Should I replace this mirror?

[cuivenion]

Being a complete noob I have managed to damage this secondry. Is this still useable or should I replace it?

[HumptyMoo]

Borderline from what I can see, if you have a Cheshire combo/Sight tube check to see if you can notice the chip as it may just sit in the area where you'd expect to see the primary mirror clips which only really show when using a collimation cap. If it's no great hassle for you to change then maybe you should for peace of mind.

Assuming you can collimate it well you probably would only see an edge of the chip in the wider FOV EP's, but for most parts would go unnoticed.

Someone else may be able to offer more insight as I am still a little shaky on the experience side.

[brantuk]

If it's just a chip on the edge then you can probably get away with blackening it using a black marker pen. It's not on the active part of the mirror so you should be ok.

(I had a similar thing a couple of years ago)

[ronin]

If it is the bit at the top you will probably be OK, they are a bit oversize, and that would I think fall ouside the section of the mirror that is actually used.

[John]

I think it will be fine. Blacken the chip with matt black paint. I've seen secondary mirror clips larger than that chip. 

[LukeSkywatcher]

Not worth worrying over or replacing. As brant says..............a black marker and you wont even notice any side effects. If you leave it untreated, im thinking it may cause a bit of light to scatter and bounce around when observing. If "blacked out", it really wont have any visual difference.

[cuivenion]

Thanks for the replies, I'll black it out and see how I go.