Orion Optics v Skywatcher!

[mik]

Be interesting to see how a OO 150 compares to a Tal 150

ok i will get my coat

Mick

[ngc2403]

Arthur, you're a bad man

[philsail1]

"hmmm,

i think that perhaps not in normal visual use but if you take your scope to the darkest skies then i would want to be able to take full advantage of them and for that i think you need better than (mass produced) 1/4th wave."

Ah! "ally"

This may be the critical "prrof of the pudding" factor when I next compare (under better seeing conditions).

(You fooled me there Arthur - but they were onto you!!).

Regards,

philsail1

[ngc2403]

Phil i think the proof is in the eating too,

the mirror report will be good and am sure very interesting but if you are a visual astronomer then is the extra money for the mirror going to make a huge difference. their are many in here who think not but it seems the longer this goes on the more others are saying that under testing the OO are better.

the final say is up to you though and i nor anyone else can tell you what you want.

ally

p.s. i think i am going to be bored for the next few days without the OO threads, that is until the ZIGO report, (he sayes sharpening his battle axe)

[Whippy]

Be interesting to see how a OO 150 compares to a Tal 150

ok i will get my coat

Mick

TAL's are known for having quality optics so don't go to the cloakroon just yet .

There is only really one way to have an impartial test and that's to take both mirrors to an independent testing facility. If someone is prepared to stump up the readies for this then TBH taking both mirrors to OO is a pointless excersise because OO owners will say 'told you so' and everyone else will say 'fix!'.

for imaging i think that better mirrors show this on a more regular basic. example the contrast in images when you are imaging things like the double cluster, bright stars. the better telescopes will have darker backgrounds compared with the stars, because more of the light has gone into the star's pixels that the surrounding ones due to mirror error.

If you look at the imaging boards, there's plenty of top drawer images taken with Skywatcher scopes so either your statement is wrong or SW's optics are far from 'shaving mirror' quality.

Tony..

[kniclander]

this is indeeed a fascinating thread both for what it says about mirrors and for what it says about human nature. i can't wait for Friday...

[philsail1]

Well, as you might guess "ally," I am secretly hoping the OO mirror will come out tops - even if only by a small margin. This will justify the ££££££! I spent on it, and give the old Skywatcher brand a satisfying result.

(If after the test OO offer me a free packet of "Bic" disposable razors, I'll use the first to cut my throat!).

Seriously though (you have to laugh though!), I know both scopes are in their own right - excellent (is there such a thing as the perfect scope - perfect in "every" way).

Regards,

philsail1

(Where's Arthur gone!).

[philsail1]

I'm dreading it Ian!

(feel I've opened a right can of worms!!)

philsail1

[ngc2403]

for imaging i think that better mirrors show this on a more regular basic. example the contrast in images when you are imaging things like the double cluster, bright stars. the better telescopes will have darker backgrounds compared with the stars, because more of the light has gone into the star's pixels that the surrounding ones due to mirror error.

If you look at the imaging boards, there's plenty of top drawer images taken with Skywatcher scopes so either your statement is wrong or SW's optics are far from 'shaving mirror' quality.

Tony..

thats an unfair twisting of my words, i never said that images taken through SW telescopes were an bad. i meant that the better the strehl the better the image because of the contrast improvement.

it was a general comment on the factors which limit the quality of images and never meantioned any telescope manufactures.

other things are diffraction and the CCD that they are using.

however if you think that SW telescopes are reason for the great images, then perhaps they should make the Hubble replacement or is that an unfair twist on your words?

am sure i wouldn't cost $2billion though

ally

[Whippy]

And you're not twisting what I said....

You know what I meant, same as I know what you meant. If you want to take offence to it then go right ahead, no skin off my nose. Like I said earlier in the thread, I couldn't care less what the outcome of the test will be. What I do care about is people having the wool pulled over their eyes on SGL and owners of certain brands of scopes getting over defensive when 'their' brand has negative comments posted up. There's no need for it.

Tony..

[Milamber]

Oh dear - allow me to have a proper say here, since this thread seems in danger of getting silly-serious again!

Observationally, in essence I would expect an experienced observer to be able to tell a good mirror from a not-so-good one - and I would expect images from all sorts of mirrors to be good *and* bad. Let me explain... it takes years to learn how to look through a telescope, ask any old astronomer and they will tell you exactly that, it's hard to know what you are actually seeing without that experience.

Imaging-wise, get a scope with an average mirror and a good post processer and you will likely get similar results to an excellent mirror and a not-so-good processer. The most memorable images come from those that have excellent equipment *and* excellent post-processing skills, while those of us at or near the bottom of the hierarchy have to put up with more mundane results.

As I have said before, visual mirror testing is a subjective rather than an objective thing (and I hope I have also proved that using images as a test is also a subjective thing - though related to experience that may be easier to obtain as well as the perceived viewpoint of the person looking at the image) and for any review to be accepted one must trust the reviewer, be it Phil in this case with his visual testing or OO with the Zygo tests... you either believe and trust them or you don't. There's no point bitching about it either way though since subjective results are *always* going to be susceptible to peer review and ridicule. It's what is to be expected in any field really, is it not?

Arthur

PS - Astro-Baby, I would really, *really* hate to live in your world.

PPS -

(Where's Arthur gone!).

Boo

[narrowbandpaul]

tony,

ally did not mean or say in any way that skywatchers cant take good images. And he is right about a high strehl mirror putting light where it ought to (no scattering). This does mean better images..not amazing images far better than a skywatcher. No-one said that latter statement.

