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.

SilverAstro

2sec x 100 captures Leo Triplet !

Recommended Posts

I have been experimenting with 2sec exposures, Canon 60D + vintage 135mm lens, on a fixed tripod. Originally to track down some faint asteroids but I got sidetracked into imaging my first galaxies, not intentional  !
Nothing pretty here but quite interesting. A stack of 100 when vigorously stretched has revealed the Leo triplet (just!) way down in the noise with stars down to mag12 (13 with good luck and imagination !)

Why am I finding this interesting? well if there was to be a supernova in a galaxy of similar surface magnitude I stand a chance of capturing one, since SNs outshine (usually?) their parent.

Below is my less than pretty pic, the full frame on the top left with beta Leo far left and the area where the triplet are in the top right corner. This corner is enormously stretched and scaled up a bit indicated by the yellow lines.
With a larger annotated version below.
The compression to jpg has not helped ! they are still there but are clearer in the original TIFF in Gimp.

EDIT : the magnitudes are from CdC / UCAC4

Now for my question :- I have approx 1400 more to process from last night in batches of 100, do they all need to be stacked in DSS at the same time or can I stack them in groups and stack the group TIFF images in DSS again to make the final ? Will the s/n ratio still stack up ?

TripletS.thumb.jpg.48ddadf851f54ddb190bd3e614e1eb21.jpg

Edited by SilverAstro
  • Like 2

Share this post


Link to post
Share on other sites
34 minutes ago, SilverAstro said:

Will the s/n ratio still stack up ?

I commend you for trying this :-)

I guess there's one way of finding out. Certainly look forward to seeing the result of your labours.

Beast regards,
Steve

Edited by SteveNickolls
  • Like 1

Share this post


Link to post
Share on other sites

I'd imagine a stack is a stack. I did do a experiment in the past by stacking all subs, than subs in groups and honestly I didn't see any difference after stretching each stack.

But that said, I personally still stack all my subs sequentially rather than groups of stacks.

  • Like 1

Share this post


Link to post
Share on other sites

Ambitious! I have a sneaking feeling that stacking the stacked batches doesn't gain you the same noise reduction as stacking all at once. Bit early in the morning for proofs :icon_biggrin:. I used to stack a couple of hundred frames with DSS, though with a moderately fast computer, but only 32-bit. If you've got a decent amount of RAM then the new 64-bit version of DSS would be worth a try.

Ian

Share this post


Link to post
Share on other sites

Try AstroArt for your stacking. It is orders of magnitude faster than DSS, though it isn't free. (You can try it for free.)

The SN will be better using 'the all into one' mode and sigma clip but with those numbers stacking the stacks will work.

Olly

Share this post


Link to post
Share on other sites

+1 for AstroArt. It punches well above it’s weight.

Highly recommended.

 

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.