Description

Custom Collimation Tool for Secondary Mirror Alignment Takahashi Epsilon

This eyepiece will make it much easier for secondary alignment.  When using the Takahashi eyepiece the black center region hides the reflection of the secondary mirror making it very difficult to see.  Even with good illumination, it is a bit of trial and error.  This telescope requires perfect alignment of both mirrors when imaging.  While the Takahashi eyepiece is excellent for aligning the primary mirror, it’s not easy to align the secondary.  This custom eyepiece will make it much easier to see when perfect secondary alignment is achieved.

You will use this along with the Takahashi eyepiece to collimate your Epsilon Telescope.

The eyepiece is made from a translucent PETG which allows you to illuminate the view by holding a flashlight against the side.  It has a black PETG printed crosshair centered around the central aperture.  You will install this into your Takahashi collimation tool in place of the Takahashi eyepiece.  Simply adjust the secondary until the crosshairs from the Takahashi tool and the custom eyepiece align.  Then swap out the custom eyepiece for the Takahashi eyepiece and align your primary mirror.  Recheck secondary collimation with the custom eyepiece and make an adjustment if required.  You may go back and forth between the two eyepieces as you refine your collimation.

Tip-  Orient the crosshairs of the custom eyepiece so that they match the spider vane, and orient the crosshairs of the Takahashi eyepiece so that they are 45 degrees from the custom eyepiece.  This will make it very easy to tell when the two crosshairs center on each other.  Also, make certain that the eyepiece is set all the way in and level.

See product image for view through Takahashi eyepiece: It’s very easy to see that the primary is well aligned.  The black reflection from the center of the tak eyepiece is centered within the primary circle.   I cant for the life of me tell if the secondary is perfect.  You can see the that the reflection of the spider vanes in the center look pretty good.  In this image I overexposed it so you could see the reflection of the secondary spot (out of focus football in the center), but to the naked eye this is invisible.   *Please note that it is very difficult to take pictures of this.  It looks like the outer annulus ring is not perfect, but it is.  It’s just uneven illumination. 

See product image for view through the custom eyepiece:  As you can see it’s extremely easy to tell exactly when the secondary is aligned in the optical axis.  By lining up the reflections of both the tak tool crosshair and my eyepiece crosshair there is no debate as to whether it is centered.  The view is crystal clear when illuminating the side of the eyepiece with a flashlight.