Meade High Precision Pointing (HP) - What is it? What is it for? And why it's so darn cool!
There is a feature in many of Meade's popular GOTO telescopes that you need to know about. It's called High-Precision Pointing (HP). An exclusive Meade feature, the High Precision mode in the Meade LX90, LXD75, LX200, LX200R, and RCX400 telescopes is truly a gift for anyone looking to start imaging the night sky with their telescope.
High Precision Pointing is a feature you turn on or off - its a feature you either use or not use. Meade telescopes such as the LX200 series are some of the most accurate pointing commercial telescopes available. For regular visual use, the High Precision mode is not needed. With Meade's easy alignment procedure, when you choose an object to GOTO, the object will be dead center in your eyepiece. After your alignment procedure is complete you may choose to use the Guided Tour mode - a personal chauffer of the best objects in the sky. Press the Saturn button, and you go to Saturn - dead center of your eyepiece. This will all happen without the the High Precision Pointing mode.
What happens when you have High Precision Pointing on?
When the HP mode is turned on, GOTO mode will act a bit different. When you choose an object for the telescope to slew to, M51 the Whirlpool Galaxy for example, when you press "GO TO" the telescope will first slew to a bright star near the Whirlpool Galaxy - the telescope will ask you to center this star in your eyepiece (for even more accuracy, you may use a illuminated reticle eyepiece with a cross-hair). Many times, the star it first moves to will already be centered in the eyepiece (thats how good Meade telescopes accuracy is) but may not be perfectly centered. The telescope will ask you to center this star and press ENTER when finished. Simply use the control pad and center the star in the eyepiece or cross-hair eyepiece. When you press ENTER - the telescope will move to the Whirlpool Galaxy - and it will be dead center in the middle of your field of view.
So what is the High Precision Pointing Mode used for?
Generally the High Precision mode is used for astrophotography. When imaging with a CCD camera or Digital SLR camera, its important to get the object your trying to shoot framed correctly on a small CCD chip. Its very important to have the object centered in the field of view. Suppose you wanted to image a very distant galaxy or a nebule that was hardly visible in your eyepiece, and really only visible through the process of long-exposure astrophotography. Having your disired image centered correctly on the CCD chip of your camera can be the difference of getting the image or not.
High Precision pointing can also be usefull for visual use. On very faint objects having the object centered in the eyepiece will assure you that your looking at the object. For example, the planet Pluto is very much in the reach of most telescopes, however in the eyepiece, it will appear just like all the stars around its field of view. Its important to note that for most all visual use, the telescopes normal pointing accuracy is extremely accurate and will put objects in the center of your eyepiece without the High Precision Pointing mode turned on.
Tips and Tricks with the High Precision Pointing Mode.
One of the most difficult parts of astrophotography is getting focus. Let's say your trying to take an image of the Orion Nebula with a Canon Digital Rebel DSLR camera. Unless you are using a flip mirror - your camera is attached to the scope and now you no longer have the luxury of using your eyepiece. Besides, the focus of your eyepiece and the focus of your camera on an object are completely different.
You can use the popular focusing technique aid called a Hartman Mask. With your camera attached and the High Precision mode turned on - when you choose an object, the telescope will first move to a star near the desired object (in this case the Orion Nebula). When the telescope moves to that star, you can simply release your shutter and take an image of this star. Using your Hartman Mask, you can focus on this one star only. Simply continue to take images of this star making adjustments to the focus until you achieve good focus. You can then also center this star in your camera by taking images of it and adjusting until its centered. When finished press ENTER as the telescopes keypad asks and the scope will go to the Orion Nebula. Release your shutter again on your camera and you will find the Orion Nebula in focus and centered in your camera!
For more information on the Hartman Mask focusing aid please visit our Hartman Mask page. And for a step by step process of taking a simple image with a Digital SLR camera check out our page Imaging the Orion Nebula - How did you do that?
Meade High Precision Pointing - A great extra feature exclusive to Meade telescopes.
Many Meade telescope owners will never turn on the High Precision Pointing mode and many didn't even know it was there. Its a feature that when used during your nights of imaging distant deep sky objects can be the difference of success or packing it up for another try another night.