Film-Tech Forum ARCHIVE: Lense cleaning...

This is topic Lense cleaning... in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Ron Davis (Member # 4124) on 01-30-2008, 07:14 PM:

All: I have dust/dirt/debris on my projector lenses. I imagine these are pretty expensive so I want to be SURE I'm cleaning them right before I damange them. I have some 'lense cleaning tissue', but wasnt sure if they were supposed to be used by themselves or if I needed some kind of cleaning soloution as well?

I know this sounds like a basic question, but I figure 'better safe than sorry' ...

Thanks!

-Ron

Posted by Gordon McLeod (Member # 33) on 01-30-2008, 07:44 PM:

when cleaning an optical surface I usually recomend the following
1 brush the lens with a camel hair brush to remove the dust ( if a camel hair brush is unavailable use a folded piece of lens tissue to make a puff type brush
then moisten a tissue with a lens cleaning solution suitable for the lens in question and in a circular motion wipe it clean

Posted by Mike Blakesley (Member # 26) on 01-30-2008, 08:47 PM:

Also, don't clean lenses more than necessary. Daily cleaning is not needed. Too-frequent cleaning can damage the lens surface.

Posted by Gordon McLeod (Member # 33) on 01-30-2008, 11:15 PM:

daily proper cleaning with an air, or camel hair brush will not damage a lens

Posted by Mike Blakesley (Member # 26) on 01-31-2008, 10:08 AM:

I was referring to rubbing the surface with a cloth. Some people think a lens is the same as a window.

Posted by Frank Angel (Member # 248) on 01-31-2008, 10:28 AM:

I guess sandpaper is out of the question then, eh? [Razz]

Posted by Floyd Justin Newton (Member # 1316) on 01-31-2008, 01:44 PM:

Frank--

Use a JACK HAMMER... that'll get ALL that crap outta the barrel! [thumbsup]

Posted by Alan Gouger (Member # 543) on 01-31-2008, 02:31 PM:

The good part about using Sandpaper is never having to question any
cleaning method after that:)

Posted by Charles Caron (Member # 3247) on 01-31-2008, 09:01 PM:

A 50-50 mix of hydroflouric acid and uranium hexaflouride would work well....Once....Make sure to wear your gloves and goggles!!!

Posted by James Westbrook (Member # 3690) on 02-01-2008, 11:36 AM:

Some of the lens are way too small for a jack hammer.
That is what the SOS pads are for. [Smile]

Posted by Mark Gulbrandsen (Member # 72) on 02-02-2008, 10:15 AM:

quote:
A 50-50 mix of hydroflouric acid and uranium hexaflouride would work well....Once....Make sure to wear your gloves and goggles!!!

Be sure to ONLY use this method if you are shielded behind 6" leaded glass with remote manipulator arms... HEX is pretty nasty stuff [puke]

!! Also, it might discolor the Anodize of the alumnium barrell... just thought you guys should know...... [thumbsup]

Posted by Frank Angel (Member # 248) on 02-04-2008, 08:23 AM:

But seriously....I've noticed over the years that "dust" seems to change its composition from place to place and from one period in time to another. Years ago in Texas, in a small town with very little pollution, dust was this very light, gossamer kind of consistency; it was gray in color. It could be brushed off surfaces easily. When I lived in out on Long Island, practically farm country at the time, dust was of that makeup -- you could use the camel hair brush to easily brush it off lenses. Over the years, however in New York City, I've noted that dust has become something very different. It now is black in color and has a heavy consistancy and an oily quality to it. It won't just "dust" off surfaces lightly, but will smear and leave a black, sooty trail that needs a solvent to remove it.

I am sure this has to do with the pollution in the air in various parts of the country and I am sure it has changed over the years whereas in some parts of the country and even areas within cities, dusting with a lens brush will not do the job.

We have an ionizer in the booth that charges the air -- it puts negative ions into the air. It reduces static electricity and forces dust particulate to get charged and then the particles are pulled like a magnet to oppositely charged (grounded) surfaces. As little as 10-15 years ago when it was first put into the booth, you used to be able to just wipe the area around the ionizer off with a wet cloth. Now if you wipe that area around the unit, you just get a black smear on the wall that won't be removed by water or even by a household cleaner like Fantastic; you have to use a solvent. Quite the nasty stuff. I am glad the ionizer deposits it on the wall, however little of the overall amount in the air does get caught is that much less of that stuff in my lungs. It dramatically shows what garbage we constantly breath in.

One of these days I want to collect a sample of this goo and have it analyzed for chemical content. The findings may be interesting....if not scary.

Posted by Thomas Hauerslev (Member # 566) on 02-04-2008, 08:27 AM:

For large particles on the lens, lens hammers of rubber are quite effective too - [Smile]

Posted by Mark Gulbrandsen (Member # 72) on 02-04-2008, 09:44 AM:

More than likely the dust contains some remnants of 9/11... [Eek!]

Posted by Martin McCaffery (Member # 37) on 02-04-2008, 10:55 AM:

If you are interested in contemplating dust, here's an informative pop-science book to get you started:

The Secret Life of Dust: From the Cosmos to the Kitchen Counter, the Big Consequences of Little Things by Hannah Holmes

Posted by Bill Enos (Member # 440) on 02-07-2008, 10:33 AM:

A guy who worked here while earning his chemical engineering degree now works for the state dept. of environmental quality says that most of the dark/black dust that is difficult to remove is probably tire dust if you're in a city location.

Posted by Jack Ondracek (Member # 1466) on 02-08-2008, 12:21 PM:

After "deep-cleaning" with the sandpaper, use Bon-Ami to polish the lens. Those who ran arc lamps with silver-backed reflectors will remember how well that stuff worked.

I still remember the warning labels, telephone messages and large-lettered postings in the booth about changing cleaning habits when our first front-coated dichroic arrived! [Eek!]

Posted by Peter David Bruce (Member # 4447) on 02-08-2008, 12:51 PM:

i made a funny discovery today when cleaning our scope lens (that had been running alien vs predator 2 last night) I found a rather lifeless spider sprawled on the front of the lens. I wonder if he decided he'd camp there for the night. Took a long time for me to remove it fully as it was rather 'burnt on'. I guess he had crawled onto it during last nights show....

cant imagine what the audience thought.

We use Roscoe lens cleaning tissues and Lens Cleaning fluid from Jack Roe (cs) ltd. Guaranteed to remove even the crispiest of critters!