May also be good for astrophotographers, but I'd need to see 100% images to be sure. Price is right and considerably less than Borg, William Optics (which I suggested to them 20 years ago) and Omegon offerings of similar type.

https://petapixel.com/2023/09/22/ttartisans-new-500mm-f-6-3-full-frame-mirrorless-lens-is-just-329/

On 2023-09-23 19:14, RichA wrote:
> May also be good for astrophotographers, but I'd need to see 100% images to be sure. Price is right and considerably less than Borg, William Optics (which I suggested to them 20 years ago) and Omegon offerings of similar type.
>
> https://petapixel.com/2023/09/22/ttartisans-new-500mm-f-6-3-full-frame-mirrorless-lens-is-just-329/

Not sure how one gets to "Large Aperture" claims with an f/6.3 lens...

--
“Markets can remain irrational longer than your can remain solvent.”
- John Maynard Keynes.

On Tuesday, 26 September 2023 at 05:12:03 UTC+1, RichA wrote:
> On Saturday, 23 September 2023 at 21:05:40 UTC-4, Alan Browne wrote:
> > On 2023-09-23 19:14, RichA wrote:
> > > May also be good for astrophotographers, but I'd need to see 100% images to be sure. Price is right and considerably less than Borg, William Optics (which I suggested to them 20 years ago) and Omegon offerings of similar type.
> > >
> > > https://petapixel.com/2023/09/22/ttartisans-new-500mm-f-6-3-full-frame-mirrorless-lens-is-just-329/
> > Not sure how one gets to "Large Aperture" claims with an f/6.3 lens...
> >
> > --
> > “Markets can remain irrational longer than your can remain solvent.”
> > - John Maynard Keynes.
> In astronomy, anything faster than f.7 is fast, and f/2.8 is virtually non-existent. For whatever reason, astronomers don't use high-end (not many) telephoto lenses, preferring to loose a couple stops and use telescopes. i presume cross sensor correction in camera lenses isn't good enough, but I've yet to see any real comparisons between top end telescopes used as lenses (Takahashi FSQ-106 which is a fast scope with 4 inch aperture) or top-end modern telephotos.

I'm guessing there's very little point in comparing the two types, as telephotos are mostly for those that want something portable
and capture close moving objects. Here's also a differnce between astronomical telescopes and terestrial ones in that the terestrial
reverse the images so they are the right way up and they normaly don't need a close focus point.

On Monday, 2 October 2023 at 04:14:19 UTC+1, RichA wrote:
> On Tuesday, 26 September 2023 at 08:21:10 UTC-4, Whisky-dave wrote:
> > On Tuesday, 26 September 2023 at 05:12:03 UTC+1, RichA wrote:
> > > On Saturday, 23 September 2023 at 21:05:40 UTC-4, Alan Browne wrote:
> > > > On 2023-09-23 19:14, RichA wrote:
> > > > > May also be good for astrophotographers, but I'd need to see 100% images to be sure. Price is right and considerably less than Borg, William Optics (which I suggested to them 20 years ago) and Omegon offerings of similar type.
> > > > >
> > > > > https://petapixel.com/2023/09/22/ttartisans-new-500mm-f-6-3-full-frame-mirrorless-lens-is-just-329/
> > > > Not sure how one gets to "Large Aperture" claims with an f/6.3 lens....
> > > >
> > > > --
> > > > “Markets can remain irrational longer than your can remain solvent.”
> > > > - John Maynard Keynes.
> > > In astronomy, anything faster than f.7 is fast, and f/2.8 is virtually non-existent. For whatever reason, astronomers don't use high-end (not many) telephoto lenses, preferring to loose a couple stops and use telescopes.. i presume cross sensor correction in camera lenses isn't good enough, but I've yet to see any real comparisons between top end telescopes used as lenses (Takahashi FSQ-106 which is a fast scope with 4 inch aperture) or top-end modern telephotos.
> > I'm guessing there's very little point in comparing the two types, as telephotos are mostly for those that want something portable
> > and capture close moving objects. Here's also a differnce between astronomical telescopes and terestrial ones in that the terestrial
> > reverse the images so they are the right way up and they normaly don't need a close focus point.
> Astro scopes reverse the image and render it upside down, but it's inconsequential because you can just flip or re-orientate the image any way you like.

