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=== Tier 3: Full-sized Equatorial Mounts. === ----This kind of tracking requires a Polar Alignment (as explained in this [https://www.youtube.com/watch?v=plx6XXDgf2E video] and this [https://www.youtube.com/watch?v=oXgtGQq-3V0 video]) These are your typical "DSO's" - or Deep Space Objects. [https://live.staticflickr.com/65535/48435308061_3e32f23993_b.jpg Eastern Veil Nebula] - Credit /u/azzkicker7283 [http://apod.nasa.gov/apod/image/1407/m31_bers_1824.jpg Andromeda / M31] - Credit: /u/Bersonic (selected as NASA's APOD) [https://i.redd.it/rshr0ht4lhe41.jpg Vela Nebula] - Credit: /u/OkeWoke Don't be disappointed when you go out on your first night with new equipment and you don't get these kinds of results. Everyone makes progress, and anything is possible with determination. Typical Tier 3 rigs consist of many parts that all have to work together in order to produce an image. Being able to min/max your rig is a valuable skill, and is necessary to take your imaging to the next level. Most Tier 3 rigs consist of 5 main parts. A mount, a telescope, a camera, a guidescope, and an autoguider. The following are examples of Tier 3 rigs. ===== Some examples of typical Tier 3 rigs ===== [https://i.imgur.com/U8m3x0O.jpg /u/Orangelantern's Setup] [https://i.imgur.com/0paSGBC.jpg /u/azzkicker7283's Setup] [https://i.imgur.com/8NXRtow.jpg /u/Windston57's Setup] You'll notice these do not have guidescopes. That is because we use something called an OAG, or Off-Axis guider. This involves using a prism to grab a small amount of light that is otherwise wasted due to the size of your main cameras sensor. They work the same way as a guidescope, but are a little more difficult to use if you are just getting started. That said, they are a great way to cut down on weight and can offer even more accurate guiding, but also do not provide as much light to the guide camera compared to a dedicated guidescope. As such, it is wise to use a more sensitive guide cam. Its up to you to determine what you think will be best for you and your wallet. '''Refracting telescope on Orion Sirius mount''' ===== [https://imgur.com/a/cGwEG Breakdown of a Tier 3 rig - Visual Album] ===== ====== German Equatorial Mount ====== Your typical Tier 3 mount looks similar to this. The GEM (German Equatorial Mount) is the workhorse component of the AP rig. Equatorial mounts move at sidereal rate to cancel out earth's rotation. This allows for much longer exposures than a normal tripod, and an increased payload capacity over a skytracker allowing for larger telescopes and longer focal lengths for those small targets. Equatorial mounts also allow guiding for even longer exposures (more on this later) ====== Telescope/OTA ====== On top of the EQ mount is the imaging telescope. This is the scope that the camera looks though to take a picture. In this case, the imaging scope is an 80mm refractor. ====== Guidescope ====== The guidescope gives the autoguider its eyes. The magnification provided by the scope, as well as the extra light make auto-guiding quite accurate and easy. Many rigs use modified finder scopes as their guidescopes. In this case the guidescope is also an 80mm refractor, albeit a cheaper one. High quality glass is important for your main imaging scope, but less important for a guidescope. A simple singlet or doublet works great for this, and doesn't need to be very expensive. ====== Autoguider ====== While modern EQ mounts are quite accurate, they still require some help to track an object accurately over several minute exposures. This is where the trusty Autoguider comes in. A little CCD/CMOS chip in the camera watches a star closely, and if it moves, the Autoguider sends a signal to the EQ mount's motors to correct for the movement. The addition of an Autoguider to your rig can easily double or triple the exposure times you are able to get. Guide cameras people frequently use are the Starshoot Autoguider, ASI 120mm, or Lodestar. There are many other kinds of guidecams. The guidecam pictured here is an Orion Starshoot Autoguider. Check out the Wiki page on [[Autoguiding]] ====== Rings ====== In order to mount most telescopes to their mounts, astronomers use a type of clap called tube rings. These rings (marked in bright green) hold the telescope firmly in place. Make sure you buy the right size! Similar to tube rings are guide rings. These act the same as tube rings with one major difference. They allow the scope being held in them to be aimed. This is useful for guidescopes, because sometimes a guidescope needs to be moved to find a suitable star to guide on. This can also induce flexure, so make sure you purchase quality rings. You can also use tube rings for this purpose if you want to avoid flexure, but you will not have as much freedom to find a guide star. This is usually not much of a problem with today's more sensitive guidecams, but can still be an issue when you are shooting objects outside of the galactic plain. ====== Counter Weight ====== Telescopes and cameras are heavy! Because of this, equatorial mounts have counter weights. By sliding the weight up and down the counter weight bar, astrophotographers can balance out their rigs, as not to cause damage to the motors in the mount. Depending on your mount, it can be good practice to leave in a slight amount of imbalance to ensure your gears are properly engaged. Typically you want your telescope to be slightly heavier, but not enough to come crashing down. Just enough so that the telescope is always providing a small amount of resistance to being pushed. Overdoing it can also cause problems, so find a good balance. ====== Camera ====== This is where your camera goes. In many telescope designs such as Refractors, Schmidt Cassegrains, and Ritchey Chretiens, the camera is placed at the back of the main imaging scope. In Newtonians, your camera will go on the side of your telescope. Try to rotate your telescope so your camera is facing down as it helps with balance. ====== Focuser ====== Don't skimp here! by turning the knob, the user can adjust the focus of the telescope. Good focus is needed to obtain sharp crisp images. This focuser is a dual speed 1:10 Crayford. Some focusers can use motors for automation and increased accuracy. Look into Bahtinov masks if you are using a manual focuser as they can be a huge help with achieving perfect focus. There are also focuser upgrades, one of which is a Moonlite focuser, but they are expensive. That said, they are built with a much higher quality and are less prone to tilt. ====== Field Flattener ====== This is where your t-adapter, flattener or reducer goes. A flattener helps to correct distortion in some types of telescopes. The camera and t-ring can thread directly into the field flattener or into a standard nosepiece if you aren't using one.
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