Electronically Assisted Astronomy (EAA) means here real-time (or nearly real-time) viewing of astronomical objects (usually deep sky) with an aid of electronic device. Typically I use DSLR HDR-video or CCD live stacking, sometimes video cameras.
Electronically Assisted Astronomy comes with a moderate price tag, especially with the newest cameras. I use an Atik Infinity with my TMB 80 APO and an f/4 and f/6 Newton together with filters, reducer and flattener/reducer. The Atik Infinity is the first Atik Camera dedicated to EAA livestacking (to me different from “video astronomy”), having both the speed and sensitivity required for this rewarding technique, which with a very good, robust an simple SW. The Infinity features a Sony ICX825 sensor embedded with EXview HAD CCD II™ technology and 6,45 pixel size.
In the field I run the equipment with a very robust but small Lenovo X200 laptop. When I meet with visual observers in the field, they really like the color and details without need to collect data and rework them for hours (like for astrophotography) – it all works in minutes. It’s a compromise, EAA is semi-visual bit I still enjoy the view through their Dobsons – our eyes are the best camera(s).
Live stacking is a common-sense approach: you take a sensitive CCD camera that you already have for imaging (I have a also Lodestar X2 Guider), set for short exposures and connect to a laptop for real-time processing coupled with filters (CLS, SI II, Ha or OIII). The image is produced on the fly and improved with each new frame coming from the camera. If set for summing, the image will brighten with each new frame and the noise will diminish. Gradually the faint details will emerge … Easy! The Infinity Software registers automatically incoming frames (including shift and rotation) and also capable of basic stretching and color balancing operations. There are several programs available now: The Infinity Livestacker software (Infinity Camera Application included with drivers in the core software), the Starlight Live (free, but works only with Starlight Xpress camera), and the AstroToaster (uses Deep Sky Stacker engine) supporting DSLR and others.
In the picture above I used Pseudo HDR – overlay of a highly stretched picture and a low one over a blured mask. In PSE 12 it is not possible to work on the mask directly, but I used an adjustment layer on a sharp mask and blur it with brush and gauss filter. Photoshop Elements does support layer masks, but only with adjustment layers. An adjustment layer always comes with its own built-in layer mask, which is one of the reasons why they’re so useful. Well, what we can do is to “borrow” a layer mask from an adjustment layer, and “share” its layer mask with a normal layer.
With two or three cameras, tree tubes and filters, there are lots of combination to get the right Field of View (FOV) and sensitivity for the different Deep Sky objects and one needs to plan ahead. Sometimes I use Newton and APO simultaneously. Distance of the reducer is critical
|N f/4||ASA||65||10||11||44||Canon APS||OK|
|APO F/7.5||LP||55||0||11||44||Canon APS||OK|
|APO F/7.5||None||55||5.5||20||5.5||11||0||13||Infinity||OK K Adpt|
|APO F/7.5||None||-12.5||0||12.5||LodestarX2||L+K Adpt|
|Guider 60 mm f/4||None||-12.5||0||12.5||LodestarX2|
Of course, almost any CCD camera will do for live stacking, some even use DSLRs, but very sensitive cameras will do best. In order for EAA to work as observing tool it needs to be fast and easy to setup (e.g. no guiding, short exposures) and fast to acquire images (i.e. short exposures, sensitive) but guiding still helps.
Therefore choosing as sensitive camera as possible is a good choice. I already have Starlight Xpress Lodestar X2 B/W which I use for guiding, it is a very sensitive little camera and it works with Starlight Live, so I tried and liked it. To make it even easier I acquired the Atik Infinity which I love. IMHO live stacking is the most promising EAA approach, very natural, very versatily, quick, and as close as possible to observing/imaging. An the left there is an example with an 60Da combination of diferen filters, but reworked in Pixinsight.