power or portabillity?

[Jarrod]

thanks everyone. i have seen a 12" GSO scott, and i felt weak just looking at it! i did expect that it would be part of the assembly procedure to collimate the lightbridge, but i was kind of hoping there was away around it (im so lazy!). i'll be buying a chesire collimator when (sorry, i mean if) i get the scope.

extra eyepieces was one of my main concerns, i know i'd need more then the 26mm that comes with the scope. i was thinking of a 12mm and 6mm, that way each EP halves/doubles the magnification (it seems logical). without meaning to change the subect, would the cheap plossl EP sold at bintel be alright to start off with?

thanks, jarrod

[astroron (Ron)]

I have a truss 16" dob and it takes no time at all to collimate after I take it to pieces and reassmble at the new destination.
Just buy the scope you want,learne to collimate it and after a little while collimating wont even be a problem.
Go the 10" truss dob and you wont regret it.

[Tannehill]

You know, I don't know anything about those EPs. I horse-traded the EPs that were to come with my GSO for an observing chair...since I'd brought my EPs along from the U.S. Never laid eyes on them.

Hopefully someone can weigh in on that.

But I'd expect they'd serve well until you chose to upgrade. They wouldn't sell complete crap I'm guessing....

Scott

[erick (Eric)]

Jarrod

If you don't know any better, like me, then you will likely be happy to get started with the GSO plossl eyepieces. The scope I bought secondhand came with 26mm, 15mm and 9mm eypieces and the 2x Bintel barlow. I have since added the GSO 40mm and 6mm eyepieces. With the barlow, I have a magnification range from 30x (where my binoculars top out) to 400x (which is pushing the limit most times for my scope). Of course, we are talking $40-70 eyepieces, they are not your $29 real el-cheapos, neither are they $200-$800 eyepieces. I have taken the view that I have a lot to learn yet about using the scope and finding my way around the sky and I don't want to be spending my time desparately worried about looking after a $500 eyepiece, rather than experimenting with magnification and observing technique, and frequently swapping eyepieces in and out of focusser and onto the eyepiece rack (two in my case - I added one more). I've seen wonderful things already with these eyepieces and have enjoyed the trip so far.

(But I do have to admit that I was kindly lent a Pentax XF 8.5mm eyepiece ($215) for a few evenings and it is definitely on my "must acquire" list!)

Actually, knowing that, in due course it will get even better when I do invest in better eyepieces and some appropriate filters is the prospect of lashings of cream on an already delicious cake!

Eric

ps. My 8" f6 is not " loosey-goosey"! ....................I think???...

[Tannehill]

Eric,

Sorry, I hope I didn't stumble across an (another) idiom with disparate meanings, there!

I've learned the hard way that some of my American phrases do NOT translate the same! Someone, please tell me if 'loosey-goosey' has profane implications, here...so I don't (again) insert my size 12 American feet into my mouth at some gathering. [It's common for an American, after a good meal with friends, to lean back in the chair, pat his newly full stomach, and comment appreciatively and loudly "I'm stuffed!" It means (to us) that the food was too good and we ate too much. But, at a recent dinner with some very new Australian colleagues and friends, it precipitated a completely unintended reaction from the Australians at the table....need I say more?]

Just meant that the coma-free zone in an f6 is substantially larger than in an f5 or f4, and an autocollimator is probably wasted money on an f6 compared to an f4 'scope...it'd be hard to identify the benefit of its use.

Eric, I would never insult your telescope. Our scopes frosted together a few weeks back, after all.

Regards,

Scott

[erick (Eric)]

Only kidding Scott, because I had never heard it before and wondered what it would mean - I could guess from the context.

I guess we are a little off thread, but I have to say that collimation certainly seems to be easy-peasy ( ) with my 8" f6 dob. A quick look with a sight tool that the secondary is in place, then in goes the laser (previously collimated itself, and wrapped with some adhesive contact for a very snug fit in the 2"--> 1.25" adapter, adjust the secondary to place the beam in the middle of the primary "doughnut" spot as precisely as I can (then tap the spider a few times to check the spot doesn't move away), then adjust the primary until the return beam is coincident with the outgoing beam (easiest done before it gets dark - otherwise there is enough scattered laser light everywhere to confuse the view from the rear of the scope). If I have time, I barlow up the laser and slip a bit of paper (with hole) into the beam at the focusser and see where the return shadow of the doughnut lies. Everytime it has been centred on the outgoing beam. Might do this all while the cooling fan is running - doesn't seem to affect the operation at all - no bouncing beam!

Then I use the scope. The image looks good to me and the few knowledgeable people who have looked through my scope haven't reeled away in horror - so I guess it must be collimated reasonably well for visual.

It was essentially luck I ended up with an 8" f6 - seems to have been a good move for someone inexperienced.

[Jarrod]

Originally Posted by Jarrod

i'll be buying a chesire collimator when (sorry, i mean if) i get the scope...

would it be better to get a laser collimator? since i wont be able to look through the chesire while i adjust the primary, i thought it might be easier to buy a laser collimator. just an idea.

jarrod.

[Tannehill]

I'm not sure it really matters, to be honest. If you have the spare cash, it won't hurt. If you want to be able to turn collimation bolts while watching your barlowed laser, you'll need to get one of those that has the little right angle window you can see from the back of the scope. I don't have that type, so it was (until I hooked up the webcam) kinda amusing to watch me ping-pong back and forth.

