Orion optics and re-sale depreciation

[Paul73]

I guess that storage and transport are the big issues that affect the used price.

My £1100 16" OO 1/6 wave dob was battered, needed some tlc and new focuser. I'm delighted with it.

The whole thing seems well engineered and I get the impression that it will never wear out. I do not get that feeling with most of the, excellent value, Chinese scopes.

If I knew that I was buying a scope for the long haul. I would buy a new one (and if I had the cash.....).

Paul

[Timebandit]

3 hours ago, spaceboy said:

But would it be all that apparent living in the UK on the average nights seeing / transparency in a built up light polluted area ? I'm not knocking OO mirrors by the way, more so the UK skies. I'm sure OO mirrors are some of the best in the game but can they defy the laws of nature ? I know some years ago in my SW 200P I had the pleasure of experiencing what a 10/10 nights seeing would look like and it is really quite shocking the difference it can make to viewing the night sky objects. I'd like to think a OO mirror set would have been absolutely mind blowing on the same night but it confirmed to me that given the right conditions even using a cheap Chinese scope can perform beyond the usual expectations and is truth held back by the UK skies more so than it is the quality of the mirrors.

This would be my main reason for being in the market John. After experiencing how light your OTA was at SGLX I was sold on the idea of an aluminium tube. I admit I have some doubts in the back of my mind to the durability of ally given the size and awkwardness of handling larger dobs in and out of cars but at home I can't see it being a problem as long as I'm careful going through door ways. 

When you say you wouldn't have forked out £1K John is that because of the price depreciation? or because you feel the additional cost isn't warranted when compared to others on the market? Your not the first to say you wouldn't buy new BTW.

 

Again this is what lead me to the thread in the first place. Everyone vouches for OO scopes both for mirrors and build (customer service not included) and I'm not doubting it, yet they don't seem to hold a good used value relative to a Chinese scope. Just for argument sake. What if a SW scope came as standard rolled in an ally OTA and on a lightweight small foot print base ? Would the mirrors of an OO still sway your decision to go with the pricier used scope ??

Hello. I think that if a Chinese manufacturer did produce an aluminium tube then they would increase there price anyway ,so there would not be such a difference in cost as now existing with OOuk as the cost factor must be one of the factors of using steel.  .

I think anyone who has tried a OOuk with a high grade mirror of say 1/10 would say yes the scope is worth the extra money. This hobby is all about seeing. The mirror is at the heart of any reflector and  is the most important component IMO. And knowing that you have a 1/10 opposed to say a 1/4 mirror of a mass production scope allows two main things. First if you have say a 1/10 mirror then you have the confidence in your equipment ,and that you have the best mirror availability to you for sensible money as opposed to say a 1/4 mass production product. Also in the uk we do get nights and times of good seeing. Therefore do you not want  the best possible view of that planet or DSO than you can have. Do you not want to pick out the band's on Saturn or great red spot on Jupite with sharp crisp image, do you not want to enter that tight star clusters at high grade of image. I certainly do and I think anyone who can will go for the best equipment to achieve this. And when you take the price sometimes of a stand alone larger high grade mirror ,sometimes when you compare it to a complete scope at that aperture then the cost of a OOuk is not unreasonable 

I think people who buy OOuk scopes want quality in the scope itself and want the best available mirror out there to achieve superior views in the times and locations we do get good seeing. As for them holding second hand values a!l about supply and demand 

But in my opinion a great scope and very good mirrors the OOuk. I am happy☺ 

 

[faulksy]

4 hours ago, spaceboy said:

But would it be all that apparent living in the UK on the average nights seeing / transparency in a built up light polluted area ? I'm not knocking OO mirrors by the way, more so the UK skies. I'm sure OO mirrors are some of the best in the game but can they defy the laws of nature ? I know some years ago in my SW 200P I had the pleasure of experiencing what a 10/10 nights seeing would look like and it is really quite shocking the difference it can make to viewing the night sky objects. I'd like to think a OO mirror set would have been absolutely mind blowing on the same night but it confirmed to me that given the right conditions even using a cheap Chinese scope can perform beyond the usual expectations and is truth held back by the UK skies more so than it is the quality of the mirrors.

