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IC 1396

Photographing the Elephant’s Trunk Nebula

|Nebulae|14 Comments

As the season transitions from summer to fall, the nights have become longer and cooler in the backyard. This is beneficial for deep sky astrophotography for many reasons, with more time to capture exposure time on incredible targets like the Elephant’s Trunk Nebula being one of them.

For those that have been following my YouTube Channel, you’ll know that I’ve been testing out a new APO refractor telescope, the Sky-Watcher Esprit 100 ED. I was shocked to see just how many of my subscribers were already using and enjoying this exact telescope for astrophotography.

In the following post, I’ll show you how I captured the Elephant’s Trunk Nebula using a camera and telescope from my backyard in the city. The final image includes 1 hour and 50 minutes of total integrated exposure time.

Photographing the Elephant’s Trunk Nebula

From my little backyard, I like to choose targets that offer a long run of imaging time before running into an obstruction (like my neighbor’s roof). This can be challenging at times, and certain objects have a very small window of opportunity.

This, unfortunate reality that many of us backyard astrophotographers face often has a lot to do with the deep sky targets we choose to photograph. I’d love to simply choose the most interesting nebula or galaxy to shoot each month, but I usually opt for something that I can spend a fair amount of time on.

Total integrated exposure time is the single biggest factor to consider when executing a new deep sky astrophotography project. The best images in the world usually include 10 hours of exposure time or more, not an hour and a half.

With that being said, the Elephant’s Trunk Nebula is well placed in the night sky for plenty of exposure time during the months of September and October. I expect to collect a much more time on IC 1396 throughout the month of September.

Sky-Watcher Esprit 100ED

Setting up the Sky-Watcher Esprit 100ED APO Refractor

IC 1396

The high position of IC 1396 from my latitude is advantageous for some sharp and detailed images. This nebula stays away from the horizon and the ever-present glow of my Bortle Class 8 skies.

Targets that rise almost straight up in the sky benefit from less turbulence in the air, which (in my experience) results in tighter stars. It’s also free from the tall obstructions present on my back patio such as an increasingly tall Northern Hackberry tree.

The plan was to capture as many 5-minute exposures as possible during the brief stretch of clear nights we’ve experienced in September this month. These nights have all been mid-week, which can often lead to some groggy days at work to follow. But that’s what we signed up for.

To properly showcase this 5-degree wide emission nebula and cluster of young stars, I’ve decided to use a narrowband filter with a color camera. Not just any filter, a duo-narrowband filter that captures both Ha and OIII at the same time.

Object Details:

  • Common Name: Elephant’s Trunk Nebula
  • Catalogued: IC 1396 (Embedded Star Cluster), vdB 142
  • Object Type: Emission Nebula with embedded star cluster
  • Distance: 2,400 light years
  • Constellation: Cepheus

IC 1396 location

The location of the Elephant’s Trunk Nebula – Sky and Telescope

The Camera and Filter Used

The STC Astro Duo-Narrowband filter has been an astonishingly useful addition to my growing collection of light pollution filters. Together, with a cooled color CMOS camera, I have been able to produce some of my best deep sky images to date.

With the cooler temperatures at night, I’ve managed to lower the sensor temperature on the ZWO ASI294 MC Pro to -20C. This helps capture low-noise images that make the image processing stages so much more enjoyable later on.

The sensor size of the ASI294 MC Pro is an excellent fit in terms of pixel scale with the wide field Sky-Watcher Esprit 100ED refractor. The field of view using the Esprit 100 with the included field flattener (corrector) and this camera is perfect for large nebulae objects like the Elephant’s Trunk Nebula. I used this handy tool to calculate the field of view.

The image above illustrates where I threaded my 2-inch filter on the imaging train of this configuration. Finally, I think I’ve got the correct spacing between the camera sensor and the flattener!


The ZWO ASI294 MC Pro Camera attached to the Esprit 100 2-Element Corrector

Update: A number of folks contacted me after seeing the way I had the camera and filter connected to the field corrector in my Pacman Nebula video. Two helpful options for placing the 2-inch filter in front of the sensor have surfaced.

  1. FLO Push-Fit Adapter for Sky-Watcher Focal Reducers
  2. Starizona Filter Slider – Complete System

Thank you to Jimmy and Kevin for the tip. I appreciate the advice, guys!

Starizona Filter Slider

The Starizona Filter Slider. 

