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Short-bus / pilomar

RaspberryPi based miniature observatory
https://shortbus.blog/
GNU General Public License v3.0
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Observing an eclipse with pilomar #62

Open Short-bus opened 7 months ago

Short-bus commented 7 months ago

wyoming4wheeler on Instructables asked :

Does anyone have suggestions on how to setup the software to capture the up coming eclipse. I have scheduled a campground in the middle of Missouri to be able to setup and capture the eclipse and hopefully the devil comet all at the same time. I am concerned about the length of time of captures considering I will only have 4 minutes of the actual eclipse - but I want to make sure I am capable to capture the comet as well. Just started trying different captures. Also, do I need to use the daystar solar filter that I bought to use with the lens. Not sure whether the camera sensor will be fried looking directly at the sun.

Short-bus commented 7 months ago

The eclipse... there's an exciting challenge.

Some immediate thoughts...

Disable a few features. You don't want it to start doing admin tasks mid observation.

Set UseTracking to false in the parameter file. Set GeneratePreview to false in the parameter file. Set ScanForMeteors to false in the parameter file. If you're set up in plenty of time you can manually 'tune' the position via the motor menu, or from within the observation by pressing the 'm' key. You could do this by examining the .jpg files as they arrive in the /light folder. Print out a copy of a 'preview' image from the /preview folder in advance and us that as a reference for the adjustment values. It should keep the sun in frame for you for quite some time if setup and tuned manually.

The 'cycle time' between exposures will be quite short so you should be able to capture plenty of images. There's a quirk of 'raspistill' that the cycle time can be double the exposure time - which is noticeable for 20 second exposures, but negligible for really fast ones.

I wonder if video would be better than separate images, that's not in the current software. But you may be able to adjust the program to achieve it somehow, especially if the tracking and preview features are off.

Obviously make sure you've plenty of storage space available. You can insert a USB 3.1 memory stick into one of the blue USB 3 ports on the RPi. Format it with the label 'USBMEMORY' and I think it will auto-mount and get used automatically if you have the RPi set to boot to the desktop in raspi-config. The UseUSBStorage parameter defaults to 'true' so it should switch to using it if it's detected.

I'd expect you'd need a solar filter to protect the sensor, but haven't tried it. And I'd close the aperture down a lot too.

I'll think further on it, hopefully others have experience already of photographing an eclipse and let us know!

Short-bus commented 7 months ago

To have TWO objects in the image at the same time I suppose you would want a RADEC target which is between the two actual objects. You could build a python query using skyfield to calculate the RADEC coordinates of the sun and of the comet at the time of the eclipse and calculate the midpoint of those two locations. Then in pilomar create your own RADEC target with that averaged position. You can do this in advance, so it's available to you on the day in the 'repeat earlier observations' list.