David's Images of the Day Photoblog
Views of the sun, moon, and stars
Waxing gibbous moon with 100% illumination (data from the US Naval Observatory site). The full moon is on the 15th. This month the full moon is known as the “Thunder Moon”. Image taken just after midnight with a Nikon D3s camera and Questar 3.5″ telescope (ISO 1600, ~1500 mm, f/16, 1/1000 sec). Raw image processed with Capture One Pro and Photoshop CS5.
A DSLR video and still image of the July “Thunder Full Moon. These were taken with a Nikon D3s camera and Questar 7” telescope. The moon disk just fits within the D3s sensor, and is clipped in the video. The official full moon is on the 15th, but these images and the video were taken within 4 hours of the full moon on the 14th. I used Adobe CS5 Premiere Pro to edit the video. The digital art version of the full moon was created using Nik Color Efex Pro — Weird Lines Filter.
After several days having problem with taking video images of the moon with the Nikon D3s, I finally figured out what the problem was. I was pointed to a reference on the net about an undocumented feature in Live View that impacts video capture (Thanks to Howard Ignatius). The secret sauce is “use the OK button”
“- There is some misinformation online stating that the camera does not allow true manual control over ISO, shutter speed, and aperture in video mode. That is absolutely not true. The feature is undocumented for some reason, but if you hit the OK button while in live view, a light meter will appear and it switches to whatever mode that you currently have set on the camera (manual, aperture priority, etc). That means if you’re on manual, then you can adjust all of your settings as you please. Push the INFO button to cycle through different display modes, including a live histogram, horizon level, grid, etc.” http://www.davidbergman.net/blog/how-to-get-manual-exposure-video-mode-on-the-nikon-d3s/
Bottom line, I now have manual control of the camera when taking videos!!!!!
The following video contains 15 second segments of the moon with different telephoto lenses comparing with and without the lens “vibration reduction” being enabled. When on tripod there is a difference. Let me know if you see the difference. The telephoto lenses and telescope used include the 600 mm f/4 VR, 600 mm f/4 VR + TC-E III 20 (1200 mm), 500 mm f/4 VR, 500 mm f/4 + TC-E III 20 (1000 mm), 400 mm f/2.8, 400 mm f/2.8 + TC-E III 20 (800 mm), 300 mm f/2.8, 300 mm f/2.8 + TC-E III 20 (600 mm), and Questar 3.5″ telescope (~1500 mm). The video was put together using Adobe CS5 Premiere Pro.
I’ve also included a still image of the waxing gibbous moon (97%) taken with the Nikon D3s and Questar 3.5″ telescope (ISO 1600, ~1500 mm, f/16, 1/1000 sec).
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Jet Transiting the Waxing Gibbous Moon. I am still having issues with the video mode automatic gain “feature” with the Nikon D3s. In doors with normal light levels it doesn’t seem to be that much of a problem. However, when trying to take video images of the moon through a telephoto lens, the moon is over-exposed. During the testing, I managed to catch a jet transiting in front of the moon. I happened very quickly (less than one second). The video below shows the transit across the lower part of the moon 1) as is; 2) zoomed in from 100% to 250%; and 3) zoomed in at 250% and slowed down to 33% speed. There was also some cloud cover moving during the sequence.
[Insert Video Here]
I also took some still images of the moon with the same camera and lens, but with a TC-E III 20 teleconverter. The goal was to see how sharp an image of the moon I could get with a 1200 mm lens. Focusing was through “Live View”, and to minimize camera shake used the “mirror up” mode to allow the system to stabilize. The D3s allows the use of “Live View” and “mirror up” because “Live View” is now selected via a button on the back of the camera. You don’t have the ability to use “Live View” and “mirror up”. The first still image of the waxing gibbous moon at 92% illumination was taken at ISO 200, f/8, and 1/200 second. The second at ISO 200, f/16, and 1/50 second. If I did my calculations right for a 1200 mm lens on a FX sized sensor, the moon should only move ~0.2 pixels for a 1/50 second exposure.
A composite of 897 images looking south taken after midnight. I used the Startrails program for creating the composite.
Second day attempts for a DSLR video of the moon continued to be problematic. It appears that the camera is controlling the exposure and not allowing manual selection of aperture, shutter speed, or ISO. The only way I could get an exposure that was not way over exposed was to add a TC-E III 20 teleconverter (effective 1000 mm).
To confirm that there was not a problem with the camera or lens I took this following single image of the waxing gibbous moon with the same setup (Nikon D3s and 500 mm f/4 VR lens + TC-E III 20 teleconverter (ISO 800, 1000 mm, f/8, 1/200 sec))
