Reflector or refractor?

[Karlos]

I'm really stuck as to whether to buy a reflector or a refractor. My main use will be purely visual so quality of optics is my preference (So for me, aperture really isn't everything), I've borrowed a small reflector of 76mm so I have realistic expectations. Would the Skywatcher Evostar 90mm Evostar - Skywatcher Evostar 90 (EQ2) offer better quality of optics than that of the Reflectors - Skywatcher Heritage 130p Flextube Reflectors - Skywatcher Heritage 130p Flextube ?

Any feedback would be great

[swamp thing]

Hi

If your interest is visual you want the larger aperture.

I would recommend a solid tube 6" Dob as a first scope.

It's a great all round scope to wet your appetite.

Regards Steve

[Karlos]

Thanks for your reply Steve. From my very little experience I noticed the reflector I used before did not give any colour for visual? Is this purely down to the small aperture (76mm)?

[John]

Thanks for your reply Steve. From my very little experience I noticed the reflector I used before did not give any colour for visual? Is this purely down to the small aperture (76mm)?

Reflector scopes don't show false colour - it's a refractor issue.

[Karlos]

Yes I understand you get false colour with refractor, but when using a small reflector seeing Saturn was like looking at a white blob with a white ring, absolutely no colour to it, is this down to the aperture size being to small? Or just the way reflectors produce the image? Or maybe something else?

Going back to my question.... Can anyone answer with of those two scopes they would buy (If you had to choose)? They are ones I've lised based on budget, so any recommendations other than these scopes would be preferred around £150, otherwise is not helpful . I understand price is quality in optics, but right now I want something nice to start with, visual quality rather than being able to see DSOs. I will save more for a bigger aperture reflector for sure in the future when budget allows

[nicnac]

hi Karlos, you will get your monies worth with the 130 and it folds down nice and compact too

the Evo will be great on the planets and the moon but the 130P wont fall that far behind, a decent barlow would see you right

with my set up, Saturn's colour is somewhat "eggshell" and in excellent detail

[Karlos]

Thanks nicnac

[ronin]

My preference would be the Evostar.

The 130 will need collimating as it is f/5, also for magnification you could be better then the standard plossl's.

For sharpness and contrast the refractor should come out better, that secondary in the reflector causes the lower contrast.

[KaStern_Former_Member]

Hi Karlos,

my advise: Avoid the Flextube! The German ATM Mirror Maker Stathis Kafalis

tested several 130/650mm Heritage Mirrors and the results were bad:

Astrotreff - Astronomie Treffpunkt - Skywatcher Heritage 130P Flextube Testbericht

http://www.astrotreff.de/upload/Stathis/20100525/heritage130_fxp.gif

In addition: The Heritage`s 2-pole "truss" design does not hold collimation well.

A fast mirror has a very small diffration limited field of view.

With a fast mirror perfect colimation is essential for good viewing results.

So better get a normal tube newt with a real diffraction limited mirror.

For example a taiwanese made 6"f/6 newt or so.

Cheers, Karsten

[Moonshane]

not a criticism of FLO but how much has this gone up in price??!! Dobsonians - Skywatcher Skyliner 150P Dobsonian

I was about to recommend it as last time I looked it was £165.

anyway, in terms of the two scopes you mention I'd go for the Evostar as this can always be used for doubles and lunar etc in the future even if you eventually get a bigger scope. for me though, I'd make a few more posts and you'll then see the used section. in here you will eventually get a used 6" dobsonian like above for less than your budget and it will be a far better investment. me, I'd wait and get one rather than a 90mm refractor.

[nicnac]

yeah, i noticed too.

it was said a little while back that skywatchers prices were going up.

Karlos, if your worried about fast scopes (f5) dont be, collimation is easy and a decent barlow will increase the focal length, apperture rules here i think.

the 130P will give a brighter view

this link may be of use

http://stargazerslounge.com/primers-tutorials/45289-primer-focal-lengths-ratios.html

all in all i would say the 130P has more of a "general use" status over the EVO

[cs1cjc]

I would probably go for the refractor. It will surely show some colour on bright objects, but it will be trouble free (no collimation required) and it will show a good range of objects.

