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Post by wakoch on Dec 27, 2012 12:33:46 GMT -5
Hi Mike and Ales
I see you have very much news going on. I wonder when I can order a 204/f8.8 slim-style in "krivanek-TCR" mode. That would be the ultimate scope for me. When could it be ready for shipping?
Have fun with your new products
walter
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Post by Ales - iStar Optical on Dec 28, 2012 3:32:56 GMT -5
Hello Walter, we are actually working on 204 F/8 R30 SLIM OTA in "Krivanek-TCR" design. Attached is spot diagram, in next message I will send you basic drawing of the Rear Tube Rib. This way you get a better idea of how the scope look like and how big it is. We dont have price yet, but I expect price of the finished Perseus TCR 204-8 R30 SLIM to be in 4700 dollar range including focuser, mounting rings. We will have the actual price by middle of January 2013, stay in touch, best regards, Ales Attachments:
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Post by Ales - iStar Optical on Dec 28, 2012 3:38:32 GMT -5
Walter, here is drawing of the Rear Tube Rib. Length of the entire scope excluding dew shield (not shipped with scope) and focuser is exactly 1371mm. We will know the weight after we produce first units sometimes during spring 2013. You can be first one on waiting list if you put down 2300 dollars, rest due before shipment. Best regards, Ales Attachments:
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Post by wakoch on Dec 28, 2012 7:13:49 GMT -5
Hi Ales thank you very much for the drawings. I'm in the boat . I need 220 mm inward focus. I'm looking forward to be the first customer of that scope. You'll get an email.
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Post by wakoch on Dec 30, 2012 13:28:17 GMT -5
Hi Ales and Mike I know, it's weekend. But I have not heard of you since posting my commitment to you to buy the first krivanec 204 r30 f/8 scope and I even emailed it to you. I'm sitting on 4000 $ to be spent and now body is asking for them walter
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Post by counterweight on Jan 18, 2013 22:15:26 GMT -5
Hello Mike and Ales (Mike i'm the fellow that sent an email last week about a 204mm R30) "Ya hochoo - nuzhna! hope that translates into i "I want and need!"
I will sell the TEC if necc, but i want aperture for my eyeball, quality too. I'm one who will 'just do it' if that is where I'm steering. Did same with the TEC 160 - an amazing deal and I was stunned that on another site folks who'd never even looked through one seemed to have an opinion! "jeez, you gotta be kidding me!"
I can paperwhip with the best and have (though I do charge)... and this 'mock theta funtions as applies to the Airy" discussions are just ridiculous. Ales I've appreciated your common sense and realistic approach in responding (over there). I do have the impression there is an unfortunatye bias (at that place) that is unfounded. So i guess all I am getting at is that I'll spend my money and use my eye(s) and consider myself impartial to the paperwhipping (I'll assume you are doing a good job there and reports verify that confidence) and not impartial to enjoyment.
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Post by Ales - iStar Optical on Jan 20, 2013 13:28:17 GMT -5
Hello Counterweight, In your case I would not sell your TEC 160 APO and think that Istar R35 SLIM will outperform or meet this APO Triplet. These are two totally different optical designs and R35 is inhanced quality Apochromatic doublet while 160mm TEC is an APO triplet (I didnt look into this in any detail I only assume that you got a triplet). TEC is known for excellent optical quality for the price of course. These new R30 and R35 still show considerablel amount of CA even though some 35 percent less compared to any classic achromat out there. Unfortunately I cant stay tuned for regular discussion, I got on line for about 30 minutes, first day of my overseas travels. I will try to get back to this forum and reply to what ever questions you may have. Talk more with people who have R30 doublets than make up your mind. Be well and thank you for being wiht the Istar Scope Club crown too, cheers, Ales
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Post by Mike on Jan 20, 2013 20:27:33 GMT -5
Hey Guys, I agree with Ales. Our 204 and your TEC 160 are entire different scopes. One is certainly not a substitute for the other. I have a lot of time on a 160 FL and some time on a 160 ED. These scopes are the epitome of Triplets in quality. In my opinion, unmatched in the 160mm category. The 204 is however much larger. It will show more detail on DSOs. But Ales is right about the CA. On bright planets like Jupiter the CA is not terrible but certainly there. I would say whatever you gain in aperture over the 160 you would lose in contrast due to the CA. However, when Raycorr is released it will eliminate a considerable amount of color. We want to be realistic when it comes to scopes like TEC. After all, it costs 3 times our 204. We would be happy to have you as a customer but you should weigh all the facts. Mike
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Post by jamesling1000 on Jan 21, 2013 1:47:21 GMT -5
Hi All...
