Tinkering Story #04 – Joe the Alien Astrophotographer – Deep Sky photography under £500

This is the story of an alien that travelled 4.246 light years to learn some basic stuff about Earth’s astrophotography. I was the first Earthling he came across so he asked me, how we shoot the stars.
Joe has no clue about the equipment or the techniques we use so I tried to teach him the basics.

Telescopes, lenses, cameras, mounts, tripods, shooting and post-process techniques. With so many choices, Joe doesn’t know where to start so I’m here to suggest a lightweight, easy-to-use setup, suitable for an introduction to deep sky imaging.
The suggested setup is the one shown below, without the auto-guiding extras (auto-guide scope, ZWO camera and laptop).

Conveniently enough, Joe speaks English!

Hi Earthling. I’m Joe.

Wow! Hi Joe. I’m Chris. Where are you from?

Just around the corner. I’m from a small rocky planet called ‘Cheeseburger’ near Proxima Centauri.

Welcome to Earth Joe! How can I help you?

Chris, I’d like to try some deep-sky imaging from Earth’s perspective. So… How do I shoot the stars from here? I know how to do it from my planet, but I’m not familiar with Earth’s equipment. Also, I’m on a budget as I spent nearly everything on the intergalactic trip. The equipment must not exceed £500.

You came to the right place, Joe! The first piece of advice is to educate yourself about Earth’s night sky and your options for observing and taking photos of the Cosmos. Astronomy books are fine, but if you are a practical person like me, a guide that walks you through the basics of amateur astronomy would be useful. The night sky, constellations, the motion of the stars and planets and equipment to use depending on what you want to shoot.

A guide? What guide?

I suggest Nightwatch by Terence Dickinson or a similar book. This is the one I started with many years ago. It is easy to read, has many illustrations and it’s a great introduction for an amateur astronomer. Investing £10 and a few hours of your time could save you thousands of £££ for equipment you may not need.

That’s great, Chris! What would be your second advice?

Start with the photo! Astrophotography can be many things. Planetary, the Moon and Sun, deep sky, shooting galaxies or nebulae or star clusters, shooting wide field such as constellations and/or the Milky Way, landscape astrophotography, star trails… So, start with the photo you like, and then move on with the equipment you need to take this photo.

Okay. And what about equipment cost?

Astrophotography can be a really expensive hobby. This doesn’t mean that you cannot take amazing photos with modest equipment.
For high-quality planetary imaging, you need a big and expensive reflector telescope, a CCD camera and a big mount to support it. Celestron C14 is a flagship SCT telescope that would give you excellent views and photos of the planets and Moon close-ups. A 10″ DOB is a cheaper alternative.
For shooting nearly all galaxies, the basic equipment is a high-quality apochromatic refractor, a camera and an accurate equatorial mount that will allow you to take long exposures.

OK, Chris. All these are interesting but I’m a bit worried now. The equipment you describe costs thousands… As I said, I like deep sky imaging but I can only spend £500 on all the equipment. Is this even possible? Also, you promised me excellent results with modest equipment.

Sure it is possible! Grab a pen and paper, Joe. This is my suggested equipment.

