The Moon, Mars, and Venus are reflected in the still waters of the Mullica River in the Pine Barrens of New Jersey during morning twilight just before dawn. This image was shot with a 18-55mm f/3.5-5.6 zoom working at 34 mm of focal length at f/5.6 with a single 10-second exposure at ISO 1600 with a Canon Digital Rebel XS (1000D) DSLR on a fixed tripod.

Wide-angle shots of the crescent Moon with Earthshine and bright planets nearby can make remarkably beautiful images.

They are a great way to get started in planetary photography because they can be done with just a simple wide-angle zoom lens and DSLR camera on a fixed tripod. You don't even need a telescope.

Pay attention to what is going on in the sky. Be on the lookout for visually interesting conjunctions between planets and the crescent moon and planets. Be on the lookout for interesting locations. File these away for when you get something interesting going on in the sky.

Use a planetarium program for planning. Check out the morning and evening skies in advance.

Especially look for young crescent moons next to bright planets like Venus and Jupiter. Young crescents are usually located low in the sky when the sky still has beautiful color from twilight. Young crescents also usually have Earthshine, that incredibly beautiful light reflected from the Earth that illuminates the dark side of the Moon.

Magic Time

You will want to shoot during "Magic Time". This is the time when the exposure for the available light for the sky matches the correct exposure for the crescent moon with Earthshine. It's hard to predict exactly when this is, start shooting early and continue until past when you think it looks best.

A beautiful conjunction between the crescent Moon with Earthshine, brilliant Venus, and Jupiter is seen in the fading twilight after sunset during "Magic Time". This image was shot with a 70-200 mm zoom working at 200 mm of focal length at f/4 with a 1 second exposure at ISO 400 with a Canon DSLR on a fixed tripod.

Shoot a lot of frames. Use the professional photographer's secret technique - bracketing. Bracketing simply means varying the exposure! Shoot some frames at 1 stop under exposure from the meter reading in the camera. Shoot some at 2 stops under, some at 3 stops under. Shoot some at 1 stop over exposure, 2 stops over, 3 stop over. Experiment! Sometimes the best image will come from an exposure that will be different than what the meter calls for in the camera.

For some events, like a twilight conjunction, you will have plenty of time to shoot and experiment. For others, such as an ISS solar or lunar transit, they can be over in less than a second. You have to give yourself plenty time to get to your observing location early and get setup. Things always take longer than you might think.

Follow the simple rules of composition. Don't always put the main subject dead center in the frame. Try putting the main subject at the intersection of imaginary lines that divide the frame into thirds. Compose the image so that the main subject is framed by something like tree branches. Put something interesting in the foreground.

Move around. Try different angles. Try a low angle with the camera on the ground. Try different compositions, both vertical and horizontal.

F/8 And Be There

In the old days, photojournalists used to have a saying that they would use when they were asked how they got a particularly memorable news photo.

They would reply "F/8 and Be There!"

The F/8 part meant "know your equipment", but it was mostly a joke. It meant that you had to know your equipment like the back of your hand, but that the technical settings weren't as important as actually being there and taking the picture when there was a picture to be made.

Remember that luck favors the prepared, but don't discount the random aspect of it. If you run across something that looks like an amazing picture, shoot it when you see it, because I can guarantee that it won't be there when you go back the next time.

Know Your Equipment

Venus and Jupiter set in the twilight. Shot with a 50mm lens at f/2.8 with a 2 second exposure at ISO 200.

Get to know how your equipment works. DSLRs can be complicated. Play with your camera in the daytime when you are just sitting around. Dig into all of the menus and sub-menus and try different settings. Experiment and practice until you know how everything works and what different settings do. Read and study the camera manual. Believe it or not, there is actually a lot you can learn in it.

Since you don't have to buy film or pay to get it processed, it won't cost you anything to practice with a digital camera. Shoot a lot of practice images until you know your camera and how it works.

Learn how to use your camera in full manual mode. Automatic settings don't always work with astronomical images. The great thing about DSLRs is that you can see the image on the back of the camera to get immediate feedback as to whether or not your shot was successful. You can check exposure, composition and focus by zooming in. If something is not right, you can correct it and still get a good picture.

