Page 65 - BBC Sky at Night - September 2017 UK

THE SKY GUIDE SEPTEMBER 65

STEP BY STEP

STEP 1 STEP 2
Decide what sort of capture you’re after. A general wide shot is easier Pick a location that gives an unobstructed view towards the east that’s
than a close-up of the Moon’s crescent, but the shape and appearance free of bright lights. If you have to travel to achieve this, make sure you
of the crescent will be hard to pick out with really short focal lengths. arrive in good time to set up properly. If you’re using an equatorial
Try a focal length between 100mm and 1,000mm. Connecting a mount, a rough align with Polaris should be fine. If Polaris is hidden,
camera to a telescope is a great way to achieve a larger image scale. a compass is a good way to get an approximate alignment north.

7 3 7

STEP 3 STEP 4
Set your camera lens to manual focus, then focus on a bright star A low ISO (100-400) can be used if a tracking mount is being used.
or planet. Use Live View if available. If using a standard lens, open A fixed tripod necessitates a higher ISO and shorter exposures to
the lens fully (set it to the lowest f/number) then close it by a couple avoid motion blur. For longer focal lengths, adjust the exposure to
of stops. This avoids distortion which may occur with some lenses achieve a bright image avoiding pure white. For wide-field shots,
when fully open. Set the camera to manual operation. overexposing the crescent often reveals earthshine.

STEP 5 STEP 6
Use a remote shutter release cable to avoid camera shake. Bracketing If you’re using a wide-field setup to capture nearby planets as well, a
exposures is also good practice. For example, if you think that a dramatic diffraction burst effect can be achieved by stopping a standard
six-second shot is best, take one followed by four more lasting five, lens down (increasing the f/number) to around f/16 or f/22. Here
four, seven and eight seconds. Shoot in RAW+JPG. The RAW files you’ll need to raise the ISO, or with a tracking mount extend the
give the cleanest results while the JPG ones offer quick editing. exposure. Take the shot, examine and adjust to suit your taste.

skyatnightmagazine.com 2017