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Photographing the Geminids Meteor Shower

The 2023 Geminids Meteor Shower is almost upon us, with its peak overnight Thursday 14th December in to Friday 15th December (Perth, Western Australia). The Geminids is typically our most consistently performing meteor shower to observe here in WA.

This post provides some basic information on how to photograph the Geminids Meteor Shower. If you would like more info to be prepared for future metoer showers then jump on one of my workshops where I teach astrophotography.

A meteor shooting across the northern horizon during the night of 2017 Geminids Meteor Shower. Photographed by Roger Groom in the Central Wheatbelt (WA). Single 30s exposure cropped from a 12mm lens on Fuji X-E2 camera (APS-C crop sensor).

When to Photograph the Geminids Meteor Shower in 2023

The basics of when to view or photograph the 2023 Geminids Meteor Shower from Western Australia are:

  • Date: Thursday 14th December – Friday 15th December 2023.
  • Time: Approximately 10pm – 4am

The reality is that Gemini the constellation, in which this meteor showers’ radiant is extending from, rises late in the evening. Parts of Gemini are above the horizon not long after sunset but the constellation as a whole does not rise nicely above the ground until about 10:30pm.

What if I can’t view them on the 14th you say? Well these meteor showers come and go over time, so you will likely see meteors on nights either side, with the rate decreasing night by night. There’s no harm in giving it a try on other nights, or even doing a practice run in the nights leading up to the peak night.

Where to Look for the Geminids Meteors

Meteors can appear anywhere in the sky but generally speaking point your camera towards the constellation of Gemini which is in the NE before midnight, North between about midnight and 2am, NW between 2am and 4am.

Until the constellation is above the ground chances are a reasonable proportion of the meteors simply won’t be above the ground either, and so your chances of seeing one is reduced until the constellation has risen higher in the sky.

The night sky as viewed from Perth Western Australia at 10pm on December 14th 2023. Gemini is the large constellation shape to the NE. During the night this moves across the north to the north-west. Point your camera toward the constellation of Gemini.

Give Yourself Time

Observing a meteor shower is not something you do by simply ducking outside for 20 minutes. Even if the Zenith Hourly Rate (ZHR) is high you still need to be outside looking up (or photographing) for a decent period of time to have a chance of seeing/photographing any meteors.

  • Let your eyes adjust over a minimum of 20 minutes
  • Use a head torch with dimmable light to use low level white light or red light when moving around outside or using your camera, so you have more chance of seeing a meteor.
  • You need to be observing the night sky for a good few hours if you are going to capture (or see) any decent number of meteors.
  • If you tire of being outside, set your camera up to leave your camera taking exposures over a long period of time, many hours if you can, while you go back inside or to sleep. Cable release/intervalometers, or intermanal camera intervalometer, and possibly an external power source such as USB power brick powering the camera by USB-C can allow this.
Use a tripod or what you have at hand to mount your camera on a rigid prop angled to view the north-east sky after sunset, north around midnight, north-west after 2am.

How to Photograph a meteor shower with your Phone

Photographing a meteor shower with your mobile phone is a tough ask, I’ll be honest! You will probably only capture the brightest of meteors.

Most modern mobile phones are capable of some nightscape/Milky Way astrophotography. They do this using along exposure time, usually of about 10 seconds. Meteor showers present a particular challenge where the camera needs to capture a brief burst of light very quickly. This is difficult for mobile phones.

The algorithms used for mobile phone astrophotography typically “accumulate” the image over time and perform some smarts to smooth out noise and combine the accumulated images. This means that small brief changes like a flash in the sky might or might not, depending on your particular phone, be represented in a final image.