• Camera Settings

  • Manual Mode - You can try shooting with your camera in one of the automatic modes, but you will probably get better results by using manual mode because you have full control over the exposure.

  • ISO - Modern cameras are very low noise, so you can probably use a higher ISO than you might think, but start out with a low ISO. You may have a situation where you are using your lens wide open and a longer exposure would be correct for the scene, but objects in it will be trailed at that exposure. Increasing the ISO can let you use a shorter exposure to prevent trailing.

  • F/Stop - For most astronomical scenes, you will want to use a fairly fast f/stop. "Fast" means the lens diaphragm is used at a wider setting which lets more light in. For example, f/4 is a faster (and wider) f/stop than f/5.6 or f/8. Lens performance gets better as a lens is stopped down, but your choice of f/stop will end up being a compromise between needing the light gathering ability of the lens at a wider f/stop and the sharper performance you get when it is stopped down to f/8. Start out by shooting some frames with the lens wide open. Then shoot some more frames with it stopped down one f/stop from it's maximum aperture as this is a good compromise for wide-angle scenic shots.

  • Shutter Speed - Try different shutter speeds. For twilight shots with a wide-angle lens, magic time usually comes when the exposure is around 1 second at f/4 at ISO 400. Take a test shot and examine it on the LCD on the back of the camera. Enlarge it with the zoom feature and see if it has unacceptable trailing. If it does, use a shorter exposure.

  • Color Balance - Use daylight white balance. This will usually record the colors of the sky more accurately. Auto color balance is normally the default, so you have to specifically change it. Auto color balance may make a twilight sky full of beautiful color completely boring!

  • Mirror Lockup - It's usually a good idea to use mirror lock-up, even if you are using your camera on a tripod. The mirror flipping up can cause vibration that will cause movement in the image and reduce sharpness. You can turn on mirror lockup in the menu settings. Using mirror lock-up usually requires pressing the shutter release once to flip the mirror up, and another press to open the shutter. Give the camera a couple of seconds to settle down after you have flipped the mirror up before you open the shutter.

  • JPEG and Raw - Most cameras allow you to shoot JPEG and Raw file formats at the same time. I always do this. The Raw file format give you some leeway later in processing if you make a mistake and miss the exposure by a little bit.

• Tripod - A sturdy tripod is an excellent tool to use with a DSLR camera for all kinds of astrophotographic images. I highly recommend using one. But if you don't have one, you can still take time exposures by using something like a beanbag, or by just propping the camera up against something.

• Remote Release - An inexpensive remote release is a real help in preventing movement when you open the shutter because you don't have to physically touch the camera to start the exposure. You can find these for about $15 on Ebay.

• Self Timer - If you don't have a remote release, you can still open the shutter without touching the camera by using the self timer that is built into the camera. Read your camera manual to learn how to use it.

• Focus - To shoot most wide-angle scenics you will want to focus your wide-angle lens on infinity. This is actually more difficult than you might think!

Most DSLR cameras and lenses come with autofocus set as the default. If you are in one of the automatic exposure modes, and the camera doesn't detect an object on one of the little auto-focus squares in the viewfinder to focus on, not only won't the camera focus on infinity, it won't even let you open the shutter because it thinks the subject is out of focus.

Note that the infinity focus mark on most modern lenses is not accurate. Don't trust it. Use manual focus or autofocus.

In addition to using the camera in manual exposure mode, it is a good idea to put the camera into manual focus mode also. There is usually a button on the lens that switches from auto focus to manual focus.

Once you have the lens set to manual focus, you can use Live View and magnify the image 5x or 10x and focus manually. If this doesn't work for you, you can focus on something very far away. You can even do this in the daytime, but if you do, it is a good idea to tape down the focus ring on your lens so it doesn't accidentally move and throw off the focus before you go to use it.

Live View Manual Focusing Tips

Here are some tips to using Live View with manual focus for astronomical subjects:

• Use manual exposure and manual focus.

• Use ISO 1600, bulb shutter-speed, and a wide aperture.

• Use a bright star or planet to focus on.

• Get close to focus before you try to use Live View. Just eyeball it through the viewfinder, or manually turn the focus ring to the infinity mark.

