Should i operate?

[Jeff RV]

The dust etc in my ota is bugging me, I need to remove correcting plate with secondary to clear it by gentle brushing, my wife's got some nice soft make-up brushes all i need is some cotton gloves. Read how to on "Jans LX90 pages".Do you think i should give it a whirl?.........Jeff.

[GordonCopestake]

Unless the dust is excessive I wouldn't. You have a central obstruction of about 33%, the dust on your corrector doesn't make up 1% so the effect on your viewing is negligible.

[geppetto]

I'd leave it..

Wont make any difference to your viewing

[Jeff RV]

The viewing through ep is clear now but through the ccd it still appear's, Do you think i would see dust bunnies on secondary in imager?

[GazOC]

I'd guess its either on the chip or the diagonal, probably the chip.

[Jeff RV]

I agree Gaz but if i rotate the ccd the bunnies don't, should'nt they rotate as well?

[FLO]

If you can see them on the image, they are either on the CCD or very close to it.

[Jeff RV]

I'll ave a look with a magnifier, If so do you clean the chip in the same way as an ep? as i've dusted it already.

[FLO]

Last time I spoke about cleaning CCDs it ruffled some feathers so this time, I'll post a link and let someone else take the flack

http://www.bythom.com/cleaning.htm

[Jeff RV]

Acording to that i may not be giving it enough stick,Hate to ask for Methanol here in Spain could end up with anything! but i will try the optician and chemist. Thanks for the link Steve....Jeff.

[Kaptain Klevtsov]

If you rotate the camera and the dust doesn't rotate ON THE SCREEN the the dust has moved with the camera. The dust is therefore on the camera or the glass cover of the camera.

Captain Chaos

[Jeff RV]

Found some on chip using a mag,Think i removed it but it was stubborn,Yet to try it will let you know. fingers crossed!

[Kaptain Klevtsov]

I'm guessing here, but going by the pixel size and the size of the dust bunnies, you should be looking for a dust bunny at a distance from the chip of (diameter in pixels) X f/ ratio X pixel pitch, so for my setup with a bunny diameter of 10 pixels:-

10 X 5 X 0.007 in MM, so about 0.35mm.

- so dust bunnies are always on the chip or very very close it seems.

Captain Chaos

[Jeff RV]

OK. Thanks to all your advice i think I've succeeded in removing it. It was on the chip under the IR filter as you all suggested, probably there since manufacture. At moment only checked in terrestrial but clear at last! Thanks for your input, it is much appreciated......Jeff.