getting started with ASI294MC pro + SharpCap

[jonstarrysky]

So I bit the bullet on this camera, wanting the wider field for my long FL scope and EAA....

Apologies for some basic newbie questions:

Initial testing in the garage - installed the ZWO driver and imaging software on my tablet and followed the ZWO instructions on how to get going. Seemed to all work as you'd expect, good communication with the camera eg responds to change in temp, gain, exposure settings etc. Live view window made sense. Lens cap was on, so image looked black, intensity histogram peak near the Y axis, but with histogram auto-scale ticked it revealed the live background noise (10s, 200 gain).

Closed the ZWO software and opened SharpCap. The camera was correctly listed by SharpCap and seemed to remember the gain setting I'd left it on (200). But not seeing any sign of life on the live view window. And selecting bin2 in SharpCap camera settings the live view went plain white (saturated), even when reducing the exposure to low milli-second. Any ideas ? Maybe the camera should be powered-up & connected fresh with SharpCap already open, and no prior communication with ZWO software ? Or perhaps its something to do with the histogram(s) ?

What strikes me is how feature-packed SharpCap looks compared to the ZWO acquisition software. The latter looks really simple and easy to get going with. SharpCap-Pro I can see is an incredible system and the obvious way to go, with the unavoidable inherent learning curve.

Jon

[admin]

Hi,

well done on getting your new camera!

The issue with no frames until you picked bin2 might be related to the 'Turbo USB' setting - setting that too high (and sometimes auto can be too high) can allow the camera to be detected but prevent frames from running. Try turning that control off of auto and turn down the Turbo USB.

For the white image, the first thing to do is to open the camera with the CTRL key pressed, which stops SharpCap from re-loading previous settings (the camera itself may remember settings from other apps, as you have noticed). Also, cover the camera/telescope with something to prevent light getting to it - that should change the image to black. If you don't see it change to black check that you are getting images (frame count increasing bottom left) .

The binned image will probably be brighter than unbinned, but shouldn't be that far out.

cheers,

Robin

[jonstarrysky]

Thanks Robin, will try these ideas.

Getting to grips with basic settings... "Capture Format and Area", "Colour Space": RAW16 would be the clear choice (over RGB24) for live-stacking EAA viewing with a OSC using SharpCap, mostly for DSOs ? Seems counter-intuitive to be specifying an unprocessed raw file format when we want to live-view a nice looking colour image of the target. I assume what is happening is SharpCap is enabling that raw data to be transformed to be displayed as an attractive image ?

"Output format" the main choice would be PNG or .FITS ? I read that "save as seen" files will automatically come out as 8-bit PNG anyway ? Maybe final tweaks from a "save as seen" file would be done in photoshop so PNG would work best.

Under the Live Stack Controls, I see "Raw Frames"_"Save Stacked" can be ticked to allow the stacking and image settings to be worked on at a later time using SharpCap, maybe getting a better version of the "save as seen" file. If this were done the choice of "Output format" is more relevant but would still work with either PNG or FITS ?

Jon

[admin]

Hi,

the 'Colour Space' controls the format of the data sent from the camera to SharpCap, so picking the highest quality (RAW16) is the right choice for deep sky. If you were just saving to file then the RAW16 data would go to file, which is good because it hasn't been processed so you can process it however you choose later. For things like display and live stacking, SharpCap knows how to deal with the RAW data properly and will take care of it.

I tend to use FITS format these days for deep sky work - PNG can hold the same 16 bit image data, but has less internal metadata containing camera settings, etc. Also, some image viewing programs can read 16 bit PNG but automatically (and silently) change it to 8 bit when reading it, which is a pain. Of course PNG files will be smaller and a bit faster to write, but that's not usually an issue. The best thing to do is to set the 'Default Still Format' to FITS in the SharpCap saving settings.

If you plan to save raw frames, FITS is a good choice, as other stacking programs (or SharpCap itself) will be able to load more information out of a FITS file and will know (for instance) the exposure time and gain etc when processing the files.

cheers,

Robin

[jonstarrysky]

Thanks Robin this is clear now. Key point I missed is the camera settings colour space is for what the camera sends to SharpCap, not what SharpCap its self generates. So RAW16 a no-brainer, ensuring that SharpCap has the best data to work with. Re file type default can be set to FITS, but when exporting "save as seen" from the Live Stacking panel, this can be set to whatever at the time I guess. Points noted on the benefits of FITS re preserving 16 bit depth and metadata, though I hear PNG can be easier to work with for limited final tweaks eg in Affinity Photo.