• Zoom in to 10x to focus.

Autofocus

You can, of course, try to use autofocus with a camera lens on something bright in the sky like the Moon, or a really bright star or planet. A secret here is to set the camera to only use the center focusing square. Read your camera manual to find out how to do this for your particular camera mode. Then make sure the object is exactly on that square when you use autofocus.

The Moon and Venus set in the twilight. Shot with a 16-35mm lens at 35mm focal length at f/2.8 with a 1 second exposure at ISO 200. Autofocused on the Moon.

A problem you will encounter is that when you then re-frame the scene, the chances are that the object you focused on won't be on that focus square anymore. When you go to press the shutter release to take the image, the camera will then try to autofocus again. Not finding the subject on the central autofocus square, it may rack in and out of focus and then just give up trying. Even if you could trip the shutter at this point, the image will be out of focus.

The solution to this problem is to autofocus on an object, and then turn autofocus off with the switch on the lens for Canon lenses, or on the body for Nikons.

• Exposure- First try shooting a test shot at the exposure indicated by the camera's meter. Examine this image on the LCD on the back of the camera and adjust the exposure as necessary to make it correct.

• Miscellaneous

  • Dew - If you are out all night shooting astronomical images, and you try to take an early morning wide-angle scenic shot in the twilight before dawn, you may find that your camera lens will dew up if the environment is humid. Since your camera equipment has had all night to cool down, even if you have kept the camera lens in a camera bag in the car, it doesn't take much for the lens to radiate some more heat away when exposed to the clear open sky, and drop below the dewpoint, and have dew form on the front element of the lens.

    It's usually not a good idea to try to wipe the dew off at this point as that may scratch the lens. If you have a filter on the lens you can try removing it and that may give you a little bit more time before the front element of the lens dews up.

    The best way to keep dew off a lens is to keep it slightly warmer than the dew point. You can make a home-made anti-dewer with a couple of resistors and a battery, or you can use a commercial anti-dewer such as those sold by Kendrick and Dew-Not. You can use a 12-volt hair dryer to blow warm air onto the lens. They are sold in marine supply stores. You can even wrap a chemical hand warmer around the lens with a rubber band. But be careful not to change the infinity focus if you do this.

  • Batteries - It's always a good idea to carry a spare camera battery with you. Make sure it is charged! Camera batteries have the nasty inclination to die at the most inopportune times, especially in cold weather.

High Dynamic Range Images

A more advanced technique involves shooting different exposures and compositing them together to create a High Dynamic Range (HDR) image.

The Moon is seen during totality during the lunar eclipse of December 21, 2010 among the winter constellations of Gemini, Auriga, Orion and Taurus. This eclipse also happened to occur on the day of the Winter Solstice. Even though the Moon is very dark during a total eclipse compared to a normal full moon, it is still bright compared to the faintest stars that are visible. A single exposure could not record both the faint stars and eclipsed Moon. This high-dynamic range image was made from a composite of 8 frames with exposures made in one stop increments ranging from 60 seconds for the starry background to 1/2 second for the eclipsed moon. An 18-55mm f/3.5 - 5.6 wide-angle kit zoom lens was used at 20 mm of focal length at f/4 at ISO 1600 with a Canon T2i (550D).

Some scenes have a brightness range that is just too great to be recorded in a single exposure. For these kinds of scenes, we can record one exposure for the brightest part of the scene, and then a series of other exposures exposure for the less bright parts.

These various different exposures are then composited into a single image using either layer masks in Photoshop or HDR software.

The Moon is seen near Saturn (lower left) and Regulus in Leo during the total lunar eclipse of February 20, 2008. This is a more fanciful "artistic" shot made from a composite of two frames, one 4-second exposure of the Moon and one 30-second exposure of Saturn and Regulus made with an 85mm lens shot on a tracking mount. The red glow around the Moon comes from a fog filter and long exposure which were used on the wide-angle shot.

The above image of the totally eclipsed Moon in Leo is also an HDR composite. But this is an image that is not representative of the way the eclipse really looked. It takes more artistic license with reality to create an interesting image, in using a fog filter on the long exposure of the starry background to create the red glow around the Moon.