Astronomy - David Mathre Photography

Wednesday (13-July-2011) — New Jersey

Backyard Summer Night Sky in New Jersey. Waxing Gibbous Moon. DSLR Night Video + Telephoto Lens Testing.

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).

Tuesday (12-July-2011) — New Jersey

Backyard Summertime Night Sky over New Jersey.

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.

Waxing Gibbous Moon (92%). Summer Night in New Jersey. Image taken with a Nikon D3s and 600 mm f/4 VR lens + TC-E III 20 teleconverter (ISO 200, 1200 mm, f/8, 1/200 sec). Raw image processed with Capture One Pro 6, and Photoshop CS5 (David J Mathre) — Waxing Gibbous Moon (92%). Summer Night in New Jersey. Image taken with a Nikon D3s camera and 600 mm f/4 VR lens + TC-E III 20 teleconverter (ISO 200, 1200 mm, f/8, 1/200 sec). Raw image processed with Capture One Pro 6, and Photoshop CS5

Waxing Gibbous Moon (85%). Summer Night in New Jersey. Image taken with a Nikon D3s and 600 mm f/4 VR lens + TC-E III 20 teleconverter (ISO 200, 1200 mm, f/16, 1/50 sec). Raw image processed with Capture One Pro 6, Nik Define 2, and Photoshop CS5 (David J Mathre) — Waxing Gibbous Moon (85%). Summer Night in New Jersey. Image taken with a Nikon D3s camera and 600 mm f/4 VR lens + TC-E III 20 teleconverter (ISO 200, 1200 mm, f/16, 1/50 sec). Raw image processed with Capture One Pro 6, Nik Define 2, and Photoshop CS5

Monday (11-July-2011) — New Jersey

Backyard Summertime Night Sky in New Jersey. Star, Jet, and Firefly Trails.

A composite of 897 images looking south taken after midnight. I used the Startrails program for creating the composite.

Star, Jet, and Firefly Trails. Summer Night in New Jersey. Image taken with a Nikon D3x and 14 mm f/2.8D lens (ISO 200, 14 mm, f/4, 8 sec). Composite of 980 images combined using the Startrails program. (David J Mathre) — Star, Jet, and Firefly Trails. Summer Night in New Jersey. Image taken with a Nikon D3x and 14 mm f/2.8D lens (ISO 200, 14 mm, f/4, 8 sec). Composite of 980 images combined using the Startrails program.

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))

Waxing Gibbous Moon (85%). Summer Night in New Jersey. Image taken with a Nikon D3s and 500 mm f/4 VR lens + TC-E III 20 teleconverter (ISO 800, 1000 mm, f/8, 1/200 sec). Raw image processed with Capture One Pro 6, Nik Define 2, and Photoshop CS5 (David J Mathre) — Waxing Gibbous Moon (85%). Summer Night in New Jersey. Image taken with a Nikon D3s and 500 mm f/4 VR lens + TC-E III 20 teleconverter (ISO 800, 1000 mm, f/8, 1/200 sec). Raw image processed with Capture One Pro 6, Nik Define 2, and Photoshop CS5

Sunday (10-July-2011) — New Jersey

Summer Backyard Nighttime Sky in New Jersey. Star, Moon, Jet, and Firefly Trails.

A composite of 980 images looking south taken before midnight. I used the Startrails program for creating the composite.

I had actually gone out to see what type of video I could take of the moon using the D3s camera and a telephoto lens. The moon phase (according to the US Naval Observatory site) is waxing gibbous (76% illuminated). I started by shooting some single images and found that ISO 200, 500 mm, f/8, 1/50 second should be about right. Even though I had the camera set to shoot in manual mode, all of the images of the moon were way over exposed. It didn’t appear that I had manual control while taking the video. I made sure that the ISO setting was fixed (not Auto), that Active D-Lighting was off, and that the white balance was fixed (4000 K). I need to try this again!

Star, Moon, Jet, and Firefly Trails. Summer Night in New Jersey. Image taken with a Nikon D3x and 14 mm f/2.8D lens (ISO 200, 14 mm, f/4, 8 sec). Composite of 980 images combined using the Startrails program. (David J Mathre) — Star, Moon, Jet, and Firefly Trails. Summer Night in New Jersey. Image taken with a Nikon D3x and 14 mm f/2.8D lens (ISO 200, 14 mm, f/4, 8 sec). Composite of 980 images combined using the Startrails program.

Saturday (18-June-2011) — New Jersey

Backyard Night Sky over New Jersey.

I think that this image of the waining gibbous moon with the D3x and 500 mm telephoto lens is sharper that the one I took with the D3x and 600 mm lens of the full moon 15-June-2001. Both were on a Gitzo tripod and Wimberley head, remote shutter, mirror up with 30 sec delay.

Waining Gibbous Moon over New Jersey. Image taken with a Nikon D3x and 500 mm f/4 VR telephoto lens (ISO 100, 500 mm, f/4, 1/160 sec). Raw image processed with Capture One Pro 6, Focus Magic, and Photoshop CS5. (David J Mathre) — Waining Gibbous Moon over New Jersey. Image taken with a Nikon D3x and 500 mm f/4 VR telephoto lens (ISO 100, 500 mm, f/4, 1/160 sec). Raw image processed with Capture One Pro 6, Focus Magic, and Photoshop CS5.