How to make more astro-images and less bloopers with your digital camera.
After using an assortment of digital cameras for the past 9+ years and
making bazillions of images I have learned a few things that I thought I would share so you can begin making your own amazing astrophotos.
Mega pixels are overrated
Don’t be buffaloed into thinking you need a zillion mega pixels or an
expensive camera to make great images because that’s just not true. If
you have a good eye, you can make killer images with your cell phone!
You do need a steady hand, (if you are hand holding the camera up to the eyepiece) patience, good seeing, a creative eye and a bit of luck.
An adaptor to connect the camera to the telescope is recommended for sharp images or if you are going to stack images.
Get rid of the shakes
Image Stabilizers- Cameras with built in image stabilizers are great for minimizing the blurs and
shakes and just about every other camera made today has some sort of anti-shake system built in.
Dim it down
Cover your camera screen or at least dim it.
The light from the screen on the back of the camera is bright enough to illuminate a highway at night!
Cover it or turn it off, especially if you are making photos near others that the bright light might bother.
The light illuminating the screen also creates a tremendous amount of heat=(NOISE).
Rubylith film taped over the screen works well to dim it, but it is hard to determine
if your focus is sharp while viewing through it. There is an option on some digital camera models to turn the screen off.
This is a very good feature to consider if you are going to use the camera for astro-imaging-especially around others.
TURN OFF THE FLASH !!!!!
Need I say more? Buying a camera
that has a flash off feature is more important than the number of mega
pixels the camera has.
If you just want to see weird reflections, white blobs, and offend your
observing neighbors then go right ahead and blast away.
Occasionally the flash can be used to illuminate an important foreground
subject to add more drama to a scene, just make certain you’re not going to upset the light police
if you go around flashing in the night!
Besides, flashes only have a range of about 12 feet…nightsky targets are much farther away- if you see one closer, you need to run!
Get a grip
If you are hand holding your camera up to the eyepiece (afocal) to make
images, it’s a good idea to loop the camera’s wrist strap (if it has one) around your hand so you don’t accidentally drop the camera.
Check your camera settings
Especially the auto off setting. Most cameras have a power save mode and automatically turn themselves off after a certain idle period. This will always happen just before you are all set to press the shutter.
Make sure you have allowed yourself enough time to align, focus, compose and press the shutter button.
More IS truly better
Use the maximum quality .jpg setting and the maximum quantity pixel setting.
The .jpg algorithm compresses the black background of most astro images
very efficiently. You will actually get more images than your memory card says you will because of this compression.
If your camera has a TIFF or RAW setting and you plan to make adjustments to the image later with a
photo editing program– use it.
You also want to use large settings if you plan on sending images to any of the astronomy magazines or
want to print a larger photo to display on your wall. The bigger the better!
Just because you press the shutter, does not mean it will take the image that instant.
Some digital cameras have a shutter delay. Learn to live with it, or
figure out about how long the delay is in order to compensate for getting the image you want.
Press the shutter slowly and evenly. Don’t jab at it or push it suddenly.
If you are mounting the camera directly to the scope use the delay timer function for the shutter or use a remote cable to reduce vibrations.
Use a memory card reader
Instead of connecting the camera to the computer to download the images just insert the memory card into a reader. This will also save your camera’s battery life. There’s a BIG tradeoff here though. If you are constantly removing and reinserting your card into a reader and back into the camera there’s a risk of damaging the contacts on the card or worse, inside the camera.
It’s really best to use the cables that came with your camera to hook up to your computer for downloads.
Keep a set of spare batteries charging. No other explanation needed here.
Keep it cool
Turn the camera off if you are not using it.
The camera can get hot. Hot cameras are not happy cameras.
Focus the telescope by eye and then allow your camera to auto focus through the eyepiece.
makes the image bigger
Optical zoom increases detail by spreading the subject out over a greater# of pixels on the CCD chip.
makes the pixels bigger
Digital zoom spreads out the existing pixels and fills in the gaps with
estimated values. Don’t use digital zoom. You get NO additional detail.
You are kidding yourself if you think this is better. Enlarge an image
you used this on and you will see why.
In a bind
Don’t block or bind the Camera lens while it extends or retracts
The parts inside making this happen are probably plastic. Plastic breaks easily under stress.
Be a square
Make sure the camera lens is squared with the eyepiece.
The image will not be focused around the edges if it is not and images
will be oddly vignetted and round objects will look like eggs. This is
the hardest part of hand holding your camera. Take care to avoid
scratching the eyepiece or camera lens.
Use the widest FOV eyepiece possible to avoid vignetting.
Vignetting makes the image appear as if it is in a tunnel.
(Vignetting can be used creatively to make an image look like a flyover
through a porthole and adds an interesting effect.)
Fill up the memory card
Since you are not using expensive film, go for it. Increase your odds of capturing that once in a lifetime image. The delete key is your friend for getting rid of the unwanted dim fuzzy “dim fuzzies” and retrograde images of objects not in retrograde.
The Moon is your new BFF!
Who knew? It’s easy enough to find. The terminator, close up craters,
and Earthshine are just a few jpgs away. It will change your attitude
toward this once upon a time pesky night sky illuminator.
Other fun stuff
Sky Documentation and Science Projects for Students
Sun’s movement- Solstices and Equinoxes
Occultations and grazes, eclipses, conjunctions
Satellite passes, ISS, HST, and Iridium flare events, space junk, etc.
Be creative and experiment with different eyepieces, binoculars, filters, diffraction grating, all-sky/blind spot mirrors……. There is no limit!
Becky Ramotowski firstname.lastname@example.org