How is Takahashi Sky90

Gary · Post by **Gary** » Fri Sep 09, 2011 1:43 pm

@cloud_cover - Not sure about others but your posts and other's posts in this thread did not make me angry. lol.

As this is a forum, we should welcome and contribute constructive debate and discussions as long as we adhere to the rules and decorum of this forum. This can only attract more members to be more active and express their views openly. I believe the posts here are already of some value to the OP and readers regardless of what conclusions they may draw for themselves after reading them.

I also speculates that Canopus did not deliberately find a lower costing 5" SCT just to make his point about WO 88mm have a image quality and usefulness advantage over it. But as I have mentioned in my latest reply to Mooey, it could be subconscious thing - perhaps a convenient or habitual forgetfulness to reflect on the price of a premium refractor after it is bought? So whether intentional or not, it is still an unfair comparison to me at least from a value-for-money perspective/bias.

Btw, what is the name of this 1/6 wave scope you owned? Didn't hear you mentioned about it before? lol

MooEy · Post by **MooEy** » Fri Sep 09, 2011 2:07 pm

If we purely compare what we can get for the same amount of money, it seems that you can always get a much bigger Celestron. This is what I mean in theory. The celestron would always seem to give more value.

However we have to be practical, given the same amount of bulk that you are going to carry, a 4" refractor would be similar to a 8" cassegrain. At this point we have to carefully decide, which would provide better views?

Cost of the OTA may seem like a factor initially, but once you start moving up in terms of size and quality, it quickly becomes obvious that money spent on a cheaper scope vs a premium scope quickly becomes a non-issue.

There are alot other cost involved. The price of the eyepieces and mount comes into the picture. Given a nice goto mount cost in the range of 3-4k, the cost of eyepiece are hovering in the 300-600 usd ranges, does a 1-2k difference in the price of the ota matters anymore?

Let's also not forget the cost of transportation. How much does that shiny car cost you? Even that taxi trip is money. That trip up to north is money too. Even if we ignore the cost of transport, the effort to carry scopes should also be considerations. How many of us can just lug out a C11 every other day?

Can we ignore all these and say, for the price of 3k i could get either the Tak 102 or the C11? Is there any value in comparing these 2 scopes? Does the C11 truly provides better value? I strongly disagree.

Neither the CPC9.25 nor the C11 gets as much use as the smaller scopes. If we were to charge $10 per inch per session, 30-40 bucks for use of the smaller refractors and 110 bucks for the use of the larger SCT, you will notice that we will get alot more money from the smaller refractors. Bang for the bucks, I would say the big celestrons are very poor.

Who wouldn't want a 17" CDK over a puny 4" Tak? The question to ask is, how practical is it?

Anyway, let's bring this somewhere else, the original poster is asking abt sky90, not sct vs refractors.

~MooEy~

andeelym · Post by **andeelym** » Fri Sep 09, 2011 3:29 pm

Not to mention that a bigger scope requires a bigger and beefier mount that is more expensive.

Gary · Post by **Gary** » Fri Sep 09, 2011 3:35 pm

Hi Mooey and friends. I have started a thread to continue our discussion. Enjoy!

"Considering similar OTA price point when comparing scopes":
http://www.singastro.org/viewtopic.php?p=71863#71863

Again, this is not about refractor vs SCT. It is about comparing scopes OF ALL KIND using similar price point as a fairer basis of comparison.

orly_andico · Post by **orly_andico** » Sat Sep 10, 2011 12:30 am

I think....

1) folks who buy premium stuff will defend their choices to the death (this also works for.. LV or Prada leatherware, Swiss watches, German cars...)

2) folks who can't (or won't) buy premium stuff will endlessly point out that they are getting 90% of the value for 20% of the price

And.. both viewpoints are correct.

Me.. I fall in the 2nd category. But I would be lying if I said I will not get a Tak (or TEC.. or AP..) given the right set of circumstances.

The premium goods have just that extra tiny bit of quality that can make a difference when it counts. Yes the bang-for-buck is probably not there, but sometimes that tiny difference can mean everything.

Some people really just want to buy the best they can afford, and not have to keep second-guessing themselves as to whether they made the right choice of hardware or not.

If the OP wants to buy a Tak and can readily afford, I say good for him!

Hobbies are by definition money sinks. It's just a matter of how much money you sink..!

