Wednesday, July 9, 2014

Moon and Saturn

The Moon passed very near Saturn, from our perspective here on Earth, on the night of July 7, 2014. The image below is a composite of two sets of exposures taken with my Orion ShortTube 80, an Orion yellow #15 filter, and my Canon EOS Rebel T3.

The Moon and Saturn, July 7, 2014.

I used the yellow filter to test how well it might reduce chromatic aberration (CA). I wish I had taken an unfiltered image of the Moon for comparison. My experience has been that in order to get a decent shot of the Moon with my ST80 I need to use the stop down cap, which basically converts the scope from a 80mm f/5.0 to a 43mm f/9.3. CA is reduced, but at the expense of image detail.

This image was taken at 80mm f/5.0, and the red/violet CA was greatly reduced. I also used a technique that I learned to remove most of the remaining CA. I will write an article on that technique in the near future.

The color of the Moon has been enhanced a bit. This normally doesn't work out very well with lunar images on the ST80. I suppose that has something to do with the reduce aperture and CA. I thought it worked out pretty well here, though.

2 comments:

  1. Wow, you've been busy, Rory! I like the last method of diminishing blue halos, and the North America Neb. looks great! I thought Saturn was very cool, too. I thought about shooting it, too, so I'm really glad you got it. Very nice.

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