RedCat 71 First Light (Alex Roberts)

Celestial hemisphere: Southern · Constellation: Monoceros (Mon) · Contains: IC 2177 · NGC 2335 · NGC 2343

Powered byPixInsight

RedCat 71 First Light

Powered byPixInsight

RedCat 71 First Light

I recently purchased a William Optics RedCat 71 to be the basis of a "grab and go" setup that will be used mainly for travel to dark sky locations. I plan to fit it with a mini PC, a ZWO EAF autofocus, a Pegasus Power Box and a small guide scope later.

So far, I'm impressed with the build quality of this little scope. I wanted a Petzval design scope to eliminate the need for a separate field flattener or be concerned with backfocus distance. At least, I didn't think backfocus distance mattered. To my surprise, I found that it did in my case. I started out with a 55mm backfocus for some testing and found the field was not as flat as I'd hoped for. After changing the backfocus to 60mm per the diagram on the William Optics product page, I found it did indeed make for a flatter field. (See revisions B and C for a CCD Inspector comparison of field curvatures for 55mm and 60mm backfocus.) Apparently, backfocus makes a substantial differnece on this scope. Has anyone else noticed this? Does this mean this scope is not a true Petzval, but some sort of proprietary hybrid design?

I hope this information helps those who have this scope or are considering buying one. I welcome feedback and commentary on this. Especially from those who are experts about optical design.

Original
B
C
Final
D

B

Title: Field curvature at 55mm backfocus

Description: CCD Inspector report.

Uploaded: ...

C

Title: Field curvature at 60mm backfocus

Description: CCD Inspector report.

Uploaded: ...

QHY268M/ZWO2600M Images
WO Redcat 71 Group

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	7370735
PixInsight job	n/a
PixInsight queue size	n/a
PixInsight stage	n/a

Image Index:

Contribution Index (beta):

RedCat 71 First Light

RedCat 71 First Light

Equipment

Acquisition details

Description

Comments

Revisions

B

C

Sky plot

Histogram

In these public groups

		...
You have no new notifications.

Image Index:

Contribution Index (beta):

RedCat 71 First Light

RedCat 71 First Light

Equipment

Acquisition details

Description

Comments

Revisions

B

C

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?

Delete this revision?

Delete this revision?

Delete this revision?

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