How does an equatorial wedge work

At this point you can do one of two things. You can cut triangular pieces of wood to insert underneath the telescope mount board and hold it at a fixed angle, or you can cut larger pieces to attach on the outside of the long base board to support the telescope mount, but also give you the ability to modify the angle if needed. The tricky part here is the geometry.

The top surface of the telescope base mount must be raised to an angle equal to the latitude of your location you did write that down in step 1, right? That angle needs to be as accurate as possible, but for amateur purposes the tolerances need not be microscopic. Build the supports. You can and probably should use a wood router to make dado cuts and apply glue. I used wood screws. Raise the board to the desired angle. Remember to measure the angle of the top surface of the board.

Triple-check the angle, secure the board and drill holes on each side slightly smaller than the wood screws and into the edge of the board.

Insert screws. At this point you should have a working wedge. All you need is a clear night, and an understanding of how to polar align the telescope. The shelf under the telescope mount board can be used to store eyepieces, or a larger battery to power the scope's electronics. Sand everything down to remove any splinters and sharp edges and finish to your preference. On "Things you will need" - " If you consider all the pieces you have to cut, that's a safe bet.

If you can do the layout better than I can, you may be able to get away with using less wood. Yes No. Not Helpful 0 Helpful 1. Step 12 answers your question. It shows how to set the angle of the wedge after determining what the angle should be based on your location. Not Helpful 0 Helpful 0. For the bottom tripod plate, where to mount it to balance it properly and not be front heavy?

Your OTA is probably way too big for a wedge. I have never seen an 11" OTA on a wedge. Not Helpful 2 Helpful 0. Include your email address to get a message when this question is answered. The reason a wedge is needed for astrophotography is that if you do not align the telescope to true north, a photographic exposure of any significant length will show trails on all points of light except the one at the center of the image.

The polar axis of an equatorial telescope mount must be pointed towards the north celestial pole, which is the point in the sky at which all of the stars appear to rotate around. The RA motor in an equatorial mount slowly moves in one motion to match this speed of motion for accurate long exposure astroimaging. Here is a helpful list of mounts that are suitable for deep sky astrophotography. All of these models are widely used in the astrophotography community and are behind some of the most beautiful images shared on Astrobin, Flickr, and Reddit.

This design allows the attached instrument your camera or telescope to stay fixed on a celestial object by driving one axis at a constant speed. The equatorial axis is known as right ascension, while the perpendicular axis is called declination. The right ascension axis RA , rotates in one revolution every approximately 24 hours.

The mechanical design of an equatorial mount is better suited for astrophotography than an altazimuth mount alt-az. The latter will rotate the object in the focal plane, and generally have a harder time guiding the object.

For those interested in prime-focus astrophotography, a computerized equatorial telescope mount is essential. Right ascension is the axis that rotates around the north or south celestial pole depending on which hemisphere you are located in. The telescope mount must be accurately polar aligned to match the rotation of the night sky in RA.

In order to balance the telescope correctly in the RA axis, a counterweight must be used for balance. Equatorial mounts usually include 1 or 2 counterweights as a package, depending on the payload capacity of the mount. The RA right ascension disc is graduated into hours, minutes, and seconds, whereas the declination disc is graduated into angular measurements degrees, arcminutes, and arcseconds.

Setting circles are used in an equatorial mount to find astronomical objects in the night sky by using their equatorial coordinates. These coordinates can be a useful way to pinpoint objects on the celestial sphere and is often used in star charts.

Because the RA coordinates are fixed on the celestial sphere , the RA disc can be driven using a clock drive running in sidereal time. They measure the angle that the telescope is pointing, displaying the coordinates in digital format.

The celestial sphere is an imaginary sphere used for astronomy and navigation purposes. This is a practical method of plotting objects in space using the equatorial coordinate system. The primary structure of a GEM is a T-shape, with the right ascension axis at the lower diagonal position, and the declination axis on top.

The telescope is placed on the DEC axis, with a counterweight attached at a balanced position on the other end. A GEM is the best possible choice for long-exposure astrophotography.

In recent years, a new take on the German equatorial mount design has surfaced. The image below shows a new center-balanced design from iOptron, the CEM When the telescope is able to secure a target in place for hours at a time, you can then attach your camera and collect several long exposure images. This is essentially what deep sky astrophotography is all about, and almost every other aspect is geared towards improving this tracking accuracy with techniques such as autoguiding.

Align your mount using EQ North or South align and follow the onscreen instructions on the hand control. NOTE: Even though there are about named stars in the hand control database, only 82 can be used for alignment and related tasks. Here is the list. From refractors to reflectors to Cassegrains—there are so many telescope optical designs to choose from, Love Astronomy and Saving Money?

Although the alt-azimuth mount is simple and easy to use, it does not properly track the motion of the stars. In trying to follow the motion of a star, the mount produces a "zig-zag" motion, instead of a smooth arc across the sky. The zig-zag motion in the figure above is exaggerated and simplified for purposes of illustration; actually there would be more steps, and each step would be smaller. This makes this type of mount useless for taking photographs of the stars. The equatorial mount also has two perpendicular axes of rotation -- right ascension and declination.

However, instead of being oriented up and down, it is tilted at the same angle as the Earth's axis of rotation. The equatorial mount comes in two varieties:. When properly aligned with the Earth's poles, equatorial mounts can allow the telescope to follow the smooth, arc-like motion of a star across the sky. Also, they can be equipped with:.