This would be my main reason for being in the market John. After experiencing how light your OTA was at SGLX I was sold on the idea of an aluminium tube. I admit I have some doubts in the back of my mind to the durability of ally given the size and awkwardness of handling larger dobs in and out of cars but at home I can't see it being a problem as long as I'm careful going through door ways. 

When you say you wouldn't have forked out £1K John is that because of the price depreciation? or because you feel the additional cost isn't warranted when compared to others on the market? Your not the first to say you wouldn't buy new BTW.

 

Again this is what lead me to the thread in the first place. Everyone vouches for OO scopes both for mirrors and build (customer service not included) and I'm not doubting it, yet they don't seem to hold a good used value relative to a Chinese scope. Just for argument sake. What if a SW scope came as standard rolled in an ally OTA and on a lightweight small foot print base ? Would the mirrors of an OO still sway your decision to go with the pricier used scope ??

hi again space boy

what i found with my 00 dob was you could always use high power and have great detail 200 - 300x most nights without thinking about it and on good nights getting close to 450x and i dont mean 10/10 nights. the scope i had before it was the celestron 9.25 which was brilliant but you could never use that sort of power. so i put that down to the optics

[spaceboy]

Thanks for all the input guys. So it looks like I need not worry about the poor resale value being a reflection of a poor scope and look more into making someone else's unfortunate scope depreciation into a positive for me

One last question. Would I be right in saying even with 1/10 pv if you don't have the greatest set of eyepieces your not going to get the best results out of the scope ?

[Timebandit]

13 minutes ago, spaceboy said:

Thanks for all the input guys. So it looks like I need not worry about the poor resale value being a reflection of a poor scope and look more into making someone else's unfortunate scope depreciation into a positive for me

One last question. Would I be right in saying even with 1/10 pv if you don't have the greatest set of eyepieces your not going to get the best results out of the scope ?

 

Hello. In my opinion to get the best out of a 1/10 mirror set up then you do need to use top quality eyepieces. As otherwise the eyepieces are just going to hold back the wonderful views that a 1/10 set up are able to achieve under the right seeing conditions. The eyepiece is half the scope and the Optics/mirror of the scope are the other half 

A scope is only as good as the weakest link in the optical chain☺

 

[Paul73]

Agreed. Budget Astro this ain't ....

I'm getting paranoid that my Paracorr Mk1 isn't good enough. And my scope only has the rubbish 1/6 wave mirror!

Paul

[Timebandit]

4 minutes ago, Paul73 said:

Agreed. Budget Astro this ain't ....

I'm getting paranoid that my Paracorr Mk1 isn't good enough. And my scope only has the rubbish 1/6 wave mirror!

Paul

 

 Hello paul. If it's a OOuk mirror you may be in luck. There is a rumour that OOuk under estimate there mirrors so yours might be in the 1/7 range?. 

I hope the rumour is true as my OOuk might be 1/11 really and not just a 1/10 ? 

This might now start another debate ??   

[Paul73]

I hope that you are right too!

We do need to remember that PV estimates are only one way of assessing a mirror's quality. I believe that several top mirror producers never publish their mirrors' PV score....

But, in the mass produced market, it is a pretty good pointer. My mirror is noticeably better than most of Chinese mirrors that I have come across.

Paul

[John]

As I understand it, the smoothness of the figure is more important than the PV value in terms of impact on performance.

When you specify a certain quality mirror from OO they generally produce one that is a little better than what was ordered. My 12" F/5.3 was specced as an 1/8th wave PV but is actually pretty much 1/9th wave according to the Zygo report on it.

The best test of all is to view though the scope though !

 

[andrew s]

30 minutes ago, Paul73 said:

We do need to remember that PV estimates are only one way of assessing a mirror's quality. I believe that several top mirror producers never publish their mirrors' PV score....

