Posts Made By: Jason Khadder

Hello Rex,
As the person who came up with the offset pupil idea and as someone who spent extensive time evaluating the XLK, I will be more than happy to answer any questions you might have about the new autocollimator. As stated in the Catseye website, the 2nd pupil improves the ability to detect and correct collimation residual errors.
Jason

There is a general misconception that somewhat out-of-calibration laser collimators are useless. That is not true. Even if re-inserting/rotating the collimator yields different results, it can still be used to achieve a “reasonable” collimation as long as the following procedure is followed:

1- Insert the collimator and secure it. It should not be touched along with the focuser throughout the procedure.
2- Adjust the secondary to redirect the laser beam to point to the center of the primary mirror center mark. If there is too much laser glow, you can shine light down the tube to reduce the laser glare.
3- Adjust the primary mirror to redirect the return laser beam to the source

Nothing new about the first 3 steps

4- DO NOT re-evaluate collimation if you touch the laser collimator or the focuser. DO NOT re-evaluate collimation if re-inserting/rotating the laser collimator moves the laser beam away from the primary center.

A slightly miss-calibrated laser collimator does an OK job with the primary mirror axial alignment which is critical to minimize “coma”. It does a poor job in aligning the focuser axial alignment which is not as critical for visual observation.

Of course, as others suggested, using barlowed laser is the recommended method for aligning the primary mirror.

Jason

I am someone who actually replaced the XT10 stock mirrors with premium ones. My new primary 10" Pyrex mirror was made by Ed Stevens -- a reputable optician who used to be part of the Zambuto team. My secondary mirror is quartz from ProtoStar. I also replaced my focuser with a Moonlite with tri-knobs. The cost of these 3 upgrades was in excess of $1500 -- 2.5X the cost of my original XT10.

Would I do it all over again? Yes
Would I unequivocally recommend the same upgrades to other XT10 owners? No
I said “No” because the improvement is subtle and might not be worth it to everyone. To appreciate the premium optics, you need to be an experienced observer; otherwise, you will hardly tell the difference. Do not expect a jump in view quality akin to the jump for an old CRT TV to a new High-Definition TV. It is more akin to the difference between a low-end HD TV versus a high-end HD TV.

If you are keen on improving the quality of your views then make sure you have covered your less expensive basics such as flocking and mastering the art of collimation before considering premium optics. A perfectly collimated stock optics might outperform a less optimally collimated premium optics

Bottom line, based on my experience I have more appreciation for premium optics and more respect for stock optics.

Jason