I fully agreed with both ales and Mike have said....
I have owned this 8" F8.8 and is not the latest R35 version....
Let me relate my true experience when 2 years ago the 8" Istar did a shoot out with my friend 152 APM triplet APO.....
Beside the CA causes the 8" Istar edges to be softer, there are no distinct differences you can see on the surfaces of Jupiter, from both the scopes... The only another distinct difference very noticeable is the shadow of the transit of the moon from the APM APO is very dark, while the 8" IStar is lighter.....
And the Istar can achieve such a high quality of contrast is only when the object is at , or near to the overhead.....
So with the new R35 lenses, the 8" Istar is definitely going to perform much better.....maybe higher power.....and still maintaining a good contrast....
And once the raycorr is out, and if it is going to improve by another 50%, on the CA, the 8" ISTAR R35 is really perform like ED APO....
Regards
James Ling
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Post by counterweight on Jan 21, 2013 12:05:40 GMT -5
Thanks all very much for the intelligent responses, very much appreciated. Yes the TEC is quite a fine scope and there you do get what you pay for. James - I observed similar results, my first light on my 160ED scope was watching shadow transits on Saturn with a 4mm ZAOII and unusually co-operative seeing. I'm hoping not to be making a gross concept error (gce) in thinking that the combo of increased aperture and the raycorr corrector would have more 'punch' than my 160? No possible way can I even consider owning a ~200mm triplet new or even used (same goes for 180mm), so i have to consider optimizing within my financial limitations. My experience so far... 2008 till now with refractors is that 2" aperture increases are significant. I started with 80mm and a Tak FS-102, then up to the FS-128, then to the TEC APO160ED. Bracketing the -80mm and 128mm- and then the -102mm and 160mm- the increases are jaw dropping. This on emission nebula, globulars, and planets/Luna. I know there are endless debates on it all, but I do think for each of us perhaps, there is something to the concept of grabbing the light in sufficient quantity to begin with to even discuss issues of contrast at that resolution. Going away from planetary observing lets use M13 and M42 as example - both are showboats. this entirely just my opinion. 80mm(doublet/triplet)... 'meh' something is there... 102mm... m13 just beyond a smudge, a little more that something is there, few stars and grey smudge. M42 begins to be more than a small bright patch- large scale features/textures detectable. 128mm... m13 now seeing some stars around the bright smudge obvious 'globular characteristics', M42 showing large scale features and texture handily, smaller features are detectable 160mm... m13 now clearly a globular with depth of stars and start of 'chandalier effect' - showing increased starcount to brightly illuminated core. m42 begins to be astonishing, medium scale features obvious and small scale features easily detectable. I'm just going through this to demontrate my point about what entirely 'In my Opinion only' aperture brings to the table and i suppose i should include 'on these objects only' just to be concise. M13 going from a 'meh' to an internally illumated star chandalier, M42 going from a little bright patch to a jungle of features and textures. There are so many objects 'up there' but in reality I think I spent a majority of my visual time on a fraction of them, and of that at least 50% on my 'favorites'. Planetary observing also IMO is an object by object talk. And then for me though Uranus and Neptune are 'interesting' and have a unique color, and Mars can be interesting at times(in terms of spans of years) Jupiter and Saturn are the king and queen. Luna is interesting even in my finderscope But Jupter and Saturn each have things unique... Saturns rings and ring shadow on planet and planet shadow on rings are prominent but the banding is not so much compared to Jupiter. Jupiter has it's banding and festoons, spots and barges, and unique features withing them, but no rings. Then there's the issue of transits and orientations... Both are always interesting and I always look at them when they are up, but for 128mm just starts to do it... 160 does it better. Here IMO the most important point is that the 'possible' feature resolution is sky conditions far that aperture. Not even a contest going from 80mm to 160mm even in moderate seeing, the minimum feature detail in lower powers of the larger aperture will still IMO trump the small aperture. To summarize, I think any talk of resolution and detail is intertwined significantly with both aperture and