PDA

View Full Version here: : Polarising Filter with PST


sheeny
26-08-2006, 02:18 PM
I received my GSO Polarising Filter from AOE the other day for the princely sum of $15.

Today I got the first chance to try it.

I set up the PST and had a bit of squiz at sunpsot 905, etc. Got everything settled down and then put the filter into the system.

The image was noticeably less bright, but how much dimmer probably depends a bit on the orientation of the filter.

Unfortunately I only got about a half hour of observing in before the clouds rolled in... but it seems that the contrast is improved, and that depending on the angle of rotation of the filter (attached to the end of the EP of course) different features stand out. In one position the bright plage stands out, at another the sunpot is pronounced, and surface detail is better in another.

I didn't get a chance to really check out prominences, but I don;t think they're as definite with the filter in because the image is dimmer.

Anyone else tried a polarising filter on their PST yet?

Al.

OneOfOne
28-08-2006, 08:28 AM
I have a twin polarising set (for the moon). I will try one of them on the PST when I get a chance...now all I need is some Sun while I am not at work!

Bruce
29-08-2006, 09:18 AM
Sheeny, I tried using one of the rotating polarizing filters on the ep of a PST. The idea was to rotate the the ep to get the best image. All I got was a dimmer image. I believe (and if quoted I'll deny it) that the PST is a polarized image already.

I had no improved quality. YMMV.:shrug:

sheeny
29-08-2006, 11:43 AM
Yes, I know the PST is polarised. That's why the filter is supposed to work. You will notice variation in image brightness as the filter is rotated, but the reports are that some improvement in contrast is achieved using the filter in differing orientations. I can't recall where I read this, but I'm sure if you google it you'll find it.

I haven't rigorously tested it myself - still cloudy here. My initial impressions were not outstanding but I suggest there was a noticable improvement in contrast at some filter positions, and none at others. Perhaps some parts of the image are more polarised than others or polarised at slightly different angles:shrug: . I don't know about the mechanics of it. But for the cost of a filter I figured it was worth a try. I will post more when I get a chance to test it again.

Al.

sheeny
29-08-2006, 11:44 AM
Here's the link...

http://www.astro-engineering.com/Coronado/coronadoaccessor.html

Al.