Dobson Skyliner 200P problem

[Astrid]

Hello! 

I have a friend that bought a SkyWatcher 200P Skyline Dobson 10 months ago. (https://www.firstlightoptics.com/beginner-telescopes/skywatcher-skyliner-200p-dobsonian.html)

Even though it has a 4mm deepsky eyepiece and a good aperture, she cannot observe nebulas or even large galaxies (like M31). The planets look ok (no problems here). 

I was assuming that the problem was the collimation, but she checked it and the telescope seemed collimated. Perhaps the problem could be the EP...?

The place where she observes is not light polluted (from what I understood she goes somewhere in the countryside, not in the middle of the city or anything like that) 

  Is there anyone that owns a 200P or had a similar problem? 

Thanks in advance! 

 

Edit: she said she tried with both the 10mm and 25mm EP and still nothing...

Edited September 12, 2020 by Astrid

[Knighty2112]

They probably need to use a lower powered eyepiece than the 4mm EP which is Ok for the Moon and planets etc. Maybe a 15mm or 20mm EP would suit better to view galaxies, nebula etc to give a wider view and brighter image to be able to pick out these objects.

[Kyle Allen]

Plenty of nebulae and galaxies are visible in an 8 inch scope. A 4mm eyepiece gives 300x magnification in that scope. That’s far too much for faint objects like galaxies and nebulae - even the Moon and planets cannot take that much on some nights. Try using the lowest power eyepiece first (e.g. 25mm) and then increase the power once you have found the object. 

Is your friend sure that she is looking in the right place? Even with a low power eyepiece, you will only see a small part of the sky and it is very easy to miss the target completely. Make sure that the finder-scope is aligned to the telescope. 

Also, what are your expectations like? Most deep sky objects look like faint patches of light and can be underwhelming to a beginner. However, with practice and patience more detail can be seen. Try starting with brighter, easier objects such as M57 (the Ring Nebula) and M27 (the Dumbbell Nebula), which are both well placed in the evening sky at this time of year. 

[Dark Vader]

The 4mm eyepiece in that scope I think will give 300x magnification and should be better for lunar and planetary use. The more mag you use, the dimmer the image seems to get.

Galaxies and nebulas should benefit from way lower mag than that, maybe 20 - 30mm. I'm sure someone more experienced than me will be along shortly with a better explanation 😀.

[laudropb]

The 4mm ep gives a magnification of 300x and that is far too much for most DSOs  The addition of an O III filter will also help to see detail in some of these targets.

[Guest]

31 minutes ago, Astrid said:

Hello! 

I have a friend that bought a SkyWatcher 200P Skyline Dobson 10 months ago. (https://www.firstlightoptics.com/beginner-telescopes/skywatcher-skyliner-200p-dobsonian.html)

Even though it has a 4mm deepsky eyepiece and a good aperture, she cannot observe nebulas or even large galaxies (like M31). The planets look ok (no problems here). 

I was assuming that the problem was the collimation, but she checked it and the telescope seemed collimated. Perhaps the problem could be the EP...?

The place where she observes is not light polluted (from what I understood she goes somewhere in the countryside, not in the middle of the city or anything like that) 

  Is there anyone that owns a 200P or had a similar problem? 

Thanks in advance! 

I own the same telescope and really only use the highest magnifications (3.2mm and 5mm) on the likes of the moon and Venus, when conditions permit...

Edited September 12, 2020 by Guest
typo...

[John]

I agree with all of the above !

4mm is simply not the right eyepiece for seeing nebulae and galaxies.

30mm - 20mm eyepieces are much more useful for this task.

Collimation makes little difference where such targets are concerned.

 

 

[jetstream]

5 hours ago, Astrid said:

she cannot observe nebula

Unless experienced the only nebula viewable without a filter is M42- did she try this one?

 

5 hours ago, Astrid said:

where she observes is not light polluted

Is the Milky Way visible and defined?

[Timebandit]

 

 

Hello. If your friend has seen photos of these DSO in books , then do not expect the same views through the eyepiece. AP and observations are two different things especially with the faint fuzzies.

Make sure your friends site , is really a "Dark site" . The difference when it comes to observation can be vast. Things that pop in true Dark sites ,cannot be seen in light pollution areas.

Finally, is your friend looking in the correct place in the Sky's?  Get the book " Turn left at orion" at great book to get the novice used to finding objects .

 

Hope the above helps 

 

 

[Alkaid]

As a note to help finding objects, a 50mm finder will spot almost all well known Messier objects from a dark sky site.  
 

Just a thought, what finder is being used? Is it aligned with the scope? It’s important to do this before or at the beginning of the session, either in daylight on a distant object or at night on a bright star or the moon. Once the finder is pointing at exactly the same place as the scope, good to go.

Pop in lowest mag eyepiece, aim finder and get object in finder view. Look in main eyepiece...object should be there.

As a final note, if looking for faint objects, do not turn on torches or any lights for at least 20min...it’s your dark adaptation that will get you there. (None of that matters for the moon & planets, as they’re bright).

Good luck!