seeing conditions for that particular object. Yes all the scopes I list have very good optics. Also worth mention is that one object is not necessarily a good example for all of it's class: planets, nebula, globulars. Though a significant amount of time is spent talking about relative amounts of CA, SA is also important to keep uner control and that is where I look to quality of figure. CA you are pretty much stuck with what the glasses will give you for the focal ratio and I rely entirely on the designer to have an appropriate presription to where folks consider it reasonable. The fact that IStar is looking to create a third lens group (the RayCorr) to reign this in is fantastic. Having control over the process 'soup to nuts' should allow for some very pleasing results, though I don't think it's an easy road? I can infer some (about other objects) from my examples above that if M42 looks like this or M13 looks like that... but I think that process is quite personal and based a lot on experience. So though it is a complicated calculus, I think it can be further complicated by generalization. Don't worry that I'm expecting something like a TEC200 triplet, I'm not. The overall where and exactly how it might differ I will never know as I'll never own a TEC 200 unless I win the lottery and can find one on the used market. I expect the true answer for me would be as varied and complicated as the objects up there. Sorry for the long winded post and all the typo's...
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Post by mikey cee on Jan 21, 2013 12:27:38 GMT -5
Hi CW....I dunno that 204 with a Raycorr 6 may fool ya'. If Ling's assumption and I know it's a guess is correct.... I'll be in "hog heaven". With my 10" f/11 R30 if I only get an accumulated 80% reduction in CA I''ll take it. Right now I see little CA on Saturn and a little more on Jupiter. With another50%(?) knocked off as far as I'm concerned I'll have an apo like performer. I know technically it won't be "close" but in reality it'll be a no brainer. I believe you won't see any visual difference but in AP you will. Who gives a RAT's patootie! When you start splitting hairs like this you're ready for the nut house anyways. Mike
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Post by jamesling1000 on Feb 24, 2013 3:17:56 GMT -5
Hi ALL..... I just want to share with all of you, whether you have plan for the Istar 8" F9 or F12 , R35 or std......, bigger or smaller Istar aperture...., from my last night shootout using my 8" Istar F9 against my friend C8 edge HD..... The following are what have been observed through these 2 scopes.... 1. We tested the collimation of the C8 edge HD at Sirius at 200X , followed by another 5mm ep at 400X....and the scope is very well collimated.... with the diffraction patterns symmetrical and concentric... 2. Both scopes first pointed at the 14 days old moon, and my goodness, is very very bright last night, without a filter.... We used polarized filter, instead of the moon filter, so that the moon looks white and black which is more pleasing.... Both scopes show surface details so clearly, that you always hear many people say nothing much to observe towards the full moon period....which I think it depends a lot on the scope itself...... 3. As usual on the CA, the Istar will show a trace of greenish yellow over the edges of the moon, but that don't seems to affect the surface details, except some people just can't tolerate that "EXTRA"....little thing.... And last night, to our surprise, the C8 edge HD also shows a very very tiny trace of greenish yellow over the edges of the moon... And this is not noticeable if you are not trying to look for CA......... 4. The next target is M42, and this is what make the difference between the refractor and SCT..... Isn't in CN, a lot being mentioned that the light throughput of the refractor , of similar aperture to a SCT or Mirror scope, is lesser, and now when against the edge which is XLT, And is very clearly shown in the Istar , that the C8 edge HD is not able to show like following...... i) the gas clouds stands out in the Istar..... ii) the Istar last night picks up star E in the trapezium, but not the C8 edge... I even swap my baader zoom ep over to confirm....that is not due to ep issue... I just want to give my sincere comments to all those who are going for the Istar refractor, especially those who are going for the 8" aperture, you won't regret with the quality that is able to produce.....through the Istar scopes.... Regards James Ling Attachments:
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Post by Ales - iStar Optical on Feb 24, 2013 5:57:14 GMT -5
