Also, sometimes the windows come out a bit streaky. I've tried cleaning some of the windows with a lens tissue after I use the Webril Wipe to get it as spotless as possible, but you can still see some *slight* streaking. I know that ideally you are not supposed to see any of the picture on the port glass, but in reality is this ever going to happen?

Are Kim Wipes OK to use as lens tissue? Until this theater, that's what I've always used. I am currently taking a soldering class and we use Kim Wipes to clean the flux residue off the boards. The instructor said they have fiberglass in them, which raised a red flag in my head. I've never known them to damage a lens, but I just wnated to make sure. thx.

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This one time, at Projection Camp, I stuck a xenon bulb....
 

And, yes...as Gordon and David suggested, be very careful on what grade of Kim-Wipe you use.
 

I don't know if those windows were coated. I think they were the Kelmar windows. They were on a hinge and you could easily get to the other side without having to trek up a ladder.

If anybody knows the real name of this product I've described, please post it here...I'd like to order some of it.

Any camera store should carry proper lens tissue and lens cleaning fluid. That's what I've always used.
 

--jhawk

Get yourself lens cleaner, McDonald's napkins and a small 2x4 inch sanding block from a hardware store. Using 3-4 napkins at a time, wrap them on the sanding side of the block and douse the napkins fairly generously with lens cleaner. Wipe the inside of the glass with medium pressure (nothing strenuous) in a vertical motion. Then IMMEDIATELY take a few more napkins and lay them on the sanding block and press HARD on the glass to wipe it dry, again using vertical strokes. Repeat this procedure for the auditorium side, but wipe this one in a horizintal fashion. Then turn on the projector and xenon with no film in the projector and take a look at your glass. If you see any vertical streaks, they are on the inside of the glass and you can generally touch them up with a dry napkin. If the streaks are horizontal, they are on the outside of the glass and again you can generally fix it with a dry napkin.
There's just something about those McDonald's napkins that works wonders on optical glass. However you must have the sanding block to do a good job. Don't try and use other kinds of napkins, as McDonald's has the only good ones for this job. The lens cleaner will get off that baked on cheap glass cleaner residue. When you are done, you will not be able to tell there is glass in the window frame.

BTW, could you tell me who manufactures the Webril Wipes. I will have our buyer try to get some. The MikeyD's near the theatre really don't like to see me!! :-)

For the collectors/reflectors I just tried Simichrome today and it's amazing!

My new tech turned me on to it. We were able to find it at the local motorcycle enthusiast shop. It's a paste and it comes in a tube.

It says that it is for metal products, so I don't think I'll be using it on glass (although it might work just fine).

Webril is made by BBA Nonwovens in Walpole, MA 02081
 

It sounds to me like you were using Glass Wax to clean your ports. I have used it for years and it works very well. You do have to remember to buff it or you will have a cloudy coating and you will see all the picture on your glass. Once buffed the glass virtually disappears.
 

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This one time, at Projection Camp, I stuck a xenon bulb....
 

Y'know, not to turn this to cars, but I learned something interesting not long ago from a professional auto detailer. He told me that a lot of glass streaking didn't come so much from the cleaning product, but what was used to wipe it on and off with. He advised me never to use a rag that had gone thru a wash cycle with fabric softener, it seems that most glass cleaners will cause the residual softener to leave the rag and streak the glass (and as it turned out, most paper towels, like Bounty, et. al., have a type of softener on them from manufacture. He used plain newsprint paper, which he got from a packing/shipping store. He also raved about a spray glass cleaner, Stoner Invisible Glass, which I've seen at Pep Boys.
 

Although Bon Ami is unlikely to scratch plain glass, it may be abrasive enough to damage an anti-reflection or dichroic coating.

------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Research Labs, Building 69, Room 7525A
Rochester, New York, 14650-1922 USA
Tel: +1 585 477 5325 Cell: +1 585 781 4036 Fax: +1 585 722 7243
e-mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion

Josh
 

The second type of powder is called "Bon Ami Cleanser" and it contains bleaching agents...I've been able to find this in the local grocery store, but not the "Original Cleaning Powder" or the cake. Looks like they're impossible to find locally.

I ordered the Bon Ami cake online.

Back to my original point: Be careful not to use the more commonly found "Cleanser" because I'm willing to bet it's not appropriate for the booth windows.
 

Josh: We used Plexus on the aircraft windows. I think NASA and the military use it, too. Still, I can't say if it's gentle enough for a projection booth window.

There's also a product called Novus that comes in a kit of three bottles. I use the #2 to remove fine scratches from the iPod, but don't think it's intended as a general-purpose cleaner. It's great for removing scratches though.

