Projection Solar Viewing

Ok, so, tell me what you know about solar projection viewing.

I'm trying to set up a solar viewing system. I have a couple of refractors which are ideal. I also have a couple of white-light filters.

If I use one of the white light filters, there is not enough light to project.

What happens if I take the filter off? Seems to me that the light rays will pass right on through and "project" the image onto a white reflective surface about a foot or two away.

Is there a problem with that? Will it generate too much heat as the light is passing through? Will I fry an eyepiece? or what?

Alex

I used to do solar projection with my little 60mm Unitron all the time. It came with a projection screen, but I eventually made one where the screen itself was shaded more effectively.

I always used to eyepieces that came with the Unitron, and never had any problems. A friend of mine did manage to melt a cheap plastic Kellner he used. If you stick with a modest aperture, keep the Sun centered, and avoid very long periods of projection you are probably unlikely to fry an eyepiece - but an inexpensive eyepiece dedicated to the task might not be a bad idea for peace of mind.

At one convention I attended, a gentleman had a rotating screen to project the Sun on. That worked pretty well, but he later gave it up for a well shielded non-rotating screen.

When I used solar projection at public events, I was very careful to stay with the scope all the time, and never left it unattended. Kids can be quick and often do unexpected things (kiss a 35mm Panoptic, for instance).

Clear skies, Alan

Have a look at my web site.

http://www.america.net/~boo/html/sun_gun.html

Regards

Bruce

Eyepiece projection works. I have done it for many years with a 4" newt, with plossls, kellners and barlow. Ep's have never gotten hot. Even during eclipse runs.

Remove the finder! It ain't needed anyway.
Never leave the scope unattended, as already mentioned.
Pick up few modest plossl's, dedicated for just this. You can experiment on which focal lengths you might want by Lunar projection.
Always cap the scope first when packing up. The only ep I've ever smoked was one I capped before the scope. Ruined a perfectly good ep in a wink.

Here's the simplest and best solar projector bar none. It mount on a camera tripod and projects a 8.5 inch solar image.

Ed Jones

Attached Image:

In my pre-PST days, I used a projection box behind a homemade 3" refractor. The box was a truncated square-based pyramid made of white building board (the foam and posterboard stuff used to make model houses and display boards). The interior was lined with black felt. Viewing of the projected image on the box's bottom was done through a small window in one side. The box was mounted to the scope with 2 wooden yardsticks and large pipe clamps that supported it. The box couldn't be used on windy days because it was so large and light.