Build a Barn Door Tracker The camera platform carries the camera and finder scope. It is hinged at one end and supported by the drive board at the other. Where the platform rests against the drive board, a hard strip of Nylon provides the "sliding point of contact." The camera bracket is made from 0.125" × 2" aluminum. A commercial ball head is mounted on the bracket to hold the camera. The ball head is the single most expensive component in the project, costing $40 — more than I paid for the stepper motor and gearbox. Careful mail order shopping will save you a lot of money on the ball head; I bought mine at a local camera store. The camera bracket can be mounted anywhere on the camera platform, although mounting it near the hinged end of the platform will provide the best stability. Also, you should select a location where the mount is least likely to interfere with your ability to look through the camera's viewfinder. I've already decided to mount at least one additional bracket on the lower part of the platform to make it easier to use the viewfinder when the camera is pointed at the northern sky.

The finder scope is used to polar align the mount. It is mounted on a piece of aluminum channel and held in place with a rubber band. The orientation of the channel was adjusted until it holds the finder precisely parallel to the mount's hinges. The photos show a 5x24 finder, but I recently switched to a 6x30 finder and a better finder bracket, which is a major improvement. There are two separate operations required for accurate polar alignment: When preparing for a photo session, I spend as much time as necessary to assure that the finder is precisely parallel to the hinges of the mount. Then, and only then, can the mount as a whole be accurately aligned with the celestial pole. Poor polar alignment is the leading cause of tracking error in barn door mounts, so it's worth doing it right. Aligning the finder with the hinges is easier said than done, but it is absolutely essential. Point the mount at any convenient star field. The region around the celestial pole makes sense, since you want the mount oriented in that direction anyway, but any star field will do.

Or, you can align the finder with the hinges in the daytime, using a distant object. While looking through the finder, swing the camera platform through its range of motion. custom french doors perthDo the finder crosshairs remain pointed at exactly the same spot as you move the camera platform? used garage doors for sale manitobaProbably not, which tells you the finder is not parallel to the hinges. kitchen door hinge cutting jigAdjust the finder slightly, and try again. bi-fold wardrobe doors for saleKeep doing this until the crosshairs stay on the same spot as you move the camera platform. sliding door tracks richmond

At that point, the finder is parallel to the hinges. It can easily take me 20 minutes to get it right on. Once the finder is aligned with the hinges of the mount, you can proceed to align the mount with the celestial pole. door hanger template aiThe latitude screw on the latitude wedge is first set to its mid-range. garage door parts hartford ctThen the tripod legs are adjusted to make the bottom of the latitude wedge roughly level. While viewing through the finder scope, the entire tripod is then carefully moved in azimuth and the latitude screw adjusted until crosshairs in the finder are on the celestial pole. I used SkyMap Pro to print a finder chart that matches the view in the finder scope and lets me estimate the location of the celestial pole quite accurately.A simple tracking mount, which can be made with a few dollars in parts

cam really enhance night photography. An isosceles type barn door tracking mount tracks well for about 20 minutes if the polar alignment is good. Here are images for my barn-door mount. Using a 1/4-20 screw, the distance from the hinge pivot point to the center of the screw is 11.42 inches. I used two 1.5 x 3/4 inch oak boards cut to 14-inch lengths (NOTE: I recommend using a 2-inch wide board because putting some of the hardware on is pushing the limit (e.g. Figure 6, below). I mounted a Giotto MH1302 ball head (which is impressively sturdy for such a small low cost head) to hold my camera. It holds a Canon 1D Mark IV with 24 mm f/1.4 lens (2.17 Kg = 4.77 pounds) very well. rig with ball head and arca-swiss mounting plate and Allen wrench for the 3/8 bolt, as shown in Figure 1) weights just 0.99 kg (2.18 pounds). To track the stars, I orient the mount to push the boards apart (hinge on the west side in the northern hemisphere).

Then I turn the crank by hand with 1 rotation per minute. I typically do 30-second exposures with my 24 mm f/1.4 lens at f/2. So at 15 seconds, it should be at 1/4 rotation. On the bubble level shown in Figure 6, I drew circles for 2 degrees off vertical. I use a compass to orient to north (there is little offset between the magnetic pole and true pole there), and the level to set the angle down to the celestial pole. As one may pretty restricted in location, one may not be able to see the either pole due to trees or clouds on the horizon. The bubble level and compass works just fine. wedges for other commonly used latitudes and mount a bubble level on the wedge. An error of a few degrees off the pole is of no consequence for short exposures of less than about a minute with wide angle lenses. I was initially concerned about vibration from hand cranking, but it does not seem to be a problem. But do note, that I have the screw coming up from the bottom.

from touching the crank are on the arm that is on the tripod ball head, and not on the arm with the camera ball head. One might get more vibration with the crank on the arm holding the camera. I use one finger touching the side of the crank lever to turn it, so vibrations are minimal and I have never seen a problem. But I have not tried to track with anything longer than 24 mm. A diagram with other details is shown in Figure 7.The tracking screw (see Figure 1) is too long in my design. I had one case with the camera pointing up where the screw touched the camera and destroyed the tracking. The screw should be at least an inch shorterThe Milky Way Galaxy Over the Serengeti. The Milky Way galaxy stands tall over the Serengeti in this view to the northwest from Ndutu. about 110 degrees tall and 80 degrees wide in this 10-frame mosaic. The Pleiades star cluster is just above the left edge of the large acacia tree, and above the Pleiades is the planet Jupiter.

Just above the largest acacia tree, center, is a red smudge: that is the California nebula, NGC 1499. The constellation Orion is at the upper left edge and with Orion's belt nearly vertical. The 3 stars in the sword has the bright Orion nebula (M42) in the center of the 3 stars. The sword stars point toward the north celestial pole, which is 3 degrees below the horizon near the left side of the image. The bright star at the center near the top edge is Procyon, Alpha Canis Minor. The small star cluster to the upper right is M44. The Milky Way Galaxy in this part of the sky is the faint part of the Milky Way, as we are looking away from the Galactic center. the bottom of the image we see faint red and some green in the sky: this is auroral airglow. northern horizon appeared bright, even though this is some of the most remote and darkest places on Earth. Lights from the Ndutu lodge illuminated the trees.Canon 1D Mark IV, 16 megapixel digital camera, 24 mm f/1.4 L lens at f/2.