So at the end of the day, making "value for money" comparisons on something which has no value or ROI is meaningless.

I used to (strongly) believe that Aperture is King. Maybe I still do.

But on the rare occasions that I actually observe from my balcony.. I end up using my Zenithstar! (in fact in the ridiculous position of putting the Zenithstar on my CGEM) This in spite of the fact that the C9.25 is just sitting there and I just need to lift it onto the CGEM saddle, so setup time is minimal.

That said, I think everyone deserves to have the option of having aperture when they want it.

Hence in addition to the Tak, the OP ought to budget for a larger compound scope. A C8 is probably a good deal since it won't be used much, but if he wanted to take that premium ideal to the extreme, there's that nice Mewlon 250.

Gary · Post by **Gary** » Sun Sep 11, 2011 5:50 pm

orly_andico wrote: Hobbies are by definition money sinks. It's just a matter of how much money you sink..!
So at the end of the day, making "value for money" comparisons on something which has no value or ROI is meaningless.

@Orly - I beg to differ.

Let's take a look at the meaning of value:

Source: http://dictionary.reference.com/browse/value

(1.) relative worth, merit, or importance: the value of a college education; the value of a queen in chess.
(2.) monetary or material worth, as in commerce or trade: This piece of land has greatly increased in value.
(3.) the worth of something in terms of the amount of other things for which it can be exchanged or in terms of some medium of exchange.

If you only meant (2), I do agree with you to a certain degree. For example, whenever we resell our telescopes, we end up selling it a lower price we purchase it for. But even then, there are exceptions. Some out-of-productions famous/classic scopes may fetch even a higher price then its original retail price.

So when you say something has no value without qualifying which aspect of value you meant, I take it you meant all possible definitions of value.

Since I have purchased my telescopes, the purchases allows to me to learn about their pros and cons more deeply (knowledge). The purchases allowed me to enjoy the views through it (visual pleasure). The purchases allowed me to share the views with others and feeling their sense of joy of seeing through them (family bonding, joy of sharing). The purchases allowed me to make friends with those who sold their scopes to me (friendship).

Thus, from such a hobby, I get lots of value in terms of knowledge, visual pleasure, mental stimulation, family bonding, joy of sharing and friendship. Hard to measure in absolute financial figures as they are intangible values, but they are value to me nonetheless.

Since, there IS value (especially as defined in (1) and (3)) in the purchase of a telescope, value-for-money comparisons DO mean something.

Had I not make meaningful value-for-money comparisons at the point of purchase, I will most probably not enjoyed the values I just mentioned. For example, I bought a used C8 at what I feel is a great value-for-money purchase. At that relatively low price, it gave me:

- Peace of mind that I am not breaking my bank to buy it. I don't have to substantially change my lifestyle financially until my next pay cheque.

- More willingness to share it without others without getting overly nervous about them spoiling it.

- Less financial risk in the rare event I want to give up this hobby. Because thanks to the value-for-money comparison I made, I know I could easily sell it off at the same price I purchased it or just slightly less, "suffering" only a small financial "damage".

Had the seller sold me at double the price, I don't think I will say to myself since there is no value in this sinking hobby, I will buy it at that doubled price anyway.

Another very recent case in point, after a seller greatly reduced his prices for 3 telescope OTA, they were sold very quickly. I guess the buyers also made similar meaningful value-for-money analysis. Now, you may say from the seller's perspective, he lost a lot of value financially. I agree with this fact but I think he also gain a lot of other value in the form of goodwill and utmost respect for his altruism and staying true to what he felt and said - "let fellow enthusiasts enjoy astronomy rather than have my stuff lay idle at home for the next few years".

Coming back to one of the OP's question - "Is there a big difference between this and FSQ106 in terms of visual?". Doesn't that imply value-for-money consideration is important and meaningful? *Assuming* if a FSQ106 gives double the visual performance of a Sky90 but cost 4 times the price, I am not sure if this factor is absolutely not of any importance in his decision-making process.

orly_andico · Post by **orly_andico** » Mon Sep 12, 2011 1:38 pm

Hi Gary,

Yes the values are all intangible. That is why it is meaningless to make "value for money" comparisons.

Is the view through a Sky 90 less valuable than the view through a C8? we can talk about "tight star images" and "flat field from edge to edge" -- these have "value" that the C8 doesn't have.

