Why do I need the Explore Scientific 2" Extension Tube for my ED APO telescope?
You need this extension tube if you cannot reach focus because your focuser is racked all the way out. This often happens when using accessories like DSLR cameras, some flatteners or reducers, or certain long focal length eyepieces that require the focal plane to be further away from the telescope tube.
Will this Explore Scientific 2" Extension Tube work with focusers from other brands?
This extension tube is specifically designed for the 2-inch rack and pinion focusers found on Explore Scientific ED APO telescopes. While it may physically fit other 2-inch focusers, a perfect mechanical and optical match is only guaranteed with the intended Explore Scientific models.
Can I reach focus with my DSLR camera on an Explore Scientific ED127 using this 2" extension tube?
Yes, this is a primary use case. A DSLR camera's sensor is recessed deep within the camera body, requiring significant out-travel from the focuser. The Explore Scientific 2" Extension Tube provides the necessary spacing to bring the ED127's focal plane to your DSLR sensor for prime-focus imaging.
I'm using a 2-inch diagonal and a long focal length eyepiece on my Explore Scientific refractor and can't reach focus. Will this tube help?
Absolutely. Some combinations of diagonals and long eyepieces consume less light path than the telescope was designed for, requiring the eyepiece to be positioned further out. This extension tube will bridge that gap, allowing you to achieve a sharp focus with your low-power, wide-field eyepiece setup.
How does the Explore Scientific 2" Extension Tube attach to the focuser?
The extension tube inserts directly into the 2-inch drawtube of your Explore Scientific focuser, just like an eyepiece or diagonal. You then insert your accessory into the other end of the extension tube and secure both using the focuser's and the tube's compression rings or set screws.
Does adding the Explore Scientific 2" Extension Tube affect image quality?
No, the tube itself contains no optics and is simply a spacer. As long as it is securely fastened and your optical train is properly aligned, it will not degrade image quality. It is designed to be a rigid, passive component in your imaging setup.
