Barlow Laser Collimation Technique Question

After viewing explicitly with a 6” f8 scope for 2 years, I recently acquired an Orion XT10. As I have found out, careful collimation is much more important at f4.7 than at f8.0. The scope came with a Lasermate which helped in aiming the secondary, but was frustratingly “twitchy” when trying to adjust the primary. A bit of web surfing turned up the barlow-laser technique which works quite well, other than the need to run back and forth between the adjustment screws and viewing the target screen.
But, I recently noticed that the “donut” is also visible in the viewing window of the lasermate. It is enlarged, due to the barlow I assume. In fact, by chance, it neatly fills the 2nd of 3 rings in the viewing window(see attached image). Sure makes final tweaking a snap, and it doesn’t seem to be bothered by the less than snug fit of the lasermate.

OK, finally my question (hehe)

Is there anything technically wrong with this approach? A bit of web surfing did not turn up anybody else using this approach.

Thanks in advance for your comments.

Steve
Fort Worth, TX

Attached Image:

Stephen
It looks good to me and nothing wrong as far as the barlowed laser and primary alignment are concerned. As long as your Lasermate is collimated and your center dot with donut is centered you should be good to go. One addition to really nail the collimation would be to add an autocollimator to finish off the collimation and make any final tweaks.
Buck

Is there anything technically wrong with this approach?

There's nothing wrong with it, but it isn't as insensitive to errors in pointing the reflected focuser axis towards the centre of the primary as the more cumbersome approach.

For best insensitivity to focuser axis errors, you want the virtual point source made by the laser plus barlow to be at the other side of the focal plane to the reading screen (and to have both at the same distance to the focal plane).

The rear view barlowed laser is, in this regard, probably unbalanced, though racking the focuser in completely will probably reduce the sensitivity to focuser axis errors.

If the laser itself is well collimated, though, that shouldn't be a problem, given that the focuser axis should be well set after having used the unbarlowed laser to set it.