The image below was captured on my iPhone whilst sat in my armchair, pointing the phone at a wall at 15:00. I think the app is iPhone only?
There might be similar planetarium software available for other types of phones.
Thanks for that suggestion! I'm a Windows/Android user, but fortunately, there is a version for Android and I purchased it and installed it on my phone. It is impressive how it works. It was difficult to pinpoint whether it showed its image of the Sun directly on the actual Sun because the Sun is so bright and Luna is currently only two days from New Moon and is not visible here at the moment.
Because its title is “Ephemeris: Sun and Moon Seeker”, I had presumed it only pinpoints those two celestial objects. But upon re-reading your message, it implies that it also will provide a marker for others, such as Polaris, and hopefully more? But I was not able to find a way to display anything other than Sun and Moon even thought any object nears the Celestial Pole (a la Polaris) is always in the same spot.
Is there a way to display celestial targets? Does this work only when the Sun goes down and we enter night mode?
Regardless, this is a cool app and I thank you for recommending it.
Thanks for your suggestion! Unfortunately, you may be correct that this is an iPhone only app and I am and Android only user because I could not find it for Android.
However, I do use Stellarium often and also the ASI Mount software which controls the AM5 mount. For whatever reason, neither SharpCap nor ASI Mount move the AM5 to exactly where the selected target actually is – this is the problem I’ve been having since converting to the AM5 and why I contacted Robin in the first place. And try as I might, and trying all of Robin’s many and insightful suggestions has not fully resolved the problem. Initially, SharpCap pointed the scope in entirely wrong directions for where the target actually was. Robin suggested installing and using ASI Mount to somehow sync SharpCap with the ASI Mount settings and that made a huge difference, but the scope still doesn’t point exactly where it should.
What I’m going to try this afternoon is determine whether or not the dovetail on the scope is directly in line with the C8 axis or something similar. And I also want to test if I can determine that the error or difference between where the scope ultimately points and where the target actually is always has the same error, such as 1.7 degrees in the same direction. If it’s always the same, then I may be able to find a way to mechanically align the scope properly and it should work on all other targets. If it varies, this would be a bankrupt approach that won’t work.
Alternatively, and easier, is if I can set a permanent offset to the mount programmatically through a setting in SharpCap or ASI Mount. That would certainly be easier and more accurate than a mechanical offset.
Of course, there could be a problem with the AM5 mount itself, but I doubt it. I’m going to contact High Point Scientific where I purchased the mount this afternoon. They’ve got great tech support, and hopefully, they’ve seen and resolved this issue for other customers. If such a solution exists, I will share it on this forum for other users.
I'll only point it at the Sun when the Sun is below the horizon and I want to photograph it rising being a lighthouse, for example. I'll do the same for the Moon.
It just shows the Sun and Moon, but I figured in your case you needed to verify that Polaris is where you hope it is. Do that by clicking the button for Equatorial Grid. At approximately 90 degrees declination on the grid will be Polaris.
I should have turned on the grid and what you just mentioned would have been obvious - Brain lapse. I know Polaris is not exactly at the pole, but at 0.67 degrees off, that isn't much, nor can I see with that resolution, so it's definitely close enough.
determine whether or not the dovetail on the scope is directly in line with the C8 axis
You state you switched to the AM5 mount. On your previous mount, did it work correctly with the C8? If yes, that implies that the scope/dovetail alignment is 'good enough'.
Previously, the C8 was a CPC-800 I bought from a friend, so it was an Alt/Az mount. The images I was getting from it were very good and it passed the Star Test handily, so I decided to keep the scope, de-fork it, and get a harmonic EQ mount.
The dovetail can only mount one way of the OTA and in checking the alignment it appears to be spot on. I called HighPoint Scientific and they said there are known problems using the AM5 mount for aiming, but several of the staff use it with the ASIAir and are very happy with itl. Is that just a way to sell another accessory? Possibly, but as I mentioned earlier, HighPoint has been great about standing behind their products and I've never had them trying to push any product. Because I'm experiencing that the mount aiming is poor, I bit the bullet and ordered an ASIAir. If that doesn't work properly, I'll definitely complain and return it, but HighPoint has never steered me wrong yet, so I trust them.
I'll let you know what happens. The Air should be here in a few days and I'll install soon after. The bigger issue lately is all the cloudy nights we're experiencing - that can delay my testing. Because of the weather, I'm feeling like it's time to move to a drier clime or mountaintop, somewhere that we can experience much more clear sky weather.
Thanks for the link to alternative apps for GoSkyWatch! I'll check them out,
If a camera's back focus is not correct, can that cause an inaccurate polar alignment?
I ask this because I've just realized that, compared to my prior use of Celestron StarSense, which is a completely self-contained system that includes it's own scope and purpose-match camera) to aim my prior alt/az scope. Conversely, my current polar alignment with my AM5 is with my C8 (which is now doing double duty for astro photography AND polar alignment. With the alt/az scope, I never worried about back focus distance accuracy because I was stacking and had to cropped most photos anyway, so was not concerned about round stars in the corners. But now I'm using SharpCap or the ASIAir to polar align as well as to shoot photos, and the AM5 doesn't quite aim accurately enough no matter how I polar align, yet it tracks superbly and I've had what seems like perfect tracking for over 30 minutes with no guiding. Therefore, I'm finding it hard to believe the mount is the problem, and yet know that it also can't be SharpCap or the ASIAir because thousands of astronomers are using both very successfully.
So, I'm asking whether a back focus that isn't accurate enough can affect polar alignment, and as a result, make it somewhat in accurate. I'm about to order some narrower tube sections and shims and wondering if this is a bogus path to explore.
shouldn't be an issue - the way that SharpCap detects the current pointing of the RA axis is equivalent to the way star trails arc round the pole in a long exposure, but there is no movement *at* the pole. It doesn't matter which way you point your camera, what position on the earth you are or how your lenses are set - the stationary point is always the pole.
If you are tracking well then that indicates good polar alignment (at least in the direction at right angles to the current position of the mount). Poor slewing with good alignment could be caused by cone error - if your errors are largest when the mount has performed a flip from one side to the other then that is definitely something to investigate.
