orion optics vx6

[chrish10]

Looking for first telescope (newtonian reflector).

After lots of research I'm tempted by the skywatcher explorer 150p.

Which seems ok and about what i wanted to spend.£250

I then spotted the orion optics vx6 (tube only)which is about £100 pounds or so more.

Is it worth saving up the extra money and buying the mount later.?

Can you use any mount with the tube so long as it's a good one.

Or shall I take easier option and get the skywatcher.

Sorry lots of questions,grateful for any help.

Don't want any computers by the way.

[Moonshane]

welcome to SGL

optically, the VX6 (1/6 PV) will have better optics and for another £43 you could improve the optics to a really world class grade (to 1/10 PV) and I'd go for the VX6L which will be a far better all rounder, especially on planets and the moon. It will also work well with cheaper eyepieces.

you could make a dobsonian base easily if you are any good at woodwork or even buy a mount in a little while when funds allow. the OO newtonians are quite light so you have a lot of mount choices.

the easier and cheaper option is the skywatcher which is still a good scope but not a patch optically on the VX6

[TheThing]

To be honest, you wont see much difference between the SW and the Orion. Waves are all very good, but for the beginner, you wont notice any difference.

I'd go for the complete package of the SW. Brilliant all round, you don't have to pay out for anything else and you can get out and viewing straight away.

[russ]

I have the Orion (in its previous guise as the Europa Deluxe 150 with 1/8th PV/Hilux) and would like to believe it is better than the Skywatcher 150P but alas at the eyepiece i've seen no evidence of this. Perhaps on an exceptional night with incredibly rare seeing, it may show it's full worth. But so far, sat next to a 150P, the views have been near identical.

[John]

I own a 250mm F/4.8 Orion Europa which is optically the same spec as the VX6 (1/6 wave, Hilux coated). I can't see any difference in the views over the Skywatcher equivilents. The mechanicals of the lower end Orion Optics scopes are not quite as good as Skywatcher in my opinion. Not bad scopes but not worth the extra £'s.

OO scopes tend to depreciate a lot as well !.

[chrish10]

Thanks,very helpful. If you say the skywatcher is quite well made I think it think it will be fine. I admit know little of the night sky which is why i want a manual telescope but if i can see some rings around saturn i will be very happy with the skywather. Is it difficult to see the moons of jupiter?

[TheThing]

Not at all. You can see them in a pair of bins, but the SW will show them very well. They appear as no more then dots of light, but it is satisfying to see them and watch them move.

[Ags]

Out of curiosity, I have a question for those who have compared an OO system alongside a SkyWatcher equivalent: when you say you can see no difference, what sort of objects were you looking at?

As I understand it, the mirror quality would only be apparent when using high powers (200x plus) on planets and maybe the moon.

[Hypernova]

I'd agree with most on here that you would be hard pressed to tell the difference between the Skywatcher with standard optics and the OO with 1/6 PV optics, unless you really know what to look for. It wouldn't all depend on the PV value but also on the roughness of the mirror, it could still be a 1/6 wave but also be rough by having lots of variations, you can never quite tell what to expect as OO mirrors are all figured individually, most by machine but some by hand working if they need it that bit better.

Not knocking OO but I'd rather save my cash and buy the SW, better value for money with optics that would satisfy most people.

[johninderby]

Should note that all OO mirrors are hand figured. They do use machines for the most basic shaping, but then complete the shaping and polishing by hand and then test them with a laser interferometer. All that skilled hand labour is expensive, which is why they cost more than mass produced mirrors. With a 6" scope you should get the 1/10PV mirror as it's not much extra.

It makes the scope a better all-rounder than a mass produced scope such as a SkyWatcher. Less light scatter from the smoother OO mirrors increases contrast and the high reflective coatings reflect more light. Planetary observing is where you will notice the most difference. For DSOs contrast isn't so important so not too much of a difference.

The SkyWatcher newts are great value for money though. As the OO newts are hand built and made to order they're never going to be able to compete on price with a far eastern mass produced scope. One other thing to consider is that as each OO is hand made you can have them customise it to your requirements. Different focuser, change the colour of the tube etc.

John

[Hypernova]

Sorry to disagree John but most of the mirrors that they produce are placed on an array of machines that work them with laps, mirrors are only worked by hand if they need it say if zones have appeared and need rectifying (turn down/up edges), have astigmatism or need it from the offset (ODK 16 as an example). Mostly the intervention needed is properly adjusting the machines and testing the mirrors.

[johninderby]

The statement I got from OO was "They are done by machine up to about 1/4PV and tested and then hand finished up to a higher standard".

John

[Hypernova]

I'll tread carefully here as I may be labelled as biased as I worked as a figurer for a month and a half and that is what we used, I did once make a 10" 6.3 even up to 1/10 by machine only.

