From Refractor to Newt

[Drac0 (Mark)]

Hi All,

Looking at selling my refractor and jumping into the world of fast newtonians. Looking to start with something smaller & more portable - thinking of a SW Quattro 150P - before maybe adding an 8" or 10" later if I enjoy using the newt. Just looking for advice on what to look out for & extras I might need to have.

I'm aware of coma correctors, collimation, light leaks and such, but are there other things I need to be aware of before taking the plunge in this new direction? Or additional bits'n'pieces I might want to make life with a newt more enjoyable?

Cheers,
Mark

[ChrisV (Chris)]

Don't know if this is for visual or AP. For newt astrophotography I started at F5. I would recommend there (or even higher - others might know better). Collimation not too fidgety. But you will need a coma corrector for AP at F5 - I found a cheapish Baader coma corrector was adequate. I had a lot of fun with a GSO 8" F5 and a Canon camera then an asi071 (bother aps size).

I've since gone to F4 but can't recommend it to start with. You are in for a world of pain unless you fork out for a good coma corrector - and a proper collimation tool like a cats eye (it's just the greatest!). The baader CC just didn't cut it at F4 so I swapped to the skywatcher/GPU CC. There's a few threads about this - one by startrek - read it and believe!!

[Drac0 (Mark)]

Thanks Chris,

I believe the Quattro 150P comes with the CC so should be ok there for a start at least. Don't want to go for the 8" or 10" yet, really looking for something portable to start with, that's easy to cart to dark sites. Anything bigger will probably be relegated to home use only. Was already looking at various collimation tools. Will certainly have to find Martins post, always great advice from him & is very experienced with newts!

Cheers,
Mark

[Startrek (Martin)]

Originally Posted by Drac0

Thanks Chris,

I believe the Quattro 150P comes with the CC so should be ok there for a start at least. Don't want to go for the 8" or 10" yet, really looking for something portable to start with, that's easy to cart to dark sites. Anything bigger will probably be relegated to home use only. Was already looking at various collimation tools. Will certainly have to find Martins post, always great advice from him & is very experienced with newts!

Cheers,
Mark

Hi Mark,
Just read this post now , apologies
For your first Newt I would stick to a 150mm f5 or f6 ( have used both extensively)
Folk who have jumped straight into an f4 or faster seem to have all the issues for the sake of a slightly faster scope and a wider FOV mainly because they are temperamental due to the dynamics of the optical train ( unless you want to shell out big dollars on a super high end fast newt or astrograph )
f5 and f6 are easy to collimate , hold collimation well and don’t have the optical issues like severe coma to deal with ( I still used a coma corrector on my f5 and f6 scopes in any case. Initially the Baader Mk3 and in the past 2 years the TS Optics GPU )
My 8” and 10” f5 carbon fibre newts hold collimation that well I only have to tweak them during change of season. I used steel tube Newts for 6 years which worked fine but carbon fibre is the way to go particularly from 8” and up.
NB: Most Telescope retailers will always ask you “is the new scope for imaging ?” , then they direct you straight to an f4 or faster without any personal experience.
My advice is to leave the f4 until you get some experience under your belt and can afford a quality f4 later.
However it’s your choice in the end and you have to happy with that.
Good luck with everything
Clear Skies
Martin

[glend (Glen)]

Mark, in my experience a 8" f5 is a great beginners scope, and frankly, Newts are the best bang for your buck when it comes to cost effective aperture. I would avoid f4 and below, as they can be more difficult to collimated. The shorter focal lengths also limit your sky reach. I have owned, 8", 10", 12", and 16" newts, all f5s. The quests for greater resolving power drives us to bigger scopes, but with bigger scopes comes increased weight, transport and storage issues etc, so think about that before you buy.

For astro photography, you want to ensure you get a Newt which is set up for imaging, ie the camera can achieve focus on the scope. Visual and photographic newts are not the same. You can use an imaging newt visually with a focuser extension tube but you cannot image on a visual Newt with significant optical work.
Have fun.

[alan meehan (Alan)]

Hi Mark newtonion scopes are the the way to go f/4 easy to collamate using a laser which you will need ,also a coma corrector for sure ,i have been using a meade schmidt newt for yrs,which iam selling too old to lift no spikes on the stars skywatcher quads are good as well I but only for imaging good luck

[Drac0 (Mark)]

Hi all,

Thanks for the responses. I ended up getting the 6" Quattro F4 (~F3.5 with CC) and am now enjoying it after a few changes/tweaks (mainly replaced the focuser & added mirror mask). I haven't found the collimation too bad and it seems to hold well, though I think I am yet to get it "perfect".

Originally Posted by alan meehan

i have been using a meade schmidt newt for yrs,which iam selling too old to lift no spikes on the stars skywatcher quads are good as well I but only for imaging good luck

Too bad you you didn't have it up a few months ago, I might have been tempted! Sadly I need to wait a few more months before looking at anything bigger than the 6", which I will be doing eventually.

Cheers,
Mark