From personal experience, whenever I try to describe to someone who’s never seen what the rings of Saturn look like through a telescope or how a sunspot moves and changes shape as it transits the chromosphere over the course of weekend, there is definitely something lost in the telling. Wouldn’t it be great if even a novice astronomer with just some basic gear and knowledge could capture their own images of heavenly bodies to post on social media or (to go old-school) print them and hang on a wall?
Well, wish no more, dear reader! We live in The Future, and there are pieces of gear that are surprisingly affordable that allow you to do just that, and they are called eyepiece imagers. Whether you look at the sun, moon, planets, or deep sky stuff like nebulae or galaxies, there’s an imager that can capture it. But there’s more to merely capturing images… it’s the magic that happens in post where you are able to stack tens, hundreds, or even thousands of images into a single composite one that allows you to tease out minute details and produce unique one-of-a-kind pictures. In fact, you’ve probably seen dozens of these composite pictures already—you just didn’t realize it. Virtually any picture you’ve ever seen of a planet, star, galaxy, nebulae, or just about any other celestial object (besides the moon, but if you want to know more about photographing it click over here later) was most likely stacked and composited from thousands of individual images; and with an eyepiece imager inserted into your telescope’s holder in place of an eyepiece, and some (usually free) software on your computer, you can make your own unique images.
Two notes of caution before we dive in:
- Manage expectations You shouldn’t expect Hubble-quality images from a backyard telescope, so keep your expectations in check… what you see and how well you can capture images will greatly depend on the telescope you use, the type of mount you have, atmospheric conditions, and (of course) light pollution.
- If you want to image the sun, you must take all of the same safety precautions you would for observing it, because at some point in the process you will be looking at it. Failure to use the proper filters for your telescope and yourself can and will cause catastrophic damage to your gear and to your eyes, up to and including permanent damage and blindness. Be smart while you’re out there.
First, you have to decide on whether you want a monochrome or color imager. Monochrome is NOT black-and-white, so we need to not think in those terms when discussing imagers. A color imaging sensor has alternating Red, Green, and Blue pixels that capture color and, by combining these primary colors, they can make any other color imaginable. With a monochrome camera, you use 100% of the available pixels 100% of the time. This full use reduces background noise and results in better, clearer, images.
So, I hear you ask: if mono is so much better, why do they bother to make color cameras? Glad you asked.
Color
The problem with color sensors is that they tend to have more green pixels than red or blue, but what you are generally imaging is more at home in the red band of the spectrum, which means you have a lot of wasted pixels, more noise, and off-band colors. Again, you ask, “WHY would I want a color camera?” The answer is simple: Time. By using a color camera, you are capturing the full spectrum in a single exposure (or series of exposures), so while you may have background noise and your colors might be a bit off, you can do all your imaging in a single burst or just several bursts. This is important, especially if you have an alt-azimuth mount.
Mono
As we saw above, shooting in mono has many advantages, with one exception: it’s time consuming. When you shoot in monochrome, you need to pre-filter the imager to target a specific color wavelength, capture a series of images first in red, then change filters and capture in green, then change filters again and capture in blue. Once you have all your single-colored images captured, you then stack them in post to produce one color image. As you can see, it’s a process. You also need colored filters. And you need to have a mount that is tracking your subject. Oh, and it should be an equatorial mount.
Why an equatorial mount? Because if you’re going to be capturing a planet or other celestial object during the course of a night or three, you want to make sure that the surrounding star field remains in the same orientation as your subject. If you use a GoTo or tracking alt-azimuth mount, you will experience a phenomenon known as field rotation, where your subject remains centered in the view, but the stars around it rotate, which will cause fuzziness in the composite photo.
Now that you’re ready to start imaging, let’s consider some options out there. The good news is that manufacturers know the color/mono conundrum, and some thoughtfully produce imager models in both options.