To give your mobile phone the best chance of recording a meteor:

  • Mount the mobile phone on a tripod. Manufacturers such as Leofoto have tripod mounts for mobile phones.
  • Turn off the flash
  • Use a pro app to do interval shooting:
    • allowing you to take a continuous sequence of photographs one after the other for a long period of time (hours ideally, but as long as you have).
    • each exposure would be about 10-15 seconds ideally
    • no gap between exposures
  • Use a long exposure time (if able to configure this in your app) such as 10 seconds. The longest exposure time you are likely to want is 15 seconds.
  • Use a external USB battery to power your phone for a longer period of time.
  • Do a test run beforehand with the Timelapse function on your phone camera. If it will take long exposures during the timelapse then it may be useful, but many will limit the exposure time to very short in this mode.
Use a tripod with phone mount adapter to hold your camera rigid and pointing up at the night sky. Your images will be sharper and in the case of most modern mobile phones also higher resolution. Shown is a leofoto mobile phone adaptor on my Leofoto MT-03 tripod.

How to Photograph a meteor shower with your DSLR/Mirrorless Camera

Photographing a meteor shower is similar to nightscape astrophotography with a few critical differences:

  • Ensure Long Exposure Noise Reduction is disabled in your camera so it does not take a second exposure with the shutter closed (excluding Canon 6D which buffers the dark frame).
  • Your camera needs to run over several hours. Use an external battery source and a large memory card, together with cable release or intervalometer to have continuous exposures.

Those are the main differences between a normal nightscape and a meteor shower session. Now I’ll go through the full set of settings I would use for a meteor shower photography using a DSLR or Mirrorless camera:

  • Lens:
    • Use the fastest lens you have (smallest F number, such as F/1.8 or F/2.8)
    • Use a wide lens, such as 12mm, 14mm. Anything down to as narrow as 24mm is useful, but widest the better.
    • Put the lens/camera in manual focus mode so it doesn’t focus hunt every exposure
    • Put the lens shade on, to help keep dew/condensation off the lens
  • Camera:
    • ISO 1600 – 3200 is a general good starting point, depending on many factors unique to your situation, but check your images for noise and decrease ISO if too noisy.
    • Shutter speed: Generally up to 15s (see notes below)
    • White balance: AWB or fix it on something such as 4500k for consistency
    • Long Exposure Noise Reduction: Off
    • High ISO Noise Reduction: Low or off
    • Drive mode: Continuous (low or high speed)
  • Accessories:
    • Remote trigger, cable release, intervaolometer or such to ensure continuous ongoing exposures one after the other.
    • Dew heater/strap if in a moist environment prone to condensation
    • USB battery pack to power your camera (if compatible)

Here’s how you go about it:

  1. Let your eyes adjust and get to know your camera in the dark.
  2. Set your tripod on a sturdy tripod.
  3. Configure settings.
  4. Focus manually on a bright star/planet using Live View. Some modern cameras will autofocus on stars in which case do this then switch to manual focus.
  5. Test run on short (5s) exposures to check focus and composition.
  6. Set to a longer exposure time such as 10 or 15 seconds.
  7. Use intervalometer, cable release or other mechanism to take continuous exposures.

A note on shutter speed:

  • A longer shutter speed (15s, maybe 30s) will mean less images to process/store, and show a brighter night sky in each individual exposure.
  • A shorter shutter speed (5s – 10s) will mean you can use the exposures to build a timelapse video with smoother transition, as well as use the exposures in their own right as individual photos. The individual exposures will not show the night sky as bright, but the decrease in shutter speed won’t affect how bright the momentary meteors are in your images.
  • Your camera and lens combination, and where you are pointing your camera in the sky will dictate what the longest shutter speed is you can do before stars trail. The 500 rule is a guide (500 divided by your lens’s 35mm equivalent focal length) but doesn’t cater for all this. Do some test shots and check your playback.

Enjoy the night!

I find it hard to stop the technical work at the camera and actually enjoy the experience of being under the stars and seeing meteors in person, but we should try! As dedicated as we may be to the cause of astrophotography 🙂

Roger Groom standing under the southern sky, with a meteor shooting down below the Large Magellanic Cloud.
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LED lights that blind you at night!

it continues to amaze me how much equipment specifically made for astrophotography is produce with indicator LED lights bright enough to read by. LED lights which frequently impact your astrophotography. Lights such as on/off indicators, or mode indicators.

More understandable but no less frustrating is camera gear with lights that cannot be turned off. You know, those busy indicator lights which will splash some unwanted red in to your nightscape foreground, or that focus illumination light that just can’t be turned off or magically comes back on at the most inconvenient time!

