Skywatcher 80ed pro...oil between the Objective lenses????

[Mick UK]

I noticed a halo on my images taken through my 80ed pro and when ive checked the objective lens there seems to be what a first looked like a hairline crack inside the lens near to the edge about an inch long, but on closer inspection when i rotate the scope the "crack" moves about and looks more like oil.

Anyone have an idea whats happened and how to best deal with it?

I was thinking of gently heating it with a hair drier but im not sure if that might make they problem worse by misting up the space between the 2 objective lenses?

[ollypenrice]

Not good. The doublet will be air spaced so you may have fungal growth or condensation in there. Keeping it warm and dry for a long time might sort it.

Olly

[Mick UK]

Thanks Olly, i think i might try the Air drier on it and see if that helps, if it is condesation i guess the sooner i get rid of it the less chance it has of turning into fungal growth.

[daz]

I had the same thing a couple of years ago and successfully split the doublet and cleaned it.

Provided you go carefully, you shouldn't have a problem. All the nebula images on my website gallery are taken with it post cleaning!

[Mick UK]

Cheers Daz...i had already done just that!

its funny, looking down the front of the scope the optics look clean apart from the contamination that had gotten in, yet when i had removed the focuser housing and looked up the tube at my kitchen strip light, the optics were anything but clean! it was like looking through misted up class, yet down it was still clean looking.

I carefully removed the lenses and cleaned them with a micro fibre cloth an some 99.4% isopropyl alchohol and now everything is crystal clear..BOTH ways!!