------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Research Labs, Building 69, Room 7525A
Rochester, New York, 14650-1922 USA
Tel: +1 585 477 5325 Cell: +1 585 781 4036 Fax: +1 585 722 7243
e-mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion

Any material with a higher Mohs Hardness rating will scratch glass. Dichroic and antireflection coatings are likely to be more fragile.

------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Research Labs, Building 69, Room 7525A
Rochester, New York, 14650-1922 USA
Tel: +1 585 477 5325 Cell: +1 585 781 4036 Fax: +1 585 722 7243
e-mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion
 

Once there is no liquid on the surface, even soft cloth will scratch plexi. Again, Lexan may resist such easy scratching. But compaired to double side coated waterclear glass, plexi is dirt cheap. Even if you accidently scratch it, you just cut a new piece and replace it.

John made the reference to that fact that plexi may pipe light, so it would transmit a bit less light than its more expensive coated glass counterpart, but without seeing the actual number comparison, and going my observation of how each worked in my theatres, I would bet that light transmission loss by using plexi wouldn't be significent, at least not proportional to the cost differential.

Frank
 

HOWEVER, Novus #2 is mildly abrasive, so if there's any special coating on the "glass" it will probably not be good for it. As long as it's uncoated though, it would be worth a try for removing scratches.

Interesting: XeKleen II says it can be used on lenses.

Nobody's mentioned their method(s) of cleaning a lens yet....

I decided to experiment with garden-variety Comet from the grocery store and I'll just say now that the glass is so clear that I'm going to have to put little stickers on it to spare my nieces/nephews from running into it.

Comet was mentioned earlier because it contains the same ingredient as Bon Ami. The concern is that it also contains a bleaching agent.

I started with a weak solution of Comet-to-water to get the initial layers of grunge off; for stubborn areas I dipped the damp cloth into a dish with a heavily concentrated paste of Comet/Water.

A lot of elbow-grease later, the glass is perfectly clear.

Note: This is just feedback and a general FYI. I'm NOT saying to go ahead and try this on a booth window if it's coated or optically pure or what-have-you.

It certainly did not scratch, fog or haze the glass like I thought it might.
 

Companies like Edmund Industrial Optics sell cleaning supplies specifically designed for optical components:
http://www.edmundoptics.com/IOD/Browse.cfm?catid=250

Here is their information about cleaning optics:
http://www.edmundoptics.com/TechSupport/DisplayArticle.cfm?articleid=278
http://www.edmundoptics.com/TechSupport/DisplayArticle.cfm?articleid=265

------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Research Labs, Building 69, Room 7525A
Rochester, New York, 14650-1922 USA
Tel: +1 585 477 5325 Cell: +1 585 781 4036 Fax: +1 585 722 7243
e-mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion
 

------------------
Jan Hackett
Theater Operations Manager
Extreme Screen Dynatheater
NM Museum of Natural History Foundation
 

What about coated optical port glass? I've never worked anywhere that could afford it, but I can't imagine that Windex would be the appropriate means of cleaning it.
 

------------------
Jan Hackett
Theater Operations Manager
Extreme Screen Dynatheater
NM Museum of Natural History Foundation
 

quote:

---

What do you use to clean plexiglass ports?

---

Are these in your home setup?
You might try replacing them with optical glass.

With the millions of dead photocopiers & scanners stuffed in all corners of our world now, you should be able to find a good, inexpensive piece without spending too much time looking.

I agree that Plexiglas and Lexan are not the best choice for port "glass". They scratch easily, and may introduce considerable flare, reducing image contrast. The suggestion of finding anti-reflection coated glass from old copiers is a good one.

------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Research Labs, Building 69, Room 7525A
Rochester, New York, 14650-1922 USA
Tel: +1 585 477 5325 Cell: +1 585 781 4036 Fax: +1 585 722 7243
e-mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion

Thing is, I looked at the glass on both our big expensive copier and a retired scanner and the glass in neither looks like it's coated -- at least not as I can tell just by eyeballing it. I wonder if there is the same need in the scanner application for coated glass as there is for projection. I'll see if there are any more technical details somewhere on the manufacturers' websites. The other thing I notice, although I haven't yet dismantled the scanner, is that it doesn't seem like the glass is as thick as port glass. That would bother me as we only use a single piece, not double.

I'll report back when I find out some more.

Frank
 

I was impressed with the glass cleaner from General Motors, so I decided to use it along with newsprint.

