Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.

sgl_imaging_challenge_banner_supernovae_remnants_winners.thumb.jpg.a13d54fa405efa94ed30e7abd590ee55.jpg

Rusted

Sun 14.1.19

Recommended Posts

All day sunshine but cold, 35F, very windy from NW with occasional small clouds pm.

Sun only 12 degree altitude. Several small proms visible on a largely blank disk.

I was seeing the proms before they showed up on Gong.  Roundtoit or what?  :biggrin:

Using 65x [20mm EPs] in the T-S binoviewer in 120/10 [150/8 + PST.] No Barlow. No GPC.

Still need to experiment with the angle of my internal 90mm D-ERF. Not sure it is causing the "ring."

A couple of afocal 'snaps' for your amusement. :wink2:

IMG_2400 rsz 500.JPG

IMG_2408 rsz 500.JPG

  • Like 3

Share this post


Link to post
Share on other sites

I think you'll find that the ring is a PST tuning artifact that probably expands and contracts as the tuning ring is turned. Trick is to find the optimum position and not all etalons are as obvious. The Barlow lens screwed into the nosepiece of the binoviewer mitigates this effect somrwhat.   At least you have some Sun!     🙂

  • Like 1

Share this post


Link to post
Share on other sites
2 hours ago, Peter Drew said:

I think you'll find that the ring is a PST tuning artifact that probably expands and contracts as the tuning ring is turned. Trick is to find the optimum position and not all etalons are as obvious. The Barlow lens screwed into the nosepiece of the binoviewer mitigates this effect somewhat.   At least you have some Sun!     🙂

Thank you Peter.  It is still clear here but just above freezing and windy.

The ring acts rather like a shadow. As I move the telescope around the ring moves about across the sun.
There is more obvious surface detail in the ring. When I 'blew up' the original image I can clearly see the surface "orange peel."

I just discovered my T-S binoviewer is badly misaligned.  I didn't notice it on the sun at lower powers up to 65x .
On the Moon it was absolutely horrendous at higher powers! There is a strong vertical displacement.
I tried every power including the Barlow and GPCs with the binoviewer in the 7".
When I looked up at the sky afterwards every bright star was double and vertically displaced by several moon diameters! :cussing:
It took ages for my [naked eye] seeing to return to normal. 
Now I've got a splitting headache from an hour and half staring at the moon [for the first time] with the binoviewer
Looking through the exit port of the bare binov. at arm's length the moon is overlapping its double by about a quarter of its diameter. :crybaby2:
I'm going to have to look at re-collimating it myself.  I doubt the vendors have any interest and can always claim it was dropped. 
It has been treated with kid gloves and has hardly been used from new.

Share this post


Link to post
Share on other sites

You might find that the extra magnification induced by the Barlow/binoviewer combination will place the ring outside the field of view. At the same time, the Barlow will, as far as I can deduce, magnify the 5mm blocking filter giving a wider apparent field.  Sort the binoviewer out first.    🙂 

Share this post


Link to post
Share on other sites

Thank you, Peter.

I'll start a new thread on TS binoviewer destruction collimation.

The increased surface detail in the darker ring can be brought out by deliberately pushing the image:  It isn't pretty! 👀

IMG_2400 sun surface.JPG

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.