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Main
Date: 09 Jun 2007 09:54:59
From: Rich
Subject: AP should be making ultra-high quality telephoto lenses
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If they made super high end 300mm-800mm telephotos (yes, I know the
scopes can be used) incorporating autofocus and IS/VR, they could
clean-up with nature and maybe sports photogs. The prices that Canon
and Nikon (or Leica) charge for some of those things might even make
it feasible for an aftermarket product to fluorish. Right now, the
aftermarket (Sigma, Tokina, Tamron) are there as a cheaper, generally
lower quality alternative to OEM. No one has tackled a high end
aftermarket yet. Reason I mentioned this is that I found a little
Williams Optics 66mm ED easily beat out a couple telephotos I had (and
the apo is used wide open) but of course it has the traditional
telescope focuser so it's not acceptable to telephoto users in it's
current state. There have been users of apos who have done
terrestrial photography to good effect, but only on stationary
subjects. Does anyone remember the Questar 700? One of the few good
mirror lens telephotos ever made. No reason that a telescope maker
couldn't do a refractive telephoto.
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Date: 13 Jun 2007 01:31:34
From: thad@thadlabs.com
Subject: Re: AP should be making ultra-high quality telephoto lenses
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On Jun 12, 8:12 pm, Davoud <s...@sky.net > wrote:
> t...@thadlabs.com wrote:
> > Details here:
>
> > <http://www.nikonusa.com/template.php?cat=1&grp=5&productNr=2139>
>
> > That lens is magnificent, one of my best. FWIW, it has 21 elements.
>
> Have you used that lovely hunk of glass -- er, glasses -- for
> astrophotography? On an Nikon body /or/ an SBIG camera, e.g.? If so, do
> you have any results to show?
Though I have an SBIG STV, I use it for astrometry (and guiding the
few
times I've dabbled in astrophotography).
One of several examples using one of my scopes with a Nikon is here
(but you're probably going to be surprised :-):
<http://thadlabs.com/PIX/LX200/ >
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Date: 12 Jun 2007 18:15:35
From: Rich
Subject: Re: AP should be making ultra-high quality telephoto lenses
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On Jun 12, 3:11 pm, Chris L Peterson <c...@alumni.caltech.edu > wrote:
> On Tue, 12 Jun 2007 12:01:17 -0700, Rich <rander3...@gmail.com> wrote:
> >Which has been criticized (at least for telescopes) as producing
> >elements that are not very good.
> >But at "prime focus" (no real additional magnification) that would
> >not likely harm the qualilty of a camera lens's image.
>
> What has been criticized for telescope optics?
>
The molding of lens blanks (and slumping) rather than grinding from
unpressed blanks.
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Date: 13 Jun 2007 03:56:09
From: Chris L Peterson
Subject: Re: AP should be making ultra-high quality telephoto lenses
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On Tue, 12 Jun 2007 18:15:35 -0700, Rich <rander3127@gmail.com > wrote:
>> What has been criticized for telescope optics?
>>
>
>The molding of lens blanks (and slumping) rather than grinding from
>unpressed blanks.
I don't buy it.
_________________________________________________
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com
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Date: 12 Jun 2007 13:01:49
From: thad@thadlabs.com
Subject: Re: AP should be making ultra-high quality telephoto lenses
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On Jun 12, 12:07 pm, Rich <rander3...@gmail.com > wrote:
> On Jun 10, 6:56 pm, Havril...@aol.com wrote:
>
>
>
> > On Jun 9, 1:51?pm, Davoud <s...@sky.net> wrote:
>
> > > Rich wrote:
> > > > If they made super high end 300mm-800mm telephotos...
>
> > > A telephoto lens one had to wait more than five years to buy would not
> > > do well in the market. Furthermore, an AP telephoto would not have a
> > > performance advantage or a price advantage over the superb Canon and
> > > Nikon lenses in this range.
>
> > > Davoud
>
> > > --
> > > usenet *at* davidillig dawt com
>
> > For what its worth. I made resolution measurements using the parallel
> > lines target and found no difference between the the lenses
> > mentioned. One thing of interest is that a camera lens can reduce the
> > fstop which typically improves performance edge to edge. One
> > seemingly adantage is that telescope lenses are designed fot flat
> > field at infinity to flat field at focus. This simplifies
> > calculations. Remember telefoo lenses have to be perfectly color
> > compensated
>
> Very few are. Some are very good (Nikon's 70-200mm zoom)
Details here:
<http://www.nikonusa.com/template.php?cat=1&grp=5&productNr=2139 >
That lens is magnificent, one of my best. FWIW, it has 21 elements.
