- Autoguider Comparison, SBIG ST- i vs Starlight Xpress Lodestar Review by Ed
I had the opportunity given to me by Woodland Hills Camera to test concurrently these two autoguide cameras during June of 2012. I could find no record of anyone else doing the same type of evaluation, so approached Farah with the idea. Both of these autoguiding solutions need a computer. Both are powered by USB.
Some observations –
Both are intended to fit in a 1.250 inch eyepiece opening, only the Lodestar did so, consider this to be minor and may well be fixed by SBIG as others have reported it. The sample I had did fit in a 1.253 hole.
The ST- i has industry standard connectors, while the Lodestar has an unusual connector on its guide port ST-4 interface. Some have reported problems with the Lodestar autoguide ST-4 output cable connection reliability, so decided to use my usual setup using computer USB to ST-4 converter (GPUSB, about $80 from Shoestring Astronomy).
I use the PHD Guiding program for autoguiding and Nebulosity 3 for image capture. Both of these Stark Labs programs are quite popular. This is where I had driver problems with the ST-i. The SBIG unit, being newer, isn’t yet supported by Nebulosity and needs a pre-release version of PHD (1.13.1). SBIG does include two programs on its CD that can be used for autoguiding and image capture. I’m told that Maxim DL works fine with ST-i, for both autoguide and capture.
The Lodestar driver was a normal Windows install.
The ST- i has finer resolution due its smaller pixel size but gathers fewer photons per pixel, take your choice.
ST-i camera pixel size: 7.4u x 7.4u formatted in a 648 x 486 array, 4.74mm x 3.55mm.
Lodestar camera pixel size: 8.2u x 8.4u formatted in a 752 x 580 array, 6.4mm x 4.75mm.
The ST-i has built-in shutter for taking darks, Lodestar not.
6/21/12 (Posted on 6/23/12)