The Wooden Wedge

We had a terrific stretch of great viewing conditions in September 2017. Meanwhile, I’ve authored an astronomy article for Northern Home, Garden, & Leisure magazine. It’s a publication targeted to residents of neighboring Clinton county, NY. The September issue can be seen on-line here.

The Wooden Wedge

I’ve been experimenting with a home-made equatorial wedge, in an effort to determine whether it’s worth investing in a commercial metal wedge. The wooden wedge is made from pine boards and a piano hinge. It’s far from rock-solid as required of an equatorial wedge, but is sufficient for experimentation.

An equatorial wedge allows the telescope base to be mounted at an angle matching the latitude of the observing location, thus aligning the fork arm with the northern celestial pole. This is important for astrophotography.

IMG_4593Setting up the wedge and properly aligning it to the north celestial pole takes considerable time, which has always been the source of my hesitation in dealing with polar alignment. But I’ve been practicing in hopes of reducing this to under an additional 15 minutes. If possible, it might then be worth setting up the wedge for my impromptu observing sessions at the cemetery. So far the experiments have been encouraging and I’ve taken some improved pictures.

HD Pro wedge
Celestron HD Pro Wedge

I’m sufficiently pleased with the results that I’ve decided to order a Celestron wedge and will be trying for longer exposures in coming days. The Celestron wedge is rock solid and weighs about 30 pounds.

Lagoon Nebula 1.1 2017-09-26
Lagoon Nebula taken on September 26, 2017. It’s a stack of four 60-second exposures, ISO 800, taken with the wooden wedge and after polar aligning relative to Altair (without any drift alignment). Processed in Nebulocity. The moon was six days old.
2017-09-26 Dumbell Nebula 1.0
Dumbbell Nebula taken with the wooden wedge under the conditions mentioned above. Note the stars are reasonably round and sharp, which indicates improved tracking over my prior attempts. Still, the exposure time is only a minute. I’d like to achieve even longer periods.

I took about ten to twenty one-minute exposures of the above photos, and then picked a few of the best frames to stack. It was still hit or miss. The wedge is not stable and was affected by the slightest breeze or vibration. The Alt-Azimuth telescope is still not as smooth as I imagine a true equatorial mount would be.

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