Cassiopeia Observatory

Moon and SkyShed POD, Jupiter Video Tests

Posted: 14 January 2014

At 1815 MST, viewed the waxing gibbous moon, 83X. Then did a quick tour of the moon at 222X. Seeing was not very good. At 1822 MST, viewed Jupiter, still low in the east, 222X. Three moons were visible.

Went back to the moon and began preparations to photograph the moon projected onto the dome of the SkyShed POD. I last did a "moon on dome" photo on 15 May 2011 with an 18mm lens. This time I wanted to use my 8mm fisheye lens. I placed the D7000 DSLR on my "POD Roller Desk" and began taking photos at various exposure settings. This is a f/3.5, 10 second, ISO 500, exposure:

It nicely shows the interior of the observatory illuminated by the red rope lighting, but the moon on the dome is lost in the red illumination on the dome.

This f/3.5, 2.5 second, ISO 1600, exposure, with the red lighting dimmed way down, shows the moon projected onto the dome and the POD illuminated by moon light:

The view of the sky and the SkyShed POD illuminated by the bright moon was very nice, so I took this handheld fisheye photo, f/3.5, 1 second, ISO 1600:

The moon is at the upper right, with Jupiter below the moon. Several stars are also visible in the photograph.

I ended photography at 1847 MST. Resumed observing Jupiter, 222X. Seeing was better now. And four moons were now visible as one had completed its transit of the Jovian disk. I tried viewing at 444X, but seeing was not quite good enough. By 1904 MST, the Great Red Spot was just barely becoming visible at the limb of the planet. I continued to observe Jupiter, 222X, as it rose higher in the sky.

At 1944 MST, I began making preparations for video recording tests of Jupiter using both the D7000 DSLR and the iPhone 5s. In both cases I used the star Betelgeuse as a focus test using the Bahtinov Mask. This D7000 DSLR image is a stack of 630 frames from an HD video recording (24 fps), prime focus + 2X PowerMate, made at 1/200sec, ISO 3200:

The Great Red Spot is just barely visible on the right side below the Southern Equatorial Belt.

This next image is a stack of 603 frames from a D7000 DSLR HD video recording, eyepiece projection 444X, 1/30sec, ISO 3200:

The image was not upscaled, and shows the size increase by using eyepiece projection. The Great Red Spot is more easily seen in the larger image.

I then switched to the iPhone 5s. And yes, you can use the Bahtinov Mask for a focus test image with the iPhone. This is a cropped iPhone 5s photo showing the mask pattern that simplifies accurate focusing:

This image of Jupiter is a stack of 3535 frames from an iPhone 5s slo-mo video recording (120 fps), afocal 444X:

The Great Red Spot is visible near the central meridian. Two points about the iPhone image: 1. no moon filter was used to reduce Jupiter's brightness, and 2. the auto-exposure/auto-focus lock was not enabled. I had tried both of these on other video recordings, but the results were not as good as this.

I'm getting closer to yielding good results with the video tests, but have more testing to do on future sessions.

I ended the Jupiter video tests at 2038 MST, and slewed to the moon. This iPhone 5s full-frame photo of the moon was afocal 77X:

I resumed Jupiter observing, 444X, at 2054 MST. Seeing was not perfect, but at times of steady seeing, some good details were visible in and around the Great Red Spot. The view of the planet was really excellent using 222X. At 2100 MST, the Great Red Spot was nearly at the central meridian. At 2104 MST, I ended Jupiter observing.

Next, I wanted to try to see Sirius B (the "Pup" star) with the bright moonlit sky reducing the glare of Sirius A. I have previously seen Sirius B with the 8" LX200-ACF, but recent attempts have failed to show it. Slewed first to Rigel to check its companion star separation (using 222X), which is similar to the separation of Sirius A and B. I then slewed to Sirius and began using various techniques to try to observe Sirius B. No luck this night.