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New Istar Optical APO 140 f6.5 - first light

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#1 Psion

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Posted 19 October 2020 - 12:07 AM

Istar Optical made new lens Apochromat triplet 140 f6.5 (will be deliver together with Apex 5-elements reducer/flattener - effective ratio f4.2). I received from my friend first picture from this lens and notes:

 

I was able to get an image of M31 with the 140 triplet last night.  The stars at the top are not perfect because of tilt in my questionable wooden OTA, so if you share the image with any potential customers, make sure they know that.  But the scope optics look great and the image is otherwise pretty nice!  I think if we can get a real OTA, we could get some very good images, but this is probably the best we can do with this test setup.  I probably wouldn't post this image on the website because the stars don't look perfect.  If we get a real OTA we can get some better images to post.

The image was with the ZWO ASI2600 color camera and an Optolong L-Pro light pollution filter.  Exposures were only 60 seconds long and I took 60 of them, so this is just one hour of total time. The scope becomes f/4.2 with the Apex reducer in place.

 

Istar is planning on introducing a completely CNC machined OTAs with tube rings and 2.5” large format MoonLite focuses with dual accessory bracket. A complete package for estimated $4495.

Attached Thumbnails

  • M31_LPro_Istar140_Test-1.jpg
  • Istar_Test_OTA-1.jpg

Edited by Psion, 19 October 2020 - 12:08 AM.

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#2 sg6

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Posted 19 October 2020 - 02:37 AM

I like the wooden OTA most. Just looks good for whatever reason.

And no tube currents to deal with.

Absolutely brilliant.


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#3 PKDfan

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Posted 19 October 2020 - 03:56 AM

I also have much lust for this Beautiful scope(cant call this one a tube😋)please I cant take any more! I just bought a scope!! That photo has busted the 500k limit for sure. How? Amazingly lovely photo! If I had the wherewithall this would look just fine in my home,outside my home just not in somebody elses home.😅


CS & GS

#4 Psion

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Posted 19 October 2020 - 05:23 AM

The photo has 406 kB, thank you for your comments guys smile.gif



#5 ISTAR Optical

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Posted 19 October 2020 - 01:53 PM

Thank you, Psion, for posting some of this preliminary info. These lens in cell combo is already available and we shipped several units to customers in the US and Canada. Detailed info can be found on ISTAR website. Just so everyone understands, what you are looking at is only a quick crude way of testing the optics on actual deep sky object. This is not something we would be offering to our customers. As you have correctly indicated, Psion, we are planning on introducing a complete CNC machined OTA with 2.5" MoonLite focuser with dual accessory bracket. 



#6 ISTAR Optical

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Posted 19 October 2020 - 02:01 PM

I like the wooden OTA most. Just looks good for whatever reason.

And no tube currents to deal with.

Absolutely brilliant.

We used to design and sell so called TCR models in the past. The lightest, easiest to handle, fastest lens cooling time refractor with performance identical to the enclosed tube models. But general public did not like the idea and it was widely rejected. People who never looked through one or never saw one in person had the strongest opinion so I simply abandoned the idea. Im keeping one 204 F8 as my own grab-n-go refractor because yes, even an 8" monster suddenly becomes "easily manageable" in this construction/configuration. You can easily handle the 8" scope with one hand.



#7 Alrakis

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Posted 19 October 2020 - 02:34 PM

Ales, 

 

I looked it up and the TCR used a magnesium alloy. How does the wood design compare? Just thinking from an ATM standpoint. Also, would using cables under tension help increase the stiffness of the TCR design for longer OTAs or with material (such as wood) that is not as stiff as a magnesium alloy? 

 

Chris 



#8 Psion

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Posted 19 October 2020 - 04:11 PM

I like the wooden OTA most. Just looks good for whatever reason.

And no tube currents to deal with.

Absolutely brilliant.

It just “quick crude set up to test the optics”, this is not an actual telescope, the CNC machined OTAs with tube rings will be early next year.



#9 Alrakis

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Posted 19 October 2020 - 05:04 PM

To Ales' point it seems that most people were put off by the TCR design. I am not one of them, I would have bought a TCR type refractor if I had the money for it. I am in the process of grinding and polishing my own doublet and thinking of how to mount it. The TCR design and a Serrurier truss design are, in my mind, my top two contenders to build for the OTA. However, my main concern is if I could build or modify the TCR design with a CNC machine.

 

Chris 



#10 ISTAR Optical

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Posted 02 November 2020 - 03:20 PM

To Ales' point it seems that most people were put off by the TCR design. I am not one of them, I would have bought a TCR type refractor if I had the money for it. I am in the process of grinding and polishing my own doublet and thinking of how to mount it. The TCR design and a Serrurier truss design are, in my mind, my top two contenders to build for the OTA. However, my main concern is if I could build or modify the TCR design with a CNC machine.

 

Chris 

Chris, send me an email to ales@istar-optical.com if I find our old drawings I will share them with you. They may help you with your own design. 


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