Sparkly Blotchy Silver Screen Issue

[Yang Miller]

One of our 3 screens has gradually become sort of sparkly and blotchy.

The other 2 screens don't have this issue. I've heard it could be the reflectivity of the silver screen.

This screen has never been washed as far as I know. It does seem to be slightly sticky to the touch.

The bulb is adjusted and putting out correct light.

Projecting on DP2K10s

Any thoughts on this?

Thanks so much for any input.

[Frank Cox]

If people are touching it then that's your issue.

Silver screens are particularly susceptible to damage from any touching or rubbing or attempts to clean them and so forth.

[Sam Chavez]

Are all the screens the same brand? How about age of screens?

[Steve Guttag]

I've heard it could be the reflectivity of the silver screen.

The bulb is adjusted and putting out correct light.

Well, that's impossible (with the above screen). Perhaps some portion of the right light is correct.

I've seen gain screens do this (silver being a form of gain/coated screen). In fact, if the screen was left in a rolled state for too long, it can come out of the tube that way. The screen gets a bit of a glossy finish to it. Unfortunately, a screen in that condition needs replacement. I think Sam's questions above are relevant.

[Carsten Kurz]

Maybe it's popcorn grease. Depending on building and air circulation, that could affect an individual screen, but not the others.

[Mark Gulbrandsen]

Is there an HVAC outlet or air returns above or behind the screen? Yes, I have actually worked on a cinema that had air returns behind the screens. Does not matter if they are air return or air outlets because its gonna help keep airborne crud up at the screen, and or draw air through the perforations. The same is generally true of the booth. I serviced a relatively new 12 screen theater that did not bother to exhaust the popcorn popper outside. They also generally left the booth door open. Stairway was right behind the candy counter and all the crud from the Popper went right up those stairs and went right into the air intake of the two projectors that were at the top of those stairs. Made a heck of a mess out of the lamphouses. Only after we installed digital on one screen and found the inside of a Christie CP2000 dripping popcorn oil did they realize they had to vent the popper outside. The cleanliness of the air outside also matters as does how well the HVAC system filters the air. Silver screens are especially sensitive to airborne oil and grease. Also, the surface of a silver screen can not be washed, cleaned or even touched. You can only vaccum the backside of them to keep the perforations open.

[Yang Miller]

Thanks All!

The screens are all about 12 years old and all the same brand. Unfortunately there are no tags on the back of the screens and no information. The auditorium in question is nearest the popcorn machine. The sparkly area is out of reach of anyone touching it's all over but mostly in the center and really noticeable on whites. It almost seems like it could be dust attached to grease on the screen? I'll try to get a photo.