[alowen]

I would probably go for the refractor. It will surely show some colour on bright objects, but it will be trouble free (no collimation required) and it will show a good range of objects.

Seconded, its what helped me choose me refractor.

Al

[KaStern_Former_Member]

Hi Chris,

I would probably go for the refractor. It will surely show some colour on bright objects, but it will be trouble free (no collimation required)

I often read statements like yours. I would like to add a commend:

1) not all refractors are well collimated when they arrive at the stargazer´s home

2) some reflectors have so bad mechanics that they never are well collimated

3) once you have a newtonian with good mechanics you only need collimating

after you bang it against something hard.

I own an ATM newt and that one only needs colimation after several trips or if

I hit a wall or so during transport.

I admit that most comercially newts do not provide good mechanics.

Cheers, Karsten

[Moonshane]

Already put my views on the scopes mentioned and a possible alternative above. On the question of reflector or refractor (and being a total beginner myself two years ago) I can confirm that for me the fact that a reflector is Apochromatic, cheap for the aperture and easy to collimate (I do mine every single session (just a minor tweak, usually takes less than a minute and I have five foot tubes)) I'd always generally recommend a reflector.

Refractors do give slightly tighter star images but for me it's usually aperture that rules for visual astronomy.

[spaceboy]

Yes I understand you get false colour with refractor, but when using a small reflector seeing Saturn was like looking at a white blob with a white ring, absolutely no colour to it,

Do you mean there was no detail or you couldn't see the colour as you do in pictures and the image section on SGL?

[Karlos]

Thanks for all your replies guys ...but both scopes now sounding equally appealing to me. However, could I just clear a few things up... With the listed reflector, would I see more (Possibility of more/some DSOs) but visually might not be as clear and pleasing as the refractor?

As for collimation, I'm not concerned about the maintainence. I'm willing to do whatever it takes for clear viewing and I often find most things don't work out of the box!

As for the prices, I'm hoping to keep my first scope to around £150 and then maybe another £50 for a reasonable barlow (Any recommendations?), then whilst I have something to keep me entertained and give me time to save, then I'll probably go for the 8" or 10" Skyliner

@Spaceboy

It wasn't detail I was expecting (For a scope that size), but thought maybe it would have a slight tint of colour to it? I could clearly see the planet with the ring very crisply it just appeared white.

[John]

For deep sky objects, aperture is the key, whatever the scope design. For resolving detail and seeing contrast on the planets and double stars the refractor does have some advantages although the CA in fast (eg: F/5) achromats undermines this "edge" to some extent I feel.

What you can actually see through a given scope will depend a lot factors such as the observing conditions, the experience of the observer, the quality of eyepieces and the collimation of the scope.

As it happens, I had my best ever views of Saturn through an 8" schmidt-cassegrain where all the above came together just right

[brantuk]

I'm with John on this - aperture is important on both refractors and reflectors. The thing is, for equivalent diameters, you get more for your money with reflectors so they represent very good value.

With refractors a lot depends on quality of the glass and in this price bracket I wouldn't be expecting great stuff. Good glass is expensive and a fair proportion of the money here is going to be spent on the mount.

My preference would be for the largest reflector within budget. Hope that helps

[cs1cjc]

As for collimation, I'm not concerned about the maintainence. I'm willing to do whatever it takes for clear viewing and I often find most things don't work out of the box!

In that case I concede, a reflector it should be.

Good luck!

[Karlos]

Thanks guys for your replies, its nice to be given knowledge from experience without having all the hiccups others before may have had. So once again thanks very much

[John]

Thanks guys for your replies, its nice to be given knowledge from experience without having all the hiccups others before may have had. So once again thanks very much

No problem - thanks for starting the thread

On some forums this subject might have degenerated into a slanging match but not on SGL