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_android_vs_ios_winners.thumb.jpg.803608cf7eedd5cfb31eedc3e3f357e9.jpg

Astrofriend

DIY, High efficient narrow band camera system

Recommended Posts

Hi,

What can you do during a rainy and boring day?

Yes, write something about about old project ideas that newer have been realized.

For many years I have been wondering how to construct a beam splitter system to make more efficient use of exposure time when doing color or narrow band imaging.

I have today written down my ideas here:

http://astrofriend.eu/astronomy/projects/project-high-efficiency-narrow-band-imaging/project-high-efficiency-narrow-band-imaging.html


There are a lot of interesting links there too to read.

/Lars

  • Like 1

Share this post


Link to post
Share on other sites

I'm not an expert but wouldn't the split beams be dimmer than the input beam thus you'd have to increase the exposure time?

Share this post


Link to post
Share on other sites

That's a very interesting idea. So a beamsplitter doesn't spread the different wavelengths out like a normal prism? Of course, if it did then the idea wouldn't work as the different blue wavelengths, for example, would hit different parts of the sensor.

59 minutes ago, kbrown said:

I'm not an expert but wouldn't the split beams be dimmer than the input beam thus you'd have to increase the exposure time?

I believe the idea is that the "blue" sensor would receive all the blue wavelengths, just like using a filter.

Share this post


Link to post
Share on other sites

Here's the theory of it:

https://en.wikipedia.org/wiki/Dichroic_prism

If anybody feels particularly brave, then how about a wrecked 3ccd broadcast camera as a source of a tricroic prism bloc:

https://www.ebay.co.uk/itm/Sony-DVCAM-DSP-WS-Studio-Broadcast-Camera-USED-DAMAGED-835/222731637408?_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D20131017132637%26meid%3Dd56ec756752b488ca2ce9b8cbcb2b792%26pid%3D100033%26rk%3D6%26rkt%3D8%26sd%3D272800656087&_trksid=p2045573.c100033.m2042

https://www.ebay.co.uk/itm/Sony-Power-HAD-EX-Professional-Video-Camera-USED-DAMAGED-832/222731627942?hash=item33dbd6eda6:g:1xIAAOSwvD5aGEW3

(DISCLAIMER: the guy selling these has not mentioned model numbers, they both LOOK like pro 3CCD models, but I'm not putting my neck on the line)

CCD targets are probably bonded to the prism, so not easy to remove, but would be worth a punt for anybody interested in playing with the idea.

Me, I'm finding controlling one camera difficult enough:icon_biggrin:

 

Huw

 

  • Like 1

Share this post


Link to post
Share on other sites

Hi,

It will catch three wavelength in parallel, one telescope, three cameras. Normally you only have one camera and one filter, then to get a rgb color from a mono chrome camera you have to take three exposures. Of course you can have three telescopes and three cameras als, then no need for a beam splitter.

Normally when doing rgb photos with mono cameras you block 2/3 of the incomming photons.

With other beamsplitters you can divide the incomming light in one visual and one IR beam. Then you need a mirror telescope. Some use the IR beam to autoguide on.

Lars

  • Like 1

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.

  • Similar Content

    • By Anne S
      Following a filter size upgrade I have an Astronomik LRGB set of filters, 1 1/4 inch. Probably around 12 years old. Kept in a filterwheel when in use but they have also been stored for a couple of years in their original box when I acquired some Baader ones to match my Baader narrowband filters. No scratches or coating issues. I have tried to show this in the images attached. 
      Looking for £80 posted given their age. 
      Anne



    • By Serg10
      I joined the forum to learn more about risks and success of filter removal for UV and IR photography.

      Back in 2011, one of the group's members, was trying to do just that:

      Unfortunately Stephen hasn't been active in the group since 2014, but the filter removal appears to have gone well (at least the S3 wasn't killed in the process).
      I have the same exact camera and I'm looking forward to try the same exact procedure. Does anyone has any tips on how to do this successfully/safely?

       
    • By thomasv
      Both little used, 'as new' condition, selling due to change of camera.
      Price incl. shipment: Ha: £99; CLS: £49
      These are compatible with Canon 5D / 6D, etc, here are the links for details on these filters:
      https://www.365astronomy.com/optolong-h-alpha-7nm-narrowband-deepsky-filter-for-for-full-frame-canon-eos-cameras.html
      https://www.365astronomy.com/optolong-cls-city-light-suppression-filter-for-full-frame-canon-eos-cameras.html
      Regards,
      t


    • By Owmuchonomy
      For sale is my Daystar Quark, Chromosphere version.  It has had infrequent use and I can't justify keeping it. Works superbly with my ED80.  It was purchased in July 2017 from Widescreen Centre so is still well within the 5 year warranty period.  I am looking for £625 posted to a UK mainland address.  Everything is complete in the box including instructions, USB cable and power adaptor.  Payment by bank transfer please.



       
       
       
       
    • By Kronos831
      Heyyy its meee kronos and i have been wondering about getting a filter...I really want the best contrast and brightness i can on my nebulas(i want to view M42 M57 M27 M31  M81 M82 and lots more) with my future 8" dob. Is this filter really going to help me?
      https://www.firstlightoptics.com/uhc-oiii-visual-filters/es_uhc_filter_125.html
      If it just a matter of quality of the filter itself  can you suggest a better one in the same price range?
      Or will not the uhc filter help me in general .IF so can you reccomend another one?
      Also is this         https://www.firstlightoptics.com/uhc-oiii-visual-filters/uhc-filter.html         this       https://www.firstlightoptics.com/uhc-oiii-visual-filters/es_uhc_filter_125.html        https://www.firstlightoptics.com/uhc-oiii-visual-filters/baader-uhc-s-filter.html               this better?
×
×
  • Create New...

Important Information

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