You can always go to a $2 shop and get a cheapie head lamp, then the newsagent and get red cellophane for about $1. Cover the head lamp with three or four layers of red cellphane and you've got your illumination source for less than $10.
The added benifit is that you can use this "new" red head lamp to illuminate what every gear you may be chasing down in the dark, including more detailed star charts.
I use these all the time. Including while doing my sketching at the eyepiece.
Indispencible. I don't think there are many astro boys and girls that don't have these in their kit.
With the cellophane that's left over, you can cover over a couple more torches, as backup or for other illumination needs.
