Is this fair?

[Stargazer_00]

So i've been going backwards and forwards in my thinking about what does 1/10 wave optics mean at the eyepiece. Read a number of threads through searching on SGL about it and there seemed to be people baiscally saying the views were not really appreciable unless absolutely perfect conditions and even then it was close.

I was just thinking about my holiday later in the year, going to a dark site for a week in September. Taking my 150p/AZ4 (don't think the 10" will wash with the wife). I want to get as much out of the dark sky as possible and was considering a 1/10PV mirror set upgrade (£300) or just straight up buying a 1/10 PV VX6 OTA (about £400 w/ dual focuser)

I am drawn time and time again to the graphic on the OOUK site showing the difference between PV.

I'm sure you have all seen it but here it is again for context.

When you look at that you just think "gotta have it"

then I thought some more and it occured to me, and this may seem so obvious, but Saturn isn't that big when I look at it.

So I reduced the image to a size that I think I could achieve in my eyepiece at a push and this is it

So finally getting to the point. Do you think that reduction is a fair representation of the difference between the optics? It's much less pronounced but still evident once reduced to a more realistic size. On that basis I dont think the mirror upgrade would really show much at all. I also intend to primarily look at DSOs to which I think it would show little to no performance increase at the eyepiece.

I appreciate this is barely eyepiece related. I thought possibly the more discerning visual experts might contribute better here was all.

[estwing]

there was a fantastic thread here about this..http://stargazerslounge.com/topic/174659-mirror-wave/page__hl__%20mirror%20%20pv.....

[8kids]

I would say if you have the cash buy the best you can afford, you can't do any more than that.

[Vince1963]

Hi Graham, I'm No expert, but as i see it i wouldn't think your eye would pick out the subtle differences like in these images which are obviously timed exposures.. And what with the rest you have to deal with, I personally wouldn't think the reduced images are representatives either. Having said all that i always try to buy the best with in my budget that allows... If money isn't the issue here i say go for it

[estwing]

just read this again...one of my best threads

[cotterless45]

You're going to be hard pushed to get such visual clarity at high magnification. Main factor will be seeing conditions which may change over a short time. With a Newt your collimation would have to be spot on with a lasered Barlow to ensure you're squeezing the best out of the system.

Personally I just don't think that upgrading to a research grade mirror is worth it unless you're imaging.

Seeing conditions are priceless, find an ep and magnification that gives you the best and most comfortable view. For me this is between x150 and x200 for planets. We're coming up for a couple of years of planetary dip when they won't be as well placed .

So it won't be big beans for a while !

Deep sky is another more forgiving , just use the aperture that you have using x40 to search and x80 for galaxies and higher for planetary nebulae.

Above all other factors will be seeing conditions,

Nick.

[Stargazer_00]

I'm pretty much going to be look at galaxies and clusters from the site. I'm not convinced that it'll make any difference. I'd probably be better of slapping a moonlite on the scope and getting perfect focus instead I'm thinking.

A VX6 would be nice, of course. But it's not a planetary scope and i'm not looking to split doubles.

Whatever i buy will delay my purchase later in the year of a 10" to 14" upgrade. I just want to take the best I can with me to the dark site but keep it sensible, I'm not made of money but I wont get to a dark site like this very often either. It's 20 miles from Kelling Heath and as or perhaps even more dark.

[John]

I've recently started using an Orion Optics 12" F/5.3 newtonian (on a dob mount) with their 1/8th wave PV optics (actually 1/8.8th) and a strehl ratio of .987. What I notice about using the scope is that it is able to support higher magnifications than I'm used to without the image degrading. I've owned other newtonians from 8" to 12" in aperture but they were not of the optical quality of this latest scope. This is the first scope to show me Sirus B, the central rille in the lunar alpine valley, at least 7 craterlets (as pits with ramparts) on the floor of the crater Plato, superb detail and contrast on Jupiter at 265x and 318x, etc, etc.

I guess the above is less important for viewing faint fuzzy objects but I spend much time on the moon and planets so I really value this high power performance potential.

I've not enough experience with the scope to judge the comparison pictures from the Orion Optics web site but I've seen enough already to be very impressed.

Since I've had the scope up and running ( a couple of months really) the observing conditions have been pretty varied as we have all experienced but quality optics do seem to deliver great results despite that.

[alan potts]

Myself I think high quality optics gives you an edge if seeing is of the highest order and you have a good dark sky. I have never been one for pushing magnification but based on Johns report ,which I am absolutely sure is true, if I were to do this on my LX I am sure I would not see the same under the same conditions. He has a scope, not that I know a great deal about them, that has a figure of how good the mirror is. I have the advertising from Meade that the scope is better than diffraction limited, that to me means little. If it is stating that the mirrors and collector are high quality then I don't really believe it any longer. I also know that he has seen Sirius 'B' with the scope something I have never done with mine after years of trying from a better location.

This to me suggests that quality of the optics is playing it's part, how big that part is we do not know.

I for one given my time over again would pay for better quality optics just as in the same way I have paid for better eyepieces. For me there are differences but whether they are worth the hard cash is another matter, then I think other factors come into play, like how often you can use them.

Alan

[Stargazer_00]

Thanks for all the responses guys is appreciated. What I'm hearing is it might be a better idea of my 14" had better optics when I get it but it probably won't make much difference on the 6" which can't get to 200x with any conviction in my opinion.

[swamp thing]

IMO the £300 you are thinking of spending on mirror upgrade could be better spent on hiring another car to take the 10" with you.

Or bribing your wife

[Stargazer_00]

Maybe I'll source a 6mm or 5mm ortho from somewhere first and see what performance a that gives. As I understand it orthos give the best quality views of any eyepiece type at high magnification, albeit while looking through a straw.