Newbie Lightbridge 12" - better planetary viewing?

[cjpops]

Hi all, theres already a fair bit of threads regarding LB's eyepieces here but i dont feel right hijacking somebody else's thread..

Im fairly new with eyepieces, my last scope came with a barlow and 3 'cheap' eyepieces over 8 years ago.. I recently got myself a Lb 12" and it came with a standard wide view 26mm eyepiece. I've also got a 15mm 1.25 piece thrown in the package.

When i looked at Jupiter it was fairly bright and i could make out the surface stripes a little.. Can i achieve better results (more surface details) with a barlow adapter or would you recommend a particular eyepiece that will give me a much more detailed viewing?

Ive beem Lookibg at a Meade 4000 eyepiece kit, would this be a good start?

Hope i make sense here - Any suggestions would be great..

[chrisp9au]

Hi Craig,

Depends how much you want to spend...

A tight budget made me look around carefully for eyepieces for the moon and planets.
Finished up buying 2 University Abbe Orthoscopics, 12.5mm and 5mm.
Very happy with them, nice sharp views, and the price was brilliant, although I notice they've gone up a bit since!

Check them out at: http://www.universityoptics.com/125inch.html

My research on IIS and CloudyNights suggested these were a good choice, and the recommendation was that it's better to buy individual eyepieces rather than use barlows.

Cheers :thumbsup:
Chris

[robz]

Before you go and spend a fortune on E.P's to supposedly improve your planetary images, be wary of Jupiter and it's lack lustre display of late.

The last couple of weeks here in Perth have had real bad jet streams coming in and out as they please.
For example, last night, my scope was fully cooled and there were moments where a few stripes and the one major equatorial band was just visible.
I tried a cheap,crappy 4 mm SR Tasco eyepeice and then a giant 70 degree 2 inch 3.5mm monster made by Synta on my 8 inch newtonian.
Not such a great difference(except for the fantastic field of view!)..........trust me.

On the minus side, the image would out of nowhere, suddenly go to a ''boiling mess'' and then steady again.

At this time of the year, you have to wait and/or wake up in the early hours of the morning to check if the turbulence has settled.
If it has, you will be surprised how the supplied eyepeices will perform;)

[cjpops]

Thanks for that Chris.. Those eyepieces look better built than the cheap 'standard' ones i've been looking at.

Might order the same 12.5mm & 5mm eyepieces you mentioned.. Should these give me more details i.e. Jupiter?

[cjpops]

Hi Robz,

I did notice the 15mm eyepiece give me a blue/orange effect around Jupiter, the Moon eventually came out and i saw what was some air turbulence of some kind.

Will give the early morning a tryout hopefully early Saturday Morning.

Cheers

[chrisp9au]

When the seeing is good, yes.
Hang off until Snake Valley and try mine out before you buy!

Cheers :thumbsup:
Chris

[ausastronomer]

Hi Craig,

I would get the 9mm and the 7mm, if you can only afford 2. The 5mm will give you 300X in your 12"/F5 which more often than not will be way too much magnification and give poor quality images due to atmospheric conditions. The 7mm will give you 214X which will be "useable" on an infinitely more frequent basis than the 5mm and probably hold up on 70% of nights. The 9mm will give you 166X which will be useable "almost" every night.

Cheers,
John B

[cjpops]

What a good idea Chris, I'll hold off buying an eyepiece until after the Snake Valley trip.

Thanks for your info John.B - i'll hopefully check out other dob users eyepieces and make a decision from there.

I got a feeling i might end up holding off buying an 'budget' eyepiece and saving up for a much more expensive one. :lol:

[Jeff]

I agree with John B ... 7mm is probably the lowest FL eyepiece you'll want for most conditions. I had a 5mm Nagler at one stage, but ended up selling and getting a 7mm William Optics UWA which gives much crisper views under normal viewing conditions.

BTW, a moon filter (ie. neutral density filter) is sometimes handy when viewing Jupiter which tends to be very bright.

Cheers,
Jeff

[Satchmo]

Learning to really collimate on a star at high power( not just with a laser) is the easiest thing a newbie can do to improve their planetary images. Wandering around the field at IISAC I was often amazed at what people's idea of adequate collimation on a Newtonian was.

[mental4astro]

Hi Craig,

Very sound advice is being given focal length wise.

Here is another very good option for you. Sylvain has got his mits on some new TMB Planetary 6mm & 9mm eyepieces he is selling here for $50 each! I've had the 6mm for close to a year now (from somewhere else and a few more pennies), and just got the 9mm from Sylvain. These EPs have a 60 degree FOV which allows for a longer drift time through the eyepiece of an object if your scope doesn't track, and the eyerelief on both is amazing- you don't need to park your cornea on the eye lens:

http://www.iceinspace.com.au/forum/showthread.php?goto=newpost&t=66161

While it might seem that their focal lengths are fairly similar, with my big dob they give significantly different magnifications that warranted the purchase of the 9mm. The 6 gives me 333X which is way, way too much for most occasions. The 9 gives me 222X which is much more frequently useable. This totally concurs with what is being said about the atmosphere being our greatest limiting factor for magnification.

In your 12" f/5 scope, the 6mm gives 250X, the 9mm 166X.

These are by far the finest high power EPs I've used.

I wrote a short report on my new 9mm TMB in the above thread.

[cjpops]

Ooooo thanks for that!! Promising review! Ive left a pm so hopefully theres stock left.

[cjpops]

Re: collimating

Hi Mark, im actually too nervous to muck around with the mirrors, ill have to go to a stargazing event to see how others collimate their scope..

