Does anyone have any published guide on properly sighting a 3" prism?
All the young guys just sight the spiderweb in the glass and don't know what how or why a target card is even there, or the importance of pointing the prism.
> Does anyone have any published guide on properly sighting a 3" prism?
>
> All the young guys just sight the spiderweb in the glass and don't know what how or why a target card is even there, or the importance of pointing the prism.
What offset? I've found the -40mm offset prisms I've been using have almost negated the alignment error that is prevalent in -30mm offset prisms.
If you try one, you'll likely not go back to the -30mm offset.
> Does anyone have any published guide on properly sighting a 3" prism?
>
But to address your original question, why not set up the total station and prism in the back parking lot and conduct your own experiment showing the crew the differences by sighting the center of the prism and then tilting the scope of the instrument down the prism pole? You could further show the crew the magnitude of centering errors by rotating the prism further and further away from the line of sight between the instrument and the prism.
Just show them this sketch, made by Bill93 sometime ago.
In my opinion, the advantage of shooting the target of a zero offset prism is that it makes it pretty much fool proof with respect to making sure the prism is aimed directly at the instrument (and the target is often easier to see in the woods at 600' than the prism itself).
You can shoot a prism with an offset without a target (see the sketch), but you've then got to make sure that your offset is recorded properly in the data collector. Shooting a zero offset prism with target makes for one less thing to worry about.
> Does anyone have any published guide on properly sighting a 3" prism?
>
> All the young guys just sight the spiderweb in the glass and don't know what how or why a target card is even there, or the importance of pointing the prism.
I'm a young guy and I was taught to use the pole as close to the ground as I could see it for the horizontal angle. Then turn up to the glass and verify that the pole is plumb by where the crosshairs fall relative to the target guides. For vertical you just have to use the crosshair and target guides. I was also told to use the double part of the crosshair not the single line. I don't always follow that one though. It depends on the situation sometimes as to which way is easier to line it up.
I hardly ever spend any time behind the gun anymore.....thank God....not really the part I enjoyed doing
Get the popcorn ready.
I sight the prism pole or the candy cane I put between the prism mount and the tribrach.
