Astronomical Imaging Hardware

The latest technology often includes noise reduction and more sensitive sensors, making digital cameras very useful for some types of astrophotography. Canon, Sony and Nikon seem to be most-favoured by amateur astro-photographers.

Canon L-series lenses offer excellent optics for astronomical use, where we push optics to their limits (and sometimes beyond). As Canon says “these lenses use special optical technologies [such as] Ultra-low Dispersion UD glass, Super Low Dispersion glass, Fluorite elements, and Aspherical elements to truly push the optical envelope.”

Canon EOS digital SLR cameras and Canon L series telephoto lenses

I use two unmodified Canon mirrorless cameras to capture astronomical images: Canon R (30 megapixel) and Canon R5 (45 megapixel). Canon led the way for using consumer cameras for astrophotography when they developed some of the best low noise, high sensitivity CMOS sensors years ago.

I use these cameras for prime focus photography on a wide variety of telescopes, including my superb Borg 101 ED f/4 Astrograph apochromatic refractor mounted on a Skywatcher HEQ5 Pro mount. I also mount the cameras and telephoto lenses directly on an Astrotrac travel mount or directly on the HEQ5 mount. The Canon CMOS sensors produce superb, low noise images. I normally save images in Canon RAW format, giving 48 bit dynamic colour range instead of the 24 bits used by the standard jpg or tiff formats.

The Canon RF 100-500 L series zoom telephoto is a sweet lens for astrophotography, since it is like having a widefield refractor telescope, but in a smaller form factor. I have the Canon 2x RF Tele-converter, which gives a 1,000mm focal length when used on the 100-500 zoom. I first used a 400mm telephoto L-series with a Baader solar filter for my shots of the 2006 Total Solar Eclipse in the Libyan Sahara Desert. I have subsequently used several other L-series telephotos for taking wide field Deep Space images, and find them to be perfect companions for travel. My current favourite is the Canon RF 15-35mm f/2.8 L wide zoom – a great for wide-field astrophotography with its fast, tack sharp optics.

The Canon TC-80N3 Timer Remote Controller is an important piece of gear for an astro-photographer such as myself. It replaces using a laptop computer to run automated sequences of shots.

Astrophotography makes use of the fact that taking a series of images and “stacking” them will create a single resultant image with a superior signal-to-noise ratio. For example, a series of 20 images taken for 1 minute exposure time each will yield a noticeably better image (when stacked together) than a single 20 minute shot. The exposure timing and programming available with the TC-80N3 to control the Canon dSLRs saves me from doing an otherwise tedious manual timing and recording task during my astrophotography sessions in the field.