My solution to such lights has always been: Electrical insulation tape. Specifically:

  • Black electrical insulation tape where I am wanting to completely block the light
  • Blue electrical insulation tape where the light is still required but needs to be dimmed

So here are some frustrating examples I have solved with this method.

Infuriating LED’s #5

Focus illumination lights. While in theory they can be disabled in most camera bodies, they often find a way of coming back on when you least expect them. You know how it happens – you have a family evening event and foolishly think it will be useful to turn on the focus illuminator, of course forgetting to turn it off again when you next rock up at a astro star party, only to cause mass blinding of your unsuspecting fellow astrophotographers. I can hear the dazed screams now.

The solution: Black insulation tape. Just never use that light. If you have a modern nightscape DSLR you can focus in low light anyhow.

A black square of electrical insulation tape covers the focus illuminator light on my Canon R6.

Infuriating LED’s #4

Countdown delay flashing lights.

While the same light as often used for focus illumination, you might well discover that it is simply impossible to disable the light when using a delay (eg 2 second, 5 second or 10 second exposure delay, using in-body functionality). Of course what we all need is 10 seconds of a bright strobe illuminating our unsuspecting subjects before, now finally and completely enraged, being photographed.

The solution: same as for the focus illuminator – completely cover it. You will never need it.

A black square of electrical insulation tape covers the focus illuminator/delay indicator light on my Fuji X-T30

Infuriating LED’s #3

Intervaolometers and remote triggers that don’t understand they may be used for astrophotography. Not only the hand controller but the wireless “dongle” attached to the camera. The flashing LED on the front of these will easily reflect on to objects, showing up in nightscapes.

The solution? Black electrical insulation tape obscuring all but a very thin slither of upward facing (distinctly NOT frontward facing) light. Enough light remaining visible to remind me that I need to turn it off when it goes in to the bag.

A thin slighter of the bright green LED is left visible facing up (not forward), to remind me I should turn it off when packing up my astrophotography gear.

Infuriating LED’s #2

Vixen Polarie, of all the brands, should have known better. The lights on their Vixen Polarie (mind you, now superseded model) are bright enough to reflect and intrude upon any nightscape.

I’ve had this green light bounce off tripod legs, filters, t-shirts, just about anything, finding it’s way in to nightscape photos.

Solution: black-out except for a tiny little pin prick of light which is still bright enough to indicate it is on star tracker mode, to remind me to turn it off. You might wonder why I didn’t use blue – well the green light doesn’t shine through the blue well enough to be effective yet tinted. Perhaps I should try another colour?

Infuriating LED’s #1

The most irritating lights by far, are battery indicator lights on head torches. This current model Black Diamond head torch is absolutely fantastic in every single way, EXCEPT that every time you turn it on or off it insists on illuminating battery indicator LEDs that are bright enough to read by and completely destroy your vision when they shine down on to your glasses catching the lenses and frames full of light!

Every. Single. Time. that you turn your head torch off, you get dazzled for 3 seconds unable to see beyond your glasses. This was without a doubt the most infuriating LED in this class.

The solution: 3 (yes that’s right, it takes three!) layers of blue insulation tape to dim the lights to a level they are still easily visible but not disruptive at night.

Make your gear work for you

Take the time to customise your astrophotography gear to make it work for you. Reduce the frustrations that can occur when trying to capture awesome photos of the night sky. Remember to:

  • Block unwanted lights that bug you
  • Customise your camera to make it work efficiently for you in the dark

You can take the time to do this on your couch at home. Turn off the lights and test it out. You’ll thank yourself later.

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Mount Magnet Nightscapes Workshop

It’s september 2023 and Mount Magnet’s “Astro Rocks” festival is back in a smaller way this year with long table dinner organised by the Shire of Mount Magnet at the race course together with telescope viewing, and a astrophotography workshop provided by myself at The Granites the night prior.

The nightscapes astrophotography workshop I faciliated at The Granites was a small group, being only advertsied for a short time prior and 600km drive from Perth on a Friday, but it was still great fun of course.

