What will I see through Sky-Watcher Skyliner-250PX 10 inch Dobsonian Telescope ?

[JohnDenim]

Once again, thanks Mark!

[WayBig]

You'll certainly get lovely close up views of the clouds if you buy a new scope

[yoda]

Hi Liamsantini the 10'' dob is great I was out lastnight looking at open clusters,globular clusters,galaxys,saturn,orion nebulea,jupiter and fore moons, and the moon.

It's a fantastic scope and I live in a LP area.

Whatever you decide good luck.

Thank's for the links guys, thay are fantastic.

Edited February 8, 2011 by yoda

[naiteekv]

This is a great scope and as you can see its my main instrument for viewing DSOs. Depending on your light pollution you will get great views of all the Messier objects.

I have viewed Jupiter this year and seen the major belts and also watched the shadow transits of its moons. Your socks will be blown off viewing Saturn.

Do you want anything else? I have attached a pdf on the Messier objects to help you find them.

Enjoy the scope.

Mark

Hello mark i could not find the pdf document u r mentioning... can u plz guide it to me... thanx

[Andy250px]

I know this is an old post but I'm needing some advice about my skywatcher 250px dobsonian. I've had it since about the end of last winter so didn't have much opportunity to check out many dso's. The last couple of weeks have given me seriously clear sky's considering I stay in a small town but I don't seem to be getting great views. Orion nebula looks good but still kinda faint and last night I struggled to find the ring and dumbbell but even when I did there wasn't any more detail than a faint galaxy. I have seen jupiter but the belts are very faint and saturn is just tiny with a glimpse of the ring. I've tried collimation with laser and Cheshire but it doesn't seem to make much difference. Cleaning the main mirror made a massive difference but I was only looking at the moon to begin with. Any help would be appreciated. I just feel something isn't right. 

Andy. 

[knobby]

Hi Andy, I had a 250 Dob for a while and loved it, the main thing I found with it was to allow a good hour or so to let it cool to match surrounding conditions ... The big 10" mirror holds heat which then ripples the air around it, once it was cooled it was superb.

Don't expect too much from Saturn or Jupiter at this time as they are well past their best now, pretty low down in the atmosphere murk. They look much better when higher up.

Also, what eyepiece are you using, the 25 that came with mine was ok but the 10 was fairly poor ?

Edited November 13, 2017 by knobby
Spelling

[Andy250px]

Thanks for the speedy reply. I forgot to mention it's the flextube if that make a difference. I have the scope in my conservatory and when I think it's going to be clear I open the outside door and sit the scope there before it even gets dark lol. The eyepieces I have at the moment are the baader zoom mrk3 and a 30mm 2" Altair. It came with a 20mm and a 5mm both not great compared to the zoom.

[Ricochet]

If your conservatory is in the sun then the scope could get relatively hot and need longer to cool. I would be inclined to leave it outside at about 45° with the caps off to cool rather than just by the door. 

With regards to contrast on DSOs you might find there is an advantage to be found by adding a shroud over the open central section. Likewise flocking the inside of the tube and baffling the mirror edge can help control stray light. 

For planets you might want to invest in a barlow to use with the zoom. You can probably go down to about 5mm if the conditions allow but you are currently limited to 8mm. The extra magnification will make the planets larger although they will never be massive in any scope. 

Generally you will find it best to observe celestial objects when they are highest in the sky and when the moon is below the horizon. You should also aim to observe over vegetation rather than houses or other structures that will hold onto heat and release it throughout the night. 

