Cleaning internal lenses and optics

[hkv]

Hi,

I read in the Olympus manual and also in the Zeiss cleaning manual that you should *never* clean internal optics yourself, but let an authorized service center do the cleaning. Does any one here have any experience or knowledge from this and what would be the reason? Is it so that the coating is "weaker" in the internal optics and more easily scratched or are there other reasons?

I hate to send my trinocular head to an authorized service center just because there is a grease spot on the lens.

[JimT]

HKV, part of the reason may be because most people would probably have trouble reassembling the components and if not cleaned would result in damage.

Here is a site that discusses how to clean lenses.

http://www.microscopy-uk.org.uk/mag/ind ... clean.html

[hkv]

Thanks, yes, I guess you are right. People tear it apart and, woosh there goes alignment and precision. I cleaned some lenses in the trinoc head, and it still looks like it works

[gekko]

My 5 cents' worth: As I'm sure you know, the most important thing is not to grind dust into the optical surface: I try to dislodge loose dust by blowing using a bulb (not compressed air from a can!) followed by a clean sable hair lens brush, before using any lens cloth or lens paper (and never dry, and never rubbing, but very gently wiping, and a fresh piece after every wipe). I think inside (normally unexposed) optical surfaces should be treated as being especially soft and easy to scratch, and easy to remove anti-reflection coating.

[Rodney]

I have cleaned several objectives but my advice would be to purchase another objective because your chance of failure would be very high esp. with the high powered objectives at 40x and above. With the internal sections of old damp basement microscope objectives the ones I cleaned were old objectives and they were sort of easy to take apart. The time trying to get them cleaned and aligned is not worth the aggravation and with very little guarantee of success.
With that said a few objectives I cleaned were usable and did not go in the trash can.
Good luck if you try.

Rodney

[hkv]

Thanks Rodney. I do not plan to take the objectives apart. Mine are still clean, but trinoc heads and photo eyepieces sometimes needs cleaning. I used distilled water and dish wash and it seems to work ok. Very mild cleaning and no rubbing. I hope the coatings did not get hurt.

[apochronaut]

Depending on who made the heads, there could be either prisms in there or first surface mirrors and prisms plus several optical windows and a lens. Gekko's advice is good, with gentle blowing being the best course of action but dust can adhere tenaciously and there are also circumstances in some older heads, where a fine film of airborne particles coats everything, lowering the contrast.
With the exception of a few surfaces in certain designs, everything can be cleaned without disassembly. I tend to use long shafted cotton swabs. Moisten with a cleaning solution if you have to but for general dust p/u a really clean fine, good quality 00 to 1 artists brush does well. Tenacious dust can be dis-adhered at least, with one of those, and blown free with air.
First surface mirrors require special care and accidental scratching is possible, even by professionals. However, minor scratches can rarely be detected in use. The aluminum surface is not hard, so yes, rubbing is a no-no. I use a moisten and drag technique with a tissue being lightly dragged by a cotton swab, finishing with several very light cotton swab sessions. The potential for lint from swabs and tissues is real but it is easily removed after the fact and the benefits of cleaning murky mirrors, far outweighs the difficulty of removing a bit of residual lint. The glass of prisms is much tougher, so accidental scratching is unlikely.
As far as coatings go. Usually the coating is consistent throughout but in older Leitz optics the internal coatings in the objectives is of a different formulation and is very difficult to clean without damage. Austrian made Reichert optics from the 60's and 70's( 160mm stuff) also had soft coatings, easily removed.

[CaptainKirk]

Hi,

I read in the Olympus manual and also in the Zeiss cleaning manual that you should *never* clean internal optics yourself, but let an authorized service center do the cleaning. Does any one here have any experience or knowledge from this and what would be the reason? Is it so that the coating is "weaker" in the internal optics and more easily scratched or are there other reasons?

I hate to send my trinocular head to an authorized service center just because there is a grease spot on the lens.

what
a
cash
grab.

