12"Dob ❤ Ortho

[Scosmico]

I did struggle few years with a colimmation issue in my truss 12" Dob. The collimation would vary unacceptably depending on the angle the dob was.

I normally collimate at the begin of each session at 45°.  However, at zenith or at low south objects were badly affected by changes in collimation.

Temperate was my first suspect but even on night when the temperature didn't swing the collimation was changing.

All screws were tightened. This has reduced the changes, but still I had to collimate during the sessions.

But I found the reason... heavy 100°  eyepieces were bending my Dob's truss.

So I have decided to use only my ortho eyepieces with my Dob. Since, the collimation is spot on all night, which only enhances the experience with my orthos.

I must say that my dob and my orthos are going to be together forever. Love is in the air.

[John]

Thats a very interesting finding. What type of dob do you have ?

 

[Scosmico]

My dob is a 12" Explore scientific.

 

[Paz]

It's good that you've identified the issue but a shame that the scope is struggling with eyepieces one would reasonably expect to use.

[Peter Drew]

2 hours ago, Scosmico said:

My dob is a 12" Explore scientific.

 

I'm surprised that the truss deforms so easily being as it is a proper 8 component Serrurier truss. 

[Scosmico]

3 hours ago, Peter Drew said:

I'm surprised that the truss deforms so easily being as it is a proper 8 component Serrurier truss. 

Yeah Peter, perhaps the bulky eyepiece is the last straw in the camel's back, or should I say cage.

The setup overall is not that heavy. A TS RC finder 8x50, a Rigel quick finder, standard focuser.

[jetstream]

A widefield, but lightweight option could be the 28mm 68 deg ES weighing about a pound.