How does seeing and light pollution affect which telescope I should use?

[Entrpy53]

Hello, I am a young and new ametuer astronomer and I live in Singapore, a small island city. It is Bortle 8-9 here and the seeing is around 4-5/10 (sometimes 3) on the Pickering scale. Quite bad conditions. I heard that the seeing limits the useful aperture I can get for a telescope but then the bad light pollution makes me want to go a little bigger. Right now, I am considering an upgrade to a 127mm Skywatcher az5 Mak f/11.8 and the 130mm Skywatcher az5 Newtonian f/5 for visual, maybe a few snap photos using my phone. I currently own a Celestron astromaster 70az. I do not know if those two skywatchers above will give me much better views of the moon, planets, double stars, open star clusters than the Celestron astromaster 70az because of the seeing. But I also heard of something called a Mak to sct adapter and a focal reducer to make the Mak into a Low f/ratio scope to replace the Newtonian. I want those two scopes because the newtonian would be for dso while the mak is for high mag of moon and planets and double stars. So I have a question: Should I get the Mak and Newtonian ota with one quality altaz mount or should I just consider the Mak with the mount and get a sct adapter and a focal reducer. I do not know if the Mak to sct adapter and visual back would be needed for the skywatcher az5 skymax 127 or i only need a focal reducer to lower the f/ratio without a adapter and a visual back, i hope someone who owns the az5 package can help clarify,Thanks! 

-Entrpy53

Edited June 2, 2020 by Entrpy53

[Demonperformer]

Hi, Entrpy53, and welcome to SGL.

I can't give you specific advice to your question, but aperture can help cut through light pollution to some extent. But nothing beats being able to get a scope under a dark sky. I don't know how "mobile" you are and if getting away from the city is a possibility for you. But, if it is, I would definitely factor that into your upgrade. You will be able to purchase a bigger dobsonian for a similar sum compared to the 130mm. [Yes, I hate it as well when someone comes along and tells me to consider a different purchase than the one I have decided upon!]

Another thing to consider is that, whilst adding extras may seem a cheap way of getting extra kit, every piece of glass you add to the system (like reducers) reduce the quality of what you are seeing to some extent.

The only other thing I can recommend is that you go for one scope (only) first. Decide where your main passion lies (planets & moon or deep sky objects) and get the one best suited to that. Then, when you have experience with that one, you will be in a better position to decide how to extend your kit.

Enjoy the journey.

[ZiHao]

I think if you want to avoid light pollution, travel to Mersing which I believe is close to your location.

[Dr Strange]

The better option would be a combination kit that you can easily move around with. The Skywatcher AZ-GTi mount would work well for that. Add to it a 80-102mm refractor like the Explore Scientific 80mm APO or 102mm APO (depending on your budget) for double stars and large DSO and a Skywatcher 127mm Mak for the moon and planets. Double stars, open clusters, the moon, and planets are not that impacted by light pollution. Other DSO like globulars and galaxies as well as nebulae are going to be and dark skies are important. I would buy the 80mm ED Essentials Explore Scientific and the AZ-GTi 127mm Mak combination as well as a 11mm and 18mm Explore Scientific 82 degree eyepiece. This combination will not be cheap but will serve you really well.