Lens Care

[Rod-AR127]

Whether it be the objective lens on a frac or the lens in your exotic eye pieces, what is the general view on taking care of the expensive multi coated glassware.
Firstly, don't touch them, l know that much.
What about dew? I'm leaving the lens cap off my little ED72 for tonight after viewing the moon at its Zenith. Didn't realise how much dew was on the objective until l came inside with it. Like frosted glass.

Any do's or don'ts that l should know about.

I've only just been hearing fungus mentioned since browsing the classifieds, how does that work?
:)

[AdamJL]

Hi there, Rod

I'm not too fussed about dew. I've had ice form on the objective before when I didn't put the dew heaters on correctly. Just make sure to dry it up as soon as you can.
If I ever need to clean the objective, first I try and blow off as much dust as I can with my Hurricane air blower. You can use a rocket blower to similar effect. Once that's done, well it's up to you! I've used lens pens, microfibre cloths (specifically for glass), and the brush side of lens pens as well.

All of them work. What I don't recommend is using isopropyl. I know it gets advised a lot, but I can never ever get rid of the streaks.

Fungus forms if you have humidity. It's actually usually formed inside the tube because there's rarely ever any air flow there. Fungus doesn't like dry air so any moisture build up inside will encourage fungal growth. It isn't too difficult to clean in an OTA unless it's a petzval as you can reach in from the back with say a long tube with a cleaning cloth at the end and clean it that way. Very difficult on a camera lens which would require dismantling of the unit. That said, I wouldn't want to have to clean it at all. Best to keep your scopes stored in a nice dry place away from moisture.

That's my 2c. I'm sure others have their own ways of cleaning their stuff. I've been using these methods on my photographic equipment for years.

[Rod-AR127]

I googled telescope fungus, pretty straight forward, dry your OTA if it gets dewy.
Dry it carefully. I just left the lens cap off and lying at an angle so any droplets would run down the dew sheild and not pool against the objective.

[mura_gadi]

Fridges are very low humidity zones if you have a spare for the space.

4-6hrs in a fridge will remove a lot, 24hrs+ and it should dry most things if you can turn occasionally as well.

Drops accumulating are the main reason to turn regularly, otherwise it should be fine.

PS. Its a good idea to place your ep's, barlows, diagonals etc in the fridge for a few hours if its been a hard dew night.

*Most of the time you pack up at 90%+ humidity, you should remove lens caps and such the next day when it 50-60% humidity and leave up capped for an hour or so before recapping.