01-August-2011

Startrails and Lens Distortion.

One problem I had with the startrail images I just published was that the circles  looking toward the north star were not exactly round. This is probably due to the non-linear distortions characteristics of wide-angle lenses, especially toward the edges. There is a program, DxO Optics Pro that corrects for distortion of various cameras and lenses. (Note that the current version of Adobe Camera Raw also does lens corrections for some camera/lens pairs, but not for the Nikon D3s and 24 mm f/1.4G lens used for this image). I used the DxO Optics program to process and correct the 328 images. It took over 12 hours for DxO to process all of these images.I then ran the reprocessed images with Startrails. Let me know (comment, or send me an e-mail) if you think the resultant image looks better, no different, or worse.

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North View Star Trails. Summer Night in New Jersey.  Images taken with a Nikon D3s and 24 mm f/1.4G lens (ISO 400, 24 mm, f/4, 1/30 sec). Raw image processed including Nikon 24 mm f/1.4G Lens Correction with DxO Pro. Composite of 328 images combined with StarTrails Program. (David J Mathre)
North View Star Trails. Summer Night in New Jersey. Images taken with a Nikon D3s and 24 mm f/1.4G lens (ISO 400, 24 mm, f/4, 1/30 sec). Raw image processed including Nikon 24 mm f/1.4G Lens Correction with DxO Pro. Composite of 328 images combined with StarTrails Program.

31-July-2011

Northern View Startrails. Summer Night Sky over New Jersey.

Going from sunspots to startrails. The view is from my back deck over the roof. A tree in my front yard just blocks the north star. The image is a composite of 326 30-second exposures combined using the Startrails program. There are at least four jet trails, and a couple of meteor trails. The meteor trails are too faint in the composite, so I included a crop from a single image showing a meteor trail. I’ve also added a version of the startrails in B&W, converted using Nik Silver Efex Pro 2.

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North View Star Trails. Summer Night in New Jersey. Image taken with a Nikon D3s and 24 mm f/1.4G lens (ISO 400, 24 mm, f/4, 30 sec). Composite of 326 images combined using the Startrails program. (David J Mathre)
North View Star Trails. Summer Night in New Jersey. Image taken with a Nikon D3s and 24 mm f/1.4G lens (ISO 400, 24 mm, f/4, 30 sec). Composite of 326 images combined using the Startrails program.

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Meteor Trail. Summer Night in New Jersey. Image taken with a Nikon D3s and 24 mm f/1.4G lens (ISO 400, 24 mm, f/4, 30 sec). Raw image processed with Capture One Pro, Nik Define, and Photoshop CS5 (David J Mathre)
Meteor Trail. Summer Night in New Jersey. Image taken with a Nikon D3s and 24 mm f/1.4 lens (ISO 400, 24 mm, f/4, 30 sec). Raw image processed with Capture One Pro, Nik Define, and Photoshop CS5

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North View Star Trails. Summer Night in New Jersey. Image taken with a Nikon D3s and 24 mm f/1.4G lens (ISO 400, 24 mm, f/4, 30 sec). Composite of 326 images combined using the Startrails program. Converted to B/W with Nik Silver Efex Pro 2. (David J Mathre)
North View Star Trails. Summer Night in New Jersey. Image taken with a Nikon D3s and 24 mm f/1.4G lens (ISO 400, 24 mm, f/4, 30 sec). Composite of 326 images combined using the Startrails program. Converted to B/W with Nik Silver Efex Pro 2.

 

11-July-2011

(1) Star, Jet, and Firefly Trails. Summer Night Sky in New Jersey. (2) Further attempts to record a DSLR video image of the moon

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

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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.

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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 appature, 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).

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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))

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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

10-July-2011

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

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 a 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!

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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.