> and there is
> no arguing a 400mm f2.8 lens without noticeable colour in-focus isn't
> impressive. But with clean 800 ISO and up images from top camera
> bodies today, perhaps that kind of speed isn't needed anymore for
> normal photographic images?
I had a photo shoot last week and everyone was very appreciative
I used an f/1.4 lens so I didn't have to use flash (indoors); the
people
using flashes were very disruptive to the ceremony (a graduation).
> The high speed of camera lenses also made
> possible very short camera lenses which is important to some.
My 50mm prime is arguably one of Nikon's best (and smallest)
lenses and quite affordable.
> [...]. I
> would love to see a big lens emblazoned "AP" at an NFL game next to
> the Canons and Nikons!
Just curious: why? You could slap an AP sticker on the side of any
lens if that's what turns you on. :-)
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Date: 14 Jun 2007 19:55:57
From: Thomas Womack
Subject: Re: AP should be making ultra-high quality telephoto lenses
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In article <1181678509.136046.86890@x35g2000prf.googlegroups.com >,
thad@thadlabs.com <thad@thadlabs.com > wrote:
>I had a photo shoot last week and everyone was very appreciative
>I used an f/1.4 lens so I didn't have to use flash (indoors); the
>people
>using flashes were very disruptive to the ceremony (a graduation).
I am a little disappointed with the results of using an f/1.4 lens
wide-open on the sky:
http://www.chiark.greenend.org.uk/~twomack/orion-starry.png
has a beautiful collection of stars, but is very comatic. I suppose
actually having coma around bright stars shows up the colours well,
and faint stars simply disappear to the image looks slightly
vignetted.
Tom
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Date: 13 Jun 2007 03:12:47
From: Davoud
Subject: Re: AP should be making ultra-high quality telephoto lenses
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thad@thadlabs.com wrote:
> Details here:
>
> <http://www.nikonusa.com/template.php?cat=1&grp=5&productNr=2139>
>
> That lens is magnificent, one of my best. FWIW, it has 21 elements.
Have you used that lovely hunk of glass -- er, glasses -- for
astrophotography? On an Nikon body /or/ an SBIG camera, e.g.? If so, do
you have any results to show?
Thanks,
Davoud
--
usenet *at* davidillig dawt com
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Date: 12 Jun 2007 12:07:13
From: Rich
Subject: Re: AP should be making ultra-high quality telephoto lenses
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On Jun 10, 6:56 pm, Havril...@aol.com wrote:
> On Jun 9, 1:51?pm, Davoud <s...@sky.net> wrote:
>
> > Rich wrote:
> > > If they made super high end 300mm-800mm telephotos...
>
> > A telephoto lens one had to wait more than five years to buy would not
> > do well in the market. Furthermore, an AP telephoto would not have a
> > performance advantage or a price advantage over the superb Canon and
> > Nikon lenses in this range.
>
> > Davoud
>
> > --
> > usenet *at* davidillig dawt com
>
> For what its worth. I made resolution measurements using the parallel
> lines target and found no difference between the the lenses
> mentioned. One thing of interest is that a camera lens can reduce the
> fstop which typically improves performance edge to edge. One
> seemingly adantage is that telescope lenses are designed fot flat
> field at infinity to flat field at focus. This simplifies
> calculations. Remember telefoo lenses have to be perfectly color
> compensated
Very few are. Some are very good (Nikon's 70-200mm zoom) and there is
no arguing a 400mm f2.8 lens without noticeable colour in-focus isn't
impressive. But with clean 800 ISO and up images from top camera
bodies today, perhaps that kind of speed isn't needed anymore for
normal photographic images? The high speed of camera lenses also made
possible very short camera lenses which is important to some. Though
most large telephotos are tripod or at least monopod mounted.
There are a few niche market lens makers (Voigtlander, for e.g.) who
turn out very high performance lenses for a select group of people. I
would love to see a big lens emblazoned "AP" at an NFL game next to
the Canons and Nikons!
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Date: 12 Jun 2007 12:01:17
From: Rich
Subject: Re: AP should be making ultra-high quality telephoto lenses
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On Jun 10, 6:51 pm, Chris L Peterson <c...@alumni.caltech.edu > wrote:
> On Sun, 10 Jun 2007 09:51:49 -0700, Rich <rander3...@gmail.com> wrote:
> >MOST aspherics used in commericial lenses are molded plastic or glass
> >now.
