Tuesday, February 24, 2015

NFeeder Progress; A Good Imaging Night at Last?

I added more to the Nebulosity script generator/feeder program NFeeder:
  • It now recognizes the time lapse setting, although I really don't understand the implementation of this in Nebulosity. (If you specify an exposure time of 15 seconds and a time lapse of 120 seconds, consecutive exposures start at 150s intervals. Time lapse is usually taken to be the time between consecutive frame starts. An alternative would be to treat it like a delay, setting the time between when a frame ends and the next starts. In the example this would give 135s between consecutive frame starts. I can't think of a rationale for 150s between frame starts given a time lapse setting of 120s.)
  • The status indicator now tries to show you when you're within a time lapse delay, although the above problem messes it up.
  • It can now parse a loaded script and set all the GUI widgets accordingly.
  • It now provides the total amount of exposure time the script will require and includes it in the script as a comment. At present it doesn't distinguish between light, dark, and bias frames; they all count as exposure time. I may change this. Nor does it take into account the time lapse setting. I assume total time when time lapse imaging is not as important as the clock time span of the session.
  • Auto-cooldown is now implemented. You specify the ambient temperature (to within the nearest 5 degree multiple), the set point, and the size of the temperature and time steps. You can also specify a final time interval to allow the camera to come to thermal equilibrium once it's been set to the set point temperature. The values of time delays must be found empirically. The following issue with the Delay command may impact how well this works--if it works at all.
  • I eliminated the possibility of delays after filter changes because of strange behavior by Nebulosity. Invoking the Delay command from clipboard commands seems to cause Nebulosity to ignore the clipboard for quite a bit longer than the delay itself. It's possible I may have to apply a workaround in which NFeeder itself provides the delays.
It's now in its fourth incarnation so it has a version number of 0.4! If you choose to download and try it, be aware that the help information is not up to date and won't be until the development of the beta is almost done.

Imaging tonight? Beautiful clear sky and a temperature around 30F now, but it will be falling through the upper teens and remain quite breezy when it gets dark.  Almost a first quarter moon, too. But fine for a 135mm Ha image of Sh 2-264, the big patch of nebulosity around Orion's head. It will be nice to get another winter object done.

Friday, February 13, 2015

Some odds and ends for a Friday the 13th...

AL Bright Nebula Imaging Planning
I took some time to plan my imaging for March and the Messier Marathon night. The tentative lineup, all to be imaged using the AT65EDQ, includes four objects. The Cone Nebula (NGC 2264) and Hubble's Variable Nebula (NGC 2261) in a single frame. Both of these are Lynds brightness 1 objects and available from the onset of darkness until about midnight (3 hours or so) meaning I can probably do a nice LRGB of them. After that it's on to LBN 10, high enough for imaging until about 3 A.M., and  then LBN 1122, good from then until dawn about 2 1/2 hours. LBN 10 is a brightness 6, so it may only be L; 1122 is a 4, so maybe that will get the LRGB treatment. Dan Crowson's scheme is usually 12x600s for L and 8x300s binned 2x2 for each color channel, giving a total exposure time of four hours. I'll probably go with a much shorter plan; 12x300 L and 8x180 RGB (132 minutes) for the two bright nebulae; 20x300L and 8x180 RGB binned 2x2 for LBNs 10 and 1122.

If a miracle happens and we get some good weather in March, these plans could change to include more objects. Let's hope.

Good Luck
While planning the imaging around the Cone Nebula area I noticed that another AL Bright Nebula, LBN 943, was nearby. In fact, 943 is essentially a part of the Rosette Nebula, and it shows up in the image I had of the Rosette. I had overlooked this and failed to enter it in the "done" list. It's included now, pushing my total to 78. I wish they were all this easy!

NFeeder Progress
Not much in the last couple of days. I've designed the interface for setting up the camera, using the PHD command, and providing temperature control (including a programmed drop to the setpoint).

I've decided to split scripts into three pieces: general setup  before image capture; the imaging commands; follow-up commands (such as a slow warm up, disconnecting from the camera, and shutting down Nebulosity). I'm not sure if this is a good idea at this point.

The weather continues to misbehave
Cloudy and warm evenings punctuated by rare clear and cold nights. The long range forecast suggests no imaging for at least the next week, by which time February will be 3/4 past. Good riddance.

Sunday, February 8, 2015

Nebulosity Feeder continues development

My little project continues. A lot of changes have been made since last time, thanks to suggestions from a club member who tried it out.

For the most part, the changes are intended to make the program a little smarter about how it does things. The program keeps track of the last download image folder used and the last folder used to save or load a script. The default filter wheel information is now stored in the Windows Registry. (Non-default filter wheel sets can be saved as text files.)

Scripts now allow for external filter wheels. And thanks to a suggestion from the program tester the program now lets you know more about capture status: Which filter is being used, which frame is being captured, and about how much time the frame has remaining. Nebulosity does this, but only in small print on the status bar. Look just above the script:

The box showing the script now automatically scrolls to keep the current command in sight. The status even indicates when the latest image is being downloaded.

The Script Editor now looks like this:

A big change is that the duration and frames can be selected using drop-down lists (you can still enter other values manually.) 

Because it's possible to manually edit the created script (and thereby introduce errors), the script gets parsed and error-checked as it's sent to the Feeder screen.

Lastly, the Filterset Editor is now a part of the main program instead of being a pop-up dialog:

It's been simplified to emphasize working with the default set. On the left is something new: Preferences. There's only one setting at this point, but I've left room for more. A new object I call the Preference Manager is now running nicely and ready for more work. Preferences are stored in the Registry.

Speaking of the Registry, I've made sure that an uninstall of NFeeder removes everything it put into the Registry.

Still to come (if there's interest) are
  • Options for using a larger set of Nebulosity script commands.
  • Night vision ability, which I'm finding difficult because it will require using Qt's stylesheets.
  • Better help files.

Want to try it out? The Download is HERE

There was actually a nice night a little over a week ago and I managed to sneak in a couple of images using my 135mm Olympus lens. It captured three more images toward my AL Bright Nebula list!

The latest images were post-processed with the aid of Imagenomic's NoiseWare Professional Edition standalone noise reduction software. It's almost too inexpensive to not purchase. There's also a Photoshop plugin available at a higher price.