Planetary V.S. Deep sky:  How to choose the best camera

Astrophotography fork in the road? An introduction

So you enjoy the cosmos and want to get the best out of it?  Maybe you're new into this or perhaps you've had a go at some fun shots with your smart phone or DSLR with your current telescope and you've decided to take the next step into astrophotography and need some input.


Often times experienced astrophotographers are asked "I want to image the sun, the stars, the planets, the moon, nebulae, galaxies and more!  What do I need for this?", and the answer is not as easy as they would hope as there comes a fork in the road into different gear that is needed for different objects to image as each requires different methods of capture them.  Depending on who you ask this may come off daunting in what to chose.  


Today we will cover cameras in terms of Planetary and deep sky imaging to help narrow down what you'd like to image and the gear that best suites you.

Planetary astrophotography in short

As we make our way down this side of the fork in the road of Astrophotography, here is a brief description of the technique required to capture planetary shots.

To capture planets we use video to capture thousands of images in a couple minutes and stack the best of those in planetary stacking software, this is because of the motion of the earth's atmosphere in the sky.  Imagine putting a picture of Saturn under 2 inches of water that moves side to side, now take pictures of that.  Only so often an image not warped will show up.  That is why videos are captured versus stills.  This is called "Lucky Imaging".  


So what else is needed?  A telescope with a long focal length, recommended 2000mm and a tracking mount.


But what about chosing the right camera?

Most important before we dive deep is you want a camera that has a high frames per second (FPS) to get the most out of your "Lucky Imaging"


Cracking the code of planetary imaging:  Your starters guide to a camera selection

Diving into the enchanting world of planetary imaging? Amidst the galaxy of choices for cameras, finding the one that fits your needs might feel like searching for a needle in a cosmic haystack. But fear not! We're here to make it all make sense. By demystifying a few essential equations and principles, we'll have you choosing your camera with confidence.


Imagine planetary cameras as your tools to capture the universe's wonders. Pixel size, sensor size, and local seeing conditions act as your North Star, guiding you on this celestial journey. The first step? Understand your local seeing conditions, which greatly influence the quality of your images. To decode this factor, the Clear Sky Chart website is a handy guide.


Now, let's unveil a secret formula: Pixel Size (µm) x 6 = recommended focal ratio for planetary imaging. This simple equation will be your guiding star. Depending on how clear your skies are:


Multiply by 6 for decent conditions.
Multiply by 7 for above-average clarity.
Multiply by 5 if your skies aren't cooperating.


Think of this equation as your treasure map, leading you to the perfect focal ratio. But there's more – a set of additional equations can help you pick the right Barlow lens, camera, or scope tailored to your local conditions. These equations? Consider them your cosmic toolkit for mastering your planetary imaging setup.


As you venture into the captivating realm of planetary imaging, armed with these straightforward equations, you're equipped to decode the art and science of camera selection. With the right tools in hand, you're poised to explore the universe like never before, capturing its beauty and mysteries with finesse.

Deep Sky Astrophotography In Short

As we back up to the fork in this road, we now venture towards Deep Sky Astrophotography.

This will be your Galaxies, nebulae and star clusters.


To capture quality images, first one must learn that this method requires you to take several long exposures and in some cases over more than one night of imaging.  

Then to take those images along with calibration frames and to stack them in deep sky stacking software, for example the freeware "Deep Sky Stacker".


We do this method because most deep sky objects are faint and even the bright ones have faint structures in the field of view.  Long exposures help bring out as much detail as possible while the stacking helps get rid of unwanted noise and artifacts to create a clean image to edit.


Now of course there's more that comes with it, but for now we will discuss what is needed.

You can image deep sky at any focal length you desire, but when first starting its best to go with a short focal length of around 250-400mm.  The faster the Focal ratio the better.


Now you can actually use a DSLR or Mirroless camera quite well with Deep sky and would be recommended for beginners but the Astro dedicated cameras will help improve your quality of the final image.

When it comes to choosing a dedicated astro camera, first and foremost important is to make sure your camera is cooled as long exposures heat up the camera sensor bringing thermal noise into the frame.

Decoding deep sky cameras: Finding the right fit

Navigating the realm of deep sky cameras might seem like charting uncharted galaxies. With a galaxy of options, the perfect match isn't a one-size-fits-all affair. Your camera's pixel size needs to sync with your scope's focal length, and your local seeing conditions are a cosmic factor. Let's illuminate the path to camera selection.


Think of your camera and scope as cosmic dance partners. Pairing the two involves more than meets the eye. The focal length of your scope and the pixel size of your camera must harmonize. This dynamic duo determines your image quality. However, this harmony is influenced by the atmosphere's temperament – atmospheric turbulence, cloud cover, and humidity all shape your view. Before taking the plunge, get a grasp of your local conditions. For most of us dwelling under average seeing conditions, see the astronomy tools for more information

Measuring your seeing conditions isn't as easy as spotting a shooting star. Conditions can shift by the hour, night, or week. A reliable tool for gauging your location's average seeing conditions is the Clear Sky Chart. This invaluable resource charts your atmospheric seas over hours, days, weeks, and months. Armed with this data, you're empowered to unearth the best scope/camera combo for your cosmic voyage.


Calculate the resolution (arc-second/pixel) using the link above provided. Let this resolution blend seamlessly with your local seeing conditions. As you journey into the depths of deep sky imaging, armed with this knowledge, you'll capture the majesty of celestial wonders with finesse and precision.