You can do just fine with a laser, or a chesire.

scott

Originally Posted by Jarrod

would it be better to get a laser collimator? since i wont be able to look through the chesire while i adjust the primary, i thought it might be easier to buy a laser collimator. just an idea.

jarrod.

[Jarrod]

Originally Posted by Tannehill

If you want to be able to turn collimation bolts while watching your barlowed laser, you'll need to get one of those that has the little right angle window you can see from the back of the scope...

yeah, thats the type i meant (right-angle window), they're $69 at bintel. the chesire is $49, so only $20 extra. i was also thinking about asking the wonderful people at bintel (i hope they read this , lol) if i can have three GSO plossl eyepieces (a 26mm 2", 12mm 1.25", 6mm 1.25".) rather then the 26mm meade EP. or is the meade eyepiece too good to refuse? its a Meade Series 4000 QX 26mm (2", 70 deg' widefield).

jarrod

[Tannehill]

I have no experience with those EPs, but I can say Bintel did negotiate when I bought my dob (exchanging comparable value items, that is). So worth asking about...

First chance you get with your laser, you double check it with someone elses laser or passive tools to ensure it (the laser) is itself collimated. Then, just don't drop it, and you'll be fine. Apples. You'll be apples. No...she'll be apples. Crap, what is the phrase, again?

Scott

Originally Posted by Jarrod

yeah, thats the type i meant (right-angle window), they're $69 at bintel. the chesire is $49, so only $20 extra. i was also thinking about asking the wonderful people at bintel (i hope they read this , lol) if i can have three GSO plossl eyepieces (a 26mm 2", 12mm 1.25", 6mm 1.25".) rather then the 26mm meade EP. or is the meade eyepiece too good to refuse? its a Meade Series 4000 QX 26mm (2", 70 deg' widefield).

jarrod

[Jarrod]

dad and i went down to the astro society last night to get some opiniuns on a dobsonian, mostly regarding manualy tracking objects and transoprting them (even a lightbridge dob would take up a fair amount of boot space).

they thought that considering the amount of traveling we do (camping mostly), even a portable dob like the lightbridge would be too big to "throw in the boot". they suggested that even though a dob would give better views, maybe a scope like a meade ETX would be more sutible.

one of the members showed us the clubs etx (an etx-80 i think). ive never considered an ETX because to match the views through my current scope id need an ETX-125, and $1800 is wayout of my price range !!!. but since i could proberly buy one cheap 2nd hand (not something i wanted to do at first), maybe its worth considering. since my original plan was just to buy a higher quality portable scope to replace my current scope, and not worry so much about aperature.

im not saying i no longer want a dob, its just that i wouldent get to travel with it as much as something small like an ETX.

opiniuns welcome!!!

thanks, jarrod.

PS, sorry i keep changing my mind, but i did hardly any research before getting my current scope (BIG MISTAKE!!!). i dont want to make the same mistake agian!!!

[Tannehill]

Best scope is the one you use the most. My 85 mm refractor is deployed more often than my dob for that reason. Less average time per session, but more often. Espeically in sucker hole sky conditions...which is more often the case, anyway!

Scott

[KG8]

Go the ETX! You can poke it in the corner of the boot and set it up on a picnic table. Just don’t forget some sort of dew shield/heater arrangement. You don’t want to get caught out by dew at 9:30, just after you get started

[Jarrod]

hey guys, this might explain the increase of cloud cover in the Geelong region...

it was a six month wait, but it was worth it. i am now the proud owner of a 10" Bintel Dobsonian. I was quite suprised when my parents got it for me as a combined 18th birthday/christmas present.

the ETX would have been nice, but i was hungry for more light. my 5" will probably end up living at the farm in central vic. The dob will live here (Geelong), but will sometimes come along when there is enough room in the car.

so how is it...? GREAT!!!

amazing telescope. so far ive only used it from my backyard in Geelong, so light pollution is an issue, but what ive seen has been amazing. the detail in the orion neb is stunning, and faint detail on mars!!! ive never seen mars appear as anything more then a pale brown dot, so seeing detail on the planet, although faint, is amazing!

saw my first planetary nebula last night/this morning. not just first for the dob, i mean first ever. i dont know why, but in the 13months ive had the 5", i only once tried to view a planetary nebula (i didnt find it, so maybe that discouraged me???).

this morning i tracked down the blue planetary. AMAZING!!! its actually blue!!! really blue!!! who says DSO are always B&W?????

also found the eskimo nebula, the eight burst nebula, and the ghost of jupiter. by this time i was getting a little tired, so i didnt really take it in very well. im going to try all four objects agian tonight (if the cloud clears). amazing. no detail as such, they're just faint disks, but the colour blew me away!!!

omega centauri (sorry, if wrong spelling) and 47 tuc looked great, plenty of stars visible. i actually like 47 tuc more then omega', it just looks better to me. 47 tuc has more character, omega' is kind of dull in comparison.

centaurous A, the first time ive ever seen it. low in the sky, and with light pollution, but the dust lane was visible. also viewed some galaxies in dorado. NGC1553 and NGC1549 being the first galaxies identified through my 10" dob. they were also the first galaxies i identified through my 5". i actually spotted a galaxy last week with the 10", but i was packing up, so didnt bother to identify it.

seen plenty of other things, but these are the highlights so far.


thanks every one for all your helpful input and advise,

Jarrod.

[dannat (Daniel)]

congratulations on the new scope