But the thing is.. the value is only there for someone who appreciates it. Somebody who wants a flat field, who wants textbook airy disks.. won't get it with a C8.

So in the end, it's impossible to make a value for money comparison because everybody's definition of value is different (and subjective).

And going back to what I said.. all hobbys are money-sinks. It's just a matter of how much money you sink (and that amount would depend on (a) your perception of value; (b) your level of comfort at spending a certain amount of moolah).

Hence.. one guy's Sky90 is another guy's ST80. There's obviously value in both offerings as both have survived.

Gary · Post by **Gary** » Mon Sep 12, 2011 5:48 pm

orly_andico wrote:So in the end, it's impossible to make a value for money comparison because everybody's definition of value is different (and subjective).

Hi Orly. If a person have a clear idea of what he wants out of the hobby, it is not impossible.

Instead of talking in abstract, let me use a specific scenario to illustrate my point.

Scenario:

- John wants to get the best planetary imaging of Jupiter
- He lives in a location with great seeing
- He has private observatory in his backyard
- He has a budget of $2,295
- He does not a planetary imaging camera
- He has a tracking mount that can support a 4" refractor or 9.25" SCT

With his budget, he have 2 options:

(1) Buy a Takahashi Sky 90II OTA only
(2) Buy a Celestron EdgeHD 9.25 OTA and still have a remaining $199 to buy a used Philips ToUcam webcam

He chooses option (2) over (1).

This is his reasoning:

- Aperture is a very important factor when it comes to planetary imaging. (Laws of physics. This is something that cannot be denied just because someone somehow subjectively "value" a 90mm premium lens to be better performing than a 9.25" mirror for planetary imaging)
- Even after getting a bigger aperture scope, he can still afford a webcam and stay within his budget.

The above 2 points are extremely meaningful value-for-money related decisions that John would have most probably made out of his budget.

Too hypothetical and second-hand smoky you say? Let's look at the real world of planetary imaging. These are some of the best and their preferred choice of scope:

Anthony Wesley - 14.5 inch Reflector (16-inch reflector soon according to the great article about him in Sky&Tel Sept 20011 issue)
Christopher Go - 14" SCT (a non-premium brand name that starts with a "C")
Damian Peach - 14" SCT (a non-premium brand name that starts with a "C")

Similarly, in the real world of wide-field deep-space astrophotography, the refractors will most probably beat the a similarly priced SCT.

So once again, my main point in this post is NOT about Refractor vs SCT or vs any other scope. It is about the meaningfulness of doing value-for-money comparisons provided you have already decided very clearly what you want to achieve with your new purchase.

The OP asked if a Tak Sky90 is good for both visual and ap without elaborating exactly what he is interested in the visual part and what kind of photos he interested to capture in the AP and his budget. Thus, my initial suggestion that he could try a used 8" SCT to find out what he really wanted to achieve (SCT is well known to be the best all-rounder scope), THEN make the big budget investment. Had the OP been very clear, e.g. I want the best tightest stars in the widest fov and this is my budget, then I think most members who have replied in this thread would have replied differently, e.g. leaving non-refractors out of the discussion.

orly_andico · Post by **orly_andico** » Mon Sep 12, 2011 8:19 pm

hi Gary,
well the CO of an SCT reduces contrast for visual, but this does not affect planetary imaging due to the huge amount of processing done.

you could take the argument further and say, instead of an SCT, use a newtonian - less surfaces, less can go wrong. I believe there's a famous planetary imager in HK who does just that - Royce newtonian.

Gary · Post by **Gary** » Mon Sep 12, 2011 9:11 pm

Hi Orly. Ya, CO does reduce contrast. But because of the cheaper pricing of mass-produced SCTs, for a similar budget, it is possible to compensate that drop in contrast with a bigger aperture which improves the visual appearance of certain celestial objects under certain sky conditions. And with the difference in savings, purchase accessories to further enhance the non-CO aspects of a SCT to reduce (not totally eliminate) the design advantage of other scopes and thus increasing total value and enjoyment of owning a SCT.

The HK imager you are referring to should be Eric Ng. Unfortunately, accessing his website now gives me a 404. IIRC, he did contribute some posts in the old singastro yahoogroup.

Anthony Wesley's Nemesis is also a royce newtonian.

I believe we are getting off-topic here.