You did twist his words

why?

I agree that we dont want the wool pulled over your eyes syndrome.

I assumne that 'owners of certain brands getting over defensive' was aimed at some of the OO owners including me who expressed concern about the conclusion drawn from one single review?

Not trying to be argumentative, just state that ally never! implied that skywatchers were inferior scopes incapable of a good image

Best Wishes

Paul

[brympton]

Phil,

You might want to take a look at this before you go:

http://www.orionoptics.co.uk/OPTICS/opticsmirrorcell.html

Regards

Mark

[ngc2403]

Perhaps i should 'sort this once and for ever',

i don't mention any of the telescope types/bands during my post and i was think about the science behind the production of the best images possible. this includes things that span not only the visible spectrum but radio, gamma, X-ray etc. the formula is basically the same.

some people feel the need to pull the wool over their own eyes to justify the price or reason for buying the telescope.

i know why i got it and the report will not change that, even if the SW comes out better than 1/8th wave which it could thought the chances of it are low it is an unknown quantity and as such should be tested. one or two people seem to be getting nervous about it either because it is something that they just don't want to hear or because it may burst their little bubble. either way i look forward to the report.

i am happy for the facts, to speak from themselfs on this matter of OO vs SW.

Arthur that's a nice smiley

there are a few strange ones in the [more] window

[MikeP]

Sometimes just keeping quiet is an appropriate reply.

Mike

[philsail1]

Ah! yes Mark, I hadn't seen that before. It clearly explains how the mirror is supported - and I see what the central hole in the support plate is for - and the fact that the main mirror is set in the tube by a couple of inches to allow for installation of optional cooling fan!

Arthur - you're back! I see your point in that any mirror - no matter how accuratelly figured, may not register in the human eye - but rather better on imaging equipment.

I can only thank you for all your comments here - but sometimes particular points are taken out of context purely due to "semantics."

(click to enlarge)

(I'm beginning to think that the "Keck" mirrors never generated this amount of discussion!).

Regards,

philsail1

[brympton]

Phil,

This is an improvement and a change from the 9 point cell previously shown. There is an "upgrade" option shown at the bottom of the page, was just thinking that maybe as you are taking the cell with you you might get another freebie

Regards

Mark

[ngc2403]

(I'm beginning to think that the "Keck" mirrors never generated this amount of discussion!).

Possibly not, but then they are just toys and plus the astronomers working on them are so far removed from astronomy that they many never have looked through a telescope i their life!

maybe a quick look might of saved hubble and NASA some money?

[philsail1]

Mark, I think the mirror support shown is the same "upgraded" one fitted to my scope - mine has the same three "arms" with a central swivel, and small adjusting pads. And the plate is exactly the same shape, with adjusting screws in same positions.

"ngc2403" what can one say to that!

Regards,

philsail1

[ngc2403]

I was and horrified when my astronomy lecture told me has never seen through a telescope.

and seeming it is not that uncommon!

[Milamber]

"ngc2403" what can one say to that!

One can say "Did they do a side by side test?"

Arthur

[johninderby]

Without doubt SkyWatcher makes great mass produced machine finished mirrors that are somewhere about 1/6 PV on average and are roughly equivalent to OO's 1/4 PV mirrors in performance. I don't know why anyone buys an OO dob or newt with the basic 1/4 PV mirror as the SkyWatcher is just as good and costs a lot less.

However when you get up to the better OO mirrors with the Hilux coatings then the balance is tipped in OO's favour. Once you've looked through an OO scope with 1/10PV and a 99 Strehl mirror you just can't go back to SkyWatcher. Think of it in terms of Ferrari vs. Honda Civic (or similar), both good in their own way, but which one would you like to take home? For DSO's and the like where contrast isn't so important aperture can make up some of the difference in mirror quality. However where contrast is vital, as in Lunar and planetary observing, that's where the high quality mirror comes into it's own. As an example an 8" OO dob with the 1/10 PV mirror will clearly edge out a 12" SkyWatcher dob in performance in all areas. I know as I've had the chance to use and compare both.

Advantages of the OO mirror

• 
  [li]Smoother hand finished surface with less light scatter[/li]
  [li]Higher contrast[/li]
  [li]Hilux coating gives 25% more light transmission [/li]
  [li]Mirror coating has better than 25 year life expectancy[/li]
  [li]9 point mirror cell stops mirror distortion[/li]
  [li]Laser inferometer testing so test results are very accurate.[/li]
  [li]Borosilicate extra low expansion glass [/][/li]
  

(Pyrex has not been available for a couple of years now and SkyWatcher is using a Chinese substitute)

SkyWatcher makes a great mass produced dob or newt, but that's the point, they are mass produced, so it would be unfair to expect them to compete with a handbuilt OO scope with 1/8 or 1/10 PV optics. However you can't go wrong with buying a SkyWatcher dob or newt, they're fantastic value for money (I've owned a 10" and !2" dob) but just don't forget that as good as they are, if you want or can afford to spend more, there are even better scopes out there.

John[/]

[brympton]

At last, a well considered and inoffensively written opinion made all the more credible by an outstanding post in the Members Equipment Gallery. Thank you

[philsail1]

Nice one John!

You have boosted my confidence, and calmed my nerves! (in readyness for the big day).

(Arthur - you are a one - but I like you!).

Regards,

philsail1

[Tiny]

Of course the synta mirror could get damaged or dropped in transit.