iPad Holder for flat frame generation

# A Holder for Your iPad So You Can Use It To Make Flats
This will help turn your iPad (10th generation) into a flat frame illuminator for astrophotography. As currently designed, it works with a small aperture telescope whose dew shield outside diameter is a bit less than 93 mm (snug for 93 mm).

Print two of these, do a little cutting and gluing, screw them together and there you go.

A 10th gen iPad is 9.8" by 7.1" and those are the dimensions this device supports.

I'm providing my FreeCAD design file. Feel free to adjust the parameters for a different size dewshield or iPad.

There are at least two iPad apps you can use to create the illumination:
- HSB Light (a plain aqua icon)
- Light Panel Pro

*Warning:* In the procedure below, it's best to not make the exposures too short because I've heard that the iPad backlight brightness is controlled by PWM and if exposures are too short, you'll get banding in the flats. Better to use longer. I don't go below 0.75, but YMMV.