Still not sure whether to spend a bit extra on a laser collimator which is already calibrated out the factory (orion brand) - i might have to look up how people collimate to a star - sounds tricky

[erick]

No problem, Craig - we'll take a hammer etc. to it at Snake Valley - we'll set you right! :P

[mental4astro]

:work: :einstein: :atom: :bashcomp:

Hey, Eric, if you really go to town on it we may appease the Sky Gods to leave the sky clear for 3 months! At the rate of 1 week per inch apeture, 3 months sounds about right! :lol:

Collimation is VERY easy and straight forward once you see what is actually going on. It is just re-aligning the mirrors. It can be done just using a bright star. Once you get the hang of it, the process takes only a couple of minutes and you'll be rewarded with the best image your scope can provide!

[chrisp9au]

Please count me in on the collimation/star testing tutorial at Snake Valley. I'm always unsure whether I have got it right!

Cheers :thumbsup:
Chris

[cjpops]

Great! looking forward to snake valley, ill be there either Fri or Sat night.

But er... A hammer!?! :question:

[chrisp9au]

There are pictures of Eric with a hacksaw poised over a Jen's scope! :D

[erick]

OK, we'll settle for some collimation tools - perhaps the hammer won't be required. :D

[Satchmo]

Craig

Collimation is something you have a look at every time you assemble your telescope. If you want to see fine planetary detail its something to pay close attention to. 'Coma' on axis is the result of mis-collimation and it doesn't take much to smear out you planetary details .

Collimation on a star is the bit you can do after using a laser to mechanically check your collimation: it involves optical collimation - actually using your parabolic mirror on a star . It involves putting 3rd magnitude or fainter star in the center of your highest powered eyepiece that seeing will allow and studying the star disc as close to focus as possible where you can still see the secondary mirror shadow breaking out.

A simple iterative process of getting someone to move the correct collimation bolt, re-centering the star and reevaluating the concentricity of the rings. As you get closer you will need to bring the star closer and closer to focus , until you are just looking at the evenness of lighting in the rings. Once you learn the rules you'll find it takes a minute at most .Star testing is not done with the expanded star disc filling 1/3 the field of view as some people seem to do.

I would recommend the Astrosystems laser system which has a magnetised barlow lens attchment. This neat device works better than a standard laser as the lens attachment prevents slop in the focuser tube from effecting the quality of collimation.

I don't think I've ever seen a laser collimation job , that couldn't be tweaked further at high power on a star.

I wouldn't recommend getting more eyepieces until you have mastered collimation and been able to evaluate the quality of your optics.


Hope this helps.

[cjpops]

If weather permits, ill try the star test this evening..

I just watched a few youtube videos on this.

[cjpops]

Wasn't exactly clear tonight, bit of mist happening in the air so i didn't try the star test.

However, my partner managed to find my old eyepieces from my previous scope and they were marked as K10 (10mm i assume?) and a K25 (25mm?).

I tried out my 'K10' eyepiece at Jupiter and was able to see the Red spot for the first time (it was closer than the 15mm eyepiece).

So, i'm guessing for now i'll get myself a laser collimator (orion brand), a decent Barlow lens and perhaps a budget 6-7mm eyepiece and then i should be right for the next few months to get the hang of it before making an expensive purchase on a 'real' eyepiece.

Cheers all :D

[richardda1st]

I wasn't happy with the Orion LaserMate deluxe. It wasn't very well collimated itself, but was just usable. But in my efforts to correct it I basically destroyed it, making it even more misaligned. :sadeyes:

I'm now totally happy with an Astrosystems 2" laser, which actually cost me about the same as the orion. Bought the orion from Bintel for $129 :eyepop:

That's just my experience, I think some others are happy with their's:P

Cheers
Richard

[cjpops]

Still haven't bought a collimator yet - Bintel is selling an Orion Laser for $99 - is this the one you had trouble with??

I just like to get one that is less fuss...

[mswhin63]

I have a Saxon with 7 brightness settings, I use 2 brightness levels when colliminating.
I tried an Orion on a recent trip and found it too bright and struggled to get the secondary alignment. Swinting to locate the dot onside the ring. I do like the target which is better than mine.

[cjpops]

oh gosh.. i was going to pick up the orion laser this morning at Bintel but until i saw your post i figured i better do more research and save my money on much better one..

Might ask here if they have one for sale..

[JethroB76]

Get an Astrosystems or similar

[richardda1st]

Yes it was. I recommend a 2" laser to eliminate any inaccuracy/slop between the focuser and adapter. Also a barlowed unit is best. The only good thing about the Orion LaserMate deluxe is the angled viewing window, which allows viewing whilst you are adjusting.

[cjpops]

Bringing up my old thread...

Ive ordered the bobs knob springs for the mirror on my LB..

Can any share their experience on replacing the springs?

[barx1963]

I replaced mine shortly after I bought the 12" GSO. Makes collimating so much easier!
Springs were a little tricky, only suggestion is do them one at a time. I also put my tube up on the kitchen table with a doona on the table to stop it rolling off. Getting it that bit higher makes it easier to work with.

[Jeff]

Pretty straight forward Craig.
Just follow the installation instructions which will come with the knobs.
You can also download instructions from the website:
http://www.bobsknobs.com/page3/assets/Instructions_English_Newt.pdf

Cheers,
Jeff

[cjpops]

Thanks for that link Jeff. The springs hasn't arrived yet so will post how i go when i get them.

[cjpops]

Hey guys, the kit arrived (primary springs, secondary knobs and FarLight counterweights) - must say the installation was easy on all three.

It was definitely much easier to collimate with these new springs/knobs - you can tell easily the new springs are much more firmer.

Hope this info helps any newbies out there. :D