Review: Orion Sky View Pro 100mm ED EQ Telescope

[iceman]

Gary Syrba (Hammerman) has written a review on the Orion Sky View Pro 100mm ED EQ Telescope.

You can read the review on the IceInSpace Reviews (http://www.iceinspace.com.au/index.php?reviews) page, or directly by clicking on the link below:

Orion Sky View Pro 100mm ED EQ Telescope (http://www.iceinspace.com.au/index.php?id=41,289,0,0,1,0)

Thanks to Gary for writing the review!

If anyone else would like to contribute a how-to, article, review or other content for the site, please contact me.

[iceman]

Article uploaded.

[janoskiss]

Sure to create a bit of discussion (protests even ;)) saying that the ED100 is sharper and shows more detail on planets than an 8" Dob. You are a bad man Gary! You make me want to go out and get an ED100. :mad2:

[[1ponders]]

I think I heard Starkler stompin' around here somewhere :lol:

hmmmm...hammer, I've been trying to convince that my Orion ED80 is enough for me, but you've got me thinking harder now. Mind you I'd have to get a televue .7X focal reducer to go with it though :D

[ving]

look sorry, but a 100mm ota just doesnt have the resolving power of 200mm....

its just not going to happen, execpt in degraded seeing.
:P

[janoskiss]

Ving, you are contradicting your very recent comment in the Planetary Filter thread. :P

[ving]

i know ;)

it's all got to do with seeing and air-pocket size steve... airpockets are on average 150mm. the 100mm scope fits withing an airpocket and a 200mm doesnt, hence the seeing needing to be good...

(read this somewhere...)

[Starkler]

:whistle:

Makes me wonder how well collimated and cooled the 8" newt is.

[ving]

:lol:

it had to happen :P

[janoskiss]

What about John B? :P

An interesting comparison between a smaller apo and a Dob would be with the aperture of the big Newt masked down to match the aperture of the refractor eliminating diffraction from the spider vanes and the central obstruction.

[GrampianStars]

:screwy: what the hell is this "air-pocket size" :shrug:
I know that my 8" kills both the ED80 & ZS80 on DSO's
would suspect the same for PRO 100

[janoskiss]

It has to do with a description of turbulence based on the assumption that the velocity and pressure gradients over distances less than the air pocket size are negligible. In other words, if you were to look at the air within an air-pocket sized region of the atmosphere it would not look turbulent: it would appear to be still or in uniform motion. I personally find this picture questionable, because classical turbulence is by its very nature scale independent (fractal, like my avatar :)) until you go right down to the regime of discrete clumps of matter in the forms of atoms and molecules.

IMO a smaller aperture refractor can give the impression of being less affected by seeing because:

- magnifications one uses tend to be less with a refractor because of the shorter focal length of the scope
- limited angular resolution of the refractor does not allow one to resolve the bad seeing in any detail, i.e., the steady diffraction smearing of the image from the small aperture is worse than the unsteady smearing from bad seeing.

But the more I read about other people's experiences, the more I want to grab me a good 4-5" refractor and spend some time seeing how it really works with my own eyes.

I know that the ED80 was no match for my 8" Dob when the latter was properly cooled and collimated. The views did look "sharper" at low magnification in the ED80, but that was just the higher contrast due to no obstructed aperture and the darker background skies due to smaller aperture tricking my brains. When it came to making out fine detail, the Dob always won. But 80mm against 200mm is a very unfair comparison.

[Striker]

just a shame it's F9.

Bring it in at F6 and I will think about it.

[DougAdams]

Well, my 8" Starhopper dob outperforms my ED100 (which is still for sale, btw, for other reasons :)

[cjmarsh81]

I like the way they sent you a new mount overnight without proof of the fault in the old one. Good Customer Service indeed!

[Starkler]

Note that Hammerman is in the US of A, and for them such service is par for the course.

[Hammerman]

All I can say about my review with the 100apo vs 200 reflector issue your discussing is this....