[cletrac1922]

Liam

I have a 250mm, 10" Skywatcher dob, and use with astronomy club belong to for schools and scout/guide group presentation

Very clear images of rings of Saturn, Jupiter, Orion Nebula

Been in Southern Hemisphere, around the CRUX, Southern Cross able to observe Jewel Box, Omega Centuries globular cluster,

Been a manual scope, recommend getting a right angle spotting scope, and I also use laser pointer and just lay along dovetail mount of the spotting scope, to aim the dob at object you want to observe

Also with the dust cover, take off the small cover, and attached some Baader on underside of dust cover, and you can also observe the sun

Have included pic of my dob at a recent public viewing night with my club

Also image of 2012 solar eclipse

Where I was only had 80% eclipse

Cheers

John

   

[Andy250px]

I will definitely try leaving it outside the next time I get a chance to use it. I flocked the inside when I took the primary mirror out to clean because it looked pretty dirty up close and the scope also came with the shroud which definitely makes a difference. Not to sure what baffling is tbh?  Maybe I need somewhere better to view from but when it's really clear I can see the milky-way faintly like a long cloud,  so figured that was pretty dam good. Also one other thing that might not help is no matter how much I try to collimate I can never set my eyepieces all the way into the focuser, I always need to pull them out a few mm just to get focus. 

I keep meaning to get some solar film to look at the sun but it always slips my mind for some reason. 

Just feeling a like the potential is lost in my scope for some reason. It was a bargain and the first time I looked at the moon it paid for itself.  

Thanks for you comments guys. 

Andy. 

[Ricochet]

3 hours ago, Andy250px said:

I can never set my eyepieces all the way into the focuser, I always need to pull them out a few mm just to get focus. 

That isn't right, I can I only imagine that the telescope isn't quite extending all the way for that to happen. 

As for the telescope being or not being "right" it is probably impossible to tell without looking through it. Trying to find a local astronomy group to get a second opinion is probably your best bet, but I suspect it's probably fine. 

[Geoff Lister]

My 250PX is like the one in John's photo, above, but with the Synscan GOTO. I tend to set up mine on my patio, with power ON, well before dusk, do a "brightest star" alignment as soon as I can spot the first bright star (e.g. Vega, Arcturus or Altair), go in for tea and a warm-up, and come out again, perhaps an hour later, with the second alignment star still close to the centre of the eyepiece.

When not in use, the OTA (retracted and vertical) and base are kept in an unheated garage, with the rigid cover and "shower cap" in place and the whole OTA covered in an old bed-sheet. This seems to keep the mirrors clear of contamination.

Geoff

[Andy250px]

Think I'll need to look into my local astronomy club, I'm sure they will be able to see what's wrong just by having a quick look. Cheer for your help lads, lots of helpful advice I'll definitely be making use of. ?

[ronin]

All I can think of is the secondary. First thought was the collimation may be off sufficent that not all the light cone is hitting the sceondary and so half of it is lost off the edge. Next is that someone has replaced the secondary with a smaller one and again not all the light is getting sent to the focuser. Third did you clean the secondary as well as the primary.

First should result in pretty awful shaped stars.

I wouldn't use a solar filter for the sun on it. Basically even if the film attenuates by 100,000 you are still collecting a lot of light, and IR and UV. Basically you will be getting 7000x a eyeful which I agree is then filtered so about 14% of naked eye, and I am uncomfortable with those amounts. Just me I suspect but it is different cutting back what goes into a 70mm comapred to what goes into a 250mm.

Clubs in case you need to locate one: http://www.astronomyclubs.co.uk/

 

[Andy250px]

Is there anyway to check to see if the secondary is too small? When collomating with my Cheshire I need to have the focuser most of the way out before I can see all off the primary mirror, don't really know if that's normal or not?  I didn't clean the secondary with the primary because it looked ok but it has been sitting for a good while so maybe that would be worth a shot. Unfortunately I have no comparison for how the stars should look but to me they look fairly sharp but not perfect pin sharp.  I had though that maybe I just needed some better eyepieces but that starts to cost alot really fast. Almost bought a scientific explore 20mm 100° eyepieces for a bargain off here but the guy never got back to me so didn't get to test that theory unfortunately. 

[Paul73]

The bit about not achieving focus is interesting. Are the struts fully extended? I.e. Hard up against the stops? There are is an interim setting which is a couple of inches shorter. I think that it is to allow a camera to reach focus.

Working properly, they are cracking scopes.

