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Short Session of DSLR Jupiter Tests

Posted: 11 February 2015

Opening the observatory was delayed as I had to give an Oracle Dark Skies Committee update to the Friends of Oracle State Park. When I did open the observatory it would be for a short session due to a long day of errands the next day.

Open: Tuesday, 10 February 2015, 2049 MST
Temperature: 57°F
Session: 781
Conditions: Clear

Upon opening the observatory I discovered that the observatory digital thermometer display battery was weak. I could still read the display using a flashlight, but would have to replace the battery before the next session.

2057 MST: viewed Jupiter, 83X. Four moons visible as well as the Great Red Spot. I began setting up for D7000 DSLR eyepiece projection imaging. This night's tests would be limited to a magnification of 444X to determine whether or not that was too much magnification.

First, I did a focus test exposure on the star Regulus using a Bahtinov Mask. At 444X, seeing the diffraction pattern on the camera "live view" screen was challenging, even at ISO 6400. This 1 second, ISO 5000, exposure shows the diffraction pattern, so I knew the image was in focus:


Slewed back to Jupiter and did 60 and 120 second exposures at ISO 5000 and ISO 6400. I stacked the HD videos using Keith's Image Stacker. On the left below is a stack of 1331 frames and on the right is a stack of 1457 frames:

photo photo

Neither image is very good, certainly not as good as past images I've done. Apparently 444X is too much magnification to reliably image Jupiter using my equipment. I will do future tests using 222X.

Close: Tuesday, 10 February 2015, 2142 MST
Temperature: 54°F

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