Beginner still a little undecided

[inertia8 (Australia)]

Hi All,

I'm keen to get into astronomy and have been using my binocular's, a set of Vortex Diamondback 8x42's, on a tripod for the past couple of months. I've picked up a Chandler planisphere and a copy of Astronomy Aus 2014 to get me started for now with the binos whilst I save up for the scope and various necessities. I also got a copy of Tirion's Bright Star Atlas but it's not very clear to me yet, hoping to work on that before I get a scope!

I am located in the North Eastern suburbs, near Eltham and would like something to use in my backyard as well as take to darker skies.. I think an ASV membership will be on the cards in the near future.

My requirements:
Visual only. Umm, everything I can see I guess! So Moon, Planets, clusters, and DSO's.

I have astigmatism of around -3 in both eyes on different axes and am shortsighted and thus wear my eyeglasses all the time, however I'm entrigued by the TV DioptRx lens and am trying to find out just what other brands of eyepieces these will work with, though some say that they reduce the FoV too much. Any opinions on these?

I've been through many guides and threads and visited Bintel in Melbourne a few times and am considering either of the 8" or 10" Bintel dobsonians but I am still casting glances towards more portable SkyWatcher refractor options... That said after seeing the 10" dob several times in person it appears more and more acceptable to me in terms of size and weight. I was also considering whether to save and get the GOTO functionality of the Orion Skyquest XT10G, though it would really be stretching my budget considering I'd likely want/need to pickup an extra eyepiece or two so when I really think about it I think would rather get the Bintel unit, use it and then spend any extra money on a quality eyepiece or two with good eye relief and fov and from reading this forum that would be something from the Pentax XW, Denkmeier or TV Delos series, all with 20mm ER.

Oh and I'm thinking I'll either need something to sit on, something to sit the scope on, or both!

Thanks!

[AstroJunk (Jonathan)]

Hi and welcome!

You have already worked out the most important thing for a newbie. Hook up with a club for a while and get out to their dark sky site with them. Astronomers love showing off their kit and sharing their experiences. Take your time, make some mates and enjoy...

[astro744]

If I may paraphrase from John Masefield, "All you need is a tall telescope and a star chart to steer her by".

A 10" or 12" Dob and a copy of Tirion's Sky Atlas 2000.0 Deluxe 2 Ed. and Sky Atlas 2000.0 Companion 2 Ed. Later on you can invest in Uranomatria 2000.0 and its companion Deep Sky Field Guide as it will give you more stars, DSOs and a larger scale.

The companions are essential as they have all the data you need on every object on each atlas. Some will argue that these atlases are too advanced but I say you will soon outgrow the Bright Star Atlas.

Forget about electronic maps at the telescope as they impede viewing since the screen brightness is too bright in most instances. As for GOTO; you will find there are those that like it and those that do not and then there are those that think it can be useful but is more of a gimmick. I am in the last group and I do not need a GPS to get from A-B on the road and for the same reason I do not need a GOTO system. I rely on good charts and a sense of direction. You too will find that by start hopping, you learn the sky much better.

If you do get large scale charts like Tirion's Sky Atlas you will want to learn all about right ascension (RA), declination (Dec), hour angle (HA) and sidereal time. Once you grasp this, reading the co-ordinates on a chart is like reading longitude & Latitude on a world map. The sidereal time simply tells you what RA ('line of longitude') is directly overhead running north-south. Note from the northern horizon it ends at the south celestial pole (SCP and another term to learn) and then is 12 hours different running down from the SCP to the southern horizon. The SCP is a point in space formed by extending the Earth's axis of rotation to infinity. There is also a north celestial pole (NCP) visible from the northern hemisphere.

I think before you buy anything, join a club and have a look through other members' telescopes at a viewing night and see what you like.

As for Dioptrx, whilst it is a great idea it is best for an individual observing session. If you have company then you will have to remove the Dioptrx for someone else unless they have exactly the same level of astigmatism. (CYLINDERS only as the AXIS is not important as the eyepiece can be rotated). Also if your astigmatism changes significantly, you will have to get different Dioptrx.

Get an eyepiece with 20mm eye relief and wear your glasses and you will not have a problem. The Tele Vue Radians are great if you can find them used otherwise the Delos range from Tele Vue is good. Note Type 4 Naglers also have good eye relief as do the larger Panoptics from 35mm upward. Of course this is all a lot of extra money but you only have to buy them once although there are many that buy and sell and buy many times over and that's when it's expensive!

If you do want some sort of electronic chart for your PC then you cannot go past Stellarium. It is fantastic and you can get a feel of the dynamic sky by adjusting the time speed. Turn on the RA/DEC grid and then try the azimuth grid. Turn of the atmosphere and you will see what is in the sky during the daytime. Get your paper charts out and look at the co-ordinate index marks along the edges and you will start to understand where and when things are. Set your date to March 21 and find the Sun in Stellarium and you will see it is at 0,0, This is known as the 'First point in Aries' although due to precession (yet another term) is no longer in Aries but now in Pisces and the dawning of the age of Aquarius is approaching. (No I do not like astrology, but I do like the 1969 song, "Age of Aquarius" by the 5th Dimension).

Anyway above all have some fun and enjoy the hobby! You don't need a lot of equipment, just a clear sky.

[jjjnettie (Jeanette)]

Welcome.
I have the same binos, they are absolutely stunning to view through.
When you join the astro society, you may find that they have scopes to loan or hire for a small fee. That will give you a chance to make an informed decision before laying out all those $$$.

