Advice

[nikooo]

Hi guys, I recently bought a dobson 250/1200 telescope, and It's my first telescope that I ever bought. Do you have any advice for amateur?

[pipnina]

The best advice I can think of is to use a program like Stellarium to find objects you want to see on a given night, make a note of them and what constellation they're in, and then draw out some star hopping routes so you can find the object in the eyepiece when you're finally in the field.

It will take some practice as star hopping is a skill, and the telescope AND finder (on most dobs) will have their field flipped vertically and horizontally!

I'd look at brighter objects like M81/82, M51, Leo Triplet etc at the moment, and soon you'll be looking for the ring nebula and such. Happy hunting!

[Stickey]

Another idea is to pick up one of the monthly astronomy magazines.  They usually list interesting objects to observe AND how to find them. 

[bosun21]

The very first thing you need to learn is how to check the collimation of the mirrors and how to readjust them if necessary. There’s a lot of videos on YouTube showing how to do this. It sounds scary at first but it’s a skill you only need to learn once. HTH.

[bomberbaz]

Few things, Ref collimation mentioned above, get yourself a concenter. They have come down in price recently and are the easiest thing ever to use. Do watch video to see how someone does it who it skilled for tips.

If you get frustrated with your eyepiece, buy a zoom. The 21-7.2 by OVL is a cracker and will easily keep you going until you gain more experience.

Stellarium is a great tool for using whilst at the scope, Skysafari 6 plus is what I use and both are basically virtual maps of the night sky. Both can be put on dark mode and this can be used as an interactive map at the eyepiece. 

Go for easy objects at first as mentioned above. Search through stellarium for messier objects (M82 as an example) as these tend to be the easier things to find.

Most of all your a young chap, take your time learning, stars are going nowhere.

 

[Spile]

I’ve put a collimation guide as well as other tips on my blog (link below) and as you can see I recommend a Cheshire eyepiece and sight tube for aligning your secondary and a cap for your primary. The only other purchase I would suggest for now is a copy of Turn Left at Orion and lots of patience. 

[alexrentiers]

On 08/05/2023 at 19:07, pipnina said:

The best advice I  can think of is to use a program like Stellarium to find objects you want to see on a given night, make a note of them and what constellation they're in, and then draw out some star hopping routes so you can find the object in the eyepiece when you're finally in the field. It will take some practice as star hopping is a skill, and the telescope AND finder (on most dobs) will have their field flipped vertically and horizontally! I'd look at brighter objects like M81/82, M51, Leo Triplet etc at the moment, and soon you'll be looking for the ring nebula and such. Happy hunting!

Stellarium program is good! But it took me so long to install it! And now I am happy with it and it is very convenient and useful!HERE

Edited May 11, 2023 by alexrentiers
Error

[AstroMuni]

On 08/05/2023 at 14:34, nikooo said:

Hi guys, I recently bought a dobson 250/1200 telescope, and It's my first telescope that I ever bought. Do you have any advice for amateur?

Hi Nikooo, the first thing I would do is get to know how to use your scope. eg. how to use the finder and get the object in your eyepiece etc. Learn about objects in the sky either using an app on the phone (skychart) or via a PC based software like Stellarium.  Use the lowest magnification eyepiece and learn these.

If you find that you are NOT getting round stars then you can look into improving the collimation mentioned above in other posts. Also feel free to post your questions here once you get started. Good luck.

[Mandy D]

On 08/05/2023 at 14:34, nikooo said:

Hi guys, I recently bought a dobson 250/1200 telescope, and It's my first telescope that I ever bought. Do you have any advice for amateur?

That's pretty much what I bought as my first telescope. I've never looked back. I started with the Moon, as it is very easy to find and you can also readily check alignment of the finderscope with the main scope. Be prepared to be blinded by the Moon with such a large scope! It will be insanely bright at low magnifications! If you have the Skywatcher 250PX, it has a dust cover with a 50 mm aperture in it that is covered by a cap which you can use to reduce the brightness. I've had mine since 2016 and never had to collimate it, yet, even after it was lifted up and dropped by a customs official at Dover! He wanted to check for people hiding inside the box. Don't get distracted by the need to collimate, just yet, even though it is a really simple process because it is nerve-wracking the first time you do it. As long as the image is sharp and the stars are round it will be OK, certainly for visual, at least until you start to get more discerning and picky.