• Begin by investing £10 in the Nightwatch book. Grab a used one from eBay.
• A small equatorial mount. A simple tripod won’t do. Deep sky astrophotography requires long exposures. With only a tripod, your stars will look like small lines after a few seconds of exposure due to Earth’s rotation. I suggest Star Adventurer Pro. You can find the older, non-wifi model on eBay or astrobuysell for around £220. This little mount will allow you to shoot long, several-minute exposures and capture wide-field targets using lenses up to 200mm. This mount is too small for bigger lenses or a telescope unless used with shorter exposures such as Solar and Lunar eclipses, Moon closeups, earthshine images or Sunspots. Star Adventurer Pro doesn’t have a GoTo computerized function or a target database. You need to find the target manually. The technique is known as star hopping. You just find a familiar star or constellation and you visually begin hopping from star to star until you reach your target. Consider this as an opportunity to learn about the night sky! There are many apps to help you, showing the sky in real-time such as Stellarium.
• A tripod to put the mount on. Any reasonably stable camera tripod would do. I’m using a video camera metallic tripod I bought for £70 on eBay. It is a bit heavy but super stable. Just remove the fluid head and put the mount on with a 3/8-inch screw.
• A Canon 600D DSLR camera. This is an old but good-quality camera that you can find on eBay for as low as £130. If you modify it by removing the internal filters you would be able to better capture the vivid nebulae colours. Canon 600D has a flip screen which is helpful when the camera is upside down on an equatorial mount during shooting.
• A camera lens. Most people go for a kit lens as the first one with a new camera. A used Canon 18-55mm only costs around £50. It is versatile, with a good focal length range but the quality is not the best. Stars are the ultimate test for lenses. If you want pinpoint stars across the whole field of view, you need to invest more in your lens or telescope. Canon 50mm, the famous “nifty fifty” is an excellent value for money. My favourite one is an old legacy Carl Zeiss 135mm f/3.5 lens. This is a fully manual lens that costs around £30 on eBay. You will need an M42 to EF adapter to attach to your Canon camera. It is not really fast but not slow either and it provides really good results wide open at f/3.5 There are many people shooting wide-field, mainly landscapes and the Milky Way. On the other hand, many people shoot deep sky using telescopes. In my opinion, an 135mm lens provides a pleasant field of view that we don’t see often. For example, the Orion Belt and Nebulae fit into the 135mm. Note that the last 2 lenses are “prime” ones (not zoom) fixed at 50mm and 135mm respectively. Prime lenses are simpler in design, usually lighter and provide better quality compared to zoom lenses at a similar price range.
• A tripod mount ring to attach the lens and camera to the mount. It is possible to shoot without it but a ring will provide great flexibility for framing your target. The one that closely matches Carl Zeiss 135mm dimensions is one for Canon 70-200 lens (65mm diameter). The cost is around £10.
• An intervalometer. This is a device that allows you to program your shooting. Just grab a Chinese one and hope for the best as the genuine Canon is painfully expensive. Cost: around £15.

Oh! too much info Chris. Even for an intergalactic species! So, the total cost? Have we exceeded £500?

Let’s see.
Nightwatch book: £10
Star Adventurer Pro mount: £220
Tripod: £70
3/8 inch screw: £4
Canon 600D camera: £130
Carl Zeiss 135mm f/3.5 lens: £30
M42 to EF adapter: £10
Tripod mount ring: £10
Intervalometer: £15
1 Mars bar from 1 pound shop: £1

The sum: £500 🙂

Spot on Chris! How about optional components to improve the above setup?

Hmm… Using the Carl Zeiss 135mm lens, you should be able to get round stars with a proper Polar Alignment and up to a couple of minute exposures. For greater focal lengths (bigger lenses) such as 200mm and/or longer exposures, you could benefit from auto-guiding. The equipment you need for auto-guiding:

• A Windows laptop or a device such as the ZWO ASIair Pro.
• Laptop software: PHD2 for Guiding and Astro Photography Tool (APT) for dithering.
• A small guide scope such as ZWO MiniScope 30mm or a Chinese clone.
• A guide camera such as ZWO 120mm mini.
• An ST4 Guide cable to connect the guide camera to Star Adventurer.

A few more optional but useful components:

A clip filter that sits between the camera and the lens. There are many filters depending on your shooting preferences. Light pollution filters, colour enhancement filters and so on. A filter blocks certain unwanted light wavelengths, such as UV/IR light or light pollution, leaving only what we want to capture. A filter that you cannot go wrong with is a UV/IR cut filter.

A Bahtinov mask for better/easier focus. Nowadays is easy to find them 3D printed at low cost.

Dew can ruin your shooting if you decide to shoot in high humidity. In this case, a couple of dew heaters for your lens and guide scope would be useful.

If your DSLR camera is Full Spectrum modified, a clip filter can give you improved results.
A UV/IR clip filter will block the unwanted UV/IR light and prevent star bloating.
A light pollution clip filter will allow you to get longer exposures from light-polluted areas.

