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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.

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It’s mid-2022 and I’m still busy!

A brief update on things from myself.

My AOWA business hosting telescopes in the central wheatbelt is going well and I’m looking to get more locals hosting their telescopes in the shared facility, or in a separate RoR observatory, of which I am building a few to rent out. I’m hoping to make the site a useful resource for local amateur astrophotographers over time.

Astro Photography Australia keeps me busy with workshops every month, teaching people how to do astrophotography. These workshops range from wide-field nightscapes to telescope astrophotography. I am upgrading my portable telescope rig to better support the telescope astrophotography enthusiusts, and to use for remote events. You can find upcomin workshops on my page.

Astrofest 2022 is revving up and I’m curating the Astrofest Astrophotography Exhibition again. Entries are open 1st July – 31st July 2022. There’s awesome prizes up for grabs including a brand new Sony A7 IV! Curating this competition and exhibition will take much of my time between now and October 29th.

This RogerGroom.com site is still a bit neglected. I have made some updates to pages recently but I admit the range of images still is low. My focus these days is not on landscape/nature photography or specific astronomy projects like it was in the past.

Meanwhile, I’ve been making some effort to take a few of my own pics among things:

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I am still alive!!

You might be looking at this website thinking Roger Groom is no longer with us. After all, it’s been something like a year since I updated this site. Well, I am still here! Just busy with other things. Life gets busy sometimes.

So why haven’t I been posting here? Well, I have been busy:

  • I still have a day job (amazing, I know!)
  • I am busy running astrophotography workshops (both online via Facetime, Skype, Teams and Zoom) and in person with Perth Observatory, Stargazers Club WA and my own one-on-one workshops at various locations.
  • Astro Observatories Western Australia is a new business I am running in the Central Wheatbelt to remote host telescopes. The site has fantastic world-class dark skies, flat horizons, but, requires an awful lot of work to maintain and improve! So I am spending many days and nights there with my family working on the site.

Here are a few nice landscape photographs from a recent trip to my dark sky property in the Central Wheatbelt region of Western Australia, just to prove I still do take landscape photographs, if not published so regularly!

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A new video!

You might be wondering why I have been so quiet? Well, I am still alive, and I am still shooting photography, although mostly astrophotography now. You will find more of my recent work at https://www.astrophotography.com.au

Here is an astrophotography timelapse video shot in February 2019 from my wheatbelt property. This video features the Milky Way rising, along with the Moon and planets Venus and Saturn. Turn up your audio and enjoy the movie!

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Gloucester Tree Kari Forest

Afternoon sunlight shining through the Kari Forest surrounding Gloucester Tree.

As the sun lowered in the sky on this late afternoon walk the last rays of warm sunshine are a contrast to the cooling forest. The damp starts to settle in and the warmth of a nearby cottage starts to call. This is the karri forest surrounding the Gloucester Tree in Pemberton and I’m sure this particular view is very familiar to many who walk the short tracks around the tree. I remember the exact scene from years ago. The scene may stay somewhat the same, but the lighting and person taking the photo changes constantly.