#1 (IMPORTANT) use a dust blower (ideally one that doesn't create condensation, that would be bad)
#2 wipe off lens with optical lens cleaner and microfiber cloth, or use Kimtech wipes (better)
#3 blow off with dust blower again. Keep repeating step #1 until all dust particles removed. If not you may need
to open up your eyepiece by unscrewing it (use neoprene gloves or something to avoid putting oils on lens or just flip it around
using kimtech wipes and repeat above steps to get off oil/dust on that side.

Yes cleaning off eyepieces is time consuming. Be patient.

Why blow off dust first? Tiny grains of whatever can actually be smeared around and scratch the lens if you go right to step 2.

[billbillt]

I agree with gekko and CaptianKirk,

I have done several objectives with good results.. The best approach is the simple one..Blowing the dust off first is imperative..

BillT

[Charles]

I would add another step in between blowing with air and cleaning with lens cloth/tissue. Just blowing with air may not blow away particles which adhere to the glass, so I use a soft brush to brush the lens, air blow again and then use tissue with cleaner.

[Rodney]

When you say cleaning internal optics, are you speaking of cleaning the lens that you are not able to clean from the outside and it must be taken apart to get to the other side?
If so that is another ball game esp. with objectives. I have several objectives that were contaminated from the inside elements, but none of them were modern.
Just blowing them off would have never worked.
Rodney

[hkv]

The Olympus manual talks about cleaning eyepieces, objectives and condenser glass. It says that all other optical surfaces should not be cleaned by the user, but by an authorized service partner. There are plenty of glass that needs cleaning. For example.

1. The trinoc head and it's lenses (top and bottom)
2. The photo eyepiece which has two open surfaces
3. The DIC prisms

and so on. If I were to follow the manual in an orthodox way, I cannot clean these myself. I need to let an authorized service center do the work. My question was to understand why these are not cleanable by the user (and perhaps were particularly sensitive for some reason)

[Rodney]

I asked this question before, how do you clean the prisms properly? I cleaned a set with alcohol and a soft brush but it left a residue that could not be removed, the mineral in the alcohol became part of the element.
So I don`t know how they do it, I would like to find out, if they can.
Rodney

[billbillt]

Hi,

I read in the Olympus manual and also in the Zeiss cleaning manual that you should *never* clean internal optics yourself, but let an authorized service center do the cleaning. Does any one here have any experience or knowledge from this and what would be the reason? Is it so that the coating is "weaker" in the internal optics and more easily scratched or are there other reasons?

I hate to send my trinocular head to an authorized service center just because there is a grease spot on the lens.

what
a
cash
grab.

#1 (IMPORTANT) use a dust blower (ideally one that doesn't create condensation, that would be bad)
#2 wipe off lens with optical lens cleaner and microfiber cloth, or use Kimtech wipes (better)
#3 blow off with dust blower again. Keep repeating step #1 until all dust particles removed. If not you may need
to open up your eyepiece by unscrewing it (use neoprene gloves or something to avoid putting oils on lens or just flip it around
using kimtech wipes and repeat above steps to get off oil/dust on that side.

Yes cleaning off eyepieces is time consuming. Be patient.

Why blow off dust first? Tiny grains of whatever can actually be smeared around and scratch the lens if you go right to step 2.

I have taken four objectives completely apart and cleaned them.. Only one was ruined.... As far as the prisms go, all I have needed to do is blow the dust off from what I could see.. If I ever come across a speck of dust that can't be reached, I will just live with it.

BillT

[gekko]

... #2 wipe off lens with optical lens cleaner and microfiber cloth, or use Kimtech wipes (better) ...

Sorry, but I would quibble with the use of Kimwipes/Kimtech for cleaning optics (good quality lens paper would be fine if not used dry, I think) and I fully agree with the recommendation to us a fine, clean, lensbrush after blowing to remove dust that adheres to the lens.