lestergibson

I found that a colli cap works better for me than a Cheshire for sorting out the secondary. I use the Cheshire only for the primary. I'm assuming that you're using a Dob so here's a few linkies that helped me out. http://www.cloudynights.com/page/articles/cat/articles/collimation-and-the-newtonian-telescope-v4-r2599 http://www.propermotion.com/jwreed/ATM/Collimate/Chesire.htm http://www.viewfromascope.com/how-to-collimate-a-telescope/ http://www.andysshotglass.com/Collimating.html

The only reason I asked was that I've read on numerous threads and articles that the secondary holder had to be centred so this is good to know, guys; thanks.

This one did my crust in and searching hasn't turned up an answer so here goes. Sorry for the detail! I decided to check my collimation after transporting the scope over rough ground for the past few nights. I've been getting what I thought was a decent enough image in the ep but I thought I check it anyway, just to be sure. The thing is, my OTA doesn't seem to be perfect circle; it measures 234mm, north to south and 237mm, east to west. I sussed this out when I made a stiff cardboard disc, as per AstroBabys' instructions to make sure that the spider vanes were centred.. The cardboard disc is bang on, according to my tape measure, but when I removed the rim cover from the end of the OTA and inserted the disc, I noticed a gap between the edge of the disc and the OTA at the 'west' position. I think this would explain why I was having a real nghtmare trying to get the secondary centred while getting the prmary clips into view. If I centred the secondary, there was nowhere enough range in the secondary allen screws to get the primary clips into view. The only way I could get the clips into view was to move the secondary closer to the primary but, of course, this threw the secondary off centre. I recentred centred the secondary between the ends of the OTA and took a photo through the colli cap to post here for advice but when I looked at it, I could see that, although the secondary was pretty much centred, top to bottom, it wasn't centred between the left and rght sides of the OTA. I don't know how to do this but guessed that the vanes must've been off somehow. I then started playing with the adjustment screws for the vanes and managed to get the holder centered left to right. After doing that, getting the clips into view in the secondary took minutes. This was after grinding away at it for four headbangingly frustrating nights in a row. After that, getting the primary into line was simple. The thing is, although the collimation looks good (I think), the secondary holder is now off-centre along with the OTA seeming not to be a perfect circle. I've attached a new post-collimation photo, taken through the colli cap and another with the cardboard disc inserted into the OTA for you guys to check. I'll be getting the scope out later for a star test but can you tell me what you think of the collimation and whether or not my issues with the OTA and the now slightly off-centre secondary holder are going to cause problems? Cheers!

The Skyliner 200p and the Orion Skyquest XT8 seem to be the main contenders but they both basically use the same components. I've got only used the Skyliner 200p but I've no complaints at all with it. The Orion SkyQuest XT8 Classic is well thought of too; it's got a better focuser than the Skyliner (I upgraded the manual focuser in my 200p with an after-market motor focuser which made it a lot nicer to use) and you can get the Orion with a 'push to' option i.e. you carry out a star alignment then select a target from the controller and move the scope in the direction indicated by the arrows on the controller display. Like I said, I've not used this scope myself but it looks pretty good. However, I'm still very pleased with my Skyliner and would recommend having a look into into it as well as the Orion. I might have a look at the Orion if I ever decide to upgrade to a 12" dob. If you do a bit of digging using the SGL Search function, you'll get plenty of threads on both scopes. Here's a few to get you started: http://stargazerslounge.com/topic/124581-advice-on-a-new-telescope/ http://stargazerslounge.com/topic/209906-skywatcher-skyliner-200p-by-a-reflector-newb-for-reflector-newbs/ http://stargazerslounge.com/topic/113631-the-skyliner-200p-f6-dobsonian/ http://stargazerslounge.com/topic/186926-orion-skyquest-xt8/ http://stargazerslounge.com/topic/111466-orion-xt8-classic-vs-skywatcher-8-dob/

Cheers, Jim. The clear nights I've over the Summer had have less than great seeing. The 16mm and 9mm were great on Saturn there one night but x266 with the Barlow on the 9mm was just serving up mush. Come on Autumn and Winter

That's what I was hoping for and the 82° would be cool for some DSOs too . As for the Barlow and eps, I'm using the Maxvision 68° 24mm and 16mm, a X-Cel LX 9mm and a TAL Barlow x2. I've had my eye on that 5.5mm for a good while now but I want to be sure as I can be befor the missus springs it for me.

Yup, I know that the seeing will need to be good for that sort of mag Ronin, and it would probably get less use than the other eps but you're right; I really do want to try it, lol, especially if does a better job than the 9mm barlowed.

I'm itching to pull the trigger on a high power ep and the Meade 5.5mm 82° is top of my list but I'm concerned that x218 is taking the mickey. I've pushed it to x266 at times with the Xcel 9mm barlowed but it's not great. Would a dedicated high power ep be a better job and, if it would, should just I stick with x200? I like the idea of the Meade because I like my MVs and the extra FOV will mean less nudging.

Your stargazing buddies gave you good advice. Get the biggest Dobsonian you can manage; they're a great all-rounder and you get a lot of mirror for your money. There'll be very little chance that you'll be disappointed.

I have the MV 16mm and 24mm. Love 'em. No experience with the Hyperion though.

Aye, John; that brilliant report of yours was what put me onto the SLV in the place:) Dude, colour me interested:) PM me on it. Thanks, Alan. I'll have a read at that. It was the Meade 5000 5.5mm UWA I was looking at.

Cheers for the replies, folks. I think I'll see about maybe buying a BGO/BCO and the SLV and A/B'ing them to figure out which one to keep. I'm a dob mobber so a narrower FOV might be a pain at higher power but I know the BGO has a stellar reputation, even with the tight ER. The Meade is on the list because it has a wider FOV and I love my MVs. The BCO comes in at £50 where the SLV is £109.

The missus wants to get me a prezzie so I've been torturing myself about what to go for as a 5mm/6mm planetary ep. I had considered a BGO but, although I don't wear glasses, I just don't think that I could get on with the ER. I've also been keeping my eye out for a used TV Radian but they've been like hens teeth for the past while. These two are at the top of my list but would anyone care to chip in? £125 would be at the limit of the budget.

I have the MV 68 16mm and I'm very happy with it. I just wish that shorter MVs were available.

+1 on taking your time to get to know the kit you have before starting to upgrade. I had the upgrade fever when I first got my scope but I forced myself to take my time and I'm glad I did because when I did start to uograde my eps, waiting helped me appreciated why they were better than the stock eps. I'd also recommend that you have a look at the Maxvision eps from Explore Scientific, at least for medium and low power. They are rebranded Meade 5000 and are a heck of an ep for the money; sharp and with a nice wide fov. I'm happy with my Xcel 9mm but I use my 16mm and 24mm the most.