A little disheartened

[Robh (Rob)]

Actually, the inability to focus is more common than you might think.
I have a 12 inch Meade LightBridge and don't have any problem with focus with any of my Meade plossls.

However, I recently upgraded to some TeleVue Ethos eyepieces. The 21mm can only be used in a two inch focuser but the 13mm and 8mm can be used in a 1.25 inch or 2 inch focuser. Using the two inch format, the 21mm focuses without a problem but the 13mm and 8mm require a 35mm extension tube.
This is because the optical elements of the 13mm and 8mm actually sit much further down the focuser draw tube than they would in the 1.25 inch format.

Perhaps designers could make focusers with have longer draws to accommodate some of the newer eyepieces.

Regards, Rob

[barx1963 (Malcolm)]

I recently purchased a 10mm Ethos and found difficulty focusing in my GSO 12". If I used it in a 1.25" adapter i couldn't rack it in enough, if it used the 2" barrell it couldn't be racked out enough and I had to sit it out a little. I solved initially by winding in all my collimation screws so moving the primary away from the focuser so I could get focus.
Eventually ended up buying a Televue High Hat adapter (see here http://www.televue.com/engine/TV3_pa...=23&Tab=_equil ) that solved the prob. The only other solution was getting par focalising rings.

[Smigatron (Ben)]

Thanks to everyone who replied to this thread and a massive thanks to Erick for showing me the ropes and pointing out my slightly embarrassing issue.

Things are looking up (pun intended).

Also, thanks to big_dave who was willing to help but couldn't due to bad weather

[Poita (Peter)]

Soo... fess up! What did it turn out to be? It will no doubt help someone else avoid the issue in the future.
So glad it has been sorted out, you should get great views through that scope, let's hope the weather behaves now!

Originally Posted by Smigatron

Thanks to everyone who replied to this thread and a massive thanks to Erick for showing me the ropes and pointing out my slightly embarrassing issue.

Things are looking up (pun intended).

Also, thanks to big_dave who was willing to help but couldn't due to bad weather

[Smigatron (Ben)]

Well in the interest of perhaps helping other people, this is what the main problem was.

When I put the scope together, I attached all of the parts that came with the scope, following the manual. One of the parts was an adapter/extension between the scope and the eyepiece which looked like it had to be fitted (all the diagrams in the manual show it fitted). Using the 10mm and 25mm eyepiece I could never achieve focus.

Erick pointed it out and removed it and like magic, the problem was solved. After a slight collimation everything was perfect. I am kicking myself for never even trying this, but to be fair, I thought that it had to be fitted to the scope in order for it to work properly.

[Poita (Peter)]

Easy mistake to make, and it is always a wonderful relief when a problem is inexpensively solved. I spent an hour after my refractor arrived becoming more and more certain it had been damaged in transit, nothing would even vaguely focus. Very cold and increasingly anxious in the dark I eventually gave up and came inside, horribly downcast. I went to pack the scope away and twisted the eyepiece end to swivel the diagonal into position with the case. The scope seamlessly extended itself another four inches....

So you're not alone! :p

[erick (Eric)]

And we actually had a great time observing with Ben's scope after checking things out, then collimating. The seeing was amazingly good and the optics were performing well. We started on the Moon and got to a 5mm Planetary eyepiece in a 3x barlow for a 720x view!! - and it held up well! We pulled 47 Tuc and NGC 253 out of a Moonlit, Sydney light-polluted sky, faint but recognisable, then moved to Jupiter as some clouds were rolling in, but not before we had seen one of these dark patches sitting on one of the equatorial bands - very distinctly.

Ben has some nice optics in his 8" Saxon. He just needs to work a bit more on the mechanics to get the movements smoother. And perhaps a better 9-10mm eyepiece. The 25mm was doing a nice job.

[desler]

What a great story! I love it. I still remember my first star camp and Eric showing us the wonders through his 12 inch dob and some amazing Bino views.


To this day my wife still talks about the emu to all an sundry!

Now the fun starts Ben and I wish you well for your future endeavours!

Darren

[big_dav_2001 (Davin)]

Great to hear you got it sorted mate...enjoy the views, hope to catch up sometime soon

Davin

[barx1963 (Malcolm)]

Good to hear it was sorted out. Yes Erick the shorter eps that come with these scopes are a bit average. It is a bit of a worry that a beginners scope is not crystal clear in their instructions.
Malcolm

[Blakout (Neil)]

Originally Posted by AndyK

Hey Ben, don't give up.

I also have an 8" DOB. It's a flex tube type which supposedly needs collimating just about every time they're used. The day I brought it home (I bought it second-hand) I simply took it out from the back seat of the car, put it together, extended the flex tube bits and waited for dark.
That evening I pointed it at the moon with a 25mm eyepiece and was rewarded with beautiful, crisp views. A few days later in really poor seeing and with Jupiter not very far abve the horizon I was easily able to make out the bands. This was all without any attempt at collimating.

I'm fairly convinced that in your case there's something not quite right with the telescope as others have indicated. I don't think it's anything you're doing. Tell us where you are and I'm sure there will be somebody who can help. Don't be disheartened ... you'll get there and believe me, it's well worth persevering.

Same here andy , used my new skywatcher 8in DOB tonight for the first time straight out the box with no collimating , moon looked amazing and I could even see jupitars bands and three little moons ( I think thats what they were )

Good to hear its all sorted out Ben