Jump to content

sgl_imaging_challenge_2021_annual.thumb.jpg.3fc34f695a81b16210333189a3162ac7.jpg

Lunt Herschel Prism


Teal Rain
 Share

Recommended Posts

Morning all.

Pardon my ignorance of the subject :D but.... with Herschel prisms does the energy that would normally be reflected by a front mounted glass or film filter have any detrimental effect on the optics of the scope used? I'm thinking of getting the Lunt 1/25" prism from TS (149 euros) to use with the FS102 so I'm a little bit nervous!

Cheers

Mark

Edited by Teal Rain
Link to comment
Share on other sites

The objective should handle the incident energy OK, and if the Herschel wedge does its job properly the emerging beam will be 100% safe. You may need additional ND filters to tone down the brightness.

Link to comment
Share on other sites

I've been using Herschel wedges (prisms) for nearly 10 years with no detrimental effect on any refractor I've used.

BTW a 3" to 4" aperture is ideal for using a Hershel wedge.

Here's my solar setup.

Lunt 60HA and a TS 80/480 triplet APO with 2" Herschel wedge and Skytee 2 mount.

John

Link to comment
Share on other sites

John, that's a great looking dual solr setup. I was thinking along the same lines for my Lunt LS60THaPT and 90mm/600 Triplt Apo with wedge. How do you find the motions on the Skytee 2 with those relatively lightweight tube assemblies? I've read that the mount needs some weighty tubes on it to perform at its smoothest...

Ant

Link to comment
Share on other sites

The "emergent beam" of the Lunt wedge doesn't emerge ... it hits a heat sink at the back which gets midly warm to the touch with my WO FLT 110. Older wedges often allow the waste beam to escape the diagonal where it has been known to ignite ties. But no danger to optics.

Link to comment
Share on other sites

I was thinking of the brightness of the visual beam.....

Yes, well, of course that's safe too, once the (supplied) ND 3.0 filter is installed on the output side of the wedge. You'll probably want some more filtering to be comfortable, the Baader Solar Continuum filter is very good, an ordinary green or deep yellow filter is nearly as good & a lot cheaper. Deep red (Wratten 29) is excellent for imaging with a monochrome camera.

Link to comment
Share on other sites

Afternoon all.

John, Brian, Merlin

Many thanks for the information - have taken the plunge and ordered the 2" Solarvue 2 from Astro Engineering! Seemed a bit of a no-brainer really to go for this one rather than the 1.25" Lunt.

Now all I need to do is take the plunge with a Lunt 60 B1200! - maybe next month :D as car tax also calls this time.

Cheers

Mark

Link to comment
Share on other sites

John, that's a great looking dual solr setup. I was thinking along the same lines for my Lunt LS60THaPT and 90mm/600 Triplt Apo with wedge. How do you find the motions on the Skytee 2 with those relatively lightweight tube assemblies? I've read that the mount needs some weighty tubes on it to perform at its smoothest...

Ant

Hi

The Skytee 2 is very smooth even with only a light load. Rather than hijack this thread I've started a new one. I've posted some more pics in the new thread.

"Show us your solar observing set-up"

http://stargazerslounge.com/equipment-discussion/138014-show-us-your-solar-observing-set-up.html

John

Link to comment
Share on other sites

  • 2 weeks later...

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.