106 replies to this topic

[Ovidiu Catalin]

Nice images Tavi, your lenes are very good.

Edited by Ovidiu Catalin, 16 August 2016 - 06:15 AM.

[Ovidiu Catalin]

This is my objective made by Tavi F nr6 good lens, i use it for Solar projection at prime focus, the diameter is 40mm / 2400.

Very good also for prime focus projection the lens does a very nice job.

The objective lens cell its mouned o a eq1 mount and rise up, using a white paper the image of the sun its delivered by the lens.

I try to make a long focus 17th century telescope out of this lens but i have faild.

Here in Romania are to poor resources, ideal will be a aluminium long tube.

But this is not a big truble, it works good has it is.

 

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[Tavi F.]

Up.

 

Thanks, Ovidiu.

[Tavi F.]

Up!

 

[Tavi F.]

By the way, you can find the description of the remaining lens in post #24. More quickly accessible at the link: http://www.cloudynig...sale/?p=7334401

 

P.S. For contact and ordering, please send me a p.m.

Edited by Tavi F., 23 February 2017 - 12:57 PM.

[Tavi F.]

And here is the lens in discussion:

 

 

[Ovidiu Catalin]

New lenes from Ovi's Optical for solar projection, aperture 30mm to 20mm stops and with very long FL up to 5m
Lens type meniscus
Extreme durability
Not For sale
Lens 1

Aperture 20mm fl 1300,
Lens 2 Aperture 25mm fl 2m
Lens 3 Aperture 28mm fl 4m
Lens 4 Aperture 30mm fl 5m

Edited by Ovidiu Catalin, 24 July 2017 - 06:13 AM.

[Ovidiu Catalin]

Optical meniscus singlet lenses at Ovi's Optical are used for non eyepiece solar projections, the same with a 40mm f50 Tavi's Optical objective.

I do not have Objectives lenes form Tavi's Optical i just sold the last pice, i have'd a set of 3 objectives.

Its not a big diffrence betwen simetrical lens and meniscus when it comes to solar projection only the aperture is reduced a little bit.

I also sold my 28mm simetrical to, because i do not realy like those lenses and i am not building 17th century structure scopes anymore, so i did not find any use for those objective lenses, it make the sun to bright and also if the aperture is reduces it will be the same with my meniscus lenses.

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Edited by Ovidiu Catalin, 24 July 2017 - 10:04 AM.

[Ovidiu Catalin]

Ovi's Optical objectives for Solar projection

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Edited by Ovidiu Catalin, 26 July 2017 - 02:27 AM.

[Ovidiu Catalin]

New Tavi'Optical objective in action for Solar projection with eyepiece this time in a aerial telescope sistem.

Lens specification:

 Duseful = 28mm;

focal length in G-channel: F = 1250mm;
- total diameter: Dt = ~35mm;
- center thickness: tc = ~6.5mm;
- high precision optical diameter: Duseful = 28mm;
- relative opening ("focal ratio"): N = F/Duseful = 44.64;
- the chromatic aberration coefficient: x = N/Duseful = 1.59

 

The objective lens cell is mounted on a pole or a normal tripod and the light will focus on a paper, with a eyepiece at the focal point provides the image. You can use a rope to center the optics.

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Edited by Ovidiu Catalin, 26 July 2017 - 07:49 AM.

[Ovidiu Catalin]

Tavi's Optical simetric lens 28/1250mm Solar projection on white paper toady in the view comes the new group AR12674 and AR12673.

Tavi's Optical 28mm objectis is the best in the world.

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[Ovidiu Catalin]

The objective can work very well on solar projection without eyepiece this is what Tavi and i have made its a greate way to have a non eyepiece sistem very good for solar viewing.

The lens is very good and has a fine surface and good optical polishing.

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[Ovidiu Catalin]

The sun today with Tavi's Optical 28/1250mm lens

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Edited by Ovidiu Catalin, 10 September 2017 - 10:12 AM.

[sarastro]

And here is the lens in discussion:

 

 

Hi Tavi,

 

Is this lens still available?

[Tavi F.]

Hi,

Yes, I just sent you the answer in pm. Thanks.

Edited by Tavi F., 30 January 2018 - 11:44 AM.

[Tavi F.]

The last lens available was sold. Thanks.

[Tavi F.]

And the singlets story is not over, after all. I will make another two types of objectives, presentable as a set, but more info at the right time... probable in the autumn or winter this year.

 

Thanks.

[sarastro]

Tavi

How are those lenses coming along?

[Tavi F.]

Update: New series of singlet lens objectives are in the making!

 

 

[Astrojensen]

How large are they and what focal lengths? Prices? 

 

 

Clear skies!
Thomas, Denmark

[Tavi F.]

There are two main types: 1) D36mm, F1800mm and 2) D63mm, F5500mm.  And I will sell them as a set of two, but more details and pricing after theirs finalization.

[Tavi F.]

Hello,

 

Due to some personal problems, the process o finishing these lenses was somewhat delayed. Sorry for that.

 

By this time I have all the small lenses complete and a few of the large ones finished, to complete the sets. One of the small lenses (D36mm) available is from BK7 glass (at the same price, available to anyone who wants it first). Apart from these a have one lens of a 3rd type, which is a D38mm, F2030mm (made also in this period). It is a BK7 lens. The rest of the smaller lens are from good plate glass (without  any striae), the one specimen from my original 8mm thick plate, thicken down to 6mm. 

 

The lowest selling prices are:

1. set of D36mm+D63mm lenses = 50 euro (16+34)
2. set of D38mm+D63mm lenses = 54 euro (20+34)
For purchasing more than 2 lenses, the price is the sum of individual prices written in the brackets.
All the lenses are individually worked and hand made.
More to come. Thanks!

 

[Tavi F.]

Update: Two sets of lenses (D36+D63) were sold. It will be sent to Australia. Thanks.

 

The D38mm lens is virtualy wanted by two persons. The first one to make a clear commitment to it, it will be his.

[DARKMATTER]

Payment sent for the 36mm BK7 lens a 38mm BK7 lens and the 63mm lens

Thanks

Simon

[Tavi F.]

Update 2: Another 3 lenses were sold. The D36mm(BK7), D38mm and one of the largest type.

Thanks again, Simon.

Edited by Tavi F., 28 March 2019 - 12:19 PM.