Astro Rocks is a festival the Shire of Mount Magnet has run for some years, typically in September or October, featuring both geology and astronomy events. This year it was watered down, but keep an eye out for it in future years, there’s normally sufficient warning to plan ahead your trip.

The Granites is breakaway landscape. Erosion of the ancient landscape leaves flat topped hills with a drop-off on one side, known as the breakaway. The colours in the earth vary from white through to rich reds.

Astrophotography of the breakaways I do find challenging, a fun challenge, because they typically present a very “one sided” subject. If the sky is in the right place for that cliff face, it works well, if not, it’s a battle to nowhere. I think The Granites would be best photographed in March-May when the Milky Way will be in the east and so behind more of the breakaway faces, and in the opposite side of the sky to the majority of mine light pollution in Mount Magnet.

Here are some nightscapes from the workshop night. I suppose as per my typical style I have tried to leave the subjects fairly “natural”. Perhaps you can see the potential if spending more time on ones own to concentrate on composition and acquiring more data.

The Granites indigenous sculpture and Milky Way with glow from background mines.
Workshop participants using their cameras under the Milky Way.
Astro Goat. 😉 A goat admiring the Magellanic Clouds. Yes you read that right, a goat.
The Granites and the northern Milky Way.

For me there was a couple of challenges on this workshop night. For some reason the auto focusing on my R6 wasn’t working. This has in the past been quite reliable, but I had my camera in “daytime mode” from a previous daytime shoot so there’s a setting I haven’t flicked back, I presume, something to look at in daylight. And the other challenge is age! I am working through testing contact lenses in the hope of bringing back some efficiency to my nightscapes astrophotography – I find using glasses with a camera for astrophotography a jarring experience – constant switching between having the glasses on or off, looking through view finder or at screen, compounded by head torches and working with unfamiliar cameras of participants. Hopefully the contact lenses will be the long term solution.

The Granites indigenous sculpture and Milky Way.
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2023-04 Exmouth Total Solar Eclipse

Well, that was a road trip! 4,900km round trip to photograph the Total Solar Eclipse and participate in other astronomy events through regional Western Australia, plus have a family holiday!

The results were fantastic, though not without frustrations, of course. The trip overall was lots of fun, with us staying at:

  • Geraldton
  • Carnarvon
  • Exmouth
  • Gascoyne Junction
  • Denham

Highlights of the trip were:

  • The total solar eclipse day at Exmouth. Challenging and spectacular, but best enjoyed with family, this was most certainly a once in a lifetime opportunity.
  • Visiting the Kennedy Range National Park from Gascoyne Junction, for landscape photography and astrophotography, this place has so much to offer.
  • Doing a tour of the Cape Range National Park from Exmouth including snorkelling on the Ningaloo Reef.
  • Chatting to media and public about astrophotography, helping people with their astrophotography be it through general discussion or my workshops, and soaking up the enthusiasm of people for astrophotography.

Preparations

Before eclipse day was much preparation including purchasing specific equipment, determining what could be fitted in the car vs stay home, media engagements, and most importantly perhaps many practice runs photographing the sun spaced over many months.

I performed at least 7 full run-through practice runs of the eclipse with my equipment at home. These were often at the exact time of the eclipse, for the full duration of the eclipse. This ensured I knew I would have enough battery power, that the equipment would be protected from the sun, that each piece of equipment fulfilled it’s tasks but also that I didn’t cart unnecessary equipment to the eclipse. At Exmouth I had a final test, the day before the eclipse:

Eclipse Day

The eclipse day unfolded in some ways easier than expected – traffic and crowds were not a problem (perhaps people put off by the prospect of such?), while equipment challenged me by way of my iOptron CEM40EC not wanting to find the Sun (or anything), or track at Solar rate. The iOptron problem was out of the blue, never experienced before, and left me with very little time to properly prepare equipment for the eclipse before partial phases started. I was “a little” stressed!

My family and I were located at the official Kalis viewing site south of Exmouth, of course in the line of totality. I was alongside others such as Perth Observatory, the GDC Observatory and University of Western Australia.

