Arch Night
The rock arch near White Tank campground in Joshua Tree. I shot a similar photo of the arch with my Rebel XT last year, but the noise and colors ended up out-of-control. Right after the sun set around 5 PM, the entire sky clouded up. We huddled around a small fire in freezing temperatures for several hours, constantly hoping that the sky would clear so we could shoot star photos. We finally decided to take turns checking the sky at intervals, and around 10:30 PM I went to bed. After half an hour, just when I had gotten warm and was drifting off to sleep, Matthew Saville informed me the sky had cleared. Michael Relich, Matthew, and I proceeded to shoot star photos and timelapse until around 6 AM, when we finally went to bed to catch a couple hours of sleep. After shooting this image, I set up my dolly and filmed timelapse of the arch.
Image Creation:
I shot 8 15-second exposures at ISO 6400 and f/2.8. These photos provided the data for the stars, and the exposure time was short enough for no star trails to appear. I also shot 4 30-second exposures at ISO 3200 and f/2.8. During these 30-second photos, I put a CTO (orange) colored gel over my headlamp and light painted the arch so it wouldn't be a silhouette. All images were shot on my tripod-mounted 7D with a Tokina 11-16mm f/2.8 at 15mm. The camera was not moved between images.
Processing:
I used DeepSkyStacker to align the 8 star images. Basically, this shifts the images so that the stars are always in the same place, in order to correct for the rotation of the Earth. I layered the aligned images in Photoshop using lighten mode, which reduces noise and brightens the image a bit. I also stacked the light-painted arch photos using lighten blend mode, which again reduces noise and evens out the light painting. I then flattened the stack of light-painted arch images and the stack of aligned star images. I blended together these two using quick masks. Finally, I massively brightened the image and enhanced contrast using Curves, increased the saturation, and sharpened with Unsharp Mask.
Arch Night
The rock arch near White Tank campground in Joshua Tree. I shot a similar photo of the arch with my Rebel XT last year, but the noise and colors ended up out-of-control. Right after the sun set around 5 PM, the entire sky clouded up. We huddled around a small fire in freezing temperatures for several hours, constantly hoping that the sky would clear so we could shoot star photos. We finally decided to take turns checking the sky at intervals, and around 10:30 PM I went to bed. After half an hour, just when I had gotten warm and was drifting off to sleep, Matthew Saville informed me the sky had cleared. Michael Relich, Matthew, and I proceeded to shoot star photos and timelapse until around 6 AM, when we finally went to bed to catch a couple hours of sleep. After shooting this image, I set up my dolly and filmed timelapse of the arch.
Image Creation:
I shot 8 15-second exposures at ISO 6400 and f/2.8. These photos provided the data for the stars, and the exposure time was short enough for no star trails to appear. I also shot 4 30-second exposures at ISO 3200 and f/2.8. During these 30-second photos, I put a CTO (orange) colored gel over my headlamp and light painted the arch so it wouldn't be a silhouette. All images were shot on my tripod-mounted 7D with a Tokina 11-16mm f/2.8 at 15mm. The camera was not moved between images.
Processing:
I used DeepSkyStacker to align the 8 star images. Basically, this shifts the images so that the stars are always in the same place, in order to correct for the rotation of the Earth. I layered the aligned images in Photoshop using lighten mode, which reduces noise and brightens the image a bit. I also stacked the light-painted arch photos using lighten blend mode, which again reduces noise and evens out the light painting. I then flattened the stack of light-painted arch images and the stack of aligned star images. I blended together these two using quick masks. Finally, I massively brightened the image and enhanced contrast using Curves, increased the saturation, and sharpened with Unsharp Mask.