Need Crosshairs

I have received a finder that has no crosshairs. Is there an easy way to make these and where do they go. I assume on the objective side of the eye lens?

Kevin

Kevin Brennan said:

I have received a finder that has no crosshairs. Is there an easy way to make these and where do they go. I assume on the objective side of the eye lens?

Kevin

Kevin: Those wires have to be tiny-tiny. Typically they do go he objective side at the focal plane of the eyepiece. You should be able to see where they had been glued in place.

Jon

Human hair works great for cross-hairs, they were used in WW2 for bomb sights.

I have used a tiny #0 machine screw. I sharpened the tip and drove it in from the side at the focal plane. This has the advantage of not needing illumination since it is so thick; the disadvantage is that it obscures about 5% of the view.

I use small strands of wire taken from stranded wire. I sampled many wires until I found the thinnest wire strand. I twisted and soldered small loops on the ends of a strand and placed it on a stretcher made from an old coat hanger. The strand is laid across the field stop and some weight is placed on the stretcher to pull the strand tight and I then place a drop of super glue at each end of the strand. When the glue cures I trim the ends with a razor knife. The cross-hairs are a little thicker than hair or spider web but I like that because it makes them easier to see agaainst a dark sky.

Hope this gives you some ideas.

John
CCD-Freak

You do not need them. If you were observing Jupiter you should easily be able to discern when a feature was on the planets' Central Meridian (midway across planets' disc) & so likewise you should easily be able to discern where the center of your field of view IS without use of crosshairs; slight de-centering is obvious. A low-power eyepiece in the main telescope will then enable centering its' view for more powerful eyepieces in turn. I find crosshairs distracting & I've not used crosshairs in my finders for over half a Century with no aiming slowdown or inaccuracy whatsoever.