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Biconvex lenses with high focal ratio, for sale

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#51 Tavi F.

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Posted 01 April 2019 - 03:59 PM

All the lens are finished. And the images below shows them after the cleaning.

 

2q1hykh.jpg

 

2icaakz.jpg

 


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#52 DARKMATTER

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Posted 04 April 2019 - 06:43 AM

Lenses arrived this morning safe and sound in the UK very very well packaged. :) 

 

Thanks again Tavi

 

Regards,

 

Simon


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#53 Tavi F.

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Posted 12 April 2019 - 01:45 AM

Thanks Simon! And enjoy the projects.

 

And here is a reconstruction of the long refractor, which had been done about 7 years earlier. It is in solar projections mode and of course, in a provisional form and personal use. This to get a better idea. But the easiest way to use the long lens in visual observations (with an eyepiece) is in Huygens type.   

 

1_Plansa%2Bproiectie%2Bsimplete%2BF5-5m_

 

Plus from 2012:

https://3.bp.blogspo...+F5-4m_2012.jpg


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#54 Ovidiu Catalin

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Posted 17 April 2019 - 06:36 AM

Amazing work


Edited by Ovidiu Catalin, 17 April 2019 - 09:08 AM.


#55 Ovidiu Catalin

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Posted 21 April 2019 - 01:23 AM

Big daddy scope, 17th century stile 26/2000mm FL cardboard tubes.

Objective lens Surplush 40mm meniscus.IMG_20190307_162209%2B-%2BCopy.jpg


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#56 Ovidiu Catalin

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Posted 21 April 2019 - 01:31 AM

IMG_20190419_155819.jpgThe 28/1250mm singlet refractor, objective from Tavi Optics, greatest quality.

 

 


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#57 Ovidiu Catalin

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Posted 26 April 2019 - 03:42 AM

The large 26/2000 refractor in observations with the Optical man.IMG_20190426_130255_646.jpg

 

IMG_20190426_125911_527.jpg

 

IMG_20190426_125400_802.jpg

 

IMG_20190426_125804_741.jpg


Edited by Ovidiu Catalin, 26 April 2019 - 05:30 AM.


#58 Tavi F.

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Posted 27 April 2019 - 08:51 AM

@Ovidiu Catalin: Thanks, but I think it's enough here. On this CN forum, there is a section dedicated for ATM, where anyone can show his own work with home-made optics (by himself or orhers) or from different commercial suppliers.

Thanks again for the understanding and keep on with your projects!


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#59 Ovidiu Catalin

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Posted 28 April 2019 - 03:02 PM

wink.gif  yes sir



#60 Suavi

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Posted 29 April 2019 - 01:18 AM

Picked up the lenses from post office this afternoon. Well packed and all four look nice - thank you Tavi.

 

Will give an update when I get a chance to start a project.


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#61 Tavi F.

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Posted 20 July 2019 - 04:40 AM

Up!

 

Observing Jupiter through a singlet lens refractor.

 

48325874146_3a74d5284f_o.jpg


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#62 Ovidiu Catalin

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Posted 22 July 2019 - 04:15 AM

Jupiter through a 28/1250mm singlet refractor afocal 20mm eyepiece and a photo of the night sky

 

 

IMG_20190626_235615_059.jpg

 

 

 

 

 

IMG_20190626_234359_417.jpg

 

 

 

 

IMG_20190627_000130.jpg


Edited by Ovidiu Catalin, 22 July 2019 - 04:16 AM.


#63 Tavi F.

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Posted 23 July 2019 - 06:50 AM

Thanks, Ovidiu. Yes, of course, it is a great joy to take images at the eyepiece with the simplest of tools, but now days, the photo process is a bit more laborious... and I am still not talking about derotating frames in winjupos (which, in my opinion, is over the limit, it is some kind of cheating). Clear sky!

 

Here is a side by side imaging through my main telescope (a DK D170mm, F/26) and my main singlet lens refractor (a D38mm objective, F/54.2). Both equipped with an ADC prism of 2 degrees, placed at the right distance from the sensor. Also a yellow filter was used on the refractor (which is cut from an old photo filter, I am not sure about its density). The final image through the singlet lens refractor was reduced to an equivalent focal ratio of 40, but it is still large in relation to the objective’s aperture.
The seeing was average. I would like to make more of these, but the weather doesn’t coopetate too often.

 

48348337757_10910da56d_o.jpg

 

(the rotation is from left to right)


Edited by Tavi F., 23 July 2019 - 06:59 AM.


#64 Tavi F.

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Posted 26 July 2019 - 12:54 AM

The golden Moon through the golden lens, in the morning day light:

 

https://live.staticf...bee1accaf_o.jpg

 

(I call it "the golden lens" because It was made from a golden mirror substrate.)

 

 


Edited by Tavi F., 26 July 2019 - 01:21 AM.


#65 Tavi F.

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Posted 09 August 2019 - 12:19 PM

Another golden Moon from a few days ago, using the same lens (D38mm, F2060mm). Canon 550D, 55 frames stacked. In good seeing. This is my best image of this kind:

 

https://live.staticf...8a8ebc771_o.jpg

 

(the focus was pushed towards red, and I think it is better this way)


Edited by Tavi F., 09 August 2019 - 12:21 PM.


#66 Tavi F.

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Posted 29 August 2019 - 05:05 PM

Up. A recent image of Saturn through my 38mm aperture singlet lens refractor:

 

48644364051_f4490d2a55_o.jpg


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#67 Tavi F.

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Posted 07 September 2019 - 02:15 PM

As a reminder, I sell only at least two singlet objective lenses, as a set. See the post #47.
- One with the focal length of 1800mm and the aperture up to 36mm;
- And the larger type having the focal length of 5500mm and the aperture up to 63mm.

 

The effective price for one set (D36mm+D63mm lenses) = 50 euro (16+34).

 

Regards,
Tavi F.


Edited by Tavi F., 07 September 2019 - 02:22 PM.



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