How Often?

[Hans Tucker]

How often do you clean your eyepieces?

What is your preferred method? Special liquid solution or Lens Pen?

[mura_gadi]

Since risks are involved it is only when absolutely necessary rather than as a timed maintenance schedule.

Start with the gentlest method possible and go from there.

Ie,
Just an air puffer;
A well laundered soft cloth like an optometrist glasses cloth and a gentle swipe;
I use 100% ISO alcohol and a 2-3 second soak after that with the lens cloth, position the EP so the liquid doesn't run into the EP. Distilled water for softening is also used.

Unless you know its a good quality and well recommended cleaning pen I would avoid them.

Using cotton buds/balls, make sure they're 100% cotton. Cotton is graded for quality, so don't go for the cheapest option, go for a good brand probably in the baby line up.

Opinions vary and good posts to be had here and on cloudy nights, just make sure you use archived in the search options if you're searching IIS.

[ausastronomer]

Hi Hans,

I clean them as needed, and that depends on how often you use them. 12 to 15 years ago that was about once every few months. With COVID and getting older and a lot less observing these days probably every 12 to 18 months.

How I clean them depends on the eyepiece. a 4mm ortho with a ~2mm diameter eye lens clearly has different cleaning constraints compared to a Pentax XW with a ~ 25mm diameter eye lens.

I usually blow the loose debris off with a blower bulb (Don't use compressed cans). With eyepieces having a larger eye lens I use Isopropyl alcohol on soft lint free cotton cloth patches cut into ~15mm squares. I then drag that around the eye lens with a Cotton Bud. With eyepieces having smaller eye lenses I use Isopropyl Alcohol on a cotton bud or a much smaller cotton patch and work that around with the blunt end of a round toothpick snapped in half, making sure the cotton is always in contact with the glass.

You can use whatever grade of Isopropyl Alcohol you like but I find the 100% stuff dries faster and cleaner. It's not expensive if you buy it from the right place. 5 litre bottle of 100% Isopropyl Alcohol from Sydney Solvents for $24.00. (https://www.sydneysolvents.com.au/isopropyl-alcohol-ipa-isopropanol-100-5-litre?gclid=CjwKCAiAhqCdBhB0EiwAH8M _GtE37Nc3k44rDYEJrc_WgvBhbHsL4yDMRT Cpb5muZEAs246KpmuqBRoCaYsQAvD_BwE) I bought a 5 litre bottle from them about 8 years ago for the same price and I still have about 1 litre left. I am about to buy some more.

[ausastronomer]

Optometrists cloths are usually microfibre and work well, but they aren't quite as soft as 100% lint free cotton which makes it slightly more difficult to work right to the edges of the eye lens. If you have some handy use them for sure, if you have to buy something, buy 1/2 a metre of lint free cotton from Spotlight for about $10 which will last many years. As Steve suggested, run it through the washing machine and dryer 3 or 4 times before you start to cut it up and use it. Also cut it across the bias (45% to the thread direction), which helps to stop it fraying, or use pinking shears. No I'm not a girl, lol, wife's a dressmaker :)



I've got a good one and haven't used it in well over 10 years. They work ok but I just like to have 100% control over every single variable in the cleaning process with all my optics.



I would just avoid them all together. I found that out the hard way. About 25 years ago I used some quite expensive cotton balls (I think they were Johnson) and either the material started to dissolve in the Isopropyl Alcohol or they had some fragrance in them (which wasn't mentioned on the packaging, which said "pure cotton") which broke down and became a white goey mess that smeared all over the lens of my binoculars. It then took many hours of cleaning with soft cotton patches, cotton buds and isopropyl alcohol to get everything properly cleaned and back in order.

Cheers
John B

[LonelySpoon]

[QUOTE. No I'm not a girl, lol, wife's a dressmaker :)
[/QUOTE]

Nothing wrong with knowing stuff, John.

Specialization is for insects.

