my attempts at SHG images continued

I LOVE finding out about different ways to appreciate the Sun and light in general. Use this forum to post your info or questions about various outside the mainstream ways to appreciate our life giving star!
Post Reply
highfnum
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 1227
Joined: Sat Nov 24, 2012 2:33 pm

my attempts at SHG images continued

Post by highfnum » Fri Jul 17, 2015 3:09 pm

still fighting with post image processing
but captures are getting better and cleaner

caH
cahadj.jpg
cahadj.jpg (99.71 KiB) Viewed 1859 times

highfnum
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 1227
Joined: Sat Nov 24, 2012 2:33 pm

Re: my attempts at SHG images continued

Post by highfnum » Fri Jul 17, 2015 3:10 pm

CaK
caKme.jpg
caKme.jpg (93.04 KiB) Viewed 1858 times

highfnum
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 1227
Joined: Sat Nov 24, 2012 2:33 pm

Re: my attempts at SHG images continued

Post by highfnum » Fri Jul 17, 2015 3:12 pm

caH orig
hey if anyone wants to process for comparisons be my guest
fc2_save_2015-07-16-181944-000050mm_003de.jpg
fc2_save_2015-07-16-181944-000050mm_003de.jpg (32.79 KiB) Viewed 1857 times

User avatar
DSobserver
Almost There...
Almost There...
Posts: 542
Joined: Sun Feb 19, 2012 2:36 pm
Location: FRANCE

Re: my attempts at SHG images continued

Post by DSobserver » Fri Jul 17, 2015 8:58 pm

hello

you look t get a good slit.

Where did you get it?

highfnum
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 1227
Joined: Sat Nov 24, 2012 2:33 pm

Re: my attempts at SHG images continued

Post by highfnum » Fri Jul 17, 2015 9:06 pm

From merlin66

User avatar
DSobserver
Almost There...
Almost There...
Posts: 542
Joined: Sun Feb 19, 2012 2:36 pm
Location: FRANCE

Re: my attempts at SHG images continued

Post by DSobserver » Fri Jul 17, 2015 9:46 pm

here is my contribution

Image

I would say that youhave to improve focus from the collimation lens : this is why the edge are focus but the surface is not as sharp.

I also would suggest you to try first Ha shot : indeed due to wavelenght, focus is easier

highfnum
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 1227
Joined: Sat Nov 24, 2012 2:33 pm

Re: my attempts at SHG images continued

Post by highfnum » Fri Jul 17, 2015 10:35 pm

So you say that prime image of sun on slit is a bit off?

MERCI for image!

Wah
Im an EXPERT!
Im an EXPERT!
Posts: 339
Joined: Tue May 01, 2012 2:14 am

Re: my attempts at SHG images continued

Post by Wah » Sat Jul 18, 2015 1:11 am

Good clean slit and no de-banding is needed!

User avatar
DSobserver
Almost There...
Almost There...
Posts: 542
Joined: Sun Feb 19, 2012 2:36 pm
Location: FRANCE

Re: my attempts at SHG images continued

Post by DSobserver » Sat Jul 18, 2015 7:39 am

highfnum wrote:So you say that prime image of sun on slit is a bit off?

MERCI for image!
no, the focus of the lens after the slit. Indeed it is the most sensitive one.

How do you currently manage this ?

highfnum
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 1227
Joined: Sat Nov 24, 2012 2:33 pm

Re: my attempts at SHG images continued

Post by highfnum » Sat Jul 18, 2015 8:19 am

Manually
just once without scope attached

User avatar
p_zetner
Almost There...
Almost There...
Posts: 899
Joined: Sun Mar 18, 2012 4:59 pm
Location: Winnipeg, Manitoba, Canada

Re: my attempts at SHG images continued

Post by p_zetner » Sat Jul 18, 2015 6:48 pm

The focusing does seem to be off. My technique: Before taking instrument into the field, adjust collimator and camera lens (without telescope in place) to get sharp spectral lines from an emission spectrum source (Ne, Na, Hg lamp, etc.) placed near the slit. Remaining focus, to be done in the field, is largely the telescope, with minor (repeat: minor!) tweaks of camera and collimator lenses. As Vincent mentions, the collimator is often the most sensitive adjustment.

Peter.

highfnum
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 1227
Joined: Sat Nov 24, 2012 2:33 pm

Re: my attempts at SHG images continued

Post by highfnum » Sat Jul 18, 2015 9:06 pm

thanks all for advice
did some tweak today

this may take several tries
before I get good feel for it

I hope I now qualify for entry into the SHG club
even at low tier

User avatar
marktownley
Librarian
Librarian
Posts: 24463
Joined: Tue Oct 18, 2011 5:27 pm
Location: Brierley Hills, UK
Contact:

Re: my attempts at SHG images continued

Post by marktownley » Sun Jul 19, 2015 6:24 am

Interesting to read your progress!
Image
http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!

User avatar
DSobserver
Almost There...
Almost There...
Posts: 542
Joined: Sun Feb 19, 2012 2:36 pm
Location: FRANCE

Re: my attempts at SHG images continued

Post by DSobserver » Sun Jul 19, 2015 10:16 am

Here my advice base on friends advice and experience for a good focus :

1- I take my camera (450D) + long lens (400mm) a manage to get infinit focus to a mountain for example.
2- remove from your shg the telescope and the camera lens
3- oriente the SHG to the sun
4- through my 450D+400mm infinit, I manage to get a perfect slit image focusing the collimator (f/8 like this I avoid any specular light from the slit)
5- place again the camera lens on your shg and focus properly the spectra on the wavelenght you want
6- place the telescope and focus it in order to get a sharp spectra edge (in fact sun edge...)
7- adjust/finalise focus with camera lens

The longer the wavelenght the easiest it is to get a good focus....

highfnum
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 1227
Joined: Sat Nov 24, 2012 2:33 pm

Re: my attempts at SHG images continued

Post by highfnum » Sun Jul 19, 2015 5:35 pm

Ok
I think I understand
The slit edge should look sharp
As well as edge of sun within slit
space

highfnum
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 1227
Joined: Sat Nov 24, 2012 2:33 pm

Re: my attempts at SHG images continued

Post by highfnum » Sun Jul 19, 2015 6:15 pm

Marktownly your next!

highfnum
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 1227
Joined: Sat Nov 24, 2012 2:33 pm

Re: my attempts at SHG images continued

Post by highfnum » Sat Aug 08, 2015 8:30 pm

oversampling error
too many frames

then when i fixed clouds rolled in!

got two partials

oversample
ovrersapopy.JPG
ovrersapopy.JPG (124.16 KiB) Viewed 1601 times

highfnum
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 1227
Joined: Sat Nov 24, 2012 2:33 pm

Re: my attempts at SHG images continued

Post by highfnum » Sat Aug 08, 2015 8:31 pm

part with no clouds
goodpart.JPG
goodpart.JPG (66.44 KiB) Viewed 1601 times

User avatar
Merlin66
Librarian
Librarian
Posts: 3164
Joined: Tue Dec 13, 2011 1:23 pm
Location: St Leonards, Australia
Contact:

Re: my attempts at SHG images continued

Post by Merlin66 » Sat Aug 08, 2015 10:54 pm

That's looking good, mate!
Keep it up.
"Astronomical Spectroscopy - The Final Frontier" - to boldly go where few amateurs have gone before
https://groups.yahoo.com/neo/groups/ast ... scopy/info
"Astronomical Spectroscopy for Amateurs" and
"Imaging Sunlight - using a digital spectroheliograph" - Springer

Post Reply

Who is online

Users browsing this forum: No registered users and 1 guest