Unable to see planets through my new 12'' SW dob

[arunbasak]

Hi everyone,

 
I'm new  here. Great site!

I'm also almost new to this whole thing. I just got my new 12 inch SW dobsonian telescope (upgraded from 6'' SW DOB).  I had followed all the steps in setting up the telescope. I hope I've done nothing wrong in setting it up.

I've came into a disappointment after trying to view through 25mm because everything came out blurry! Can understand the light is there but blurry. Also did the laser collimation as well but still of no avail.

Can someone please help me out? I'm very confused and frustrated.

Much appreciated. Thanks in advance for your help!

[Adam J]

On 10/12/2021 at 16:45, arunbasak said:

Hi everyone,

 
I'm new  here. Great site!

I'm also almost new to this whole thing. I just got my new 12 inch SW dobsonian telescope (upgraded from 6'' SW DOB).  I had followed all the steps in setting up the telescope. I hope I've done nothing wrong in setting it up.

I've came into a disappointment after trying to view through 25mm because everything came out blurry! Can understand the light is there but blurry. Also did the laser collimation as well but still of no avail.

Can someone please help me out? I'm very confused and frustrated.

Much appreciated. Thanks in advance for your help!

Have you tried focusing on the moon? Easy to find, does it look sharp?

Adam

[johninderby]

Hi and welcome to the forum. 

First thought is are you using just the 1.25” adaptor on it’s own? If not then you won’t get focus.

[Knighty2112]

Also, try focusing on a distant object (house, chimney top, tree etc) in the distance if possible more than half a mile away and see if you can get it in focus like that. If so you should be able to get it to focus Ok depending on seeing conditions etc.

[arunbasak]

6 minutes ago, Adam J said:

Have you tried focusing on the moon? Easy to find, does it look sharp?

Adam

I haven’t tried the moon Adam. I was trying to do the distance objects like trees etc . Also tried the stars one night, but nothing came up.

[arunbasak]

6 minutes ago, johninderby said:

Hi and welcome to the forum. 

First thought is are you using just the 1.25” adaptor on it’s own? If not then you won’t get focus.

Thanks John. 
 

am using the 1.25’’ adapter only-as I’m more comfortable with those than 2’’ ones.

[arunbasak]

5 minutes ago, Knighty2112 said:

Also, try focusing on a distant object (house, chimney top, tree etc) in the distance if possible more than half a mile away and see if you can get it in focus like that. If so you should be able to get it to focus Ok depending on seeing conditions etc.

Have tried them earlier, but will give another shot today afternoon. Also I have collimated yesterday night and pray something comes up ..

[Victor Boesen]

13 minutes ago, arunbasak said:

Thanks John. 
 

am using the 1.25’’ adapter only-as I’m more comfortable with those than 2’’ ones.

With my solid tube Skywatcher 250PX I had to also use the 2" extension tube (50mm long I believe) to reach focus with 1.25" eyepieces if I remember correctly. If not, someone please correct me!

[almcl]

Can't be sure but are the truss tubes fully extended?  If not, that might account for lack of focus.

[John]

21 minutes ago, Victor Boesen said:

With my solid tube Skywatcher 250PX I had to also use the 2" extension tube (50mm long I believe) to reach focus with 1.25" eyepieces if I remember correctly. If not, someone please correct me!

I think it is the opposite - you need to use either the 2 inch or the 1.25 inch adapter, but not both together.

[Adam J]

23 minutes ago, Victor Boesen said:

With my solid tube Skywatcher 250PX I had to also use the 2" extension tube (50mm long I believe) to reach focus with 1.25" eyepieces if I remember correctly. If not, someone please correct me!

This was the case with my 130PDS and i believe most SW Newtonians. 

Adam

[John]

13 minutes ago, almcl said:

Can't be sure but are the truss tubes fully extended?  If not, that might account for lack of focus.

The focuser drawtube is racked all the way inwards in the photo that has been posted.

 

[cajen2]

But perhaps @almclis right: there looks to be some truss tube projecting below the screw.

[John]

21 minutes ago, cajen2 said:

But perhaps @almclis right: there looks to be some truss tube projecting below the screw.

Looking at that photo again, I agree.

Those truss tubes do need to be fully extended.

Good spot @almcl

I misread your post and thought you were referring to focuser tubes

Edited December 10, 2021 by John

[arunbasak]

I did extended the truss tube 👍 but I used the 2’’ adapter and was able to spot far objects. That’s a good pointer @almcl. Thank you! Will take it out tomorrow night- hope it stays true to it’s forecast. Will keep you updated folks. Thanks for all the suggestions 

[arunbasak]

Just now, arunbasak said:

I did extended the truss tube 👍 but I used the 2’’ adapter and was able to spot far objects. That’s a good pointer @almcl. Thank you! Will take it out tomorrow night- hope it stays true to it’s forecast. Will keep you updated folks. Thanks for all the suggestions 

Initially I used the 1.25 adapter only.

[John]

Usually, with Skywatcher newtonian focusers, you use the 1.25 inch adapter when using eyepieces of that size or the 2 inch adapter when using 2 inch eyepieces. Focus issues are often caused when both these adapters are used at the same time (ie: 2 inch adapter > 1.25 inch adapter > 1.25 inch eyepiece). At least that how it's been in the past and the solution has been to just use one adapter or the other.

What can add to the confusion is that when you use both adapters you can actually get the scope to focus on terrestrial objects that are relatively close. It is when you try and focus on an astronomical target that the focus can't be reached.

Maybe Skywatcher have changed the design of their focusers recently though ?

 

 

 

[arunbasak]

Finally I was able to see the celestial objects 😀 but with only 2'' adapter and 2'' eye pieces. Thank you so much folks.

But only thing  bothering me is the usability of 1.25''- all my barlow  and other eyepieces will become useless  Am i missing something? 

[John]

5 minutes ago, arunbasak said:

...But only thing  bothering me is the usability of 1.25''- all my barlow  and other eyepieces will become useless  Am i missing something? 

That is puzzling. They should work of course.

[jetstream]

28 minutes ago, arunbasak said:

Finally I was able to see the celestial objects 😀 but with only 2'' adapter and 2'' eye pieces. Thank you so much folks.

But only thing  bothering me is the usability of 1.25''- all my barlow  and other eyepieces will become useless  Am i missing something? 

Most likely a focus issue IMHO.

[arunbasak]

5 hours ago, John said:

That is puzzling. They should work of course.

Le t me try again tonight . Thanks for your guidance John. Also any suggestion om how to see the nebula colours through the DOB?  I was trying to use a nebula filter , which is hardly making any difference. ( tried on Andromeda galaxy and Orion nebula)

[jetstream]

5 minutes ago, arunbasak said:

I was trying to use a nebula filter , which is hardly making any difference. ( tried on Andromeda galaxy and Orion nebula)

"Nebula" filters work on emission nebula and any filter will degrade the views of galaxies. Also, from personal experience, a sub par filter will also degrade the view a lot...

To make OIII, UHC work properly exit pupil must be in the right range-4mm-5mm so in your case a 20mm to 25mm eyepiece, preferably 2" widefields.

Of course all DSO need dark skies to see well, how dark is your sky?

Edited December 13, 2021 by jetstream

[John]

Most deep sky objects are seen in shades of grey visually I've found. You may see very subtle tints of green in the Orion Nebula but at best very subtle. A few planetary nebulae have tints of blue or green but again it's subtle. Filters such as the UHC or O-III type enhance the contrast of nebulae but usually not the colours.

The colours in deep sky objects are bought out by imaging techniques which our eyes can't match, unfortunately.