In Toronto, there are four main papers.
The Globe and Mail is read by those who run the province.
The Toronto Daily Star is read by those who think someone else should run the province.
The Financial Times is read by those who own the province.
The readers of the Toronto Sun don't give a damn who runs the province as long as the Sunshine girl on page 3 has large breasts.

I chose the Sun.

I made up a loop from a discarded trailer (to protect the lens) ran the projector with lamp, and proceeded to the auditorium. Thanks to the "brilliant" design of the non-opening ports in this particular theatre, I was forced to grab an 8 ft. ladder in route.

The picture being projected through the port-hole showed any spots I might other-wise have missed. I used the FLAT lens btw (which provided the largest image on the port glass).

Spraying the automotive glass cleaner and then scrubbing the port glass, I then let it begin to dry, and followed up with a fresh piece of newsprint.

In the booth, with the picture still running, I repeated the process (being careful not to let any of the spray hit the projection lens).

I was pleasantly surprised with the results. I had a much clearer port than I had been formerly able to achieve with Windex and Bounty.

Colour contrast in the projected image was greatly improved.

 

Now the question is, can I use ANY infrared filter, such as that sold by Edmund Scientific? Or is there some special deal with the filters in these higher wattage lamphouses? As I recall the ones sold by the manufacturer were fairly expensive and the price is by size. So what would be the problem taking a smaller piece and placing it closer to the aperture, say just behind the shutter (we're using Century DAWs) -- that would require a smaller and therefore less expensive piece. But of course a smaller piece probably won't deal with the infrared as well as a large one, right?

An auxillary dichroic heat filter should reflect the invisible infrared energy (>700 nanometres) to a heatsink, whilst passing the visible light (400 to 700 nanometres) to illuminate the film. As the power is increased or the size of the beam decreased, the heat load on the filter (watts per square millimetre of area) increases, and the base material of the filter needs to be able to withstand the heating. Usually, quartz or PYREX glass are used. Common optical glass is more likely to break, as its thermal expansion coefficient is greater. The filter should NOT be mounted rigidly, as it needs room to expand and contract with heating and cooling. With dichroic filters, the angle of reflection is critical to the "cutoff" wavelength, and needs to be specified.

------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Research Labs, Building 69, Room 7525A
Rochester, New York, 14650-1922 USA
Tel: +1 585 477 5325 Cell: +1 585 781 4036 Fax: +1 585 722 7243
e-mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion

So from what you are saying, the filter can be either an absorbing filter that absorbs infrared and passes white, or it can be a dichroic filter that reflects infrared and passes white. I wish I new which one we were getting (they are replacing the broken one -- new filter (costs over $400). If it is a dichoric, then you are saying the angle at which it is installed has to be precise? I am assuming ORCON's filter slots are designed so that will happen if it is dichroic. My gut tells me these are not, only because they don't look anything like a dichroic reflector glass material, but reflectors are a different animal, so that might not apply. Plus, I don't see any obvious heat sink.

While we are waiting for the replacement pieces (they come in two halves that are held together by the slot they sit in) I am going to have to use the filters off the old Eastman 25B carbon arc lamphouse. It is oversized enough so it covers the full shutter opening, yet compact enought that it will fit in the ORC mating cone. We'll see if it cracks into a million pieces because of the heat. The carbon arc in that lamphouse was only burning 50A, not nearly as much energy as a 4500W xenon in the ORCON.
 

------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Research Labs, Building 69, Room 7525A
Rochester, New York, 14650-1922 USA
Tel: +1 585 477 5325 Cell: +1 585 781 4036 Fax: +1 585 722 7243
e-mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion
 

To get the filter holder in place, I simply slid the lamphouse back a quarter of an inch so I could stick heat filter unit in between the ORCON exit cone and the docking cone of the Century, then refocus the bulb a tad, and we were in business.

Here's an intersting aside -- one of the reels of SPEEDY, which was a near mint print, except for 3 or 4 accordian splices at each of the reel joints (who teaches these people how to splice?), about a half of the third reel changed from B&W stock to color stock and had tinted sequences. At first I though, well, this was intended and done to recreate the original tinted presentation. But that can't be because why wouldn't the rest of the film be tinted? My guess is that a section of that reel was damaged and they replaced it with footage from another version where color film was used. Is anyone familiar with this title -- did it have a few tinted sections and most of the rest of the film was in B&W? It certainly was disconcerting, all of a sudden seeing color. And it is amazing how we forget how good B&W looks -- I mean really sharp as a tack -- then <SPLICE> and there's color -- not exactly soft focus, but not as crisp as the B&W either. Ah, how much those other two emulsion layers change the apparent resolution. I was very glad it switched back to B&W for the last reel.

Frank
 

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