My eclipse equipment included:

  • Sky-Watcher Quattro 200mm with Canon R5 (loaned thanks to Camera Electronic and Canon Australia) on iOptron CEM40EC
  • Canon R6 with Canon 70-200 F/4 & 2x Teleconverter
  • Fuji X-T30 with 33mm Viltrox lens
  • iPhone for video

You might wonder why i was using the Quattro for solar photography – Reality is I had limited cargo space and needed this telescope for other workshops and astrophotography along the way. It’s fast focal ratio of F/4 resulted in exposure times of 1/8000th second. The focal length of 800mm was fantastic for the eclipse.

Roger Groom
Roger Groom and Carol Redford

Total Solar Eclipse photograph results

I was very happy to see initial results from my photographs – Bracketed exposures through the Quattro show spectacular detail of the corona and prominences. Below are my photographs of the Total Solar Eclipse at Exmouth on the 23rd April 2023. While I always look to improve next time, I am very happy with the resulting photographs, I could have easily got much worse or nothing at all.

2023 April Total Solar Eclipse – Corona
2023 April Total Solar Eclipse – Prominences
2023 April Total Solar Eclipse – Sequence

For use of these total solar eclipse images including digital licensing and print please contact me.

Astrofest and Astrophotography Workshops

Part of my job in being in Exmouth was to represent the 2022 Astrofest Astrophotography Exhibition, a community exhibition of astrophotography from our exceptionally talented WA astrophotographers. In doing so I provided several talks about the exhibition and astrophotography, and was interviewed by media.

Roger facilitating a workshop at Exmouth

Night astrophotography workshops I facilitated at Vlamingh Head Lighthouse for the event organisers Mellen Events. While difficult to organise smoothly around the logistics of multiple organising parties and busy area with tourists and other astrophotographers, it was great to have this opportunity and catch up with surprisingly many regulars to my workshops!

Vlamingh Head Lighthouse with the Milky Way and Magellanic Clouds (also including the Southern Cross, Eta Carina and southern Milky Way)

Travelling Regional WA on the way Home

Travels on the way back included a few sights below at Gascoyne Junction and Kennedy Range National park. Unfortunately our only astrophotography night there was mostly clouded out. I always love staying at Gascoyne Junction and hope to be back again soon.

Another stop along the way back was Denham where I snuck in this quick little astro shot of Little Lagoon Creek. The crescent Moon was setting in the west with Orion in the sky and reflections of the Moon and Venus in the water of the creek. Very nice to experience in person.

Little Lagoon Creek, Denham

The next total solar eclipse I expect to “chase” is the 2028 July eclipse covering Australia cost to coast.

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Solar Filters for Photography

I’ve been asked what solar filter I would recommend for photographing the upcoming Total Solar Eclipse in Exmouth on the 20th April 2023. I thought, why not write a blog post for the benefit of everyone!

The need for a solar filter

The single most important consideration is that you purchase a certified solar filter and use that on your camera/telescope. An unfiltered telescope will likely cause permanent damage to person or equipment.

The only time you do not need a solar filter is during the totality phase of a total solar eclipse if you are directly in the line of totality. During that time you remove the solar filter and you need to be well organised and diligent to put the solar filter(s) back in place prior to totality ending.

What solar filters do I use?

I use all Baader Solar Film filters. Aside from some Hydrogen Alpha (Ha) filters and white light glass filters that I have borrowed extensively from the Astronomical Society of Western Australia in the past and used at the Perth Observatory in more recent times, I have always used the Baader Solar Film. I do not do enough solar photography to justify the purchase of a photographic Ha solar telescope or filter.

Why do I choose Baader Solar Film?

  • It gives me fantastic high resolution white-light images, full of solar surface detail.
  • I see more detail in my photographs than I see in some white-light glass filters, and conversely I do not see more detail in any glass white light filters than I see in my photographs (for the same given focal length/optical quality).
  • The Baader Solar Film is adaptable – I can cut it to size for the equipment I have
  • It lasts. I have not had any problems with degredeation, holes, cuts, or other deterioration.
  • It’s affordable
  • it’s light weight

How do I use the Baader Solar Film?