Difficult to know how to define "top" if no measurements are presented. Ok PV might not be the whole answer but at least it gives a some indication of the quality of the mirror.

I much prefer an evidence base for my decisions rather than none.

Regards Andrew

[Ricochet]

The problem I have is that I've seen the report of what happened when OO sold a mirror to someone with the equipment to test it and the delivered mirror was nothing like the zygo report that OO supplied. If I was to buy an OO product then that report is my only way of knowing that I've got what I paid for and I now wouldn't have much confidence in the accuracy of the report and would probably find myself questioning the mirror. 

[andrew s]

11 minutes ago, Ricochet said:

If I was to buy an OO product then that report is my only way of knowing that I've got what I paid for and I now wouldn't have much confidence in the accuracy of the report and would probably find myself questioning the mirror. 

And how would you assess one with no report?

Regards Andrew

 

PS This is one option https://www.amazon.co.uk/Richard-Suiters-Testing-Astronomical-Telescopes/dp/0943396905 a good read and practical approach.

[Peter Drew]

Using a mirror is quite a good way of assessing its quality. As an experienced user, if the mirror gives the best view I've seen on a consistent basis then the manufacturer can claim whatever accuracy they like.    

[andrew s]

2 hours ago, Peter Drew said:

Using a mirror is quite a good way of assessing its quality. As an experienced user, if the mirror gives the best view I've seen on a consistent basis then the manufacturer can claim whatever accuracy they like.    

absolutely but if you are not an experienced user and don't have access to one...

Regards Andrew 

[Peter Drew]

Then you wouldn't appreciate the difference. 

[Paul73]

32 minutes ago, Peter Drew said:

Then you wouldn't appreciate the difference. 

Bet that you would!?

A less experienced observer would notice (seeing etc dependent). But, they may need to compare views and may not be able to describe exactly why the view is better. Where as an experienced observer, could tell you why the view is better and may not need the reference point of a comparison to comment on a mirror's quality.

Without the expert testimony in publications or on forums such as this, all that the enthusiastic purchaser has to go on.

Paul 

[andrew s]

22 hours ago, John said:

As I understand it, the smoothness of the figure is more important than the PV value in terms of impact on performance.

The Hubble primary has a very smooth figure unfortunately it was the wrong one (PV way out). I don't think there is one single measure that captures all aspects of a mirrors performance. An MTF across several radial directions would be good good but difficult to do economically.

Yes using the mirror is good but hard to do before you have committed to a purchase.

I guess reputation is most all have to go on as Paul comments above. 

Regards Andrew

[ChrisLX200]

1 hour ago, andrew s said:

The Hubble primary has a very smooth figure unfortunately it was the wrong one (PV way out). I don't think there is one single measure that captures all aspects of a mirrors performance. An MTF across several radial directions would be good good but difficult to do economically.

Yes using the mirror is good but hard to do before you have committed to a purchase.

I guess reputation is most all have to go on as Paul comments above. 

Regards Andrew

The original Hubble mirror suffered from spherical abberation and it was immediately obvious and easy to diagnose what the problem was - fixing it was more difficult though, but the degree of abberation could be calculated from the images it was producing (modelled on a computer and compared) and the corrective optic could then be specified.

A star test is all you need but it does require experience and perhaps reference to Sutter's book.

ChrisH

[Peter Drew]

I agree that the reputation of the maker is one's best safeguard. A proven track record goes a long way with items that cannot easilt be verified by a purchaser. In the event of a slip up by a respected maker it would at least be expected that the maker would be keen to remedy the issue as this usually further enhances their reputation.  

[andrew s]

1 hour ago, ChrisLX200 said:

The original Hubble mirror suffered from spherical abberation and it was immediately obvious and easy to diagnose what the problem was

Not sure it was that obvious to the engineers at the time. Be that as it may, they were fortunate that the error in the measuring setup produced pure spherical aberration otherwise a star test would not have been so easy to understand.

Regards Andrew