The next thing I would point it at is a bright planet. Venus is nicely placed right no, so go for it. You should pick out the phase fairly easily. Mars is also convenient in the evening sky right now, but getting smaller, so don't leave it too long. I'd wait for Jupiter and Saturn to get a bit further from the Sun and higher in the sky before trying them. Right now, they are morning objects, so you have to be up before dawn.

Another easy favorite of mine is M42, the nebula in Orion. Very easy to find and well worth a look, but this is the wrong time of year. Autumn / winter is best for Orion.

Try your hand at splitting some doubles. There is a very easy one in Ursa Major, that is also easy to find. I'll not tell you which, because it is much more fun to find it yourself. With this being on a Dobsonian mount, it will be very easy to point it directly upwards, which is pretty much where Ursa Major (Big Dipper, Plough) is right now.

EDIT: I just noticed someone mentioned the Lunar 100 list, which might be of interest to you. Here is a helpful link:

https://skyandtelescope.org/observing/the-lunar-100/

Edited May 12, 2023 by Mandy D

[Guest]

I say find a astro club and take your scope to them once or twice.  They can teach you the ins and outs about your scope with your scope.  For me it was far easier to learn collimation that way then off of a video. 

Edited May 12, 2023 by Mike Q

[bomberbaz]

On 12/05/2023 at 16:54, Mike Q said:

I say find a astro club and take your scope to them once or twice.  They can teach you the ins and outs about your scope with your scope.  For me it was far easier to learn collimation that way then off of a video. 

Mike makes a very good point. 

It's all well and good us lot on this thread pointing out that we use this and prefer that, but you are who you are and what suits you may be totally different to us.

Find a local club, ask to go around and you will be welcomed with open arms. 

Take a list of questions with you and you will find the answers, as well as a demonstration where practical of these answers EG collimation.

[Guest]

22 minutes ago, bomberbaz said:

Mike makes a very good point. 

It's all well and good us lot on this thread pointing out that we use this and prefer that, but you are who you are and what suits you may be totally different to us.

Find a local club, ask to go around and you will be welcomed with open arms. 

Take a list of questions with you and you will find the answers, as well as a demonstration where practical of these answers EG collimation.

We just love spending someone elses money lol 

[JOC]

If you do find the scope needs collimating the standard SGL reference is here - https://www.astro-baby.com/astrobaby/help/collimation-guide-newtonian-reflector/  I tried and wasted cash on fancy collimators, but all you need is a cheap £20 Cheshire collimating EP which is was Astrobaby used.

However, what you asked was what advice does a newby need.  IMO my Dobsonian was never that much out of collimation that it impacted me as a learner.  I'd want to start using it if I were you, the lack of pristine collimation won't stop you looking IMO so I think I'd just try using it.  I would take it outside during the day and whilst strenuously avoiding the sun - point it away from the sun PLEASE.  Then point it at a distant object on a horizon and drop in an Eyepiece with a high value on it, i.e. 25mm not 10mm.  Then I'd teach myself how to twist the adjust knobs on finder scope so that the view in the cross-hairs on the finder scope matches the centre of the view through the telescope EP.  Thus, it will dawn on you that once the finderscope is pointed at the object of interest so is the scope.  Try not to tweak the finderscope adjustment too much when you remove it and it will be easier to just tweak the adjustment when you do it in the dark - you need to tie them into each other when you use it at night by picking a nice bright star or bit of the moon in the sky.   Then I'd look for a nice clear night coming along and get it outside nice and early - they work a bit better when they are cool and if you take it outside in the afternoon you can also set up the finderscope whilst you can see what you are doing.  Then just leave it sitting there and wait until the night comes along hopefully nice and clear.  Then get out there drop in that big numbered EP (which fit's in most sky) and start looking at stuff - see what you can find, point it at the moon and focus (you will spend hours looking at the moon the first time, just practice moving it around, finding things in the sky and learning how to focus those stars to the smallest points of light possible.  All the rest comes later, but I'd just get it out there and use it if I were you.

Edited May 15, 2023 by JOC