I've started out this note with a white lie. This is about astrophotography with only a camera and lens, where the lens functions as a telescope. My Getting Started note covers the basics of how find a camera that you can use. Here I describe in more detail the other portable equipment that I use to capture deep sky objects without a telescope.
Photographing small faint deep sky objects can require tens of thousands of dollars of high quality equipment. Fortunately many DSOs appear quite large in the sky. These don't require the large and heavy equipment needed to achieve a fast focal ratio at high magnification. Here's a first example of what can be done with just a camera and tracker:
An f2 telephoto lens will capture an image 16 times faster than an f8 telescope with a much simpler and lighter kit. These images may require many minutes of exposure, more than is needed for wide field of view nightscape images on a fixed tripod. Adding a motorized star tracker allows you to take the required long exposure images with a telephoto lens. For exposures longer than a couple of minutes, shorter exposures can be stacked in post processing.
There are lots of choices in assembling a DSO imaging kit for your camera. I'll walk though my working kit, in order to give you an idea of what else may be needed. My working kit cost about $500, dozens of times less than a telescope based kit and much lighter and faster to setup. Here's what my ultra portable setup looks like:
Caution:a long lens can be heavy. Keep all the screwed connections very tight, except for the one you are adjusting. It is easy for the camera mount or some other adjustment to loosen. At a minimum, you loose your framing. Worse, you can easily damage your equipment when it swings loose.
A tracking mount also adds new dimensions to your wide field of view nightscape images. You can stack images for to improve image quality or to capture extended events like the Perseid meteor shower.
Tracking can also add interest to time lapse images. The tracker was set to pan horizontally in this Milky Way Rising over Big Bend:
My kit shown assembled above easily fits in a small backpack (with the tripod strapped outside). This makes it easy to hike or bike to a dark spot with just the right view. Remember that the images you capture are just the start. Captured images need to be selected, aligned, stacked, stretched, poked and prodded to produce satisfying final images.
I was amazed by the images I was able to take with this small kit. It can be hard to believe that these images were not taken with a large telescope. Amazing sights are right above our heads, just a bit too dim for our eyes to appreciate without a little help.
You can take amazing astrophotographs with a camera lens and vintage camera lenses can be great values. If you are buying new equipment, telescopes can give better quality for astrophotos than general purpose lenses. General purpose camera lenses must be able to focus over a wide range and allow for a variable aperture. Even a prime lens may contain a dozen simple lense elements internally, while a telescope seldom has more than three or four. Small telescopes with 250 - 400 mm of focal length overlap with camera lenses with similar focal length and may have better performance. For example here is my camera kit beefed up with a counterbalanced declination bracket camera mount for the Vixen Polarie star tracker and a 250 mm telescope. The RedCat 51 telescopoe is designed for astrophotography, but can also be used with a diagonal and eyepiece for visual observation.
How do images taken with the 250mm RedCat APO telescope compare with ones taken with a 300mm Nikkor ED lens? Here is one example.
I like the RedCat telescope image quite a bit, but the heavier telescope requires a counter balanced mount with additional size and weight. The telescope runs about five times the cost of the vintage lens. I use both in different circumstances, but I recommend starting out with a simpler lens based kit.
Trevor Jones at AstroBackyard has a video describing his take on a low cost camera lens based kit for deep space astrophotography: My CHEAP Astrophotography Kit for DEEP SPACE!
Content created: 2016-08-19 and last modified: 2021-04-17
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