Paul

[Andy250px]

Yeah I had a check today and it's extended as far as possible. My scope only has one click at the top. I took the secondary off and gave it a clean today and collimated the scope so hopefully I'll get a chance to see if there is any difference. 

Is there any way to reduce the slack movement in my focuser other than spending a fortune on an upgrade? It's not much but there is play enough that maybe my heavier eyepieces will hinder my view quality? 

Andy. 

[newtyng5]

Hi Liam. That's a great scope you are intending to buy. My advice is look for an astronomical society near you in Aldershot.  http://www.farnham-as.co.uk/

Societies have advice and usually a dark sky area. I did a quick search and found the Farnham society which is near you.

Good luck and clear skies!

[cletrac1922]

Geoff

The solar image used Baade solar film, underside small cap of hard cover

Taken with Android phone to eyepiece

John  

[Mr niall]

On 08/02/2011 at 18:36, Mark at Beaufort said:

This is a great scope and as you can see its my main instrument for viewing DSOs. Depending on your light pollution you will get great views of all the Messier objects.

I have viewed Jupiter this year and seen the major belts and also watched the shadow transits of its moons. Your socks will be blown off viewing Saturn.

Do you want anything else? I have attached a pdf on the Messier objects to help you find them.

Enjoy the scope.

Mark

Am I missing something I cant see the attachment? Is it my computer? It sounds great I want I want I want I want!

[Ricochet]

23 minutes ago, Mr niall said:

Am I missing something I cant see the attachment? Is it my computer? It sounds great I want I want I want I want!

The only thing you might be missing is the age of the original set of posts in this thread. The attachment must have been deleted at some point. 

[Mr niall]

4 minutes ago, Ricochet said:

The only thing you might be missing is the age of the original set of posts in this thread. The attachment must have been deleted at some point. 

haha brilliant. well spotted!

[Geoff Lister]

On ‎14‎/‎11‎/‎2017 at 14:35, Andy250px said:

I can never set my eyepieces all the way into the focuser, I always need to pull them out a few mm just to get focus. 

The focuser does seem to have a short travel range (just measured at 41mm). I have not had any problems with my 1.25" eyepieces, but I too found that with the 2" eyepiece adaptor, and my one 2" eyepiece, a Meade 56mm Super Plossl, I had to pull it out about 0.75" to get focus. I resolved this by buying a 30mm-long, 2" eyepiece extension tube. If I remember correctly, from one of the other threads, it may help to use the collimation screws to move the primary mirror rearwards a few millimetres.

Geoff

Edited November 21, 2017 by Geoff Lister
41mm range added

[Geoff Lister]

On ‎13‎/‎11‎/‎2017 at 23:01, cletrac1922 said:

Also with the dust cover, take off the small cover, and attached some Baader on underside of dust cover, and you can also observe the sun

I may well try this, but the main cover has a narrow lip to grip the tube end, so I am concerned that a gust of wind could enter the large gap and push the cap off. I guess, a couple of bungee cords would give added protection.

With a solid tube design, OK; but with the open design, would stray bright indirect sunlight entering the gap, and reflected off the underside of the dust-cap, ruin the contrast?

Geoff

[JOC]

If what you are describing is one of the open sided flex tube type telescope designs that you pull open to their full length. Then if you want to view solar I think most on SGLwould recommend covering the gap up for safety.  You can buy a purpose made shroud.  I made my own from some vinyl fabric and stiffeners.  Some folks use cheap neoprene exercise mats.  You could even fashion one from stiff black card for use on a dry day (well the sun would be out!? ), or wrap a couple of turns of blanket around it, but whatever you use make sure it is light tight.  You don't want to mess with the sun.  Oh yes, and take your finderscope off too if it doesn't also have solar protection.

NB.  I also use bungees on my homemade solar filter.  I bought a small eye kit from ebay and 10 mini bungees in a pack.  Combined cost about a fiver.  Four eyes and four bungees do a good job at holding on my filter.

Edited November 24, 2017 by JOC