Where to get optics for a refractor?

[kbrown]

Hi,

I'm toying around with the a idea to design and build a small simple refractor telescope.  I have to admit I don't know much about them so I'd probably use commercially available optics. Where could I source these from? Preferably in the UK?

 

Thanks,

Kari

[Fozzie]

Hi Kari,

You could try Astroboot for cheap and chearfull, removed from an achromatic scope lens, usually 60mm or 70mm

I know IR Poyser sell doublets.. http://irpoyser.co.uk/lenses/

Ta

Fozzie

[Chris]

Hi Kari, Phil Dyer also has some nice lenses in cells, but these would make quite sizeable refractors (especially the f/12!) so maybe go with fozzie's Astroboot idea if you wan't something smaller and less of an outlay  

https://www.astrophoto.co.uk/surplusobjectives.php

[DRT]

You could also try Richard Day at http://skylight-telescopes.com

Richard is a very nice and helpful chap and if he doesn't have any spare optics lying around he can more than likely give you good advice on what to look out for and where to find something. His wonderful bespoke telescopes might also give you some ideas for your own project  

[DRT]

1 hour ago, Lockie said:

Hi Kari, Phil Dyer also has some nice lenses in cells, but these would make quite sizeable refractors (especially the f/12!) so maybe go with fozzie's Astroboot idea if you wan't something smaller and less of an outlay  

https://www.astrophoto.co.uk/surplusobjectives.php

Am I imagining things or did I just see a batch of brand new 150mm F/17 objective lenses for sale at $25 each plus delivery!!!!????  

[Peter Drew]

PCX = Plano-convex. Single element lens. I have 2 off.   ?

[DRT]

1 minute ago, Peter Drew said:

PCX = Plano-convex. Single element lens. I have 2 off.   ?

I noticed that when I delved farther into the site, Peter.

What would one expect from a PCX lens at F17?

[Peter Drew]

A couple of steps up from a kaliedoscope.   ?

[DRT]

2 minutes ago, Peter Drew said:

A couple of steps up from a kaliedoscope.   ?

Ah, so it would be Jupiter and His Technicolour Dreamcoat  

[DRT]

PS: apologies for hijacking the thread, Kari

As you were guys ? 

[kbrown]

2 minutes ago, DRT said:

PS: apologies for hijacking the thread, Kari

As you were guys ? 

No worries. I'm enjoying it :D

[Chris]

1 hour ago, DRT said:

Am I imagining things or did I just see a batch of brand new 150mm F/17 objective lenses for sale at $25 each plus delivery!!!!????  

Yeah I saw that too Derek but they're no good for astro I shouldn't imagine, so to the OP, don't buy the above, they are cheap for a reason and that reason is that it's likely to result in a scope the length of a bus, and with the correction of a single lens which can't be good even at f/17.

[Peter Drew]

Just tried one of the ones that I have with an eyepiece, loads of false colour and spherical aberration . Might have some application as a camera obscura objective.

[Peter Drew]

Kari.  What specification would be of interest to you for a telescope objective, I have several spare ones.

[kbrown]

2 hours ago, Peter Drew said:

Kari.  What specification would be of interest to you for a telescope objective, I have several spare ones.

Thanks Peter. Something along the lines: doublet 70-80mm F/5-6 to keep the size and weight down.

[Peter Drew]

Thanks, I'll have a look to see if anything is suitable.

[Merlin66]

Surplus Shed always have a heap of objectives (and other interesting optics ) available.

https://www.surplusshed.com/

 

[kbrown]

On 11/07/2018 at 22:18, Peter Drew said:

Thanks, I'll have a look to see if anything is suitable.

Hi Peter,

Did you ever find anything even roughly close?

[Ben the Ignorant]

Sorry that I didn't notice this thread sooner. Teleskop Austria sells a 72/900 for 35€ and a 83/900 for 39€. Both are air-spaced..

https://teleskop-austria.at/ACHR070_Luftspalt-Achromat-D=72mm-F=900mm-in-Fassung-Objektiv

https://teleskop-austria.at/ACHR080_Luftspalt-Achromat-D=83mm-F=900mm-in-Fassung-Objektiv