The Telescope

In late August, I was sent a Sky-Watcher Esprit 100ED APO to review. It’s a wide-field apochromatic triplet refractor, my absolute favorite type of telescope for astrophotography. I have only recently mounted the telescope to the iOptron CEM60 mount and sorted out all of the necessary accessories for astrophotography.

The Sky-Watcher Esprit 100 ED included a threaded 2-element field corrector (or, “field flattener”) and a Canon t-ring adapter. Instead of connecting my DSLR camera, I’ve opted to try the ASI294 MC Pro for some more narrowband imaging.

I’d like to eventually take advantage of the full-frame corrected focal plane with my stock Canon 5D Mk II. I may try shooting a reflection nebula using this camera such as the Iris Nebula, or Witch Head Nebula.

astrophotography telescope

Video: Unboxing a Sky-Watcher Esprit 100ED APO

Sky-Watcher Esprit 100ED Super APO Triplet Specs:

Glass: Schott/Ohara ED
Aperture: 100mm
Focal Length: 550 mm
Focal Ratio: F/5.5
Weight: 16.3 lbs.

At a focal length of 550mm, this triplet is best for capturing large nebulae and galaxies. In my early tests on the Elephant’s Trunk Nebula, the very edges of the image showed elongated stars. After correcting the spacing between my camera sensor and the threaded field corrector, I am happy to report that the stars are now pin-points to the edge of the image.

Overall the Esprit 100ED has been a welcome addition to the AstroBackyard with yet another focal length and native magnification to play with. In contrast, my Explore Scientific ED102 has a focal length of 714mm despite only being 2 inches larger in aperture.

Sky-Watcher Esprit 100ED vs. Explore Scientific ED102

My Results

The following image was captured over 2 nights in early September from my backyard. The complete photo details and equipment breakdown are listed below.

Elephant's Trunk Nebula

IC 1396 – The Elephant’s Trunk Nebula – Trevor Jones

Total Exposure Time: 1 Hour, 50 Minutes
(22 x 5 minutes)

Mount: iOptron CEM60 center-balanced equatorial mount
Telescope: Sky-Watcher 100ED Super APO triplet
Camera: ZWO ASI294MC Pro
Reducer: Sky-Watcher 2-Element Field Corrector
Filter: STC Astro Duo-Narrowband Filter
Autoguiding: Starfield 60mm Guide Scope Package

Image Acquisition in Astro Photography Tool
Autoguiding with PHD2 Guiding
Stacking in DeepSkyStacker
Final Processing in Adobe Photoshop

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M33 Galaxy – The Triangulum Galaxy

|Galaxies|0 Comments
M33 Galaxy

M33 – The Triangulum Galaxy

The Triangulum Galaxy

The M33 Galaxy is the third-largest galaxy in the local-group of galaxies, behind the Milky Way and Andromeda.  Its large size from our vantage point makes my wide-field astrophotography 80mm telescope a great choice for imaging this target. Despite it’s size, the Triangulum Galaxy appears much dimmer than M31 – The Andromeda galaxy.  If you are new to astrophotography, chances are that the Triangulum Galaxy is one of the first few galaxy names you have learned.

M33 Galaxy Photo Details:

Telescope: Explore Scientific ED80 with WO Flat III 0.8x FR/FF
Mount: Skywatcher HEQ5 Pro Synscan
Guiding: Meade DSI Pro II and PHD Guiding
Guide Scope: Orion Mini 50mm
Camera: Canon EOS 450D (Modified)
ISO: 800
Total Exposure: 7 Hours (84 x 300 seconds)
Processing Software: Deep Sky Stacker, Photoshop CC
Support Files: 20 darks, 20 flats, 20 bias

Target Acquired – Messier 33

I have managed to image the M33 Galaxy from my backyard for multiple nights over the course of nearly a week. I can’t remember the last time we have had such a long stretch of clear night skies in the Niagara region. Mind you, these clear nights occurred during weekdays, and I have to be up early for work (and to walk the dog) early each morning. Needless to say, I haven’t been getting much sleep lately.  Luckily my astrophotography equipment can be set up and ready for imaging in about 30 minutes. This includes polar alignment, calibration, focus and guiding.  

M33 Galaxy - Astrophotography

My Telescope pointed at the M33 Galaxy

But first, the Elephant’s Trunk

My first imaging session was on the night of September 16th. Smack-dab in the middle of the work week. I didn’t originally intend to shoot the M33 galaxy that night, I started with IC 1396. The Elephant’s Trunk nebula is a concentration of interstellar gas and dust within IC 1396, located in the constellation Cepheus. You can view the results of this project below.