Rather than apply/stick/adhere the solar film directly on to my equipment I make holders/caps/sleeves which I make the Baader Solar Film a part of, and then I take those filters on/off as required.

Below are three of my filters. These are for (smallest to biggest) my:

  • Canon 70-200 F/4 lens, to fit over the lens shade.
  • William Optics Megrez 80 SD refractor, to fit over the permanently attached dew shield
  • William Optics Megrez 90 APO refractor, to fit over the permanently attached ew shield
Baader Solar Film filters
Baader Solar Film filters

You can see in the above photographs I have a mixture of plastic coated paper and PVC pipe fitting used.

  • The plastic coated paper does not deteriorate with a little moisture, is rigid and a snug fit over the telescope/lens optical tube/shade.
  • The PVC approach I particularly like, because it is rigid and strong, and fits perfectly over the applicable Megrez 80 and also the lens shade of the Canon 70-200 if I don’t have the other smaller filter.
  • Use self adhesive felt to make adjustments of your filter holder to be a snug fit on your telescope.
  • Use Velcro or tape to ensure your solar filter stays attached to your telescope in windy conditions.

Before use I always inspect the filters for damage. In particular, pin rick holes. Like I mentioned earlier I’ve never found any but it’s worth checking.

When attaching the filters it’s worth doing so gently and slowly. You can find that if you have a tight fit of your OTA there can be some air pressure as you push the filter on, and you don’t want that to place undue stress on the solar filter, so just easy does it. Same for taking it off.

I also have a Baader solar filter which was purchased as a pre-made unit, for my 8″ SkyWatcher Quattro telescope. This one has worked out particularly well. It grips well, has Velcro strips to double make sure it stays on, and it’s a nice rigid yet adaptable construction. It is shown below.

Storage of Solar Filters

One of the reasons I have had such success with my filters and they have lasted so long, is that I store them well and treat them with care.

Each filter is kept in it’s own Tupperware/Decor plastic container which fits snugly but not too tight, in a way that the solar film is protected by the hard surface of the container but at the same time does not touch any surface. Almost any container will do, but you need to make sure you store your filter in a way it will not get damaged.

Where to buy solar filters for solar photography?

Buy Baader Solar Film and other solar filters from a reputable telescope/astronomy store. Some of these in Australia which I would recommend include:

Happy solar photography-ing!

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Aurora Australis, again! Feb 27th 2023

On the evening of 27th Feb 2023 we were spoiled to a great showing of Aurora Australis, as visible from Perth, the South-west of Western Australia, and even further north of Perth!

Aurora Australis photographed from Lake Leschenaultia in Chidlow, Western Australia. (Canon R6)

I’ve been doing astrophotography from Lake Leschenaultia since 2009 and this is one of several shoots for Aurora there over that time. It’s a convenient location in my local area, and one people from the broader metro area of Perth are coming to know for astrophotography.

For this night I was using both my Canon R6 with Samyang 24mm F/1.4 lens and my Fuji X-T30 with Samyang 12mm F/2.0 lens. I only had the Fuji set up second, towards the end of the aurora being visible, so didn’t capture so much on the Fuji.

With the 12mm F/2.0 the Fuji was at a wider field of view than the R6, and further more I cropped the R6 shots down to exclude some distracting scenery on the left of image. This is why the aurora appears smaller in the Fuji exposures.

Aurora Australis photographed from Lake Leschenaultia in Chidlow, Western Australia (Fuji X-T30)

Here is a shot taken with the Fuji almost at ground level showing the Canon R6 in action doing astrophotography. Even in this later exposure there is a hint of the aurora bars visible on the southern horizon, just barely.

Faint aurora visible beyond my Canon R6 which was photographing at the time. (Fuji X-T30)

For more of my Aurora Australis astrophotography over the years, and for information on photographing Aurora Australis, take a look at my page of aurora australis astrophotography.

Learn Astro photography

Do you want to learn how to photograph aurora australis? I frequently run workshops, often one-on-one, for people in Western Australia wanting to travel overseas for aurora photography. Find out more at my Astro Photography Australia website.