Neville
LSO

[Startrek]

I have an extensive set of Televue eye pieces, Powermates and a Paracorr
Never used fluids
Just a hurricane blower to remove dust , fine particles and then a wipe with quality microfibre cloths from my optometrist ( never use the same cloth twice )
I usually buy 20 or 30 at a time and this lasts me a year or more

Cheers
Martin

PS: I bought one of those lens pens from Bintel a couple of years ago and I’ll never use one again , just smeared the eye piece , didn’t clean it at all

[astro744]

I only clean an eyepiece if it has gotten a fingerprint or eyelash oil. I used to use ethyl alcohol from a chemist and a cotton bud but now use isopropyl alcohol (99.9% from Jaycar; spray bottle, DO NOT use aerosol). Ethyl alcohol evaporated much quicker and also the chemist seemed hesitant selling it unless you had a good reason. (I’m talking late 1980’s early 90s).

Tele Vue suggest alcohol, acetone or Windex (latter for water soluble stain) for their eyepieces. See https://www.televue.com/engine/TV3b_page.asp?return=Advice&id=103

If using acetone it must be pure, ie not nail polish remover and you must adhere to IMPORTANT NOTE at last para which also applies to eyepieces with blackened lens edges, I.e. do not use acetone for these. See also third last para beginning with ‘Cleaning the edge’.

I have never tried acetone for risk of getting fluid around edges of eyepieces that do have blackened edges. Also don’t want to accidentally get some on the rubber eyecups.

[Hans Tucker]

Thanks all for your responses. Great information in this thread.

Some eyepieces present a real challenge to clean because of the small aperture of the eye lens like on the Takahashi LE10 which for some odd reason is smaller than the LE5 and LE7.5.

Just a bit of blast from the past trivia but the user manual that came with my Tasco 60mm Refractor back in the 70's recommended the use of Chloroform to clean the objective .. which you could get from the Chemist back then.

[mura_gadi]

I've only used cotton buds over cotton balls, but the main thing is to use them in one direction only. Once you start swirling backwards and forwards then the strands do become an issue. A lot less so if you only use one direction ie clockwise/anti-clockwise on a clean, same with the twirl, that way you tend to wind loose threads on.

I prefer the optometrist cloths myself.

[Hodur]

Chloroform is basically bleach and thinners. You can find both recipes and process on YouTube. It’s a very harsh chemical, my guess, it’d knock of modern coatings. I’d not use it, however it’s good for quietening macro photography subjects, even then, cooling the subject works as well.

[LonelySpoon]

Has anyone considered an ultrasonic cleaner? They use one at the Sydney Observatory Museum to clean the 3D glasses...

Maybe not for smears, but those particles around the edge of smaller apertures?


Neville
LSO

[EpickCrom]

Hi Hans, I clean my eyepieces approx once every three months. I keep them stored in a plastic closed container with their dust caps on so they don't get too dirty/dusty. I use eyeglass cleaner and a soft cleaning cloth (optometrist cloth). I need to buy an air puffer for this task soon:)

[Don Pensack]

Q-Tip swabs and isopropyl alcohol works well if the eyepieces are not very dirty. Zeiss and Nikon lens cleaners are basically that.
If the eyepieces have mascara or grease or fingerprints (shudder) on them, then acetone can work well, as can lens cleaning fluids that contain a trace of detergent.

Use 1-2 drops on the swab--never spray directly on the lens.
I make a spiral pass from center to edge with the wet swab, then flip it over to the dry end to mop up. Grab a second swab and, moving from edge to just past center, move the swab back and forth in a straight line while turning the eyepiece under the swab. Keep this going until you've done two revolutions of the eyepiece.
If there are any left-over streaks on the eyepiece, repeat the procedure using pure distilled water to remove any residue.

NEVER, EVER wipe a dry lens with a dry cloth or tissue until the eyepiece has been cleaned with a fluid and there is nothing on the lens. Coatings are hard, but not invulnerable.

As to frequency, I clean them as often as I see debris on the lenses--usually once every month or two. I notice that the eyepieces I use with glasses on never seem to need cleaning. One of the advantages of needing glasses at the eyepiece. Glasses also keep the eyepieces from fogging up.

As to the frequency of cleaning glasses, well, anyone that wears them knows the answer to that...