Maybe it's because I live in the suburbs of a large city where light pollution is fairly heavy. Maybe it's because of the difference in contrast with or without the central obstruction. Maybe it's because of the baffles on the 100 help in light polluted areas. Maybe it's because I'm close to 50 and even though I don't need glasses (my Dr. says my eyes are fine), my eyes aren't as good as they were when I was 20. I don't have a good reason why, I just know what my eye sees.

I will say that the 200mm image is much bigger and brighter using the same ep's. For DSO's the larger scope is a big improvement. But when it comes to our solar system I honestly have darker backgrounds and sharper images in the 100mm scope. For the record, after 4 years I know how to properly collimate my dob. I use a cheshire site tool instead of my LaserMate, because the cheshire is a bit more accurate. Cool down times? At least an hour.... usually longer before I use it. Yes, the mirror is good... at least I get concentric circles when I do a star test after collimation. Granted it's not a high quality mirror, it's just one of the Orion Chinese made ones.

Other than that, I don't know what to say except I honestly wrote in my review exactly what I see in the eyepiece of each telescope. Maybe I should have left all reference of the XT8 out of there.

Starkler, customer service in the USA is only par for the course at a very few companies. Orion is one of the few. Sadly most companies are not that good at all anymore.

[iceman]

Gary don't feel you need to defend yourself - people must remember that reviews are subjective and what one person sees at the eyepiece isn't what another person sees.

[GrampianStars]

Yeah Gaza
NObody is baggin' yer mate ;)

wer'e just astro geeks who love to critically scrutinise
all issues

[ving]

and gary, like most things in life it comes down to personal preference on which everyone has a differing opinion. :)

[avandonk]

I have just bought one from Bintel and I am going to shorten the tube by 100mm so I can attain focus with my new experimental focal reducer. It will behave as a 576mm F5.76. The trick with FR's is to start with very good optics. I would not do this with a ridiculously expensive APO. Ok when this works I will.

Bert

[janoskiss]

Geez Bert, you're game. Taking a hacksaw to a brand new $1200 scope! :eyepop:

[Hammerman]

Sorry guys, I guess I was trying to defend myself a bit. Just didn't want you guys thinking "This bloke don't have a clue as to what he's talking about!" or "What does he know? He's from the United States." :lol:

Nothing wrong with a good, healthy bit of a debate. I have to get used to the differences in language here. We all speak English, but there is a difference in wordplay between Australia and the United States. Got to admit, I love your sense of humor here on the forum.... think I'll fit right in. :thumbsup:

Oh, and Bert? You are one brave man cutting into that scope! :screwy: :lol: However a hacksaw is going to be slow cutting. Want to borrow my chain saw?

[avandonk]

Hi all managed to get a few shots off between the clouds. This is a sixty second exposure ISO800 with the scope as it came. The image is Beta Crux and the Jewel Box. No filter but used a Hutech FR/FF with the thick ring installed to flatten the field. Obviously used the Canon 5D. Focus could have been better but the clouds did not give me much time.

There are also a couple of crops to show detail. All pictures from unprocessed JPG. I think this scope performs very well no CA etc. Before I cut the tube will take more pictures with another focuser with 50mm clear aperture as the focuser that comes with it has a 44mm baffles which vignettes on a full frame camera.

Bert

[[1ponders]]

(Off topic - Nice colour on that carbon star Bert :cool2:)

OT - Is there any talk of bringing the 100 out in a shorter focal length or is one all ready available, so us less brave souls don't have to do what Bert is doing?

[Starkler]

Paul the 100mm has to have a longer f ratio than the 80ed to maintain colour correction. To make it shorter would make it more of an achromat.

The focal ratio required to be colour free is a function of the aperture.

[[1ponders]]

There are shorter f ratio apo and "semi" apos around (Ziess 100 f/6.4, Vixen 108 f/5.4). Or is it because the Orion is a doublet and the others are triplets?