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_through_the-_eyepiece_winners.thumb.jpg.236833c5815bb321211a43f4d5214ba8.jpg

Recommended Posts

This image of M81, M82 and the Integrated Flux Nebulosity is an integration of 480 x 30sec exposures i.e. 4 hours in total.  It was taken over 3 nights (23/24/25 May 2017) at Astrofarm in France.

This is a slight re-process of an image I have already posted on the Deep Sky Imaging section of SGL.

Technical details:  H-alpha modified Sony A7S on Takahashi Epsilon 180ED.  480 x 30sec dithered exposures (4 hours total integration time) at ISO 10000.  Stacked in PixInsight with darks, flats and bias followed by DBE and Arcsinh stretching. Residual gradients removed in Photoshop CC.

M81M82IFN_20170525_v2_medium.thumb.jpg.e042d5a71aac00eed9206a02a262b960.jpg

Larger version can be found here:  http://www.markshelley.co.uk/Astronomy/2017/M81M82IFN_20170525_v2.jpg

Mark

  • Like 18

Share this post


Link to post
Share on other sites

Lovely image Mark, have you tried the same thing from home just to see the difference ?

Another project abandoned until next year here.

Dave

Share this post


Link to post
Share on other sites
12 hours ago, Davey-T said:

Lovely image Mark, have you tried the same thing from home just to see the difference ?

 

Thanks.  Yes I have tried it from home but the result was quite noisy.  I would have needed twice the total integration time to do it any justice.  The difference is totally due to the sky darkness.  At home I typically get an SQM reading of 20.9 mags/arcsec^2 but at AstroFarm it was pretty close to 21.6

Mark

Edited by sharkmelley

Share this post


Link to post
Share on other sites

More like 15 round here, I took some 30 min subs of M81/M82 this year using QSI683 and W110FLT and there wasn't a whiff of any IFN :)

Dave

Share this post


Link to post
Share on other sites
8 hours ago, Davey-T said:

More like 15 round here, I took some 30 min subs of M81/M82 this year using QSI683 and W110FLT and there wasn't a whiff of any IFN :)

I'm not surprised you saw no IFN - it was difficult enough with my fast scope and a dark site.  Here is a single 30second sub from that imaging run:

M81M82Single30sec.thumb.jpg.e991cdb0e88955b189b68afdff23fbf0.jpg

It has been software binned by a factor of 5, stretched and noise reduction applied.  Ignore the background gradients and there is just a hint of the IFN near the bottom, left of centre.  Elsewhere it is completely buried in noise (the noise is dominated by skyfog).    That's why I needed hundreds of subs.

Mark

Edited by sharkmelley
  • Like 1

Share this post


Link to post
Share on other sites

  • Recently Browsing   0 members

    No registered users viewing this page.

×

Important Information

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