M81 & M82 "wide field" from urban Denver (Ken Sturrock)

Celestial hemisphere: Northern · Constellation: Ursa Major (UMa) · Contains: Bode's nebulae · M 81 · M 82 · NGC 3031 · NGC 3034

M81 & M82 "wide field" from urban Denver, Ken Sturrock

Powered byPixInsight

M81 & M82 "wide field" from urban Denver

Powered byPixInsight

M81 & M82 "wide field" from urban Denver

This is an M81 & M82 shot taken about two miles from downtown Denver using a ZWO ASI-183 camera through an SV-70t with a focal reducer shooting at f/4.8. The image represents about 18 hours of subframes in LRGB. The subframes were three minutes each, gain was set to zero and offset to fifty.

The mount was a Takahashi EM-11 and the acquisition was controlled by custom scripts running atop The SkyX Professional, mostly on a Raspberry Pi.

I seem to have a slight tilt in the imaging system which I believe is related to the focal reducer because the effect has also occurred with a different camera. I also inadvertently cropped the image twice, so it's a bit paired down from my original intention.

Processing was fairly basic and conducted in PixInsight: flat & dark calibration, ABE, color balance, SCNR, TGV denoise, HDR-MT on luminance and then the usual masked saturation and curves.

This is really a fun pair of galaxies to shoot and is just about a perfect galaxy target for this rig. I also found the new ASI-183 camera a pleasure to use. The camera produces some background banding during short (less than a couple of seconds) exposures. This primarily impacted my flat frames, but I could mostly correct it with the PI Canon debanding tool. At the end of the day, the small pixels on this camera can support more resolution than the 70mm refractor can actually serve up.

I shot this image before with my 80mm f/6 and a larger pixel camera, but I tried to be less aggressive with the smoothing and noise reduction than with my previous attempt.

Thanks for looking.

Cloudy Nights
Suburban Astrophotography
"Simply Stellarvue"

Please note: The following tables are updated every 24 hours.

Distribution of astrophotographers

This table shows the number of distinct astrophotographers who have been assigned and IOTD/TP award compared to the total number of images awarded.
	Distinct awarded users	Total awarded images
Image of the day
Top picks
Top pick nominations

Distribution of subject types

This table shows the distribution of awards per subject type, compared to the popularity of images of that subject type.
	Image of the day	Top pick	Top pick nominations	Total submitted
Deep sky
Solar system
Extremely wide field
Star trails
Northern lights
Noctilucent clouds
Landscape

Distribution of data sources

This table shows the distribution of awards per data source, compared to the popularity of images acquired from that data source.
	Image of the day	Top pick	Top pick nominations	Total submitted
Backyard
Traveller
Own remote observatory
Amateur hosting facility
Public amaeteur data
Professional, scientific grade data
Mix of multiple sources
Other
Unknown

The “AstroBin Image of the Day and Top Picks”, or IOTD/TP, is a long-running system to promote beautiful, interesting, peculiar, or otherwise amazing astrophotographs, with a focus on technical excellence. Learn more.

Submitted The date and time when you submitted this image for IOTD/TP consideration.	...
Views by Submitters (available since September 19th, 2023) Every image is assigned to 50% of available Submitters. In the event that at least 80% of them don't view the image before its time in the IOTD/TP process expires, it's assigned to the other 50% of Submitters and the process begins anew.
Promotions by Submitters When 3 distinct Submitters promote the image, it moves on to the next stage of the process: evaluation for Top Pick status. This requirement, in addition to anonymization of images and distribution to only a subset of them, prevents biases and ensures that the best images are selected.
Promotions by Reviewers When 3 distinct Reviewers promote the image, it moves on to the next stage of the process: evaluation for IOTD status.
Early dismissal Staff members have a lot of images to inspect on a daily basis, and they can dismiss images if they believe they don't meet the requirements for IOTD/TP selection. If an image is dismissed 5 times, it's removed from the process. This streamlines the process and ensures that any bias present in promotions could be overruled by other staff members.

Status	Basic success
Started	...
Astrometry.net job	1900692
PixInsight job	n/a
PixInsight queue size	n/a
PixInsight stage	n/a

Image Index:

Contribution Index (beta):

M81 & M82 "wide field" from urban Denver

M81 & M82 "wide field" from urban Denver

Equipment

Acquisition details

Description

Comments

Sky plot

Histogram

In these public groups

Image Index:

Contribution Index (beta):

M81 & M82 "wide field" from urban Denver

M81 & M82 "wide field" from urban Denver

Equipment

Acquisition details

Description

Comments

Sky plot

Histogram

In these public groups

Notifications

AstroBin is in READ ONLY mode

Sorry :-(

Sorry :-(

Sorry :-(

Are you really sure?

Warning!

Warning!

Are you sure?

Report abuse

Slideshow settings

IOTD/TP stats (last [x] days)

Distribution of astrophotographers

Distribution of subject types

Distribution of data sources

Sorry

Sorry

Share

Upload new revision

Upload uncompressed source (XISF/FITS/PSD/TIFF)

Delete image and all its revisions?

Delete original image?

Delete all other versions?

Delete all revisions?

IOTD/TP stats

The following people like this image

The following people bookmarked this image

Warning

Flag malfunctioning thumbnails

Contains

Remove yourself as a collaborator

Plate-solving information