Thank you so much for your test results! And imagine what can be seen in the all new 204 R35... I dont like to turn down any reflector (even those equipped with expensive mutli lens correctors) but the truth is, that you can not outperform a big, well designed and well made refractor like those from Istar. Before people spend money on 8 to 10 inch SCT, they should take a better look at what is available at the other side of the scope market. This is why we produce refractors only. Optically superior to any other system on the market. We will produce few large mirror based astrographs but only because we can not make lenses in such aperture ranges (400 to 700mm). The mirrors will be produced in Europe out of super stable, super thin, fast to cool material (not glass). But before we jump into this project we must finish couple more refractors as well as the 4 element Super APO Petzval F6 astrographs. These will be absolutely top of the line both mechanically (every single part of the scope will be CNC machined, including the tube and dew shield). We wil use our patent pending lens self centering lens cells (each lens is perfectly centered on the optical path with virtually zero tilt. These will not require ANY collimation, EVER) because every single lens in the assembly is held in place by its own specially designed and made spacers. These new Super APO, very fast visual multi lens refractors/astrographs will not be cheap, but still in price range of competitor's standard triplets. We will start producing these right after we are done with the Raycorr and all 9 models using R35 SLIM anastigmatic doublets. That is by end of this year.. so more exciting news from Istar is coming soon. STay in touch and thanks to everyone willing to share their observation reports, like the one above.. cheers, Ales
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Post by jamesling1000 on Mar 3, 2013 2:08:24 GMT -5
Hi ALL..... This is another interesting report I want to make and comment on my 8" F8.8 Istar, when I did the 4 scopes shootout at my friend's roof top observatory, last Saturday... This time my astro friend, Gary use his HTC ONE S hand phone and snap photo of the 20 days old moon through the 6" APM ED APO and 8" Istar.... And the following photo shows the amount of CA from the scope.... And visually, at the moon, you cannot tell the difference in performance from the 2 scopes, with one exhibit very little or thin trace of greenish yellow, while the Istar larger amount, quite close to a std 6" F8 achro.... But when you point both scopes at Saturn, you can realized the difference..... Is not that the ED APM view is sharp , while the 8" IStar achro view is fuzzy.... Is the features of the cassini division and the cloud bands... Cassini division in the APM ED APO is very dark.... Clouds bands (lines) in the APM ED APO is darker..... And the Istar is also able to power quite high, above 300X with no image breakdown... I even use my TV 5X barlow together with my baader zoom at 24mm, at 375X, and the image is still crisp.... And in my opinion, with a reduced in CA level, this will give you an improvement in the contrast level.... Or in this case, the cassini division and clouds bands will be darker.... As such, is a wise move to go for R35 version, if you are very particular on the such results....and perhaps with the raycorr.....your scope become an ED.... And for those who can accommodate F12 setup, that will be even be better, but wide field will be affected.... But aperture is aperture..... The resolution to resolve an object really depends on the aperture size.... Take the 6" APM ED APO, performing so well on Saturn, but barely resolve star E in the trapezium on M42 on last Saturday shootout.... But the Istar did it effortlessly , and is on a 14 days old moon night..... Last Saturday night, while the rest of the scope can only point at the 20 days old moon and Saturn, my classic 8" Istar is moving around the scopio, searching for M4, M6, M7 , M8 , and M20, etc..... Simply we are in a heavily light polluted city, and the smaller aperture scopes cannot see much.... So I hope all these observations and comments made by me recently, can give members some ideas what will be the performance they should expect from an Istar doublets , whether is classic or R35 version.... Regards James Ling Attachments:
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Post by bn1777 on Mar 4, 2013 2:15:07 GMT -5
Thanks for the comparism James , the background sky looks darker in the Istar compared to the APM and the Istars contrast on the lunar surface looks sharper as well. I to have an HTC One and it takes great moon shots as well , like this one taken with my 127mm f/8 Achro . ( if I can work out how to post it ?? ) Brian.
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