> >Hand ground aspherics in camera lenses? Are any used at all now?
>
> Hand ground, I doubt it. But figured by computerized grinding machines
> is common. Molded optics are not common in high end lenses (although the
> blanks are often molded, I think).
Which has been criticized (at least for telescopes) as producing
elements that are not very good.
But at "prime focus" (no real additional magnification) that would
not likely harm the qualilty of a camera lens's image.
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Date: 12 Jun 2007 19:11:59
From: Chris L Peterson
Subject: Re: AP should be making ultra-high quality telephoto lenses
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On Tue, 12 Jun 2007 12:01:17 -0700, Rich <rander3127@gmail.com > wrote:
>Which has been criticized (at least for telescopes) as producing
>elements that are not very good.
>But at "prime focus" (no real additional magnification) that would
>not likely harm the qualilty of a camera lens's image.
What has been criticized for telescope optics?
_________________________________________________
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com
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Date: 10 Jun 2007 15:56:32
From:
Subject: Re: AP should be making ultra-high quality telephoto lenses
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On Jun 9, 1:51?pm, Davoud <s...@sky.net > wrote:
> Rich wrote:
> > If they made super high end 300mm-800mm telephotos...
>
> A telephoto lens one had to wait more than five years to buy would not
> do well in the market. Furthermore, an AP telephoto would not have a
> performance advantage or a price advantage over the superb Canon and
> Nikon lenses in this range.
>
> Davoud
>
> --
> usenet *at* davidillig dawt com
For what its worth. I made resolution measurements using the parallel
lines target and found no difference between the the lenses
mentioned. One thing of interest is that a camera lens can reduce the
fstop which typically improves performance edge to edge. One
seemingly adantage is that telescope lenses are designed fot flat
field at infinity to flat field at focus. This simplifies
calculations. Remember telefoo lenses have to be perfectly color
compensated
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Date: 10 Jun 2007 15:46:29
From:
Subject: Re: AP should be making ultra-high quality telephoto lenses
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On Jun 10, 11:51 am, Hysterical left wingers must die wrote:
> On Jun 10, 11:25 am, rpas...@eas.slu.edu wrote:
>
> > On Jun 10, 12:24 am, <Hysterical left wingers must die> wrote:
>
> > > All those spherical, easy to manufacture elements you mean.
> > > Funny how they're using molded aspherics now, isn't it?
>
> > Maybe the plastic used in your Tasco and Woxa are molded plastic, but
> > just about all quality lens and mirrors are still ground to get the
> > precision needed.
>
> MOST aspherics used in commericial lenses are molded plastic or glass
> now.
> Hand ground aspherics in camera lenses? Are any used at all now?
Nobody said anything about hand ground aspherics, they are all machine
ground. The only molding that is done is to get an approximate shape
that saves on the amount of grinding that has to be done and wasted
glass.
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Date: 10 Jun 2007 09:51:49
From: Rich
Subject: Re: AP should be making ultra-high quality telephoto lenses
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On Jun 10, 11:25 am, rpas...@eas.slu.edu wrote:
> On Jun 10, 12:24 am, <Hysterical left wingers ust die> wrote:
>
> > All those spherical, easy to manufacture elements you mean.
> > Funny how they're using molded aspherics now, isn't it?
>
> Maybe the plastic used in your Tasco and Woxa are molded plastic, but
> just about all quality lens and mirrors are still ground to get the
> precision needed.
MOST aspherics used in commericial lenses are molded plastic or glass
now.
Hand ground aspherics in camera lenses? Are any used at all now?
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Date: 10 Jun 2007 22:51:09
From: Chris L Peterson
Subject: Re: AP should be making ultra-high quality telephoto lenses
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On Sun, 10 Jun 2007 09:51:49 -0700, Rich <rander3127@gmail.com > wrote:
>MOST aspherics used in commericial lenses are molded plastic or glass
>now.
>Hand ground aspherics in camera lenses? Are any used at all now?
Hand ground, I doubt it. But figured by computerized grinding machines
is common. Molded optics are not common in high end lenses (although the
blanks are often molded, I think).
