In the second of three parts on choosing a camera, we look at choosing between brands, and whether you need a “modified” camera.
What’s the Best Brand to Buy?
The best camera for astrophotography may well be the one you already own, at least to get started and gain experience shooting the stars. But if you find its capabilities limited, then shop around for a new camera. We discussed DSLR vs. mirrorless (or DSLM), and full frame vs. cropped frame in Part 1. Here we consider some other key factors.
Old vs. New Cameras
As a rule, cameras improve with each successive generation as manufacturers perfect the process of making sensors with more pixels while keeping noise at bay. For low noise, a modern 24-megapixel camera is likely to outperform a decade-old 12- or 18-megapixel model. Review sites such as DPReview.com allow you to call up test chart images taken with just about every digital camera ever made, so you can compare the noise levels of various models.
Most brands now offer a choice of DSLR or mirrorless models. For example, Nikon’s well-respected D750 DSLR (now replaced by the D780) and their Z6 mirrorless, all 24-megapixel full-frame cameras offer a combination of specs that the lowest noise and excellent resolution. Credit: Alan Dyer
vs. Modified Cameras
Canon currently offers a mirrorless model, the EOS Ra, that is made for deep-sky astrophotography. In the Ra, the filter in front of the sensor that that blocks infrared (standard in all cameras) passes more deep red visible light. This allows the Ra to record red nebulae better than any unmodified camera, while still working well for other types of photography.
However, such special-purpose modified cameras, whether from the original manufacturer or purchased from a supplier who performs the modification, carry a premium price, and they aren’t essential for most celestial subjects and styles of astrophotography.
On the left is a long-exposure image through a telescope of the North America Nebula taken with a standard Canon 6D MkII camera. On the right is the same object with the specially-modified Canon EOS Ra camera with a sensor filter that lets through more light from red nebulosity. Credit: Alan Dyer
Canon vs. Nikon vs. Sony vs.…
Debates rage endlessly about what the best camera is, and what company makes the better models. In truth, for astrophotography, all models can do a superb job. I use Canon, Nikon and Sony.
Canon is favored by many astrophotographers, having garnered the lead early when affordable DSLRs first hit the market in the mid-2000s. But all recent Nikons, cropped- and full-frame, work well for astrophotography. Nikon’s astronomical full-frame D810a was great, but is now available only on the used market.
This 8-minute tracked exposure through a telescope with a Sony a7III at ISO 1600 reveals a number of artifacts that make deep sky photography with the Sony a challenge. Credit: Alan Dyer
Some current Sony DSLMs have an issue with annoying edge glows that make them less suitable for deep-sky imaging but are still superb for nightscapes and time-lapses. The Sony a7III is my camera of choice for still images and 4K “real-time” movies of the Northern Lights.
Some Pentax DSLRs have a unique “Astrotracer” function that can track the stars. In my testing I found its accuracy was hit or miss, and was not a replacement for using a sky tracking device.
I have not tested Fuji, Olympus or Panasonic cameras, so I can’t comment on their suitability. But I would caution buyers away from Micro Four-Thirds cameras, as their small 17-by-13 mm sensors and tiny pixels will be more prone to noise.
Some Pentax cameras, such as this K3II, offer an Astrotracer function that slowly shifts the sensor to track the moving stars during 1- to 2-minute exposures. Credit: Alan Dyer
If you have a late-model smartphone, however, give it a try in its “night mode.” The powerful on-board computers in the latest smart phones allow them to perform complex stacking and aligning of images right in the camera. They can pick up the Milky Way quite well despite their very tiny sensors and pixels.
But if you have, or want, a camera that accepts interchangeable lenses for the greatest flexibility, the quality of your images depends a lot not on the camera, but on the lens.