[raymo]

I have said this before to novice scope purchasers; although you now have no interest in taking pics through your scope, in the future you
might change your mind, so it makes sense to get a scope that will allow you to do that. Many dobsonians will not come to prime focus, so get one
that will. Skywatcher ones do; I don't know which other brands do.
raymo

[inertia8 (Australia)]

Thank you all for the responses. I think I will be targeting eyepieces with good eye relief rather than getting a DioptRx. My last prescription showed a change of .5 in the astigmatism in my left eye, the right eye was stable in that respect.

I will have to see what the included eyepieces are like and then go from there, at first it seemed a bit odd that the EP's could be as expensive if not more so than the scope itself but I guess the craftsmanship in creating them is high and the same can be observed in the camera equipment space.

Regarding the astrophotography I will consider it but primarily I wish to observe. I don't own a DSLR only midrange point and shoot cameras and I've read that you can replace the focuser with a low profile unit or, if on a budget, the primary mirror screws/tension springs with longer ones for achieving prime focus to save tube surgery. Alternatively using the eyepieces to acheive focus is it not?

[astro744]

Originally Posted by raymo

I have said this before to novice scope purchasers; although you now have no interest in taking pics through your scope, in the future you
might change your mind, so it makes sense to get a scope that will allow you to do that. Many dobsonians will not come to prime focus, so get one
that will. Skywatcher ones do; I don't know which other brands do.
raymo

I seem to have a bit of deja vu as I'm sure I posted a reply this morning. Anyway, You can use the afocal method to take pictures with any camera and a low power eyepiece. Use the zoom of the camera to enlarge the object. This method works well for the Moon and planets.

When you get into astronomy you will soon realise the there is not one telescope that does it all. Keep it simple and put all your money in the largest mirror you can afford and you will see many more objects. GOTO electronics cost about 1/2 the total cost so you end up with a smaller overall telescope. If you want to do astrophotography later then get a separate setup for that and put most of your money into the mount and get a small refractor to start with. You can always add larger OTA for astrophotography later as long as your mount can handle it.

[multiweb (Marc)]

Originally Posted by AstroJunk

Hi and welcome!

You have already worked out the most important thing for a newbie. Hook up with a club for a while and get out to their dark sky site with them. Astronomers love showing off their kit and sharing their experiences. Take your time, make some mates and enjoy...

I think that's the best advice on this thread. Short and to the point. Try before you buy.

[Renato1 (Renato)]

Do you have a dimmed down flashlight (get a regular small one, and tape red or white insulation tape over it). Then go outside with your planisphere, face north or south, hold the planisphere overhead, and use your little flashlight to find the constellations and brightest stars.

After you've figured that out, you can do the same with your Bright Star Atlas, and it will all make sense.

I've got bad astigmatism, which starts to make images bad with a 3mm exit pupil from the eyepiece, but I'm fine with smaller exit pupils.

When I'd get a new eyeglass scrip, I'd ask the optometrist to cut/grind my old lenses down to 1.25". Then I'd stick the right eye one onto my 40 and 32mm eyepieces with Blutack. And I've stuck a set into my Nikon 10X70 binoculars to get decent images. Basically, if I wear my eyeglasses, I can't read my star atlases - so I'm better off sticking the eyeglass lenses on troublesome eyepieces. But this may not be an issue for you, as you can just wear your glasses on long eye-relief eyepieces.

In my 14.5" dob, I also use a 2" 40mm eyepiece which delivers a 9mm exit pupil. So technically it "wastes" light because my pupil can't take it all in. But what I've found is that I can tilt my eye's angle - and the astigmatism disappears, without cutting out part of the image, as would happen with a smaller exit pupil.

With respect to eyepieces, you will have to decide whether or not you are "fussy". I've met plenty of people who can't stand distortion at the edge of wide angle and ultra wide angle eyepieces. If you are one of them, start saving as you won't be happy with anything but premium expensive eyepieces.

But if you aren't "fussy", then you may well be nearly as happy with inexpensive to moderately priced eyepieces on long focal ratio telescopes or moderately priced eyepieces on shorter focal ratio telescopes like the 10" dob. Edge distortion doesn't bother me too much, unless I actually see stars turn into seagull shapes at the edges - which is too annoying, and the stars will be heavily distorted in much of the field as well.

Anyhow, with Ebay and Ice in Space trading, if you do buy something you don't like, you can recoup some of your money.

Good luck,
Renato

[inertia8 (Australia)]

Once again, thanks for the advice.

I actually have a Rigel Systems 2x Red/2x White LED torch and a telrad on order from a place in adelaide (I only got the telrad at that time to balance the shipping cost of the torch as I figured I'd be wanting one at some point anyway).

I was using my Fenix headtorch with it's built-in red led but find that it is still too bright for use with the planisphere or sky atlas but perfect for illuminating the walking path, for which it was probably designed!

I also made a silly decision last month to purchase a TMB planetary II 6mm whilst still available at VTI, it's still in its box as delivered and might be OK for use without glasses due to the small exit pupil, if not it will go onto the classifieds.

As for other purchases, I will definately attempt to use the try before buy approach once I am a member of a club and have a chance to see through the different equipment in use. That said, I'm happy to put away a few $'s each month and treat myself to a decent quality piece of kit every once in a while.. probably starting with the "rumoured to be unavailable soon due to lanthanum price increases" pentax xw10... hopefully be able to have a look through one before BHPV puts the price up...

[el_draco (Rom)]

Originally Posted by inertia8

Regarding the astrophotography I will consider it but primarily I wish to observe.

Good choice. We tend to forget that visual work is amazing and many of us get to the point where the equipment would pay for a car or 3. A 10-12 inch Dob is a great start and there are a bunch of FREE atlases out there. Brilliant one spoken about in recent thread on IIS. Go observing for a couple of years and then maybe think of the photography stuff. Mind you, a 10 inch Dob will produce good moon images unguided. Thats where I started..


Rom