The Elephant’s Trunk Nebula

Version 2: 20 October 2022

It’s been a busy few months at the Urban Astrophotography HQ. I’ve upgraded a lot of my kit, and am now using an Askar 130PHQ Flatfield Astrograph (review here) mounted on a Sky-Watcher EQ6-R PRO, plus a William Optics 50mm Guidescope with 1.25″ RotoLock for guiding (review here).

Speaking of which, I recently bought an Optolong L-Ultimate dualband filter; then Askar sent me one of their newly-released Colour Magic 6nm dualband filters to review — read the review here. The tests meant I had a lot of data with these filters so decided to combine them into a “first light” image with my new telescope.

I’m happy with the result as it shows a level of detail I could never have obtained with my Askar FRA400 — scroll down to see some comparisons. The processing was tricky though, and I spent about two days trying out different versions until I settled on something I think does the source data justice. I like the colours but am not sure I could ever reproduce them!

* October 2022
* Bristol, UK (Bortle 8)
* Telescope: Askar 130PHQ Flatfield Astrograph
* Camera: ZWO ASI 2600MC-PRO
* Filter: Optolong L-Ultimate and Askar Colour Magic 6nm
* Mount: Sky-Watcher EQ6-R PRO
* Guide: William Optics 50mm Guidescope with 1.25″ RotoLock; ZWO ASI 120MM Mini
* Control: ASIAIR Plus
* Software: PixInsight, Lightroom,
* 330 x 120 seconds (Optolong L-Ultimate) plus 330 x 120 seconds (Askar Colour Magic 6nm)

Total exposure time: 22 hours

By Lee Pullen

PixInsight’s WBPP Execution Monitor report.

Compared with Version 1

This picture was taken last year with my Askar FRA400 (focal length 400mm). The black rectangle shows the field of view with my new Askar 130PHQ (focal length 1000mm). Note that I cropped my final image a bit, so the black rectangle is a little larger than my final image.

Slide to compare a cropped view of my previous attempt (left) with the same view taken with my new equipment.

Example source data

This is what a single 120-second subframe looks like, debayered and with a simple stretch.
This is the integration of 660 x 120 seconds (22 hours) just with a simple stretch, before any proper editing.

Version 1: 10 June 2021

The Elephant’s Trunk itself is the long dark structure just to the bottom-left of centre in this image. It is part of a much larger nebula called IC1396, which fills the frame.


This is one of the few images I was genuinely happy with once I’d finished editing. I had lots of good quality data, although acquisition spanned two months because of the lack of decent dark hours in the summer.

There’s loads of detail, especially in the dark dust lanes, and I think it looks good even when you zoom in. The editing benefitted from this useful tutorial on processing L-eXtreme data. In the future I may try to take and combine some regular RGB data to get better star colours.

Fun fact: this image convinced me that OSC cameras can now compete with Mono even from a city, and pushed me into making this website.

* May and June 2021
* Bristol, UK (Bortle 8)
* Telescope: Askar FRA400 f/5.6 Quintuplet APO Astrograph
* Camera: ZWO ASI 2600MC-PRO
* Filter: Optolong L-eXtreme
* Mount: Orion Sirius EQ-G
* Guide: William Optics 32mm; ZWO ASI 120MM Mini
* Control: ASIAIR PRO
* Software: PixInsight, Photoshop, Lightroom, Topaz DeNoise AI
* 480 x 120 seconds

Total integration time: 16 hours

By Lee Pullen

This image is featured in the December 2021 issue of Sky at Night Magazine:

Example source data

This is what a single 120-second subframe looks like, debayered and with a simple stretch.
This is the integration of 480 x 120 seconds (16 hours) just with a simple stretch, before any proper editing.

Annotated image


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11 thoughts on “The Elephant’s Trunk Nebula

  1. Craig says:

    Amazingly beautiful – hard to believe it is from a OSC with rough city lights! Gratefully you aimed away from the lights your neighbors windows.

    Reply
    1. Craig says:

      meant to say “the lights OF your neighbors windows.”

      Reply
    2. Lee says:

      Luckily I don’t have any really bright lights aiming down into my garden, but the skyglow is extreme!

      Reply
  2. Craig says:

    Amazingly beautiful – hard to believe it is from a OSC with rough city lights! Gratefully you aimed away from the lights of your neighbors windows.

    Reply
  3. Denis says:

    Amazing the details and quality of each of your final images, you have great skills processing astrophotography!!

    Reply
    1. Lee says:

      Thanks Denis, I’ve worked hard at improving my processing skills, particularly over the last year. Still lots to learn though!

      Reply
  4. Nana Dadzie Ghansah says:

    Great image.
    How does the Eq6r pro handle the 130 phq?
    Does it clear the legs in declination? Thanks!

    Reply
    1. Lee says:

      The EQ6R-Pro handles the weight of the 130PHQ just fine, thankfully! I have my mount on a concrete block pier. If you use tripod legs then the telescope will almost certainly collide with the legs when pointing near the zenith. A tripod extension to give the mount head some extra height would definitely help. A pier is the best solution though.

      Reply

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