Friday, March 09, 2007

Need to clean my SCT Corrector Plate

I recently got a pretty nice promotion at work (yay!) which has been keeping me very busy indeed. We've had a few clear nights but I haven't been able to get out much, if at all, because I have just been flat out like a lizard drinking.

Anyway, my LX200 has been building up some residue for a while and I have noticed that when viewing objects at high power, and when trying to take high magnification images, I can see dust particles in the FOV. So, rather hesitantly, I've decided it's time to clean the corrector plate. I say "hesitantly" because it's part of the optics, and the thought of messing with it REALLY FREAKS ME OUT!

The Meade web site has these relatively simple instructions to follow:

"Before attempting to clean an optical surface with a liquid solution, it is very important that as much dust as possible is removed by using forced air and/ or gentle strokes with a photographic grade camel hair brush. The forced air can come from a rubber ear syringe, or canned compressed air from a photographic supply store. Be sure to hold the canned air in a vertical position and try spraying compressed air on your hand before aiming at the optics to see if any of the propellant (solid material) comes out. Propellant is very difficult to remove from optics, so take care not to tip the can when using it. If you have access to a compressor hose, be sure that it is filtered to prevent oil from being sprayed on the optics.

Once you are confident that you have removed most of the dust and large particles, begin cleaning with the pure isopropyl. Pour or spray enough solution onto a pillow or wand of tissue until it is quite wet. If you are cleaning a corrector plate, use radial strokes with a smooth pillow of tissue, starting from the center out using no pressure. If you are cleaning small optical surfaces, use the rolled wands of tissue starting from the edges then spiraling in to the center, again using no pressure. Never pour or spray the solution onto the corrector plate or eyepieces themselves, as the liquid may go behind or in between lenses, where it is difficult or impossible to reach. Never attempt to disassemble an eyepiece to clean the inner elements, as you will certainly not be able to properly center and re-assemble the optical train."

Still, I'm a bit of a klutz and have an awkward feeling I'm going to screw it up. Regardless, I'm pressing on and am aiming to clean the corrector plate one night this week before a potential trip out to the country next weekend. I'll post before and after shots here when done.

Click here to see how I did!

3 comments:

imjeffp said...

I use cotton pads and isopropanol. Works fine.

Scott Ogle said...

Very nice site Phil. Your latest post brought to mind how I cleaned the diagonal from my 12.5 Starmaster (sold it a while back). It came completely covered in dust from the builder. I turned it upside down and sprayed with Zeiss cleaning fluid. The pump action of the spray got 99% of the dust off. Of course there were no internal components to worry about.

Later,
Scott

Phil said...

Thanks guys. Well I'm cleaning it tonight so it should be fun!