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Working on the Collimation

Collimation of a telescope is critical and so you need to be able to easily adjust collimation, particularly of Newtonian telescopes.

It disappoints me not more manufacturers provide the option, or default, of knobs installed on collimation screws for secondary mirrors of Newtonian telescopes. This is 2023 and sure the cost of living is increasing, but the cost of a little knob compared to a screw, if installed at the factory, surely would be trivial?

For my new SkyWatcher Quattro 200p I recently purchased a set of Bobs Knobs from https://telescopes-astronomy.com.au to improve the efficiency of my collimation. Bobs Knobs have been around almost as long as I have been in astronomy, maybe longer! I remember purchasing a set for my LX200 in the early 2000’s. They are simply a set of screws with thumb/finger grip knobs to replace what you would usually have to use hex/allen keys for.

Shown below are the small screws removed from the SkyWatcher Quattro secondary mirror housing, and the Bobs Knobs installed in their place, in the secondary mirror housing.

Having installed Bobs Knobs I am then proceeding with collimation using an OCAL camera. Collimation of the SkyWatcher Quatro is still a work in progress for me. My entire life so far I have collimated Schmidt-Cassegrain telescopes so I’m on a bit of a learning curve with Newtonians TBH.

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Moving to Lithium field battery

Since the 1990’s I have used Sealed Lead Acid batteries for powering my astronomy and astrophotography equipment.

When I was routinely using a laptop in remote field locations I was using at first a 40Ah SLA battery and then later a 120Ah SLA battery which was left in the boot of the car, a cable running to the telescope and other equipment such as laptop, USB devices, dew heaters, etc.

Curiously, for my portable rig the power demands have reduced in recent years. A combination of location and type of imaging. Running the mount with a small modern auto guider and someone else’s DSLR doesn’t require very much power. These sessions usually run for less than 4 hours which means a laptop can power its self for that time, no need for external power. Also in more recent years the need for battery power has reduced. Often my workshops are located at my private dark sky observatory where I have mains power, or at the Perth Observatory where I have mains power. If I’m not imaging there, then there’s a good chance I’m using my permanently mounted rig instead, that of course runs of mains power So, in recent years my power requirement had dropped to a 9Ah SLA battery.

Looking forward to the 2023 Total Solar Eclipse in Exmouth, and wanting to up the level of functionality in my workshop telescope rig, and looking at needing to buy a new 9Ah battery due to degradation of my existing, had me looking at alternatives which would be sufficiently over-specified they would provide for almost any workshop scenario.

The new astrophotography lithium battery

I hunted around for a light weight high capacity battery and came across https://www.auspowerbanks.com.au/

I’d seen a whole world of modern battery options, moving ahead from a simple battery with two terminals that I would need to DIY connections for. This is the direction I wanted to go.

I ended up choosing the “Outdoor Power Bank – 96000mAh (Solid Black)” pictured above. This large battery weighs only 3kg but packs a huge amount of power. It has dual cigarette lighter style outlets. it has various USB outlets.

I plug the Losmandy and ZWO ASIAir Plus directly in to the two 12v sockets. Sometimes the USB is used for powering the Prima Luce ESATTO focuser when I have been using that. I regularly have an iPad or iPhone plugged in to the USB outlets.

I have occasionally powered my Dell XPS15 laptop off the unit via a 240v inverter and the laptop’s supplied power supply.

The lowest I’ve had the battery so far is 2-3 bars out of 4, about 50-60%. The battery has been 100% reliable. The length of time it lasts combined with being Lithium type battery means I have no concern about running out of power and only charge it now and then, not after every workshop even if my workshops are weeks apart.

The unit has a bright diffused light on one end which has occasionally been useful for floodlight of a workspace to find lost screws and such on the ground.

The only thing I wish is that it had built in AC charging. It’s a shame I need to carry around a 12v power supply plug pack to charge the unit when I travel remote. That said, it’s taken only for caution because even a full weekend this unit will not run out of battery power for me.

