Recommendations on guide scope and camera

Using SharpCap's Polar Alignment feature
stephen2615
Posts: 9
Joined: Sat Mar 09, 2019 11:10 pm

Re: Recommendations on guide scope and camera

Post by stephen2615 » Thu Mar 21, 2019 8:39 am

Steve,

Svalbard was by far the best holiday EVA!!! We went there for the 2008 solar eclipse. We sailed for Franz Joseph Land but we got icebound for a couple of days. This caused a few polar bears to come up to our ship and watch and sniff us. We saw seven polar bears all up. Absolutely fantastic. We got to see about half of the eclipse. It was very cloudy but that helped us to glimpse what was going on. Highly recommended place to visit. We are also visiting the Kamchatka Peninsula later this year. No astro but hopefully some interesting volcanoes in the distance.

I contacted your suggested dealer and they recommended Polemaster for polar alignment instead of getting QHY5L-II-M. I asked about a colour version of the QHY and I was told:
It's less sensitive and the bayer matrix would degrade the resolution.
They are also doing pre-ordering of the Williams Optics Redcat 51 for HKD5680. Hide my credit card.

SteveInNZ
Posts: 39
Joined: Tue Feb 14, 2017 6:56 pm

Re: Recommendations on guide scope and camera

Post by SteveInNZ » Thu Mar 21, 2019 8:32 pm

Then, I would respectfully disagree.
I have a Polemaster. Inside a Polemaster is a QHY5 mono camera and a 25mm c-mount lens. Sound familiar ?
You can use a Polemaster with either the Polemaster software or Sharpcap for polar alignment. The Polemaster software is quite primitive compared to Sharpcap. In Sharpcap, the program does the plate-solving (find the pole within the image) but with Polemaster, you have to identify the stars and put them into circles on the screen.
With a QHY5, you have the option to change the lens and use it for guiding or put it into a telescope and do some imaging.
Their response about the colour camera is technically correct but IMHO, inconsequential for your application. Really, the only practical difference would be if you wanted to image planets through a telescope. You do see some hints of colour with stars when using it for alignment or guiding but it makes no difference to the operation. I have both and swap between them without changing the exposure time.

Any of the options will work and will work with SharpCap. The non-Polemaster options give you some added flexibility.

It sounds like I should buy less astro gear and more on travel to obscure places.

Steve.

stephen2615
Posts: 9
Joined: Sat Mar 09, 2019 11:10 pm

Re: Recommendations on guide scope and camera

Post by stephen2615 » Fri Mar 22, 2019 12:19 am

Steve,

I am grateful for your contribution to this. It is very easy to get carried away with things and a reality check is always welcome. When looking at various images on Astrobin, you can get an idea of what you are likely to see with my current setup. Nothing has any exposures longer than about three minutes so autoguiding is not on my priority list (yet).

I think a good inexpensive setup will keep me happy for a year and then I will see what happens. The ZWO ASI120MM-S and the QHY5L-II both have the same sensor. One is local and the other is imported.

Whereas the ZWO ASI120MC-S (colour version) is cheaper than the ZWO monchrome probably because the monochrome presumedly has a better sensor. Both the monchrome (1/3″ CMOS MT9M034) sensor and the colour AR0134CS sensor have a similar Responsivity. The Signal to Noise ratio is higher with the monochrome at just 14% higher than the colour camera. I don't see a lot of difference.

I have spent an awful lot on travel over the last 13 years so your equipment probably provides much more fun and besides you can sell it if you need to. My travel is just in my fading memory. :lol:
Last edited by stephen2615 on Fri Mar 22, 2019 8:30 am, edited 1 time in total.

SteveInNZ
Posts: 39
Joined: Tue Feb 14, 2017 6:56 pm

Re: Recommendations on guide scope and camera

Post by SteveInNZ » Fri Mar 22, 2019 7:51 am

The colour version of the QHY5 uses the same sensor (MT9M034) as the monochrome. The relative QE's are Mono = 75%, Colour = Blue 52%, Green 62%, Red 58%.

I don't think that any of the options would be a bad purchase. They'll get you polar aligned which is the immediate problem you need solved.

Steve.

stephen2615
Posts: 9
Joined: Sat Mar 09, 2019 11:10 pm

Re: Recommendations on guide scope and camera

Post by stephen2615 » Fri Mar 22, 2019 8:37 am

Steve,

Thanks again. I purchased the ZWO ASI120MC-S without a guide scope. That will keep me occupied for a while as I can see if I need the guide scope or not.

Stephen

stephen2615
Posts: 9
Joined: Sat Mar 09, 2019 11:10 pm

Re: Recommendations on guide scope and camera

Post by stephen2615 » Sun Mar 31, 2019 11:09 pm

As most newish houses in Australia have a back yard the size of a postage stamp, I found that when using the camera without a guide scope, the process caused some odd issues. In my favourite spot in the back yard, it seems that the camera is fascinated with my eaves. Due to the wide field of vision with the camera by itself, it would not stop seeing the eaves and then thinking there were some stars there. Crazy right? No matter where I moved the tripod around in my little back year, there was something that caught the attention of my camera. Our next door neighbours hedge confused it (he needs to cut it back). My clothes line confused the camera. After a couple of nights, I bought a guide scope and now, no more issues with eaves, etc. After finally being able to focus the camera with the guide scope, SharpCap went bingo. Now rotate the RA 90 degrees. No more bingo. There are no "circles of different radii" shown by SharpCap so I suppose I am not pointing in the right direction. My laptop was running out of power after the lengthy focusing episode (finally got it with using Nebulosity) so I gave up in disgust and it was getting cold. Perhaps tonight will be the night as the min is not going to be so low.

stephen2615
Posts: 9
Joined: Sat Mar 09, 2019 11:10 pm

Re: Recommendations on guide scope and camera

Post by stephen2615 » Mon Apr 01, 2019 9:40 am

I thought I should update this with tonight's effort. AMAZING. It took about 5 minutes to get an excellent polar alignment that drifts a bit when adjusting my camera. So much easier than looking through the view finder with the Star Adventurer. A fair amount of money but my back and my mental health wont suffer and my neighbours won't hear me cursing anymore.

SteveInNZ
Posts: 39
Joined: Tue Feb 14, 2017 6:56 pm

Re: Recommendations on guide scope and camera

Post by SteveInNZ » Mon Apr 01, 2019 8:31 pm

Glad to hear you're up and running.

Steve.

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