How to Choose the Best Camera for Astrophotography

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This article is the part of miniseries devoted to the topic of astrophotography. If you are looking for the best lenses for photographing night sky, you can find my recommendations here.

If we look a few years back, astrophotography was prohibitively expensive. It required top of the line full frame cameras and lenses that put it out of reach for 99% of photographers.

In recent years, progress and innovation in the field of sensor technologies made astrophotography much more affordable for the general public. As a result, interest in astrophotography skyrocketed.

How to Choose the Best Camera for Astrophotography

In today’s day and age, you can shoot the night sky not only with full frame cameras but with APS-C and Micro 4/3 cameras as well. The variety of choices available makes it challenging to select the best camera for astrophotography.

The goal of this guide is to identify the best cameras for astrophotography in three categories—Full Frame, APS-C, and Micro 4/3—and identify the overall winners in different types.

I excluded medium format cameras from this guide because the combination of camera body and a fast medium format lens is still unaffordable and unnecessary.

Quick Summary: Best Camera for Astrophotography

  • Sony a7 III
  • Nikon D750
  • Nikon D7500
  • Fujifilm X-E3
  • Olympus OM-D E-M1 Mark II
  • Olympus OM-D E-M10 Mark II
Sony a7 III
BEST ALL AROUND

Sensor Size: Full Frame, Megapixels: 24MP, Weight: 650g (1.43lb), Size: 127 x 95.6 x 73.7mm (5 x 3.8 x 3″)
Nikon D750
BEST VALUE FULL FRAME

Sensor Size: Full Frame, Megapixels: 24MP, Weight: 750g (1.65lb), Size: 140.5 x 113 x 78mm (5.5 x 4.4 x 3.1″)
Nikon D7500
BEST ALL AROUND APS-C

Sensor Size: APS-C, Megapixels: 21MP, Weight: 640g (1.41lb), Size: 135.5 x 104 x 72.5mm (5.3 x 4.1 x 2.9″)
Fujifilm X-E3
BEST VALUE APS-C

Sensor Size: APS-C, Megapixels: 24MP, Weight: 337g (12oz), Size: 121 x 74 x 42.7mm (4.8 x 3 x 1.7″)
Olympus OM-D E-M1 Mark II
BEST ALL AROUND MICRO 4/3

Sensor Size: Micro 4/3, Megapixels: 20MP, Weight: 650g (1.43lb), Size: 134 x 91 x 69mm (5.3 x 3.6 x 2.7″)
Olympus OM-D E-M10 Mark II
BEST VALUE MICRO 4/3

Sensor Size: Micro 4/3, Megapixels: 16MP, Weight: 390g (13.8oz), Size: 119.5 x 83 x 46.7mm (4.7 x 3.3 x 1.8″)

Most Important Characteristics for an Astrophotography Camera

Before we start analyzing cameras, let’s identify the essential characteristics of a camera that is good for shooting stars.

Contrary to common belief, shooting the night sky is not complex at all and does not require any advanced methods. I would say it is one of the simplest techniques among any type of photography because there is a minimal number of options available to choose from.

Let me explain.

When you set your camera in total darkness, you always use the widest possible aperture at your disposal. The wider the aperture, the more light that reaches the sensor.

For example, I have a dedicated lens for astrophotography—the Rokinon 12mm f/2. It is always set to f/2 so I do not even think about it.

Next, let’s break it down even further to shutter speed settings.

Logic dictates that if there is a lack of light, you need to use the long exposure technique by opening the shutter for minutes or even hours to capture the dimmest light. The logic is solid, but it does not always work for astrophotography. Because of the rotation of the Earth around its axis, the long exposure time will produce star trails. It is great if your intention is to photograph star trails. But, if you want to capture a milky way, you will capture blurry stars or unwanted trails.

There is a simple formula that lets you calculate the longest shutter speed value for any given focal length that will result in perfectly sharp stars.

In my case, I know when shooting the night sky with my Rokinon 12mm f/2 that I cannot go over 28 seconds. Typically, I set the shutter speed to 25 seconds.

What this means is that you do not have many choices in regard to camera settings because the aperture and shutter speed values are predefined.

High ISO Performance

The only parameter that lets you control the exposure is ISO. You set the aperture and shutter speed to predefined values and crank up the ISO until you achieve the right exposure. It is normal to use ISO values as high as 6400 and 12800 when shooting stars.

The conclusion here is that the single most important characteristic of a good camera for astrophotography is low light performance or high ISO performance.

Dynamic Range

In photography, the number of tones from the lightest light to the darkest dark that the camera can reproduce in a single photo is called the Dynamic Range.

When shooting at night, we always have to deal with the extreme differences between the darkest and brightest areas of the scene. The camera sensor’s ability to capture the widest possible range of light is paramount.

The dynamic range is measured in stops.

As a landscape photographer, I consider the dynamic range to be the most important characteristic of the camera. But the problem is that the dynamic range is never listed in camera specifications. You must rely on third-party companies to accurately measure the dynamic range of a particular camera.

Unimportant Specifications

Let’s take a closer look at the camera specifications that are not crucial for astrophotography.

Focusing Speed and Accuracy

When shooting in complete darkness, there is no way to use Autofocus. You always focus manually to infinity to ensure the stars are in focus. The Autofocus does not matter.

Shooting Speed

You do not need a shooting speed of 10 frames per second because you always shoot one frame every 30 seconds or so.