I’m also using a green laser pointer, adjusted on my DSLR Hotshoe to locate the less visible targets with the help of star charts and/or Stellarium.

So, a DSLR is my only option for Deep Sky?

Nope! CCD cameras are an excellent (but more expensive) choice for deep sky imaging as they are dedicated to this. DSLRs on the other hand can give very good results and can be used for many more things compared to CCDs. I really like this presentation from Tony Hallas, a guru astrophotographer, regarding DSLRs and CCDs.

What about shooting with a DSLR Chris? Any guidelines? Camera settings?

For deep sky DSLR astrophotography, switch your camera to Manual and shoot in Raw format. You need the following captures:

• Lights. Your actual exposures on your preferred target. Most lenses perform better one f/stop closed from wide open. For example, if your lens is f/2.8 you may want to shoot at f/4 for better image quality and/or rounder stars but you will capture less light. The suggested carl Zeiss 135mm lens was a pleasant surprise as I haven’t noticed much difference when shooting wide open. Your exposure per shot varies depending on the target and the light pollution from where you shoot. Also, you take many shots, to stack them and improve the signal-to-noise ratio.
• Darks. Exactly the same settings and environment temperature as the Lights but with the lens cap on. This will help remove most of the noise later in the post-process.
• Flats. Set your camera to AV, point the camera towards an even light source (the morning sky or Notepad on your laptop screen or a flat field pane) and take the shots. For better results, you could cover your lens with a semi-transparent even filter such as a stretched white t-shirt.
• Offsets. Set the camera to manual. Shoot with the same ISO as in Lights but set the highest speed (1/4000 for Canon 600D).

An example of shooting a relatively bright target such as the North America Nebula from a Bortle 5 sky:

50 Lights. F/3.5, ISO 800, 120 sec per Light.
20 Darks.
20 Flats.
20 Offsets

Okay! And what about post process?

I’m using DeepSkyStacker to stack Lights, Darks, Flats and Offsets. The export is a single *.tif file which I process in Photoshop. There is a plethora of software available. Gimp is a free alternative to Photoshop. PixInsight is a powerful dedicated astrophotography processing app. Also, I have heard good things about Siril as an alternative to DeepSkyStacker, although I haven’t used it yet.
Even for a single piece of software such as Photoshop, there are many add-ons and processing techniques. I really like this Photoshop Layer Mask process tutorial from A.V.Astronomy as it is really effective without using any extra paid add-ons.

Deep Sky photography is the main reason I’m here Chris but out of curiosity, is there anything else I can shoot with this equipment?

Sure. You can shoot star trails, the Milky Way and nightscapes using just the camera, a tripod and a wide lens. The kit 18-55 lens is a start but there are better options for this purpose such as Samyang 14mm f2.8.
Apart from astrophotography, if your camera is Full Spectrum converted it would have an advantage in Infrared (IR) photography with the appropriate filter.

Sound interesting. Would you recommend someone that converts DSLRs to Full Spectrum?

Yes. I recommend SpaceTinkerer! If you want to order a camera from my store I suggest you do it while you are here as I doubt that eBay delivers to Proxima Centauri!

Cheers, Chris! A last question. What would be a ‘next level’ setup compared to the one you just described?

There are many options out there! Assuming that you are interested in wide-field deep sky using a DSLR and a lens, I would replace the camera, lens and mount with the following:

Camera: the old, trusty Canon 6D. Full-frame cameras are less noisy, have better quality and will provide a wider field of view.
Lens: Samyang 135mm f/2. A bit pricey but an excellent lens for astrophotography. You could save some £ by getting the ‘video’ version which has the same optics as the ‘photo’ version.
Mount: HEQ5 Pro. Better, bigger and heavier. You cannot just grab it and go hiking unless you are Eddie Hall. It is more accurate and also suitable for telescopes.

Thanks so much, Chris! You are welcome anytime in ‘Cheeseburger’ planet for star shooting.

Thanks, Joe! I’m glad I helped. Clear Skies.

Setup: Star Adventurer Pro + Canon 600D Full Spectrum Modified + Carl Zeiss 135mm f/3.5

Sample photos