_________________________________________________
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com
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Date: 10 Jun 2007 09:50:29
From: Rich
Subject: Re: AP should be making ultra-high quality telephoto lenses
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On Jun 10, 6:42 am, "t...@thadlabs.com" <t...@thadlabs.com > wrote:
> On Jun 9, 10:24 pm, Rich <rander3...@gmail.com> wrote:
>
> > [...]
> > All those spherical, easy to manufacture elements you mean.
> > Funny how they're using molded aspherics now, isn't it?
>
> Not exactly, though a lot of the process is automated. Here's
> a virtual tour of Canon's processes making a 500mm zoom
> all the way from raw materials to the finished product:
>
> <http://www.canon.com/camera-museum/tech/l_plant/index.html>
Yes, i've seen it. Fascinating.
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Date: 10 Jun 2007 08:25:58
From:
Subject: Re: AP should be making ultra-high quality telephoto lenses
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On Jun 10, 12:24 am, <Hysterical left wingers ust die > wrote:
> All those spherical, easy to manufacture elements you mean.
> Funny how they're using molded aspherics now, isn't it?
Maybe the plastic used in your Tasco and Woxa are molded plastic, but
just about all quality lens and mirrors are still ground to get the
precision needed.
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Date: 10 Jun 2007 03:42:46
From: thad@thadlabs.com
Subject: Re: AP should be making ultra-high quality telephoto lenses
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On Jun 9, 10:24 pm, Rich <rander3...@gmail.com > wrote:
> [...]
> All those spherical, easy to manufacture elements you mean.
> Funny how they're using molded aspherics now, isn't it?
Not exactly, though a lot of the process is automated. Here's
a virtual tour of Canon's processes making a 500mm zoom
all the way from raw materials to the finished product:
<http://www.canon.com/camera-museum/tech/l_plant/index.html >
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Date: 10 Jun 2007 08:30:52
From: lal_truckee
Subject: Re: AP should be making ultra-high quality telephoto lenses
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thad@thadlabs.com wrote:
>
>
> <http://www.canon.com/camera-museum/tech/l_plant/index.html>
17 elements - it's a wonder they get any light transmission at all.
Very interesting site presentation - thanks for pointing us to it.
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Date: 09 Jun 2007 22:24:43
From: Rich
Subject: Re: AP should be making ultra-high quality telephoto lenses
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On Jun 9, 7:19 pm, Chris L Peterson <c...@alumni.caltech.edu > wrote:
> On Sat, 09 Jun 2007 16:09:48 -0700, Rich <rander3...@gmail.com> wrote:
> >Take a leaf from the apo designer's handbook. Maybe 14 spherical
> >surfaces aren't needed?
>
> Well, they are for the sort of camera lenses most people want to use:
> compact, with the focal plane very close to the rearmost element, and
> with a field that is very flat and also a sizable fraction of the size
> of the aperture. Yes, you can use an astronomical apo for a telephoto,
> but they tend to be slow and unwieldy.
>
> There's a reason camera lenses don't have just three elements. Or do you
> think their designers are stupid, or that they throw all those
> additional elements in their just to justify the price?
>
>
All those spherical, easy to manufacture elements you mean.
Funny how they're using molded aspherics now, isn't it?
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Date: 09 Jun 2007 16:09:48
From: Rich
Subject: Re: AP should be making ultra-high quality telephoto lenses
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On Jun 9, 2:13 pm, Chris L Peterson <c...@alumni.caltech.edu > wrote:
> On Sat, 09 Jun 2007 09:54:59 -0700, Rich <rander3...@gmail.com> wrote:
> >If they made super high end 300mm-800mm telephotos (yes, I know the
> >scopes can be used) incorporating autofocus and IS/VR, they could
> >clean-up with nature and maybe sports photogs. The prices that Canon
> >and Nikon (or Leica) charge for some of those things might even make
> >it feasible for an aftermarket product to fluorish. Right now, the
> >aftermarket (Sigma, Tokina, Tamron) are there as a cheaper, generally
> >lower quality alternative to OEM. No one has tackled a high end
> >aftermarket yet. Reason I mentioned this is that I found a little
> >Williams Optics 66mm ED easily beat out a couple telephotos I had (and
> >the apo is used wide open) but of course it has the traditional
> >telescope focuser so it's not acceptable to telephoto users in it's
> >current state. There have been users of apos who have done
> >terrestrial photography to good effect, but only on stationary
> >subjects. Does anyone remember the Questar 700? One of the few good
> >mirror lens telephotos ever made. No reason that a telescope maker
> >couldn't do a refractive telephoto.
