NGC2403 in H alpha-- comparison between 6m and 0.4m telescopes, film vs CCD (erdmanpe)

NGC2403 in H alpha-- comparison between 6m and 0.4m telescopes, film vs CCD

Some decades back, when I began teaching astronomy classes, I often pointed out the huge advancements in detector technology taking place that would revolutionize astronomy. With CCD detectors becoming affordable, amateurs could now perform measurements with modest sized telescopes that could only be performed by the giant telescopes of the previous day using film. The improvement in detector quantum efficiency changed everything.

Just for fun I put together this side by side comparison of H alpha images. One from my driveway with a Meade SC 400mm f/10 equipped with a CCD detector, and the other taken with the 6m telescope in Zelentchuk at ~2000m altitude, using Kodak 103 aE film (Astron. Astrophys. 237, 23-35 (1990)). An f/1 focal reducer was used on the 6m so the plate scale was not terribly different. The bandwidths of the Ha filters used were similar (~3nm), as was the total integration time (~3.5 hours). I just did a screen clip from the published paper to obtain the image with the 6m, and adjusted display settings for my image with a log stretch to try and match the 6m image as best I could for comparison purposes. Seeing for the 6m image was stated to be about 1 arcsec, mine wasn't so good here at the bottom of the atmosphere. The defects in the film plate make the 6m image obvious, but to my eye each reaches about as deep.

Amazing progress.

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 failed
Started	...
Astrometry.net job	9526657
PixInsight job	n/a
PixInsight queue size	n/a
PixInsight stage	n/a

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