Coming in at less than $100 is the most basic imager B&H carries. It’s made by Barska, is the easiest to use, and is probably best for beginners who want mostly to image the moon and sun, with some planetary stuff in the mix. The Wi-Fi Eyepiece is strictly color and does not require any gear other than the imager and a smartphone or tablet. It generates its own local Wi-Fi signal that you use to connect to your device wirelessly. A QR code in the manual directs you to the appropriate app for your Android or iOS device, which lets you view through your telescope, capture, and share. The smaller 0.3MP imaging sensor is really only good for the moon and sun, but you can also use it in many microscopes with removable eyepieces, so it has more than one use. It comes with two nosepieces to fit into 1.25" telescope holders and a 0.91" for microscopes.
Telescope powerhouse Celestron makes its first entry here, with its NexImage 5. This color-only imager sports a 5MP imager with a built-in IR-cut filter to reduce unwanted noise at the top of the visual spectrum. Its 1.25" nosepiece can be removed to reveal standard C-mount threads, so it can be used for advanced astrophotography techniques, like imaging through an eyepiece (as opposed to instead of an eyepiece), which gives you high magnifications for planets. The included software is strictly for Windows operating systems, so Mac users beware (or steer clear completely).
Venerable Meade Instruments makes an appearance now, with its LPI-G Advanced options, available in color and monochrome versions. Similar to the Celestron, the Meade offers both 1.25" eyepiece and C-mount options, and Windows-only capture software. Its 6.3MP sensor captures still images and video in 3072 x 2048 resolution at 59 FPS. Meade designed this model for use as a stand-alone imager, but it can also be used in a guide-scope for autoguiding with larger imaging/astrophotography rigs by using its dedicated ST-4 guider port.
Next we have the Levenhuk T800 Plus. As with the Barska, it’s a color imager but with a much larger 8MP sensor. The software suite is compatible with Windows, Mac, and even Linux systems, so just about anyone can use it. Like all the rest of the imagers we’ll be discussing, you’ll need a control and capture computer, and the imager will plug into the USB port to power the device and transfer the data to the software. The larger sensor means higher resolution, and the T800 goes up to 3264 x 2448 at 1.9 fps with variable exposure times, and auto or manual White Balance and Exposure control. This imager is designed strictly for 1.25" holders.
Another Celestron option is the Skyris line, also available in color and mono models. As with the NexImage, this one has 1.25" eyepiece and C-mount options, with a resolution of up to 1920 x 1200 and exposures as fast as 0.0001 of a second (that is the correct number of zeroes). The software is upgraded to Mac and Windows compatibility, and has fast transfer rates due to its USB 3.0 connection (backward compatible to USB 2.0 but with slower transfer speeds). It can also be used with select third-party capture and editing software like IC Capture and DirectShow if you already have an imager and are looking to upgrade.
Remember, if you’re going to be imaging in mono, you’ll want to pick up some color filters. For beginners, I’d recommend a basic set like this Meade 4-Piece Series 4000 kit. This Celestron 4-filter set is made specifically for imaging and includes a luminance filter. As I always recommend, you should include a moon filter for both visual and photographic use, so make sure you get one if you don’t have one. One last filter recommendation: pick up a light pollution filter, if you live in an area with street lamps or other industrial lighting. You can use this for visual observation, and it helps block some distracting light. It can also be stacked with other filters for enhanced views.
To Recap
If you’re new and are looking for some basic images to get your feet wet in the astrophotography realm, or if you have an alt-azimuth mount (manual or GoTo), stick with a color imager and use a moon filter if you’re pointing it at the moon (and you know you will).
Move into the mono versions if you’re more advanced and have a tracking or GoTo equatorial mount. Again, shooting in mono is going to triple or quadruple your imaging sessions, so be prepared for long nights or multiple days of imaging the same thing. Also, you NEED filters, but the good news is that you can usually use your visual filters to start.
Watch the software compatibility. Much of the free software out there was written years ago before Macs were popular, and some haven’t been updated in a decade or more.
Now that you have the basic knowledge and the tools are fairly affordable, get out there and start sharing, tweeting, IG-ing, pinning or whatever the cool kids are using these days.
What do you image with? What’s your favorite celestial object to image? Comment below to get the conversation started, and if you have questions feel free to drop them below or use B&H’s handy chat!
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