Turn Left At Orion & A Couple of questions

[Charlie_132]

Hello all, I haven't been on here for a while, had a bit of a break from astronomy....

I started stargazing 2 years ago, when i brought a 130p dob, I then sold that on to upgrade to a 150p dob, but after 5 months of owning it, i wasn't really getting much use out of it, mainly down to the viewing position and the weight of the telescope. So decided it would be best to sell it to someone who would use it more.

I currently have no telescope, but I am thinking of purchasing a 130p off ebay or astro buy and sell if i happen to come by one.

Could a skywatcher 9x50 right angled finder scope be attached to the 130p dob at all ?

I have the turn left at orion book which is based on using 8inch/10inch telescopes, but if I were to be using a much smaller telescope (130p dob) how would this affect the accuracy of the drawings/descriptions of what i'd be viewing ect ?

[Alfian]

Hi Charlie,

I have a  9x50 RACI fitted to my 130EQ which works well - but the 130P (Heritage?) is an open truss type dob which may make this more awkward - perhaps someone who has a 130P could comment. Something like a Rigel quickfinder would work well enough and is easy to use but this isn't a right angled finder.

Turn left .......is a great book and I have a copy. I wasn't aware that it restricted its application to 8 and 10" scopes - in fact it gives a key to what can be seen with smaller and larger scopes and binoculars.

If you need a hand with finding your way around and even what can be seen through the eyepiece of various scope apeture/focal length and eyepiece - download Stellarium - free planetarium software.

[bingevader]

I thought TLAO was aimed at a range of 'scopes up to about 8".

The author talks about using a 2.4" and a 3.5".

Cheers

[Astro Imp]

In the very first paragraph of the second chapter the authors say that all the objects described can be seen in 2.4" to 4" scopes in less than ideal skies.

[cussine]

I read it as the DOB views were drawn using an 8 or 10" the 10" only being used in the southern hemisphere, chapter " behind the eyepiece" fourth edition

[Charlie_132]

I haven't had a proper read of it yet, I haven't really had the time, but it seems all of the drawings are based on a 8inch telescope. Should the view I see in the 130p be roughly the same ?
I know it sounds a silly question... I know that the bigger scopes gather more light making the image clearer, but being as the drawings in Turn Left At Orion are very basic, this shouldn't matter ?

Is there any finderscope that will show up more stars then can be seen by eye, but will fit on the 130p with no modifying ?

 

[mickshere]

I notice in the description iy says views of the southern hemiphere?  Does that mean its only really of value to people living south of the equator?

[Fozzie]

Morning, I think left turn gives two views, one through at mid size dob/reflector then one through a small refractor as the two images are flipped to represent the views, it also gives a finder view as well.

its seasonal to the northern hemisphere but has a section on southern skys towards the back.

Its a great book for starting out with... lots of info

[mickshere]

Ta

[cussine]

I haven't had a proper read of it yet, I haven't really had the time, but it seems all of the drawings are based on a 8inch telescope. Should the view I see in the 130p be roughly the same ?

I know it sounds a silly question... I know that the bigger scopes gather more light making the image clearer, but being as the drawings in Turn Left At Orion are very basic, this shouldn't matter ?

Is there any finderscope that will show up more stars then can be seen by eye, but will fit on the 130p with no modifying ?

Some good general advice recently posted here

http://stargazerslounge.com/topic/203738-observing-nebule-and-andromeda/

[EagleC]

My wife bought me Turn Left for our anniversary. It specifies that it is more relevant to the northern hemisphere from 30d to 60d lat. Targeted scopes are small refractors (2-4") and 6-10" reflectors so for people like us with a 4.5" reflector it does seem like we've been missed out but it's reasonable to expect that you will be able to able see slightly more than a 4"  and less than a 6".

I've only read the first few pages explaining about the book and how to set up and aim the scope and found it quite good. My only complaint would be the form factor and that its ring bound. 

[CJ77]

Hi Charlie,

I bought this book recently, and I believe that there are 3 images for most views - one is the view through a finderscope, one is through a small SCT (about 3") viewed through a star diagonal, and one that they call an 8" Dob, although i imagine that any 8" reflector would look the same.

The reason for the 3 different views, I believe is due to the orientation of the final image as much as anything else, as the star diagonal will invert or reverse the image as compared to that seen though a reflector (I can't remember which), and the 8" will gather more light and give more detail. 

The book also gives a guideline as to the power level used for each view.

Hope this helps.

CJ

[Charlie_132]

Thanks for all the replies, they helped a lot!

now just got to decide whether I am going to buy a 130p dob for the second time.... Or a 200p with a right angled finder scope!

130p has its advantages of being able to look out the window at 4am, seeing mars, then taking a nice light scope down the stairs and having a look

200p I know for sure I wouldn't be carrying that down the stairs or out into the garden while I was half asleep!
But the views from the 200p would be much better....

I live in a light polluted town, The only DSO I would like to see is M31. The others would most likely be a small fuzzy patch with no way of seeing the shape, such as the spiral shape of m81 and m82........

Planets are my main interest, because I can capture them and try to get a half decent image out of it.

I would like to photograph DSOs, but from what I have read, it's quite expensive.....

 

[brantuk]

Hi Charlie - welcome back to SGL after your break.

I'd just like to offer a bit of advice based on your thoughts and aspirations regarding scope choice. By far the best thing you can do first is to join a local astro soc and get along to a few observing meetings. Talk to the folks about their scopes and mounts and what they are doing with them. In particular ask why they chose their scope. You'll no doubt be offered the chance to look through the eyepiece of several different scopes. I think this will reveal a lot of info that you need to make a good choice of scope that suits your purposes.

If you want to image planets then you want a long focal length for sharp, tight, focus. Depending on budget you can achieve this with either a Mak, Sct, or long fl refractor and a webcam. To image dso's you need to capture faint light fast with highly accurate tracking and a dslr or ccd camera. So you'd be aiming for a large aperture newtonian or a wide angle refractor, with a fast focal ratio. The requirements are different depending on your main object of study, this will affect your scope choice because there's no "one size fits all" telescope.

Imaging dso's needn't be overly expensive - but the equipment price will be affected by the "standard" of imaging you expect to attain. The choice of mount type and accuracy will be critical, so put a lot of effort into learning all the different types and their strengths/weaknesses. Generally you can image planets with an alt/az or eq mount and tracking, but dso's require an accurate, polar aligned, eq tracking mount.

TLAO is a great book but even the author says "all the books in the world can't beat standing next to a experienced astronomer at the eyepiece of a scope". I agree with this because I've had better guidance and learned so much more from fellow astronomers than most books can impart. Hope that helps.

[AndyWB]

FWIW, it is possible to fit a RACI to a 130p - I think Naemeth did so. It looked weird, though, and I think unbalanced the scope. To be honest, I wouldn't do it.

And I found the drawing in TLAO were pretty close to what I saw through the 130p - conditions and target depending. To put it in perspective, my 130p somewhere dark blows my 250px from town away on dim, large fuzzy things. However, in the same conditions, there is much less of a difference on open clusters.

From a very light polluted urban site my 130p has given good views of more than just M31. The Ring Nebula (Fantastic), Omega Nebula (Yay!), Orion Nebula (Wow) have all had definite shape to them. I do agree about galaxies, though - I don't even really chase them in town anymore, and after seeing M31 from somewhere dark, well, even it's a bit unimpressive compared...