63 replies to this topic

[jag767]

So I have done a little digging. Is anyone interested in the Kson 102 ed? I reached out to a company to import them and for 5 units the price is $599 each before freight, and for carbon fiber add $20. I personally would grab one for myself, but as I have no need for 5 of them which is the minimum order, is there 4 other ppl out there? I also have an image of the test for the optics which I will attach here if someone would like to interpret it for me.

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[Jon Isaacs]

So I have done a little digging. Is anyone interested in the Kson 102 ed? I reached out to a company to import them and for 5 units the price is $599 each before freight, and for carbon fiber add $20. I personally would grab one for myself, but as I have no need for 5 of them which is the minimum order, is there 4 other ppl out there? I also have an image of the test for the optics which I will attach here if someone would like to interpret it for me.

I am not navigate the market but do you have the specs on the glass and stuff?

Jon

[Jim7728]

Smart Astronomy sells that KSON ota and lists the glass as fpl-51

http://store.smartas...opmiedapor.html

[jag767]

Smart Astronomy sells that KSON ota and lists the glass as fpl-51

http://store.smartas...opmiedapor.html

First place I tried, none in stock and no communication as to when they will be, hence looking at other options.

[mwc11]

hi jag767,
I'm not sure why the KSON 1026 isn't selling like hot cakes...they are a fantastic little scope at ~ $700. It was "KON Dealer's" posts that introduced me to them (got it from SmartAstronomy - good folks in my dealings).

its superlight (I happen to like carbon fiber for tube material), nice build quality, and the optics are indeed very sharp and clear. It does have a little CA (it is after all a f/6 with a FPL51 doublet), but not objectionable IMHO.

It really shines in its portability. its literally a one handed gran-n-go with my vixen porta II (with eyepieces in the tray too!!!). I prefer it to my C6 for most nights of impromptu sessions.

[REC]

Sounds like an interesting scope. As for the little CA, how would you compare the viewing on the moon and Jupiter vs the C102 ED and the Barska ED80?

I have a very good C80ED as my grab scope, but wouldn't mind upgrading to a K102 ED if I could see a noticeable improvement and then I could sell the 80ED?

Thanks,

Bob

[Eddgie]

Color correction isn't the "Only" aberration one has to consider in a fast refractor.

The most likely customer for such a scope would be someone that images.

And at f/6, field curvature in an ED doublet starts to become an important factor for modern chips.

So, do I buy a small hugely exlensive exotic doublet, or do I buy a bigger slower, doublet and use a reducer on it?

The Televue and Tak scopes are excellent examples of fast ED scopes that simply acknolege the issue of field curvature by simply building in the reducer/corrector.

I don't know if this is the answer you your question, but there is always a tradeoff for this kind of thing, and my guess is that in this particular case, it is the fact that the field curvature is bad enough that to image, you would have to use a flattener anyway, which further increasees the price, which makes it harder to sell more of them.

And then Televue and Tak are you compention.

And excellent competitors they are.

So, f/6 ED Doublet, or f/5.4 Petzval?

[gene 4181]

check out the farpoint 102 refractor. i think it has the glass you seek.

[jag767]

So I have done a little digging. Is anyone interested in the Kson 102 ed? I reached out to a company to import them and for 5 units the price is $599 each before freight, and for carbon fiber add $20. I personally would grab one for myself, but as I have no need for 5 of them which is the minimum order, is there 4 other ppl out there? I also have an image of the test for the optics which I will attach here if someone would like to interpret it for me.

I am not navigate the market but do you have the specs on the glass and stuff?

Jon

Its FPL-51, what specs would you like in particular? I will inquire for you

[jag767]

Color correction isn't the "Only" aberration one has to consider in a fast refractor.

The most likely customer for such a scope would be someone that images.

And at f/6, field curvature in an ED doublet starts to become an important factor for modern chips.

So, do I buy a small hugely exlensive exotic doublet, or do I buy a bigger slower, doublet and use a reducer on it?

The Televue and Tak scopes are excellent examples of fast ED scopes that simply acknolege the issue of field curvature by simply building in the reducer/corrector.

I don't know if this is the answer you your question, but there is always a tradeoff for this kind of thing, and my guess is that in this particular case, it is the fact that the field curvature is bad enough that to image, you would have to use a flattener anyway, which further increasees the price, which makes it harder to sell more of them.

And then Televue and Tak are you compention.

And excellent competitors they are.

So, f/6 ED Doublet, or f/5.4 Petzval?

Yea..... Just a small difference in price.....

[glend]

I would be interested in a Kson 102ed group buy but would need it shipped to Australia.

[Eddgie]

Well, these companies sell them, so someone buys them.

It is always about business for them after all.

With limited facilities to turn out a limited number of 4" lenses in a day, the more you make of one thing, the less you can make of something else.

So, you make what you can sell the most of (Synta model), or you make a few at a high price you can get for them (Tak model).

Always about business.

[jag767]

Well, these companies sell them, so someone buys them.

It is always about business for them after all.

With limited facilities to turn out a limited number of 4" lenses in a day, the more you make of one thing, the less you can make of something else.

So, you make what you can sell the most of (Synta model), or you make a few at a high price you can get for them (Tak model).

Always about business.

And if i had the extra bankroll to purchase one it would be sitting on a mount right now . In all seriousness, when I have 2 growing businesses, it would be completely irresponsible of me to throw that much money into a hobby when it should be put to good use elsewhere. Maybe one day......

[Jon Isaacs]

Its FPL-51, what specs would you like in particular? I will inquire for you

FPL-51 is sufficient.. As I tried to write in my previous post, I am not in the market for a 4 inch F/6 FPL-53 or FPL-51 doublet. This thread is of interest to me because I would like to see a 4 inch F/6 or probably better F/7 FPL-53 doublet available at the $700 price point.. They do it at F/9, why not F/7?

My intent was to clarify if Kson was a FPL-51 or FPL-53 based doublet. Having owned the similar AstroTech 102ED with used a similar glass at F/7, I would think this 102F/6 would have more chromatic aberration. Under some circumstances it would be noticeable but very rarely bothersome.

As far as the 102mm F/6 ED scope versus the 4 inch F/5/4 TeleVue Petzvals, as you point out, there is a major difference in cost.

To Eddgie's point about field curvature, any of these scopes (except the Petzvals) will need field flattener if used with a large chip camera. These are about $200. Visual though is a different story, I do happen to have both a 100mm F/6 Orion achromat and one of the TeleVue NP-101's. The field curvature in the achromat can be seen, it is not perfect like the NP-101, but I don't find it particularly bothersome.

I see the virtues of a scope like the Kson 102F/6 ED is the compact size, it must be not much longer than an 80mm F/7, combined with much better color correction than a 100mm F/6 achromat with the mechanical niceties of the Kunming scopes and all for a very reasonable price. It's a 80ED on Steroids...

I wouldn't mind having one to replace the 100mm F/6 achromat but I couldn't justify it.

jon