Apertura AD8 - 8" F5.9 primary mirror upgrade from Optic Wave Labs (Rebate Available)
Upgrade your Aperatura AD8 Dobsonian telescope with a premium primary mirror.
The single largest factor in optical performance of a telescope is the quality of the primary mirror. While the Apertura telescope is an incredible value for what you get, it is well known that the optical performance of primary mirrors made by this manufacturer (GSO) leave a lot to be desired once you have some experience under your belt. Upgrading the primary mirror to one that meets modern optical specifications can give you a significant improvement in image sharpness, resolution and contrast. Replacement upgrade mirrors from Optic Wave Labs will provide the optical quality you don't know you are missing out on.
OWL starts with genuine GSO mirrors so this is a 100% direct replacement for your telescope. Mirrors are brought into our own optical shop where they stripped of their optical coatings and evaluated for surface quality and over all optical shape. Next, an optician uses special optical tools to hand work the mirror into the final shape. The mirror is tested and hand worked repeatedly until the optical performance is what is considered to be excellent. After the optician is satisfied with the work, it is documented and the mirror is loaded into OWL's state of the art vacuum deposition system. The atmosphere is removed from the chamber by high vacuum equipment and a new high reflectivity coating is applied.
The result is a telescope mirror that is optically superior with greater reflectivity that the original mirror that is will replace.
OWL optical quality is specified at a minimum Strehl Ratio of .960 or higher with a peak to valley wavefront error of 1/8 wave or better.
What is Strehl ratio? Strehl ratio is a measure of optical performence in terms of a percentage of what is theoretically possible. A Strehl Ratio of 1.0 is optically perfect. The Minimum strehl ratio a parabolic mirror needs to be is .8 (80%). What is considered as optically good is about .91, Optically very good is .93, Optically Excellent is .95 or higher.
By comparison, hundreds of optical tests reveal that GSO parabolic mirrors are typically of a Strehl Ratio of .5 or less.
Trade in Rebate. We offer a $205.00 rebate for the trade in of your existing GSO mirror, Provided the mirror is free from scratches, chips or any other physical defects. To take advantage of the rebate, please contact us at 844-DARK-SKY for instructions of how and where to send your original mirror. Once we receive your mirror we will evaluate it and if accepted we will promptly mail you a rebate check.