Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.


Topics - Lcs King

Pages: [1]
1
I had always been under the impression that the extra resolving power of increased aperture only manifests once you start increasing magnification, but the other night I was comparing the 3rd quarter moon in my 8" SCT with my 12" dob, and even at the same magnification, the 12" dob was showing enormous amounts of detail and texture that was just invisible in the 8" (despite better optics in the 8"). In neither case was I pushing magnification to either scope's limits. Seeing was good, but not great.

Is that normal or were my eyes just playing tricks on me?

2
I have a 10in f4.66 that will be converted to a dob, and the new carbon fibre 10in f4 will be used as my main deep sky imaging scope and I will also use it viewing rich fields.I do have some coma correctors ,>> the old Lumicon CCFF is attached to my 48mm Lumicon EzyGuider>> a Baader MFCC>> a Tele Vue 2" tuneable top Paracorr ... a recent acquisition>> also have a 2in Tele Vue 2x PowerMate .... a recent acquisitionI'm thinking either Vixen SSW eyepieces (5mm, 10mm, 14mm these are all 1.25in) and maybe NLVW 30mm (2in)orPentax SMC in similar fls 5mm to 15mm as 1.25in eyepieces.I don't mind spending to get very good quality in my eyepieces which will have to do me out , it's taken me years to get to this point.I will likely want to try eyepiece projection once the scope and ROR observatory is installed.Til now my best eyepieces have been RKEs, these may be OK using the Paracorr on the f4.66 dob but I have my doubts about using these even with the Paracorr on the f4.Comments on my eyepiece choices for the f4 Newtonian would be greatly appreciated.

3
Beginners Forum / Have to focus all the way out?
« on: January 03, 2018, 02:33:44 PM »
I have a new Zhumell Z8 that I've taken out a couple nights now. It has a 2" focuser. I've noticed that I've only been able to get stars in focus by drawing the focuser all the way out to its greatest extent. Seems to me I should have some space on either side of the focus point to adjust, rather than being at the very end of the focuser's range. Is something wrong with my alignment or other calibration of the scope? I do wear glasses, but it doesn't seem to make much difference with them on or off. In both cases the best focus point seems to be the same.

4
ATM, Optics and DIY Forum / Making a Maksutov?
« on: January 01, 2018, 03:35:01 AM »
I was just curious, has anyone on here made a Mak-Cass? If so, what size did you make? Is it easier than a refractor? How long did grinding take?

5
I have found that my 1.25" 2.5x Powermate exhibits marked chromatic aberration when used in my 16.5" f/2.9 Newtonian. Attached is a star test showing the outside/inside focus appearance. I used a 6mm Ethos giving 500x for this test on Sirius, and the chromatic appears similar with a generic Erfle. The chromatic also appears when in focus, and straight on axis. No noticeable chromatic with the Ethos alone, so the issue is clearly with the Powermate.

I know sub-f/3 Newts are not common, but they are becoming more so, esp. for really large Dobs, so eyepiece and accessory aberrations which do not show in slower scopes seems to become a real noticeable issue with these fast ones.

Hopefully, we can discuss and share examples here, of which barlows work better at sub-f/3.
Attached Thumbnails


6
Reflectors Telescopes Forum / Getting the most out of a XT12G
« on: December 27, 2017, 01:33:59 PM »
Hi everyone! You may have seen some of my other posts on here about getting back into observing and trying to pick my telescope. I have decided to go with the Orion XT12G and for those of you who may not know their numbering scheme, this is the 12 inch, solid tube, goto version. I have owned the XX12i version in the past (12 inch, truss design, with Intelliscope) and really enjoyed everything about it.This should provide the same pleasing views but add the ability of tracking an object. I think it will be awesome tobe able to just sit back and enjoy the view for as long as I want to. This will also allow me to share the view with others and not have to worry aboutreacquiring the object for them. So now that you know why I wentwith this option, I would love to hear your feedback on how to get the most out of this scope. I have a plan of attack, but that doesn't mean I haven't overlooked something...

Ihave decided to go with Explore Scientific 82 degree eyepieces (30mm, 14mm, and 6.7mm) to start with and then fill in the gaps later with the 18mm, 8.8mm, and 4.7mm.

Because I am kind of set on some really nice glass (at least for me) I want to upgrade the focuser to a compression ring style so I don'ttear them up. The MoonLite CR 2" 1.5" travel compressionringdrawtubewith 1.2" dual rate tri-knob with shaft lock seems to be the most affordable option at $290.00

I will fully flock the tube with Protostar FlockBoard (FBK-04) to improve thecontrast. This looks like it would be a lot easier to work with then the Hi-Tack self-adhesive stuff. Has anyoneused this option? If so, do you have any feedback or wish you had gotten the tried and true Hi-Tack version? I seem to remember reading years ago that some people were using a sharpie to color the sides of the primary and secondary mirrors to also help improve the contrast, but now I don't see that mentioned... Is this something to consider or something to be avoided? Any input would be great!

I will order thetube case, cooling fan, and AC adaptor with the scope. I still have the Telrad from my XX12i and will be installing it onthis one as well.

Now the stuffI could use some advise on, yep collimation tools! I still have the three piece Catseye set that Iused on my XX12i. I want to re-spot theprimary but now there are several spots to choose from! Iused the large red triangle before but I'm wondering if the HotSpot makes it any easier? If so, what color? I will be orderinga set of Bob's Knobs for the secondary though. My last question on tools is should I add a laser to my bag of tricks? I know there are several threads on this, but I'm looking for a way to have a one person, easy alignment of the primary from the rear of the scope. I know we lost Howie Glatter this year but I thought Iread somewhere that a company had started producing his design and have them available now.Will I really gain much spending theextra funds on a laser if I already have the Catseye system? I would think a solid tube would likely hold collimation better then a truss design that gets taken apart and put back together.

Thanks for any thoughts or feedback on my plan. Don't worry Oklahoma, it will be a couple of weeks beforeI order the scope, sono clouds for a little while...

7
I am eying the Zhumell Z10 and similar scopes.  I am reading that whereas the 8" has a 24mm mirror depth, the 10" has a 34mm depth, a leap at ratio and double the weight.  The springs that work for your 8" tire out on the 10".
A 24mm thick mirror could decrease scope weight about 3 pounds, and accelerate cooling.
I am contemplating grinding or buying a thinner mirror.  Am I worrying too much about this?  There's a great deal more I would also prefer to replace or tinker  this extent, and I am realizing I may as well just build a range from scratch, for 3x the price.

Pages: [1]