little help. The instruments are 26 degree S4 knockoffs that the lighting company calls Leos. I can't get the image to completely sharpen up, one edge or the other is blurry. Is this the result of poor bench focusing or the knockoff being just not as good? The gobos are Bs.

Sorry to sound pessimistic Michael, but we had a Leo here for testing when first released. The optics were very poor across the image area, regardless of the accessories used with the fixture (custom donuts of all sizes and shapes, tophats). Bench focusing was somewhat unpleasant, as the image quality would improve at the perimeter only to worsen in the center.

While Apollo carries Spotlight architectural projectors, I do not own stock in any ERS manufacturing companies or their affiliates. I would perhaps choose a different fixture designed to project patterns well.