Help please - is this mould inside my corrector?

[Gem]

Hi

There is a tiny white dot with a dark line snaking out of it on the inside of my corrector. What is it? I have never been overly happy with the inside of my corrector since I bought it. It has always seemed a little milky. However, if this is mould I will definitely have to get it cleaned.

Anyone had experience with this, or can identify what this snake is?? :(

[strongmanmike]

A better photo would help, can you photograph it in ambient daylight, at an angle that shows no reflections?

Mike

[gregbradley]

If you corrector is an oil based triplet then it is a gap in the oil. Sometimes cold weather or flying in a jet can affect the oil. It often corrects itself. If not it may need to be reoiled by the manufacturer.

Greg.

[strongmanmike]

Isn't it a SCT corrector plate here..? :question:

[casstony]

It seems fairly common for Celestrons produced in recent years to develop a milky appearance to the inside of the corrector over time; I assume it's due to outgassing from the grease they're using. If it gets bad enough after a few years it's easy to remove the corrector for cleaning, but it would be nicer if they used better quality grease in the first place.

I don't know what the snaking line is - scope lice perhaps :) It doesn't look like mould.

[Larryp]

I once had a 10" Meade Schmidt-Cass, and it developed a coating on the inside of the corrector-almost looked like moisture condensation. I removed the corrector plate, and found it was something with the coating. Had to send back to Meade and they completely replaced the optics free of charge, but I still had to pay air freight.

[gregbradley]

Oh I see. The post merely said corrector so I assumed a lensed corrector.

Greg.

[Gem]

Yes - Celestron 9.25" SCT corrector.

Thanks for the posts. Sorry about the photo quality - rainy day in Canberra and the only camera I have other than an ATIK is my phone!! :)

[allan gould]

It certainly looks like mould to me. Time to pull it apart for a clean

[Paul Haese]

Looks like you need a clean on the inside of the corrector. I have a similar problem and will need to attack that in the coming months. I have a tut on how to do this if you are game. Take a look at my website. Just follow the first part on removing the corrector. If it is still under warrantee give it back to the retailer and tell them to fix the problem.

[casstony]

In addition to reading a few tutorials on corrector removal and cleaning, here's a variation I've used for minimising the amount of contact cleaning needed:
With the corrector removed from the tube I covered the secondary housing with plastic and elastic bands, then sprayed cleaning solution/isopropyl onto the glass, then washed it off under a running tap, with the water stream hitting the lower half of the plate to avoid forcing water against the secondary housing.
This gets rid of the majority of particles and reduces risk of scratching with subsequent cleaning steps.
The main risk is dropping the corrector during handling - need to go slow.

I tried it with a C6 first and it went fine, then with a Meade 10" and 12". The entire housing comes off the C6 while the corrector has to be removed from the housing on larger SCT's. Moisture in the seams around the secondary housing can be removed with a hair dryer (not on high heat) or by sealing the corrector in a plastic bag with dessicant for a few days.

I wouldn't bother removing the corrector if the inside didn't need cleaning.