More Blogs

This is part of a blog series regarding my updated workshop telescope rig

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SkyWatcher Quattro Baader Solar Filter

With my recent purchase of the SkyWatcher Quattro 8″ (200mm) and the upcoming Total Solar Eclipse in April 2023 it’s time to test out the Baader solar filter for the 200mm aperture.

Why Baader Solar Film?

I’ve consistently found Baader solar film provides a higher resolution more detailed view of the moon than glass white light solar filters. All the glass solar filters I have looked through, have not produced as much detail by some noticeable amount.

You do need to protect any solar filter while in transit/storage well. Any scratch, hole or other defect could risk damage to your eye or camera. One thing which people prefer about glass filters is they feel that the glass is more durable than the solar film. I can imagine a glass plate may well handle an object impacting it better than the solar film would. However I have used the solar film for about 20 years and so far have no defect in any of my filters. I keep the filters stored well in boxes such that the film is not in contact with any surface but is protected from impact.

I purchased a Baader OD 5.0 Astrosolar Telescope Filter from https://www.testar.com.au/

Equipment

This is setting up the Baader filter.

Mounting on the Telescope

The Baader filter slots over the front aperture with rubber coated pegs which grip against the outside (or inside if you configure it as such) of the optical tube. It also has Velcro with self-adhesive patches to prevent it coming off if the rubber grips were to be insufficient.

Here are some photos of the Baader filter on my SkyWatcher Quatro 8″ (200mm):

Solar Photos using the Baader solar filter

So, it turns out the only problem in taking photographs using this filter on the Skywatcher Quatro 8″ is brightness – too much of it. At raw prime focus the Canon R6 I had mounted on the telescope at the time of testing was using 1/8000th second exposures at ISO 200. Anything slower and the images would risk over exposure. I am likely to use a barlow or teleconverter lens with this configuration in reality, and doing so will dim the brightness (2x barlow will approximately half the brightness, for example). If that was not sufficient then a aperture mask could be made to shade some of the filter/aperture.

The clarity and detail lived up to the usual Baader solar film quality and did not disappoint. Here is a sample exposure which is a single exposure without stacking or any editing than brightness and clarity in Lightroom):

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An update ot my workshop rig

I own a set of telescope equipment I have accumulated since 2005 which at first was my personal portable telescope gear and in recent years has been primarily used for workshop participants using their own cameras for astrophotography. This has been my Losmandy GM8 with William Optics Megrez 90 refractor and ZWO 130mm guide scope.

In 2022 I decided it was time to change this setup used for workshop participants. A few considerations coming in to the mix were:

  • My Megrez 90 has become a more permanent fixture at my dark sky observatory and bringing it back for workshops is a time killer (both retrieving it and the work to re-calibration the permanent dark sky setup).
  • I would like a faster focal ratio to achieve more for my participants quicker
  • I have become a little tired of the ~600mm focal length range telescopes, and want something a little longer but still manageable on a small mount.
  • I needed to improve the setup time – making it quicker to polar align, guide, and get going with exposures longer than 30 seconds.
  • My new equipment needs to be at an amateur astronomer achievable price point, for a mid level amateur, as this is what they’ll get to try using. There’s no point them testing out a premium OTA or mount when it’s not going to be affordable for most of my workshop participants.

My new telescope equipment

The set up so far looks like this:

  • Retain the Losmandy GM8, though am continuing to assess whether it needs to be replaced.
  • New Skywatcher Quattro 200mm (8″)
  • New Sharpstar MPCC
  • New ZWO 120MM guide camera
  • New ZWO ASIAir Plus
  • New William Optics red dot finder
  • New OCAL Electronic Collimator
  • New Prima Luce ESATTO 2″ electronic focuser
  • Custom made travel case for the Quattro with various accessories attached

I’ll introduce these to you over a few blog posts and talk about some learnings and improvements/changes yet to be made.

Here below are some pictures to bring you up to speed. The equipment is currently spending most of it’s time set up in my backyard observatory which these days largely serves as a test bed for new equipment. Setting up the new equipment here allows me to make small tweaks now and then with minimal time commitment each time. 30 minutes testing guiding or collimation, or adapter spacing or focuser software, all goes a long way.