Prime Focus Moon

I took the scope out last night in manual mode to shoot some portraits of the Moon. I took 49 shots in various configurations and camera settings as I was trying out the Canon Digital Rebel with the scope for the first time. I took many shots with the camera coupled to ScopeTronix 40mm ST Series Plössl but not one of them came out. I think the camera was so heavy that it was actually torqing the eyepiece in the tube and it caused all kinds of wierd warping of the image.

I then switched to prime focus configuration. If you aren’t familiar with this it’s where you attach the camera to the back of the scope’s optical tube assembly (OTA) which essentially turns my ETX90 into a 900mm telephoto lens!

I ended up with ONE perfectly framed shot that was reasonably in focus.

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Unfortunately I under exposed the image so some grainyness was introduced when I digitally enhanced the light levels in photoshop. I only took about 10 shots in this configuration as it required me to be a contortionist in order to frame and focus the shots — the Moon was near zenith so the scope was basically pointing straight up (which negated the need for the counter-weight, for those of you who have been following that…project?) As it happens one of the items on my Christmas list is the Canon Angle Finder C which really would have went a LONG way in assisting me tonight as I was trying to get under this.

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There was quite a bit of water vapor (and haze) in the air which was steadily increasing during the time I was outside. It wasn’t long before I began to notice a lunar halo much like the one I recently saw pictured over at Stuart’s Astronomy Blog. Here is my shot of this phenomenon.

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Lastly, probably the most interesting shot I took was of a prop plane that flew over. I was already focused on infinity so I swung the camera around and opened the shutter for about 5 seconds.

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Neato huh? At any rate it turned out to be a productive evening under the dirty skies. I finally got to bed about 4 AM (again this morning) to be awakened at 8 AM by my boys ages 1 and 3 (again this morning)… 🙁

Gotta love it!

3 thoughts on “Prime Focus Moon”

  1. That is a brilliant shot of the Moon you got there. It would make a great desktop wallpaper with the addition of some extra sky at the sides 😉

    It is interesting to see how far the Moon has moved, compared to Mars, since I took my halo image the other night.

  2. You mean the sides that got cut off? I need a wider angle lens for my camera. 🙁

    To get that shot I took about a 20 second exposure while using my finger in front of the lens as a dodge tool. After tripping the shutter I “orbited” my camera trying to keep the tip of my finger over the center of the lens in order to minimize the brightness of the moon –– difficult in the dark without actually touching the camera or tripping over the tripod.

    I took about 6 tries to get that shot which was the optimum of the bunch. The first 2 shots I hadn’t considered that I needed to keep my finger in motion… I got a nice shot with a big honking finger silhouette on it. 🙂

  3. That is a cool shot!!.I also use the prime focus method, most of the time.Lately,I have been trying to get shots using a “T”adaptor for my Pentax.I find that works quite well with only a couple minor problems which are:
    Focusing through the viewfinder(which I am ever so slowly trying to over come!)and centering the object.
    Clear skies also helps…….hmmmm,make that 3 minor problems.

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