Collimation of your scope's mirrors also requires the focuser to be perfectly square to the secondary mirror. That is why the secondary mirror has multiple degrees of freedom to be adjusted. The insertion of the plastic tube just provides a way of alerting you to the fact that your secondary mirror may not be square to the focuser. You could perhaps start moving the secondary toward true square alignment with the plastic tube inserted, and then remove the tube and finalise using a laser collimator.

If I shoot in the Scene/Star mode the camera sets the exposure length. If I shoot in M manual or B Bulb is just experiment with the exposure length to find what looks best.

Hi Phil, I don't think you need to be able to see the reflective surface of the secondary mirror to check its alignment. From the front of the optical tube, you should be able to see if there is a consistent gap between the edge of the mirror and the PVC tube. That’s all this test is about. Is the secondary mirror "square " with the focuser axis?

Haha

Here in Brisbane, button batteries are readily available at the supermarkets. Your experience is very surprising.

@@peterallison57 I'm in Brisbane, it's a federal law, something about providing them without safety instructions. I spoke with Sky-Watcher and they confirmed it's the case. They're working on a fix so they can send out illuminators to people who purchased their products but had the illuminator removed. It's frustrating but at least they're working to fix it. In the mean time I'm learning about aligning in the blind with various techniques, which is honestly worth doing anyway because Octans is hardly visible in most places.

The wider then lens, the longer you can expose for and not have tracking errors displayed in the image. I've done 12minutes with a 14mm lens on an APS-C sensor. But I think films suffers from film reciprocity failure for long exposures. This causes colours to go a bit strange. But I'm not sure if it is a problem with low-light astrophotography. Google might know. Also, achieving sharp star focus with a film camera is difficult. Digital is much easier. Good luck with your astrophotography.

@@peterallison57 Yes indeed. I know that wider lenses are more generous and allow for longer exposures with less tracking errors. I have got decently long exposure times on M4/3 with a 12mm lens without a star tracker. One thing that puts me off digital astro though is that after stacking, there is an incredibly long and drawn out post production process that I found overwhelming. Whereas with film, I like that you have a single image which is pretty much 'complete' after the film is developed. And yes, reciprocity failure could be an issue. There is someone who managed to get 45 minute long exposures with a 35mm SLR and a 600mm lens but I suspect that the tracking mount he used probably cost a fortune.

Sorry I can't be definitive, as I'm not familiar with the new model. But my guess is, yes.

Hi LoLo, I just aim the telescope at a known star, find the it's azimuth compass reading on a planetarium app and then place a marker on the ground below that reading on the plastic tube. That marker is then the reference point for all other azimuth directions. Just slew the scope and the tube moves with the scope to the required next azimuth. As I say in the video, this method is not particularly accurate, but it gets you close enough.

Hi Anzaeria. You are right, my latitude is 27.5 degrees. So, the South Celestial Pole is 27.5 degrees above the southern horizon at my location. At around the 1:36 point of the video you will see the verticle needle is roughly 27.5 degrees from the 90 degree mark of the protractor. Just ignore the actual numerals on the protractor. What you need to achieve is a tilt of the StarAdventurer polar axis above the horizon that matches you local latitude. You will see some red arrows and text on the video at about this point that indcates the required 27.5 degrees above horizontal tilt for my locaton. Actually, since I created this video there are now some better Apps available for download to smartphones. There is an excellent inclinometer app called Velux Roof Pitch that is really good for adjuusting the altitude angle of the StarAdventurer to match you local latitude. Also, there are plenty of smartphone Compass Apps that have a True North option (and not the Magnetic North option). Just select True North or South and use that to aim the StarAdventurer to the true south of the celestial pole. Using these two Apps you can get Sigma Octans into the polar scope field of view very easily.

@@peterallison57 Thank you for the detailed reply. That makes perfect sense. Apparently, the latitude of my location is 35.7 on Kangaroo Island, South Australia. There are some very clear, dark skies over here with very minimal light pollution. Actually 0 light pollution in some spots. Though I admit I don't have a star tracker as yet (Ive been doing astro shooting from a fixed tripod.) Out of curiosity, does the Velux Roof Pitch app have a virtual needle?