Buffer Size

The buffer size is not important at all because you transfer one frame every 30 seconds.

Video Specs

Video mode is not very useful in astrophotography. If you want to capture the movement of the stars, you can use the time-lapse technique. You can shoot multiple still frames of the sky over a span of a few hours and then combine them later into a video clip using a video editing program or Photoshop.

In summary, we see that the one single most critical characteristic of an astrophotography camera is high ISO performance. Dynamic Range is the second most important.

Of course, price always matters. Let’s see if we can identify the best astrophotography cameras that offer exceptional ISO performance and great dynamic range with a reasonable price tag.

Sensor Size

Let’s see how the sensor size affects the camera’s low light performance.

The digital sensor consists of tiny units known as pixels. The function of each pixel is to record the intensity of light that reaches each unit.

Let’s compare two cameras with an identical pixel count—one Full Frame sensor camera and one APS-C sensor camera. We know that the width and height of the APS-C sensor are 1.5 times smaller compared to the Full Frame. This also means that the area of each pixel on the Full Frame sensor is 2.3 times larger and has a greater ability to measure light intensity. The Full Frame sensors always outperform smaller sensors in regard to low light performance.

Luckily, the differences between full frame and small sensor cameras are now dwindling. Small sensor cameras allow us to enjoy astrophotography using smaller cameras available at lower price points.

Performance Comparison Charts

Because cameras with the larger sensors always perform better in low light conditions, I am going to compare the Full Frame, MIcro 4/3 and APS-C models separately.

Please note, this is a comparison chart. The actual values do not matter. For ISO Performance I used the performance score of the best medium format cameras as a benchmark. All the ISO Performance scores reflect the percentage of the benchmark value.

Same goes for Dynamic Range. As a benchmark, I used the highest known value in industrial sensors.

As you can see the drop in ISO Performance from Full Frame to APS-C sensors is significant, more than 50%. At the same time, the drop in Dynamic Range is less than 10%.

This is the reason I do not mind using APS-C cameras for my landscape photography because for landscapes the low light performance is not very important but dynamic range is paramount.

The drop in High ISO Performance goes even further in Micro 4/3 cameras. But the drop is much less prominent compared to the difference between Ful Frame and APS-C cameras.

I also included 2 point and shoot models with 1″ sensors, Sony RX100V and Lumix ZS100.

And we have a clear winner here. The Olympus OM-D E-M1 Mark II outperforms the rest of the cameras by a large number.

Combine Chart

For the Combine Charts, I merged together the High ISO Performance and Dynamic Range scores. But, in order to give more weight to the High ISO Performance I used the following formula:

High ISO score + Dynamic Range score / 2

As you can see, according to the Combine Performance Chart we have a clear winner. The Sony a7 III outperforms the rest of the filed including its sibling Sony a7R III, which has a greater pixel count sensor and higher price tag.

In APS-C segment, the difference between contenders is not huge. The Nikon D7500 has the highest score, but the Fujifilm XT3, Fujifilm XE3, Sony a6500, and Nikon D3400 are not far behind.

In Micro 4/3 category, the Olympus OM-D E-M1 Mark II is out of reach with the rest of the files is pretty much on the same level.

Value Chart

The Value Chart is my attempt to discover the best value cameras based on performance per dollar ratio. I simply divided Combine Performance score by the Camer Price and in order to have rounded numbers I multiplied the results by 100.

As you can see the spread in value numbers is pretty wide. The reason the Nikon D750 is an undisputed winner is that it is an older model (2014), Nikon’s D850 predecessor, and it is offered at a discounted price, skewing the value ratio. And among the latest models, the Sony a7 III edges the rest of the field.

In APS-C group there is a cluster of 5 models in the middle that shoulders above. The Fujifilm X-E3, Canon M6, Nikon D5600, and Nikon D3400, have the best value based on good performance and price below $700.

In the Micro 4/3 category the Olympus OM-D E-M10 Mark II and Olympus PEN E-PL9 and undisputed winners because of their incredibly low price.

Final Thoughts

Even though in recent years the camera models with the smaller sensors improved low light performance significantly, the full frame cameras are still undisputed leaders in astrophotography field.

The Sony a7 III is a clear choice when selecting the best camera for astrophotography with the perfect balance of the performance and reasonable price. And, older the Nikon D750 model allows newcomers to enter the full frame field at an unprecedented low price.

In APS-C segment we have more than ever astrophotography capable models with the Nikon D7500, Fujifilm X-E3, Canon M6, Nikon D5600, and Nikon D3400 leading the field. And by choosing the Fujifilm X-E3 you get a lot of bang for your buck.

And in Micro 4/3 category, the Olympus OM-D E-M1 Mark II and Olympus OM-D E-M10 Mark II are the best choices if you want to start shooting the stars.

What to Read Next:

  • Jean-Louis says:

    Hi sir,

    I’m impressed, you made here a very interesting and valuable work. What you say to conclude seems very correct, for what I have red here and there about the Sony A7III.
    Just one thing, maybe, to help :
    I own the Pentax K1. As many Pentax DSLR camera, the K1 includes the “astrotracer” mode, which allows you to compensate earth’s rotation, as would do an equatorial mount. You have NO IDEA how this is efficient and valuable ! As a regular astronomer amateur, I use it often, even on long lenses or refractor (on a Televue NP127, for instance, with 20″ pictures accumulated) : the fact that I don’t have to carry an equatorial mount with me is just priceless…

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