Owmuchonomy

We use Lunt and PST specifically designed Ha solar scopes. We do not attempt WL observing. We also give a preamble on never looking at the Sun without properly designed equipment supervised by experienced solar observers. Never leave the equipment unattended. We had a great turnout for the Mercury transit.

If you purchase a solar filter (https://www.firstlightoptics.com/solar-filters/astrozap-baader-solar-filter.html) for your 150 PDS you will be able to image in white light only. You could make your own with Baader film too. The only features you will pick up are sunspots or in periods of great seeing you may resolve some surface granulation. You can use your Nikon at prime focus but it's best to take high frame rate video and stack the results to get a final image. Best to use your ZWO ASI 120MM but check with the FOV calculator on the FLO site to see how much of the solar disk you can accommodate with that chip in your system. Remember to remove any finder scopes when observing the Sun!

It's a great topic for our visitors, and then I start explaining the (original source) wavelength of the light captured in these images by our mundane camera sensors and what that means. Minds blown!

At 8 billion LY distant, the sudden brightening in 2016 of a Quasar (CTA-102) in Pegasus is probably the most distant visual target I have shared with visitors to the obsy. Attached is an image captured too.

Great stuff Pete. Excellent work to avoid over exposure.

In order to satisfy your desire for long exposure astrophotography you have to remove all the artefacts produced by the Earth’s rotation, for example, star trails. To do that you need a device that is perfectly aligned to the Earth’s axis and rotates at the same pace as the Earth. That device is an EQ mount. The mounts are often fitted with polarscopes perfectly aligned to their axis. The orientation of other attachments such as cameras and telescopes is largely irrelevant. ‘Attaching’ a polarscope won’t give polar alignment. Your best bet is to invest in a decent EQ mount or try one of the electronic methods described above and see how it goes. If you have fixed focal length TP lenses eg 300mm try those first.

It's a beautiful target and so rich in fuzzies.

I hope you can solve the problem. Try and separate the two main functions of GoTo accuracy and PA accuracy. They are not necessarily completely interdependent. For observing it is a high priority for accurate GoTo but PA accuracy is less critical. For imaging it is very important to achieve very accurate PA but your mount must also be in tip top condition, without backlash in the axes for example. For accurate GoTo I would suggest you use the 3 star alignment as in your original set up. This process adjusts for cone error in your setup. Make sure when aligning stars in your eyepiece that you finish the centreing with an UP and RIGHT touch on the handset. I would suggest not using a camera for the GoTo setup. Mounted cameras do not necessarily mount in a concentric fashion. Use a high power reticule eyepiece if you have one.

The three star routine is best avoided for Synscan Polar Alignment. Its primary function is to the correct cone error of your optical tube. To perform an accurate polar alignment of your mount, first ensure the OTA is in the home position and the EQ axis roughly pointing to Polaris. Ignore the polarscope. Next perform a two star alignment using two stars on the same side of the meridian that you will be imaging your target. Then run the polar alignment routine on the Synscan menu. After 2 or 3 iterations of the Synscan routine using a high power eyepiece the polar alignment should be very accurate. At no point do you need your polarscope.

The Sun's disk currently has two active regions. One of them has a visible spot on the receding limb at about 4 o'clock. That should be easily visible with your set up. Use your 40mm EP and get the Sun's limb in view then check focus carefully. Other than spots you are not likely to pick out any detail in white light unless the seeing is spectacularly good when you may see some faint granulation.

Excellent description and succinct.

Most DSOs are very faint even for a 10” mirror. By far the best tool is the book Turn left at Orion. I strongly recommend you purchase that and use it as your guide when observing. Remove the light pollution filter too.

A very good experience with both my AzGti and AZ EQ 6 wifi operation. Both mounts are also compatible with a handset. I use iPhone and the Synscan PRO App which is clever enough to know which mount I'm using and if it's Az or EQ setup. Make sure you get the pro version of the App not the standard version. It's very easy to use and I even let the visitors to the obsy use it (particularly the younger ones who can work it instantly!). There's nothing to be concerned about; if I can work it anybody can. The only hidden items I know about are for solar tracking (quite rightly). Once you know where they are it's straightforward.

Have you checked your Dec axis for backlash? A lot of input corrections there trying to correct your Dec. If you haven't done so already, check the mount backlash is in good order then come back to the guiding analysis .

As above, Polaris is actually about 43 arc minutes from the NCP so will appear to circle it.

During our outreach sessions at the obsy, by far the easiest option for us is a small refractor on an iPhone controlled Az-Gti mount. We just pick the whole thing up and walk outside with families and set it up in minutes. It requires a 12V supply, either mains or battery. I use a cordless drill battery (USB output) through a 5V to 12V converter lead. It will last many evenings between charges. I personally wouldn't use the MAK we also have because its a bit like looking down a tunnel (narrow field) and focussing a MAK is not for little hands. Your budget is more than enough to cover this even with an upgraded tripod. This package is perfect for the children (supervised). https://www.firstlightoptics.com/startravel/sky-watcher-startravel-102-az-gte.html

Will you be purchasing a new mount to go with it or will you use an existing mount? The optical tubes you describe are much larger and heavier than your C5.

Sounds like you have a plan. Things would go better if you could use a high frame rate mono camera and an IR pass filter. That's not to say the DSLR results will be disappointing but you are less likely to defeat the 'seeing' issues with your set up. I'm not sure of your pixel size but I imagine they are around the 5 micron size so with your scope the 5x Barlow is a must to get the best image scale and sampling rate. Regarding software, when I used a DSLR I just used the bundled Canon package. It's more than adequate. My best results have been achieved with a combination of an ASI290 mono and ASI174 mono camera. Give it a go and let us see your results. Happy imaging.

Looking at the spec, I doubt it. It's an optimised imaging scope so one less thing to worry about. Get it collimated and then practice focusing on a bright star and imaging that before trying something more challenging.

What scope is it? Addition of a coma corrector may have reduced your in focus range considerably.

How will you power the Canon for that long?

Yes, it's visible to me but only since I purchased the SW ED150. The views through that are exceptional. I use a UHC filter too and a 28mm 82' EP (Explore scientific). As you may imagine, the same gear trained on M42 creates an awe inspiring view. I've only tried at home but I will give it a go up at the obsy where the sky is very dark when the chance arises.

....and magnetic North is not the same as true North by some margin. Identify polaris by using the pointer stars of the plough and the mark 1 eyeball then align the axis of the mount with the star. Then move on to the polarscope. There are also smart phone planetarium apps to help you identify constellations and stars when holding the phone to the night sky.

Could be you can’t get enough in-focus. Are there any superfluous adapters, accessories or tubes between camera body and focuser? I remember with my 130pds I had to have a specially ‘thin’ adapter for my DSLR.

Great story. I've been to Japan about 50 times but never to that shop. There is a whole floor of the Akiba superstore in Akihabara devoted to astronomy (and photography). Takahashi plus Vixen etc. If you are into your RC models there is also an amazing multi floor TAMIYA shop. It used to be in Akihabara but has now moved closer to Ginza. Everything is Tamiya and the prices are less than half of the imported versions. Also easier to fit in a suitcase than an f/13 frac!