Astrophotography 101

Astrophotography 101

We're in luck.  Digital photography gives us all a chance to record what we see in minutes if not seconds. 

Mare Crisium


There was a time when astrophotography was highly limited.  We used 35mm cameras with low light speeds like ASA 160 for colour and higher light speeds like ASA 400 for black and white.  Worse, we never knew what we were going to get so we bracketed shots with various exposures; were never quite sure if our motor drive was tracking properly, and we were genuinely thrilled when 2 or 3 exposures out of 36 looked good.  That's all changed.

 

Digital photography gives us immediate results and real-time feedback on our astrophotography efforts.  It's also much cheaper.  If a shot doesn't work, we delete and start over.  Better yet, there are digital photo programs from Photoshop to numerous others that allow us to easily adjust brightness, contrast, colour and colour saturation in addition to cropping.  It's gotten much simpler but there are still some basics to keep in mind.

 

Adapting your camera to your scope


There's a wide range of digital cameras available, but regardless of the features they're worthless for many astrophotography applications unless you can connect it to your scope successfully. This usually requires a T-ring adapter that you attach to the dslr camera instead of a lens that allows you to place the camera into the telescope instead of an eyepiece.





Astrophotography Without a Telescope

However, some celestial objects can be captured with a camera without a telescope.  Particularly if you have a zoom or telephoto lens for your digital camera. Here is a complete guide on how to do this called DSLR Astrophotography without a telescope. Below is an image of the globular cluster Messier 3 taken without using a telescope or a mount using this guide.


Messier 3 taken with a dslr camera on a static tripod

Messier 3. ISO 12800 (Hi2), 343 frames at 2sec, 200mm focal length

 

A picture of the moon taken with high resolution and a large file size will give you the ability to crop and adjust colour and contrast with a digital program such as Adobe Photoshop or Microsoft Office Picture Manager.  This can give you a remarkable photo without the use of a scope.  The same is true for the northern lights and meteorite showers.  In fact, a standard camera on a tripod with a long time-exposure is your best bet for capturing streaking meteorites.  A wide angle lens helps too because you can always crop and edit your photos.  Significantly, a tripod is often necessary for any astrophotography when you are using only a camera in the same way that you need a tripod for a scope. 

Northern lights over a lake with snowy mountains

 

Curiously, the best approach to astrophotography for planetary objects tends to be computer driven.  Curious in the sense that deep-space objects seem like they would require more technology, but that's not always the case.  Computer web cams can capture hundreds and thousands of planetary photos in a relatively short period of time allowing you to browse and select the best shots with the best resolution.  This requires some unique hardware and software in addition to a laptop or digital pad device. It can be pretty inexpensive to start imaging planets though. Here is a video guide on how to adapt a very cheap microsoft lifecam for planetary imaging.


Deep Space Astrophotography


Deep-sky astrophotography requires a different kind of camera.  Typically these are high resolution; high megapixel cameras that have the ability to take long exposures minutes in length.  Inexpensive cameras with this capability can be purchased for as low as £250 ($350). A DSLR camera can do the same job. The only problem is the infrared filter on DSLRs can filter out some of the red nebula gases. Some companies will mod your DSLR and remove the filter for astrophotography but if you aren’t too bothered then your DSLR will do just fine.

Messier 51

 

More expensive digital cameras dedicated to astrophotography can run as high as $10,000 (£6,100). Once you set the time for the exposure you allow the drive on your scope to track your object and when the exposure is concluded, you view the result and adjust as necessary. By far the most important piece of kit for this kind of astrophotgraphy is a very steady and sturdy mount.

 

DSLR AStrophotography Book

Ultimately, the value of DSLR digital astrophotography is that ability to view your results immediately and make adjustments.  It removes a lot of guesswork and allows you to learn as you go.  On that note, remember to keep a log and take careful notes.  As you continue to experiment you will find certain techniques and exposures that work best in certain situations for various celestial objects.  It's always easier to consult notes than try to remember what you did right at 2 in the morning on a chilly, winter night. 


Now try… Easy Deep Sky Astrophotography - Without a Telescope

Related Posts:  Astrophotography

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