An Informative Guide to Selecting the Top Equatorial Mounts for Buyers
Equatorial mounts are an important tool for astronomers and astrophotographers alike, allowing for precise tracking of celestial objects. These mounts, which come in different designs such as German equatorial mounts (GEMs) and tilted fork mounts, cancel out the apparent movement of stars as the Earth rotates. That’s especially important for long-exposure astrophotography, where any movement can result in blurry images.
GEMs, one of the most common types of EQ mounts, have a counterweight bar on one side and carry the telescope on the other. When the mount reaches the meridian, or a certain point in the sky, users must perform a “meridian flip” to adjust the counterweights and rotate the declination axis. However, tilted fork mounts eliminate the need for this flip by using a single supporting arm.
To align an EQ mount with the Earth’s axis, manufacturers typically include a polar alignment scope. However, not all scopes are created equal. Some require users to level the mount’s base and adjust the polar-scope reticule to match the time and date, while others, like Takahashi, have a more accurate and user-friendly method. Takahashi’s system includes a bubble level on the right ascension (RA) housing and a polar-scope reticule that aligns with the position of Polaris.
Another important consideration when choosing an EQ mount is the method of driving the mount. Traditional mounts use worm gears, but there are alternative options available. One interesting development is the use of backlash-free harmonic drives, which are just beginning to make their way into the market.
While EQ mounts are essential tools for astrophotography, they can also be quite expensive. Achieving tracking precision within 0.5 arcseconds, which is necessary for long exposures, requires precise engineering and advanced technology. Autoguiding systems, which provide real-time feedback to correct errors, play a significant role in achieving this level of precision.
Popular EQ mounts on the market include the Sky-Watcher EQ6 and EQ5 series. These mounts have been around since 2001 and are known for their durability and affordability. While they may require aftermarket improvements, they offer a solid starting point for astrophotography.
For those with a larger budget, the Avalon Linear GEM offers superior machining and backlash-free toothed belts. This Italian-designed mount is known for its meticulous craftsmanship and performance. Similarly, the Mesu Mount 200 from Lucas Mesu in the Netherlands eschews worm gears in favor of disc-based friction, resulting in a reliable and accurate tracking experience.
Another notable option is the 10 Micron GM 1000 HPS mount, which uses direct-drive technology to eliminate gears entirely. This mount relies on an electric motor controlled by absolute encoders to achieve precise tracking. However, this level of technology comes at a higher price.
For those looking for a more portable or budget-friendly option, there are also equatorial mounts specifically designed for star tracking or short-focal-length telescopes. These mounts are ideal for taking land and sky shots or capturing celestial events like eclipses.
Ultimately, the development of various EQ mounts has revolutionized the way astronomers and astrophotographers observe and capture images of the cosmos. From precise tracking capabilities to portability and affordability, these mounts offer a range of options to suit different needs and budgets. As technology continues to advance, we can expect further innovations in EQ mount designs, making astrophotography more accessible to a wider audience.