Which will add weight and more distotion for no gain in image quality. Nowerdays it''s done digital but in an optical atromomy
telescopes these extra optics were left out.

On 3/10/2023 1:32 am, Whisky-dave wrote:
> On Monday, 2 October 2023 at 04:14:19 UTC+1, RichA wrote:
>> On Tuesday, 26 September 2023 at 08:21:10 UTC-4, Whisky-dave wrote:
>>> On Tuesday, 26 September 2023 at 05:12:03 UTC+1, RichA wrote:
>>>> On Saturday, 23 September 2023 at 21:05:40 UTC-4, Alan Browne wrote:
>>>>> On 2023-09-23 19:14, RichA wrote:
>>>>>> May also be good for astrophotographers, but I'd need to see 100% images to be sure. Price is right and considerably less than Borg, William Optics (which I suggested to them 20 years ago) and Omegon offerings of similar type.
>>>>>>
>>>>>> https://petapixel.com/2023/09/22/ttartisans-new-500mm-f-6-3-full-frame-mirrorless-lens-is-just-329/
>>>>> Not sure how one gets to "Large Aperture" claims with an f/6.3 lens...
>>>>>
>>>>> --
>>>>> “Markets can remain irrational longer than your can remain solvent.”
>>>>> - John Maynard Keynes.
>>>> In astronomy, anything faster than f.7 is fast, and f/2.8 is virtually non-existent. For whatever reason, astronomers don't use high-end (not many) telephoto lenses, preferring to loose a couple stops and use telescopes. i presume cross sensor correction in camera lenses isn't good enough, but I've yet to see any real comparisons between top end telescopes used as lenses (Takahashi FSQ-106 which is a fast scope with 4 inch aperture) or top-end modern telephotos.
>>> I'm guessing there's very little point in comparing the two types, as telephotos are mostly for those that want something portable
>>> and capture close moving objects. Here's also a differnce between astronomical telescopes and terestrial ones in that the terestrial
>>> reverse the images so they are the right way up and they normaly don't need a close focus point.
>> Astro scopes reverse the image and render it upside down, but it's inconsequential because you can just flip or re-orientate the image any way you like.
>
> Which will add weight and more distotion for no gain in image quality. Nowerdays it''s done digital but in an optical atromomy
> telescopes these extra optics were left out.

But who is to say what is the 'right way up' ? It's all relative, and
wrong for one of Earth's hemispheres' point of view anyway.

geoff

In article <68b47b29-accb-436f-bb5d-dc3e8fe46c5en@googlegroups.com>, Whisky-dave <whisky.dave@gmail.com> wrote:

> On Monday, 2 October 2023 at 04:14:19 UTC+1, RichA wrote:
> > On Tuesday, 26 September 2023 at 08:21:10 UTC-4, Whisky-dave wrote:
> > > On Tuesday, 26 September 2023 at 05:12:03 UTC+1, RichA wrote:
> > > > On Saturday, 23 September 2023 at 21:05:40 UTC-4, Alan Browne wrote:
> > > > > On 2023-09-23 19:14, RichA wrote:
> > > > > > May also be good for astrophotographers, but I'd need to see 100% images to be sure. Price is right and considerably less than Borg, William Optics (which I suggested to them 20 years ago) and Omegon offerings of similar type.
> > > > > >
> > > > > > https://petapixel.com/2023/09/22/ttartisans-new-500mm-f-6-3-full-frame-mirrorless-lens-is-just-329/
> > > > > Not sure how one gets to "Large Aperture" claims with an f/6.3 lens...
> > > > >
> > > > > --
> > > > > ³Markets can remain irrational longer than your can remain solvent.²
> > > > > - John Maynard Keynes.
> > > > In astronomy, anything faster than f.7 is fast, and f/2.8 is virtually non-existent. For whatever reason, astronomers don't use high-end (not many) telephoto lenses, preferring to loose a couple stops and use telescopes. i presume cross sensor correction in camera lenses isn't good enough, but I've yet to see any real comparisons between top end telescopes used as lenses (Takahashi FSQ-106 which is a fast scope with 4 inch aperture) or top-end modern telephotos.
> > > I'm guessing there's very little point in comparing the two types, as telephotos are mostly for those that want something portable
> > > and capture close moving objects. Here's also a differnce between astronomical telescopes and terestrial ones in that the terestrial
> > > reverse the images so they are the right way up and they normaly don't need a close focus point.
> > Astro scopes reverse the image and render it upside down, but it's inconsequential because you can just flip or re-orientate the image any way you like.
>
> Which will add weight and more distotion for no gain in image quality. Nowerdays it''s done digital but in an optical atromomy
> telescopes these extra optics were left out.

Any astrophotography with this lens (except for the moon) would require an equatorial tracking mount and a several minute exposure.
The astro images from the article are definitely not "snapshots"

--
m-m
www.mhmyers.com

On Tuesday, 3 October 2023 at 23:11:06 UTC+1, geoff wrote:
> On 3/10/2023 1:32 am, Whisky-dave wrote:
> > On Monday, 2 October 2023 at 04:14:19 UTC+1, RichA wrote:
> >> On Tuesday, 26 September 2023 at 08:21:10 UTC-4, Whisky-dave wrote:
> >>> On Tuesday, 26 September 2023 at 05:12:03 UTC+1, RichA wrote:
> >>>> On Saturday, 23 September 2023 at 21:05:40 UTC-4, Alan Browne wrote:
> >>>>> On 2023-09-23 19:14, RichA wrote:
> >>>>>> May also be good for astrophotographers, but I'd need to see 100% images to be sure. Price is right and considerably less than Borg, William Optics (which I suggested to them 20 years ago) and Omegon offerings of similar type.
> >>>>>>
> >>>>>> https://petapixel.com/2023/09/22/ttartisans-new-500mm-f-6-3-full-frame-mirrorless-lens-is-just-329/
> >>>>> Not sure how one gets to "Large Aperture" claims with an f/6.3 lens....
> >>>>>
> >>>>> --
> >>>>> “Markets can remain irrational longer than your can remain solvent.”
> >>>>> - John Maynard Keynes.
> >>>> In astronomy, anything faster than f.7 is fast, and f/2.8 is virtually non-existent. For whatever reason, astronomers don't use high-end (not many) telephoto lenses, preferring to loose a couple stops and use telescopes. i presume cross sensor correction in camera lenses isn't good enough, but I've yet to see any real comparisons between top end telescopes used as lenses (Takahashi FSQ-106 which is a fast scope with 4 inch aperture) or top-end modern telephotos.
> >>> I'm guessing there's very little point in comparing the two types, as telephotos are mostly for those that want something portable
> >>> and capture close moving objects. Here's also a differnce between astronomical telescopes and terestrial ones in that the terestrial
> >>> reverse the images so they are the right way up and they normaly don't need a close focus point.
> >> Astro scopes reverse the image and render it upside down, but it's inconsequential because you can just flip or re-orientate the image any way you like.
> >
> > Which will add weight and more distotion for no gain in image quality. Nowerdays it''s done digital but in an optical atromomy
> > telescopes these extra optics were left out.
> But who is to say what is the 'right way up' ?

The British decide what's right same as we did with driving on the roads and spelling of English words, we have GMT too. :-)

> It's all relative,

So is incest.

>and
> wrong for one of Earth's hemispheres' point of view anyway.

I'm betting the bottom of the earth can't even see it ;-)

>
> geoff