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EntropyStar

Dirty EP or Mirror?

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Hey all,

I've been having a spot of trouble with my 7mm X-Cel EP, when I look through it, I see a lot of tiny black spots across the entire field of view, it's rendering the EP useless. I've checked to see if it's dirt but the EP looks spotless to me. My mirrors are about 18 months old and I haven't cleaned them myself, there's a bit of dust and dirt on them but nothing severe. When I use a 9mm EP I don't see the black grains at all, I suspected it maybe dirt on the primary/secondary which only becomes apparent at high mag. With that I mind I tried barlowing my 9mm last night to get a 4.5 mm EP, with that still I couldn't see any black grit or dirt marks. I believe it's the optical coating on the 7mm EP, I think it's degraded or maybe there's dirt inside the EP. I've since gone back and cleaned the 7mm methodically but no improvement at all with the view. When I was looking at the moon last night It was as if i could see 30 or so transits all at once moving across it!!!

Does anyone have any experiences they could share? Any tips or potential solutions?

Thanks for any replies.

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Black specks seen in the eyepiece of a reflector are always on or in the eyepiece, the muck on a secondary or primary mirror is too far away to focus on. :smiley:

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Black specks seen in the eyepiece of a reflector are always on or in the eyepiece, the muck on a secondary or primary mirror is too far away to focus on. :smiley:

Excellent :hello2:

Slightly annoying the EP is probably ruined (I can't see where the dirt is) but so glad it's not the mirrors!

I knew somebody would eventually respond and put my mind at rest, thanks Peter.

Edited by EntropyStar

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