[Ags]

I'm not too sure hand-figuring is that important - a good surface is a good surface after all. OO do quote a Strehl figure of at least 0.96 for all the VX scopes, which would imply the mirrors are pretty smooth.

[umadog]

The Strehl ratio is basically the RMS wavefront error. It doesn't tell you anything about how smooth the surface is. A mirror can be very smooth but figured to slightly the wrong shape or it could be figured to the right shape and be a little rough. Both such mirrors could potentially have the same Strehl value but produce different views at the eyepiece.

I don't think there's anything wrong with machines so long as the machines are properly supervised. Zambuto does fine polishing with a machine, there's a page on it on his site.

A few people say they're not seeing a difference between a mass-produced mirror and an OO with 1/6th wave optics. Quite possibly there is no difference between the two as the Chinese mirrors are frequently quite good. I have an 1/8th wave OO 10" and it gave very similar views of Saturn to my old 12" Synta mirror when I set them up side by side. However, the difference is that with the OO you know what you're getting. With Synta you simply know that it's "diffraction limited", which is somewhat vague. They have been known to consider some quite bad mirrors as passing their "diffraction limited" criterion. Your odds of a good mirror with OO are better than with a Chinese scope. If you pay extra for the higher quality mirrors then you will be pretty certain of getting something better.

Also note that some aberrations will scatter out of focus light far outside of the Airy disk and so even under "UK seeing" you will notice those defects should they be present. I would also hope that OO properly check the anneal of the glass, but I don't know what they do about that. Finally, I believe the OO mirrors are thinner then those made by the Chinese companies and so you will get faster cooling. Even a few mm thinner will help as cooling rate is proportional to the square of the mirror's thickness. In summary, buying from OO is like insurance: you're buying peace of mind.

[Tim]

I find this type of conversation very interesting, and could spend all night debating which is best and why.

However guys, please bear in mind that this is the beginners section, and the original poster is perhaps not too concerned with peak to valley ratios and the like!!

@chrish10 ..... the advice given is good. The extra money for the Orion will be spent on its mirrors, rather than fit and finish. Very experienced observers would perhaps benefit from the more expensive mirror, but as a first scope you really would be pushed to tell the difference, and as an introduction to the hobby the SW 150 is a good all rounder.

At any rate, I hope you enjoy your first scope, like us, you will likely find you become addicted

Cheers

Tim

[Ags]

Good point TJ, and my apologies if I havr taken the thread on a tangent. My question was relevant to the original poster's issue: basically, when people say they can't see a difference between OO and SW, what are they comparning - low magnification DSO views that won't show a difference or high-resolution planetary views that might show a difference?

[Steve]

Useful thread with a good mix of opinion, experience and genuine insight. And we are still on page one!

[johninderby]

A very good point that more experienced observers are the ones that will "see" improvements in mirror quality more than someone just starting out.

One thing that frustrates me when seeing a comparison between two scopes is when they limit it to the abilities of the lower quality scope (max mag, type of target etc.) instead of finding out what the best the higher quality scope is capable of and then seeing how close the other one can come in different areas.

John

[Steve]

What frustrates me is there are very few genuine attempts to objectively compare Newtonians.

[John]

I've done quite a lot of comparing of scopes and eyepieces over the years. What I've found, on both types of equipment, is that the differences in performance between good and very good quality, if they are there, only show themselves when you are really "pushing the envelope" under the very best conditions, viewing objects / features that are right on the edge of visibility and the capacity of the equipment, the observer and the conditions. Even then they can be subtle at best.

I've read many times of observers stating that a certain piece of equipment "blows out of the water" another decent piece but that's just not what I've found. Maybe I'm just not discerning enough !

I've also found that you really need to compare pieces of equipment "back to back" under the same observing conditions, on the same objects using the same accessories, and under varying conditions which implies having access to the equipment for some period of time. This is probably not feasible for most observers and possibly even difficult for group tests done for publication. The UK is not noted for producing nice sequences of good observing nights to order

[Moonshane]

What frustrates me is there are very few genuine attempts to objectively compare Newtonians.

hey, I'm trying.... http://stargazerslounge.com/discussions-scopes-whole-setups/162746-whats-best-16-f4-masked-6-7-f11-6-f11-newt.html

[Steve]

I missed that one

[libraryman]

Is the quality of a given mirror / optics more likely to show up when used for imaging as apposed to visual use?

i'm about to renew my f4.5 200mm mirrors and had considered a pro grade mirror!

i dont really want to go to 250mm

Ray

[umadog]

It is interesting, I'll motivate myself to stop down the 18". In the meantime, here are the maths behind it: Seeing error It's a little hard to extrapolate to your situation, but it seems you need a pretty large aperture for the seeing to cause a problem. The other thing that comes up a lot is central obstruction. An obstruction smaller than about 16% to 20% is not distinguishable from unobstructed: TELESCOPE CENTRAL OBSTRUCTION: SIZE CRITERIA