CurtPalme.com Home Theater Forum

lucht · Joined: 22 May 2007 Posts: 23 Location: The Netherlands

Nashou66 · Posted: Wed Apr 09, 2008 2:22 pm Post subject:

Kal can you make this thread a sticky? there are always questions about lens's and it hard to find this thread with the search engine.

thanks

Athanasios

**kal** · Posted: Wed Apr 09, 2008 2:34 pm Post subject:

Done. Thread's a sticky now.

Nashou66 · Posted: Wed Apr 09, 2008 2:53 pm Post subject:

Thanks KAL !!!!!

Athanasios

Nashou66 · Posted: Tue Jun 10, 2008 5:35 am Post subject:

What are HD-114's from? and what lens are they similar to if any?

Athanasios

Heywood Jablome · Joined: 12 Mar 2006 Posts: 1542

Pretty sure they are very short, center-focus only, lenses used in RP sets. I believe there is one or two in my Barco RetroData801 (the lenses are mismatched, with R&B getting one type and G getting the other... don't remember which got which.)
I've got a complete set removed from another RD801... I don't remember if I committed to pictures before or not. Want pictures?

Nashou66 · Posted: Tue Sep 16, 2008 1:17 am Post subject:

ok has any one tried to buff out very slight scuff marks from the inside lens caused by the front lens cover being used as a protector for the back side, i think during shipping the lens must have shifted lowering the outer casing allowing the lens to rub against the cover, now i have rings in the centers.? Isnt there some kind of coating on them?

I was thinking of useing the professional cerium powder to polish them out.

Athanasios

**AnalogRocks** · Posted: Tue Sep 16, 2008 1:20 am Post subject:

jkruger · Joined: 24 Oct 2007 Posts: 2434 Location: Carlsbad, CA

I think most use cerium oxide. Try Mcmaster.com, search # 4335A18

Nashou66 · Posted: Tue Sep 16, 2008 1:29 am Post subject:

I Ordered this stuff already Caswell Glass Polishing Kit

if it doesnt work I have other uses for it. I'll test it also on some HD8's i have first. I was planing to scuff them with 1000 grit sand paper then try this stuff.

Athanasios

wallace123456 · Posted: Tue Sep 16, 2008 1:40 am Post subject:

Nashou66 · Posted: Tue Sep 16, 2008 1:43 am Post subject:

**AnalogRocks** · Posted: Tue Sep 16, 2008 2:23 am Post subject:

Don't use 1000 grit, go finer! I use 3000 grit to polish clear coat scratches on my black truck followed by the polish. It makes for a mirror shine. 3M sells it, it's so fine it doesn't even look like sandpaper.

If you go 1000 you'll be polishing for days unless you also go 1500, 2000, 2500, 3000. Then polish. Oh and don't forget to wet sand. Don't let the paper get dry!

zGman · Joined: 22 May 2006 Posts: 598

************ The first elements are NOT glass **********

Unless the lens are so damaged that you would throw them away otherwise,
(ie. there are unwatchable artifacts on the screen), it is very unlikely you will
improve matters by attempting to polish the soft acrylic first element. And,
any abrasive polishing will certainly remove the AR coating, which will reduce
throughput, and may increase halo effect.

A gentle cleaning will remove the particulates from the scuffing, and that
may be enough - the image is not coherent at the surface of that element.

G

Nashou66 · Posted: Tue Sep 16, 2008 2:43 am Post subject:

I wasnt planning on sanding the damaged lens, I was going to test it on an HD8 with a scuff from the 1000 grit, the scuffs on my HD10Gt 17's look like a finer scuff. So if it works for that then it should work on the damaged lens'.

Athanasios

Nashou66 · Posted: Tue Sep 16, 2008 3:04 am Post subject:

Tom.W · Joined: 09 Mar 2006 Posts: 6368

Try the lenses first after a light cleaning. You would be best off retaining as much of the anti-reflective coating as possible !

zGman · Joined: 22 May 2006 Posts: 598

""the scuffs on my HD10Gt 17's""

Ouch - I missed that part - sorry to hear it! - that's just plain wrong....

I have worked with many sets of lenses - the ones where someone had
scrubbed off a good sized patch of the AR coating on the first element
were completely useless. But some with gouges that I thought would
surely show on the screen, worked just fine.

When cleaning, it is best to use a diluted (distilled water 1:1) lens solution
sprayed on a lens tissue until it is just moist enough to be limp - let the tissue
drape on the element and slowly drag the tissue to the side, using NO pressure.

Repeat this in several directions - using a new tissue each time. It
is a slow process but you can achieve good results without causing
further damage - the acrylic lens and the AR coatings are very soft.
even a gentle rubbing when there is a miniscule speck of dust will
scratch it all to heck....And don't follow the dangerous advice,
often found in various forums, of using solvents such as alcohol.

You may need to finish up with a couple times of just distilled water,
don't soak the tissue though - and don't worry so much about
small streaks - going after the little streaks will lead to scratching.
Did I mention not using any pressure?
Its hard to resist the urge to scrub.....

Do not spray anything directly on the lens & Do not use compressed
air spray bottles (they will leave a film - very hard to remove)

Hope this will help.

G

Nashou66 · Posted: Tue Sep 16, 2008 5:28 am Post subject:

here are some pics water and lightly pulling a tissue wont cut it i think Sad

Lens 1

Lens 2

Sucks huh !

I tried some fine cut car polish by hand on one it didn't do any good but it didn't do any harm either as you can see it looked the same as when i got them, the third lens isn't as bad and i think it will be fine these are another story, what do you think?

Are the HD10 lenses that same I have a set of those I could try to remove these and swap them? Is it possible?

Athanasios

zGman · Joined: 22 May 2006 Posts: 598

That looks pretty bad and very sad to see.....Can you make a claim against
the shipper or sellor? Packing was obviously very poorly thought out...

If not, you should just try them, use the worst one on blue & best on green.

I still think removing enough material to polish the scratches out will very likely
ruin the lenses, and removing the AR coating will happen in the first 0.0001
inches, right in the center....better to try and get your money back.....

Well maybe the little treatise on lens cleaning will help someone someday.

"""Are the HD10 lenses that same I have a set of those I could try to remove these and swap them? Is it possible?"""

If you are talking about swapping the first elements, it might be possible if you can find/build a large optical
spanner wrench - whether it would would work is somewhat unlikely - lenses are designed all the way
through - the ray tracing and chromatic corrections are a little bit complex and all have to add up...

But - you are quite an experimentalist - and I think that's a great quality - so I have a feeling we will
be reading more about this soon....

G