Widefield in the Virgo Cluster of Galaxies

Markarian’s Chain (bottom left) plus M87, M89 and M90. This is a small part of the huge Virgo Cluster of galaxies. The image is composed of 81 ten minute exposures (13.5 hours) taken over nine nights between 1st April and 4th May 2013.

Imaging: Sky-Watcher Evostar 80ED DS-Pro, 0.85x Reducer, Canon EOS 500D (unmodded), Hutech IDAS LPS P2 2″, APT
Guiding: Orion ST80, QHY5, PHD Guiding
Mount: Sky-Watcher NEQ6, EQMOD, Astrotortilla
Processing: PixInsight

A two pane mosaic consisting of a total of 81 x 600 seconds at ISO400  taken on 1st, 2nd, 6th, 7th, 20th April and 3rd, 4th May 2013.  109 Darks (using PI dark scaling), 330 Bias, ~25 Flats per session.

The main challenge was getting down the DSLR background noise without creating the dreaded chrominance clumps.  PI’s new TGV denoise tool was a massive help here.  Matching the two panes was also a challenge as the background noise is noticeably different between the two (blaming my 2nd iteration of light box for this, not enough illumination in the red channel leading
to more noise, which was fixed in a 3rd iteration before most of the subs for the right hand pane were taken.)

Ended up with about 123 process icons in PI, not including dark / bias library maintenance.  Probably threw away about another 50 or 60 icons on various trials and tests.

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