Cheshire reflection annoyance!

[sbooder]

Hi All,

I don’t know about you but I find that trying to centre the primary centre ring (donut) on the crosshairs of the Cheshire site-tube rather annoying (if the scope is not that far out of alignment) with the reflection of the Cheshire’s cut-out diagonal in the view, because it has a black centre too.

So I made this shroud for the cut-out to get rid of the reflection to make life a little easier and more accurate. The only thing I thought might happen was that the lack of light may hide the crosshairs…not a bit of it, they were as visible as ever.

Now aligning the secondary using the Cheshire is a piece of cake.

[Moonshane]

I have to say Simon, this is a cracking idea. just made one myself and it works a treat.

[sbooder]

Ay-Thang-Yaw!

[RikM]

That looks very smart. Will give that a go in a couple of hours before tonight's session.

[sbooder]

The white circle reflection is OK if the scope is well out of whack, because it is off to the side of the image, but when you want to tweak the secondary, it is just in the way...well that is how I see it anyway.

[Adz]

You are a genius!

[sbooder]

And it is so simple to make, a length of looroll tube will do it.

[sbooder]

Well, it made a big difference. I feel like I have a bigger scope. I was about .5 of cm out on the secondary which with the fast mirror makes for a big error in collimation, and once corrected using the shroud, and then taking off the shroud to complete the primary alignment, Saturn on Saturday night was the best views of the planet I have had in a long while.