I would start by tilting the primary (as you did for the mirror flop study) then tilt the secondary to produce the best "on axis" star.? But OSLO will probably?re-center the corrector, though I think there is a way to prevent that. If not then it may be necessary to tilt and offset the corrector to correspond to the mechanical?situation.?

It's been awhile since I played with OSLO but if you post the C-14 elements then I'll give it a try.

My guess is that primary mirror tilt (with compensating secondary tilt, i.e. "collimated") has?minor affect within?less that an?arcmin?and then quickly explodes with aberrations past?that point.??It would be interesting to see how much tilt can be tolerated.

Stan

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Christian,

The moon shots are fantastic!

The OSLO simulations are interesting.? The Sensitivity to primary mirror tilt (image shifting)?section?assumes that the primary's null position is perfectly aligned, which seems a dubious supposition. It would be interesting to see the effects of a tilted primary?with?the secondary collimated to compensate for the primary tilt, which means that the corrector becomes offset from the optical axis.?(Though if I remember correctly, that is?difficult to simulate in OSLO because of auto axis realignment.)

Stan

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You have no right to complain!

That image is competitive with Christopher Go.

I enjoy the blue streaks because they are holes in the clouds that reveal an Earth like nitrogen atmosphere.

Stan

Frustrating seeing this night. Excellent for the red channel, mediocre for green and blue!That was the pattern all night! Here is a combination of two data sets taken over 11 minutes:

Brian

SCTs are?easy to?collimate?because there is only one accessible adjustment - secondary tilt-tip.? Collimation aids are entirely unnecessary and of dubious value compared to star collimation.?Star collimation is very sensitive and precise, though it may take some time to develop an eye for assessing the?concentric placement of?diffraction rings (start with centering the shadow).?

A potential problem with most collimation aids (incl artificial stars) is that they require?collimating in horizontal position. That?can easily result in miss-collimation?when sky pointing, due to?flexure (esp of the primary). This is more likely in larger scopes but can occur for any scope.

Save your money for a sexier gadget.

Stan

Or you can spend no money and simply use a paper donut mask. It actually works very well:

I just recollimated my C14 a couple of nights back using the magnified LiveView on a DSLR. It took just a couple of minutes. Much easier than doing it visually.

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Nice looking setup.?

I'm not familiar with that mount. Do you like it?

The star shapes?look pretty good.

Stan

Personally I'd go with a Televue 41mm Panoptic or a 31mm Nagler. They have basically the widest FoV of any eyepiece in a 2" barrel, with the 41mm very slightly wider. Televue has an eyepiece calculator on their website that gives all pertinent info as regards their own eyepieces on any OTA. Advantage of the 31mm Nagler is that it gives higher magnification (darker background?), but some may find the 82 degree apparent FoV too wide with the 65 degree AFoV of the Panoptic more cosy. I suspect that since Al Nagler is so passionate about his eyepieces, their image fields are quite flat and hence suited to the Edge HD. But that really needs confirmation from somebody who has actually used them on said scope. Perhaps try asking on Cloudy Nights?

Reflections are not necessarily from the EP. Check the diagonal and everything in the image train for any unblackened surface. Also check the EP; you might be able to fix the problem.

I recommend?a high quality wide field EP in the range of 25-35mm. Buy?from Orion or other retailer that allows return for full refund.

Stan

LOL - I thought it was some DSO I had never heard of.