Astroblog

Total Lunar Eclipse of June 16, 2011. Imaged with a 4" Newtonian Reflector, 20 mm Plossl eyepiece and Canon IXUS 100 IS (400 ASA). Click to embiggen.

Unlike Solar Eclipses, which you need heavy duty solar filters (or Jatz biscuits) to observe without risking severe eye damage, Lunar Eclipses are easy to observe.

All you need is your unaided eye, and a comfortable place to stand or sit as you watch Earth's shadow edge across the Moon.

You don't need to hunt out the darkest skies (although it is quite spectacular there), you can see it all from the comfort of your backyard or local park. And you don't need fancy charts, the Moon is kind of obvious.

This coming total Lunar Eclipse on Wednesday October 8 is an excellent  opportunity to see and eclipse and share it with friends and family. It occurs early enough in the evening so young kids can watch (and is still school holidays for many states, so won't interfere with school routines). Full details of timing are here.  A printable PDF file with timings and activities is here.

While observing with your eyes is fully rewarding, observing the eclipse through a pair of binoculars of telescope will enhance the experience. Any old binoculars will do, and a simple department store telescope is fine. It's also best to use a low power eyepiece so you can see the whole of the Moon (unless you want to time when the shadow reaches particular craters).

When using a telescope, if you haven't done so for a while (or you got it at Christmas and haven't used it yet), the thing to watch for is that the guide scope which you use to line up the main scope is actually pointing is the same direction as the scope itself.

Before the eclipse, spend an afternoon in the back yard checking that the guide scope is aligned with the  main scope. Centre a telephone pole or such in the guide scope, check to see if the telephone pole is in the view of the main scope. Use the adjusting screw to shift the guide scope position until the object is centred in the guide and main scope.

Taking pictures

Lunar eclipse imaged with Canon IXUS point and shoot camera.the Moon is very small when imaged in a standard point and shoot camera.

Like with observing the Moon, you don't need a fancy camera to take pictures of the eclipse. Even a mobile phone or simple point and shoot camera will be fine with these conditions.

1) You can turn off autofocus and put the camera on an infinity or landscape setting. Autofocus can't handle the Moon and you will have a fuzzy blob.
2) You have a tripod or some solid object to rest the camera on (for mobile phones I use things like a table, solid fence, telecom cabinet etc.) so the camera doesn't move during exposer.You can get simple, portable "mini-tripods" that you set up on a desk or chair quite cheaply.
3) Night mode or timed exposure. Before the full eclipse the Moon will be over exposed except on very short exposures (you may even need daylight settings), but as the eclipse deepens you will need longer exposures, night mode will usually cover this (tends to be a 4-6 second expoure) or if you cameraa lest you set manual exposures try settings in the 4-6 second range.

Experiment a little the night before to find the right settings. If your camera has a zoom setting, zoom out to the maximum optical (NOT digital, this will make everything grainy) zoom.

Without binoculars or a telescope, the images of the Moon you  will get will be quite small (see above), but can be very atmospheric. If you have binoculars or a telescope, you can take more detailed images.

Using binoculars or a telescope

Eclipse imaged with a mobile phone held up to the lens of 10x50 binoculars.

 This is simple. You can just point the camera through your telescope lens and press the button, that works! You will need very steady hands though or the image will be blurry. Again, the night before practise taking images through the scope.

For binoculars though, other than at maximum eclipse the Moon is too bright and the bright part will be over exposed on standard settings. If you can adjust the brightness settings then this will work. I have to scrunch down the white balance on my mobile phone to make it work, and I can adjust the ASA and brightness on my Canon as well.

If you are going to use binoculars, you will need to have them on a stand or something that can hold the binoculars steady while you try and manoeuvre the mobile phone or camera into viewing position. Most modern binoculars have a screw port, which allows to to, with the aide of an adapter, attach the binoculars to a camera tripod. 

A binocular adapter and the adapter port on 10x50 binoculars	Binoculars and adapter assembled onto camera tripod	Moon imaged with mobile phone through this setup.

Binocular adapters are marvellous, although they cost around $50 (usually found in astro-optical stores), they make using binoculars to observe astronomical objects so much easier. Once set up on the Moon, you may need a bit of time to work out how to align the mobile phone or camera lens with the binocular lens so you can actually see the Moon. This can be immensely frustration. Again, practise the night before. You may find have a head  torch with red cellophane over it (so as to not destroy your night vision or mess up imaging) will allow you to align the camera lens with the binocular lens more easily.

While you can more easily line up mobile phones and cameras with a telescope eyepiece. I use a special adapter that holds my camera in place. there are also adapters for iPhones (not, it seems for android phones). These are a bit pricey (nearly $100 for astro-optical stores), but I use mine so often it has repaid my investment. After all, there are a lot more eclipses coming up.

Point and shoot camera, telescope adapter and 20mm telescope lens. Low power lenses are best for eclipse photography	Lens inserted in telescope, tightened in (important, having the lens-camera fall out can ruin your camera) and adapter attached to lens.	camera screwed onto platform, some adjusting is needed to centre the image.

The setup for the camera adapter is more complex, as you need to juggle the lens to get it aligned with the telescope lens, all while the Moon is drifting out of the telescope field of view. Again. practising the night before to become familiar with the setup is important. You will need to constantly adjust the telescope position to keep the Moon centred, although if you are using a low pwore eyepiece this is not that often.

Moon imaged thorough a 4" Newtonian scope with 20mm eyepiece using a mobile phone.	Moon imaged thorough a 4" Newtonian scope with 20mm eyepiece using a Conon IXUS point and shoot and camera adapter. The mess is junk on the CCD chip.

There you have it, with relatively cheap and simple equipment (and lots of fiddling and cursing at first) you can view, and image, the upcoming Lunar Eclipse.

However, remember that Rule 1 of astrophotography is to never let the act of photography interfere with enjoying what you are photographing. Just take time to observe the spectacle, and let the cameras be, especially if they are causing you more trouble than joy.

Labels: astrophotography, binoculars, eclipse, Moon, unaided eye