Two Moons: 27 and 28 May 2015





I took the first photograph late yesterday evening (27 May, 11:37 p.m.). I had thought that the sky was too hazy, but I looked out fairly late and saw that the moon was not too badly obscured.

I took the second photograph early this evening (28 May, 7:00 p.m.) while the moon was just climbing above some trees in our neighbors’ yards. The original full-sized image showed some very blurry foliage in the lower right corner; I cropped it out, and then I played with the image in Lightroom to create an almost black background. I increased the contrast quite a bit, as the sky was fairly hazy.

The second photograph shows the moon “lying on its back.” Both images show approximately the orientation of the moon at the time I took the photographs.

I took both photographs with my Orion StarMax 127. This scope uses a Maksutov-Cassegrain design, which has a folded light path: that is, the light passes through a glass meniscus at the front of the tube; reflects from a curved mirror at the base of the tube; reflects off a mirrored spot on the back of the meniscus at the front of the tube; and then passes through a hole in the main mirror to reach the eyepiece or (in this case) the camera.

Maksutov-Cassegrain (and Schmidt-Cassegrain) designs avoid the chromatic aberration problems that afflict achromatic refractors, and they also avoid the problem of off-axis distortion that affects Newtonian reflectors. (These designs are known as catadioptric: they use both lenses and mirrors.) Catadioptric designs also use much shorter tubes. The StarMax has a very compact tube, but its focal length exceeds that of my Meade AR5 127mm f/9 achromatic refractor (StarMax, 1540mm; Meade AR5, 1143mm).

I originally bought the StarMax back in 2001. I picked up my Meade AR5 in 2007. Because both are five-inch scopes, they should perform about equally well. But I think the Meade is actually a bit better scope. I think the images are a trifle crisper. But I need to take more photos with both scopes before I decide. I had better viewing the night I took out the Meade than I’ve had the last two nights with the StarMax.

Below is a photograph of the StarMax with my Samsung NX300 camera mounted on it. Note that I had brought the scope indoors; the tripod legs are not extended, so the mount looks a bit stubby.

Orion StarMax 127

Moon, 25 May 2015 (Just Past First Quarter)



I took this photo this evening using my Samsung NX300 mounted on my Meade AR5 refractor telescope.

Here is a photo of the setup:

Samsung on Meade AR5

I purchased the telescope back in 2007. I already owned the equatorial mount (i.e., the black metal thing on which the scope is mounted); I purchased the wooden legs in 2007, too, I think. (The mount originally had metal legs. Wood absorbs vibration better than metal.)

I hadn’t used the scope for a while–in particular, after my youngest child was born in 2008. Recently, though, I realized that I could in fact do some astrophotography. I took a few moon shots with an old Phoenix zoom lens (100-500 mm), which I mounted simply on one of my camera tripods.

I then ordered gear to mount my Samsung NX300 to a telescope. It took me a while to get the gear together (my first adapter wouldn’t work), but this evening I finally had the gear and the weather to take a photo of the moon. I think it turned out all right.

I’ll admit, though, that I’m not fully satisfied with the gear. The various adapters seem a bit wobbly to me. I may try different adapters to avoid the wobble.

In the meantime, I’m happy that I was able to take a photograph resolving features smaller than 16 kilometers across on the moon. That’s just a ton of fun for me.