The Meaning of "Cheap"

15 Mar 2014.  It occurs to me that I probably ought to justify the name of this blog by defining what I mean by “cheap” astrophotography.  This turns out to be more complicated than I originally imagined, because the cost strongly depends on what you want to do.  So I’m going to present several scenarios along with their costs, and end with what I’m actually using.  In each case I’ll list what I have or happen to have used; this doesn’t constitute an endorsement nor is it necessarily the best setup (in fact, almost always it won’t be the BEST, except possibly in the sense that it is good value for cost).  The listed prices are approximate, but close.  In all of this I’m going to ignore one of the most expensive components, the computer that is running the scope and mount and doing the image processing.  For the record, I use a MacBook Pro that was bought by my work (so for me it was free), but the model I have would be about $1500 new.  A $300 used laptop would probably be adequate for most things, but I’m going to ignore the computer in what follows.

The cheapest way to start in astrophotography is to do wide field or star trails shots.  For that, what you need is quite modest:

Starscapes	Model	Mfr	Condition	Price
Camera	PowerShot A560	Canon	new	$100
Tripod	"spider"	some off brand	new	$10
Stacking software	Deep Sky Stacker		new	$0
Total				$110

I’d consider the next step up in cost and difficulty to be lunar/planetary astrophotography.  Now you need a telescope and some means of pointing it and tracking the sky (although your tracking doesn’t have to be great for this kind of astrophotography, because you are taking short exposures).  I’ve included the CG-5 mount, which you can get used with motors for around $200.  My AT8IN scope is not really ideal for lunar/planetary work; you really want a longer focal length than the 800 mm it has.  That’s partly why I included the 3x Barlow as a necessary item.

Lunar/Planetary	Model	Mfr	Condition	Price
Mount	CG-5	Celestron	used	$200
Scope	AT8IN	Astrotech	used	$350
Imager	c270 HD	Logitech	new	$30
3x Barlow	3x	Meade	new	$40
Telrad sight	Telrad	Telrad	new	$40
Stacking software	version 6	Registax	new	$0
Total				$660

The next step, to deep sky imaging, adds cost and complexity.  You could do afocal astrophotography with a point-and-shoot camera (and that’s how I started), but I’m skipping that step here and describing the bare essentials of what I now use, a low-end CCD on an autoguided mount.  

Deep Sky	Model	Mfr	Condition	Price
Mount	CG-5	Celestron	used	$200
Scope	AT8IN	Astrotech	used	$350
Imager	DSI Iic	Meade	new	$250
Guide scope	9x50	Celestron?	used	$20
Focal reducer	0.5x	Antares	new	$25
Guide camera	DSI Ic	Meade	used	$80
PicGoto	Simplificado	Me	new	$40
Telrad sight	Telrad	Telrad	new	$40
Mapping	version 3	Cartes du Ciel	new	$0
Planetarium	ver. 0.12	Stellarium	new	$0
Stacking software	Deep Sky Stacker		new	$0
Post-processing software	GIMP		new	$0
Total				$1,005

Finally, here’s what I actually have and regularly use.  In addition to the AT8IN scope, I also have an Orion ST-80, which I originally bought to use as a guide scope.  Later I got a 9x50 finder with the AT8IN that was a lot lighter (and therefore more friendly to my mount, which can barely handle the weight I’m putting on it).  I started using the 9x50 as my guide scope and found the ST-80 could be used for wider field of view shots as long as I used a filter to cut out the UV and IR that cause pretty bad chromatic aberration with the ST-80’s non-apo doublet lens.  My current practice also uses a couple of pieces of software that are not free but are quite inexpensive.  I control my cameras with Nebulosity and also use that software for stacking.  I use StarTools for most of my post-processing.  I consider both these pieces of software to be well worth their modest cost.  Some of this is no doubt driven by the fact that I’m a Mac guy and both of these software packages have Mac-native versions that work great.  

Current Rig	Model	Mfr	Condition	Price
Mount	CG-5	Celestron	used	$200
Scope+rings	ST80	Orion	used	$80
Scope	AT8IN	Astrotech	used	$350
Imager	DSI Iic	Meade	new	$250
Guide scope	9x50	Celestron?	used	$20
Focal reducer	0.5x	Antares	new	$25
Guide camera	DSI Ic	Meade	used	$80
PicGoto	Simplificado	Me	new	$40
Telrad sight	Telrad	Telrad	new	$40
Imager	c270 HD	Logitech	new	$30
3x Barlow	3x	Meade	new	$40
UHC-S filter	1.25"	Baader	new	$70
Electronic focuser	AccuFocus	Orion	new	$75
Focus controller	FCUSB	Shoestring	new	$79
Imaging/stacking software	Nebulosity	Stark Labs	new	$80
Post-processing	StarTools	Silicon Fields	new	$60
Total				$1519

So I guess my $1519 bottom line isn’t exactly cheap, but it lets me do wide field, lunar/planetary, and reasonable galaxy/nebula astrophotography for a price that is about the same as most people’s camera or mount alone, so I still feel pretty cheap.  Fortunately, I didn’t get this all at once either.  These purchases have been spread out over about 3 years, so I didn’t feel them very much.  

My current deep sky imaging rig.