North Group APOs

[JohnH]

Originally Posted by DavidU

A laser is good for collimating the focuser. Just remove the lens cell and replace it with a round piece of white paper with the exact centre marked, so if the focuser is spot on the laser will be dead centre .Make sure the laser itself is collimated (turn it around when in the focuser).

I understand that great care must be taken when removing the lens cell as the obejctives components can move if this is not done right.

In case you have not found it here are the 127 ED's instructions:

http://explorescientific.com/telesco...mm_ed_apo.html

(slightly different model - with reversable dew shield but think the reast is the same). BTW can anyone confirm the correct way to remove the dew shild from the NG model - I assume the coloured ring unscrews? Seems very tight on mine...

[GrahamL]

Now my daughter is back at the "home"

A little harsh Emma don't you think .. maybe next time a change in password and a few choices photos from the past are in order

[Octane (Humayun)]

I vote Emma's post, post of the year.

H

[DavidU (Dave)]

Here Here !

Originally Posted by Octane

I vote Emma's post, post of the year.

H

[wasyoungonce (Brendan)]

Now you see why I go & spend my nights outside in the cold!

Pity me!

[wasyoungonce (Brendan)]

Originally Posted by JohnH

I understand that great care must be taken when removing the lens cell as the obejctives components can move if this is not done right.
.

Thanks for that David.

[DavidU (Dave)]

What suburb are you in Wasyoung?

[wasyoungonce (Brendan)]

Lilydale....between the cemetery and the lawn cemetery & the poo farm (water treatment)....

Ahhh I can feel (& smell) the tranquillity

[DavidU (Dave)]

Ah nice, much darker in Lilydale.

[Brundah1 (David)]

Brendan,

See your getting your teeth into the ED127, good on you.

I'll behind you very soon, soaking up the good advice too. Its great to have the friendly advice of those who ventured into the unknown with these great value scopes.

Just finalising all the bits n pieces, but not hopefull about the WX next month. BTW tonight is quite good here, even though BOM said it would be raining clouds and showers!

Cheers,

David

[wasyoungonce (Brendan)]

Originally Posted by Brundah1

Brendan,

See your getting your teeth into the ED127, good on you.

Hi David.

I wanted to share all experiences I am having with it..good or bad. It's a great light gathering bucket.

[Logieberra (Logan)]

Hey guys

Out of interest, what do you pay to get one of these on shore? With diagonal and advanced whiz bang focuser?

Happy for PM's if the details are super secret.

Cheers.

[wasyoungonce (Brendan)]

Ok and bit of an update for everyone.

After tests I have come to the conclusion (obviously with the assistance of others..a big thanks to them) that there is an issue with the Optics on my 127ED.

It has a prominent blue/violet flare on stars (across the field) when at perfect focus. Yes I can re-focus most of this out but it is at the expense of defocusing stars.

I have performed star alignments, Cheshire alignments, focuser alignments and lost of tests with CCDInspector.

Gilman previously sent me an article on Lens alignment and I have fiddle with this (a little) with no change. This does not appears to be a main lens alignment issue as the star test is quite good. What is causing this?...who knows?...in my limited opinion it looks as if the centre lens may be causing this aberration.

I have more pics and a video of focus on my Picasa page if anyone is interested.

Anyway I've sent an email to Gilman asking for replacement scope (send mine back) or lens cell exchange.

So ATM it's all in the lap of the Northgroup. Lets see what eventuates.

edit:

I think I'll take my frustration out on the cat...oh..we don't have a cat...maybe Emma then!

[marki]

Originally Posted by wasyoungonce

Gilman previously sent me an article on Lens alignment and I have fiddle with this (a little) with no change.
edit:

Could you post the article? Could be very helpful for a little problem I am having.

Cheers

Mark

[wasyoungonce (Brendan)]

It was only an article about the AR5/AR6 scopes...Uploaded.

It is in fact different to the 127ED lens cell. The Explore scientific owners guide is better.

[mill (Martin)]

Originally Posted by DavidU

Ah nice, much darker in Lilydale.

Lilydale and dark???
Come in my backyard and then we talk dark
I hope Gilman will get back to you soon Brendan
PS: did you get my email?

[DavidU (Dave)]

Wasyoung, here is a typical longitudinal map of RBG (a triplet APO)) trace that shows the blue is a little out of focus while the red & green are.

[casstony]

There was a write up on the myastroshop website about these refractors but the link isn't currently working. Apparently they specified a different centre element in the Prostar version which markedly reduced chromatic aberration compared to the scopes coming direct from Northgroup.(flame shield on )
They had photo's on the site showing images through both versions of the scope, with no obvious blue halo through the Prostar.

If you send the scope back, perhaps you could ask if you can get the upgraded center element?

[Octane (Humayun)]

Don't take it out on Emma -- she rocks! : )

Sorry to hear about the issues you're having. And, my apologies for my lack of assistance. I've no knowledge on optics other than how to take an image. : (

H

[wasyoungonce (Brendan)]

Originally Posted by mill

Lilydale and dark???
Come in my backyard and then we talk dark
I hope Gilman will get back to you soon Brendan
PS: did you get my email?

yes I did..and sorry ..I have been busy with wayward family and telescopes.

And...yes Lilydale is dark...if you close your eyes..and imagine!

Hopefully it will get resolved to everyone's expectations, thanks.