M45

[rcheshire (Rowland)]

Hi.

I've wanted to capture M45 for several years and on each occasion technical problems intervened. Camera tilt on this occasion. I am so used to using prime lenses that the draw tube focuser problem escaped me - lesson learned.

Processing in PixInsight with default TGVNoise reduction on the CIE Lab layers.

Cooled Canon 450D (-10C) ISO400 and 800 (about half and half). Unguided 93 frames 180s. The usual complement of bias darks and flats.

There are faint hints of the dust field behind which Pleiades is passing.

Snake Valley last year - October November camp.

Higher res

Critique is always welcome...

[RickS (Rick)]

Looks fine to me, Rowland!

[Camelopardalis (Dunk)]

That's a beauty Rowland apart from being upside-down (sorry, twisted sense of humour I know)

[Geoff45 (Geoff)]

Nice Rowland. Good capture of the nebulosity and stars not blown out.
Geoff

[traveller (Bo)]

Very nice Rowland.
The dust showed beautifully against the nebulosity.
Bo

[batema (Mark)]

Lovely shot.

[Peter Ward]

An excellent rendition.

Nice one

[marc4darkskies (Marcus)]

That's beautiful Rowland! Very nicely done!

Marcus

[rcheshire (Rowland)]

Thank you all. Much appreciated. On reflection it needs longer subs to grab more of the dust and nebulosity.

Dunk, you really had me going... upside down!

[Camelopardalis (Dunk)]

[rcheshire (Rowland)]

A complete reprocess of M45. More detail

[glend (Glen)]

Very nice Rowland. Nice colours and proof the old 450D can still produce good images. One question, perhaps its my bad eyes, but it seems to have a little tilt in the camera alignment or the focuser. Have a look at the star shapes in the upper left. Nothing too serious at all.

[rcheshire (Rowland)]

Thanks Glen. Working on the tilt. Not sure which way to go. A Feathertouch light or make up a centering device. A collar or something similar.

[Slawomir (Suavi)]

A lovely image Rowland

[rcheshire (Rowland)]

Thanks Suavi.


For what it's worth

My PI preprocessing and post processing workflow is a little unconventional, for PI, anyway. I find it better for RAW data and it is similar to the IRIS / Siril DSLR workflow and may be performed in AstroArt and Regim, but not DSS, as far as I know.

1. Pure RAW
2. Create Superbias
3. Create master dark (no bias subtraction - no dark scaling - dark = light exposure time)
4. Subtract superbias from flats and stack
5. Calibrate lights as follows; with scaling if desired

Signal = lights - master dark/master flat

Post processing

1. Crop
2. BackgroundNeutralisation - usually adequate - otherwise ABE.
3. ColorCalibration - no previews
4. HistogramTransformation
5. SCNR - reduce green
6. Extract L* - boost contrast and apply as inverted mask
7. HDRMultiscaleTransfomation
8. LRGBCombination - add luminance to RGB to saturate colour
9. HDRMultiscaleTransformation
10. ColorSaturation
11. TGVNoise with mask RGB/K and CIE Lab

LRGBCombination with L* only is a way to boost saturation with luminance retention. In find it works very well.

[strongmanmike (Michael)]

A pretty nice result Rowland, especially for such a small scope, lots of juicy dust with nice variation in colour, good job

Mike

[rcheshire (Rowland)]

Thanks Mike. Not a bad little widefield scope. Pulling up colour and luminance is a challenge.

[atalas]

Look splendid....well done Rowland

[Ryderscope (Rodney)]

Nice one Rowland. Good capture of dust in the region and presentation of detail.

[rcheshire (Rowland)]

Thanks Louie and Rodney.

Hopefully an opportunity to get more data will present itself in the coming weeks.