This area of the night sky is in a perfect spot for imaging at this time of year from my location, almost directly overhead. I captured 38 frames on this DSO on Wednesday night. The subs were 4 minutes each using ISO 800 on my aging modified Canon Xsi.

IC 1396 – Elephant’s Trunk Nebula

Elephant's Trunk Nebula

IC 1396 – Elephant’s Trunk Nebula – A tad noisy!

IC 1396 – Astrophotography Image Details

Telescope: Explore Scientific ED80 with WO Flat III 0.8x FR/FF
Mount: Skywatcher HEQ5 Pro Synscan
Guiding: Meade DSI Pro II and PHD Guiding
Guide Scope: Orion Mini 50mm
Camera: Canon EOS 450D (Modified)
ISO: 800
Total Exposure: 2 Hours, 24 Minutes (36 x 240 seconds)
Processing Software: Deep Sky Stacker, Photoshop CC
Support Files: 15 dark frames

The Elephant’s Trunk nebula can be seen in the top center-right of the photo above. It is a dark patch with a bright, sinuous rim. The rim is the surface of a dense cloud that is being illuminated and ionized by a very bright, massive star. Faint objects like this are difficult to image from light-polluted skies in the city. I found myself battling with horrible gradients and noise when processing this image. I will likely add more time to the Elephant’s Trunk Nebula during the weeks that surround the new moon in October. Another 4 hours should help me pull out more detail with less noise.

Canon 450D attached to my telescope

Canon Xsi 450D for astrophotography – attached to my telescope with the William Optics 0.8 FF

On to the M33 Galaxy…

After achieving a steady graph in PHD guiding, and a tight-focus on my reference star (Alderamin) I set BackyardEOS to take 50 frames, and I headed to bed.  I set my alarm for 2:00am, and managed to stumble back out to the patio to check on my results.  The Elephant’s trunk nebula was too far west, and my telescope would soon by aiming directly at my garage!  Because the sky was still crisp and clear, I figured I would add some time a second object for the night.  I imaged the M33 Galaxy back in 2012, but that was before I self-modded my 450D for astrophotography.  The Triangulum Galaxy contains some beautiful pink nebulosity within it that I knew I could now capture.

The following 2 nights of the week were also clear, and I took full advantage. This time, I shelved my plans for the Elephant’s trunk, and focused all of my efforts on Messier 33. I captured an impressive 49 subs the following night at 5 minutes each, and then I added another 17 light frames the night after that!

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M33 Galaxy

M33 – The Triangulum Galaxy

My total number of frames on this object was now over 100! That’s a lot of imaging in one week. All that was left now was to stack and process all of the data acquired. I set Deep sky stacker to use “the best 90% of frames” to register and stack, which resulted in a final stack of 84 images total, or exactly 7 hours. I even had success with my creation of flat and bias frames. I shot the bias frames through the telescope with the lens cap on, at the fastest shutter speed my camera allows (1/4000 of a second). The flat frames were created by shooting through the telescope, pointed at the early morning blue sky. These were shot with the camera in Av mode. I shot separate bias and flat frames for each night, except the first. Only dark frames were used for that imaging session.

Processing a photo with 7 hours worth of data is quite enjoyable.  There is less noise, and more detail than I am used to.  As with all of my astrophotography images, I am sure I will re-process my photo of Messier 33 several times until I feel like I have done the galaxy justice. Everyone has their own taste, and at the end of the day, you have to be happy with it.

BackyardEOS 3.1

I finally purchased a copy of BackyardEOS 3.1 Classic Edition. My trial period has ended, and I am very happy with the software. The focus and framing tab, dithering control, and file organization features are my favourite, and make me wish I had upgraded to this software a lot sooner. I always had a hard time getting accurate focus using the live-view function of my DSLR. The focusing function built-in to BackyardEOS allow you to view a digital readout of the star size in real-time as you focus your telescope. The lower number you see on-screen, the better your focus! The filename for each sub lists the ISO, object name, exposure time, date and even the temperature! This is extremely handy when stacking a large number of frames from multiple nights.


Screenshot of the BackyardEOS 3.1 Software

I would love to hear what you think of my results for this galaxy image.  You can also follow me on twitter to see more of the “behind-the-scenes” stuff from the backyard. As always, if you have any questions about the equipment I used, or my processing techniques, please leave a comment below.  Thank you so much for visiting my website.

Backyard Astrophotography

Another night under the stars in the backyard

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