>
> AP can barely make astronomical scopes as it is. If they got in the
> camera lens business I guess the wait for a telescope would go up to a
> few decades.
>
> If AP made a typical high end lens like those from Canon or Nikon, I
> guess you'd be looking at a $100K product. Those camera lenses are at
> least an order of magnitude more complex than any apo, with many
> surfaces and hundreds of mechanical components.
Take a leaf from the apo designer's handbook. Maybe 14 spherical
surfaces aren't needed?
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Date: 09 Jun 2007 23:19:00
From: Chris L Peterson
Subject: Re: AP should be making ultra-high quality telephoto lenses
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On Sat, 09 Jun 2007 16:09:48 -0700, Rich <rander3127@gmail.com > wrote:
>Take a leaf from the apo designer's handbook. Maybe 14 spherical
>surfaces aren't needed?
Well, they are for the sort of camera lenses most people want to use:
compact, with the focal plane very close to the rearmost element, and
with a field that is very flat and also a sizable fraction of the size
of the aperture. Yes, you can use an astronomical apo for a telephoto,
but they tend to be slow and unwieldy.
There's a reason camera lenses don't have just three elements. Or do you
think their designers are stupid, or that they throw all those
additional elements in their just to justify the price?
_________________________________________________
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com
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Date: 09 Jun 2007 17:35:19
From: Editor
Subject: Re: AP should be making ultra-high quality telephoto lenses
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a nudder dumb idea from his garage -
Rich wrote:
> If they made super high end 300mm-800mm telephotos (yes, I know the
> scopes can be used) incorporating autofocus and IS/VR, they could
> clean-up with nature and maybe sports photogs. The prices that Canon
> and Nikon (or Leica) charge for some of those things might even make
> it feasible for an aftermarket product to fluorish. Right now, the
> aftermarket (Sigma, Tokina, Tamron) are there as a cheaper, generally
> lower quality alternative to OEM. No one has tackled a high end
> aftermarket yet. Reason I mentioned this is that I found a little
> Williams Optics 66mm ED easily beat out a couple telephotos I had (and
> the apo is used wide open) but of course it has the traditional
> telescope focuser so it's not acceptable to telephoto users in it's
> current state. There have been users of apos who have done
> terrestrial photography to good effect, but only on stationary
> subjects. Does anyone remember the Questar 700? One of the few good
> mirror lens telephotos ever made. No reason that a telescope maker
> couldn't do a refractive telephoto.
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Date: 09 Jun 2007 18:13:22
From: Chris L Peterson
Subject: Re: AP should be making ultra-high quality telephoto lenses
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On Sat, 09 Jun 2007 09:54:59 -0700, Rich <rander3127@gmail.com > wrote:
>If they made super high end 300mm-800mm telephotos (yes, I know the
>scopes can be used) incorporating autofocus and IS/VR, they could
>clean-up with nature and maybe sports photogs. The prices that Canon
>and Nikon (or Leica) charge for some of those things might even make
>it feasible for an aftermarket product to fluorish. Right now, the
>aftermarket (Sigma, Tokina, Tamron) are there as a cheaper, generally
>lower quality alternative to OEM. No one has tackled a high end
>aftermarket yet. Reason I mentioned this is that I found a little
>Williams Optics 66mm ED easily beat out a couple telephotos I had (and
>the apo is used wide open) but of course it has the traditional
>telescope focuser so it's not acceptable to telephoto users in it's
>current state. There have been users of apos who have done
>terrestrial photography to good effect, but only on stationary
>subjects. Does anyone remember the Questar 700? One of the few good
>mirror lens telephotos ever made. No reason that a telescope maker
>couldn't do a refractive telephoto.
AP can barely make astronomical scopes as it is. If they got in the
camera lens business I guess the wait for a telescope would go up to a
few decades.
If AP made a typical high end lens like those from Canon or Nikon, I
guess you'd be looking at a $100K product. Those camera lenses are at
least an order of magnitude more complex than any apo, with many
surfaces and hundreds of mechanical components. The reason you can get
them for as little as you can is because of the economies of scale
enjoyed by Canon and Nikon.
How about we just let a maker of astronomical optics stick with what
they do best... astronomical optics.
_________________________________________________
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com
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Date: 09 Jun 2007 17:51:50
From: Davoud
Subject: Re: AP should be making ultra-high quality telephoto lenses
|
Rich wrote:
> If they made super high end 300mm-800mm telephotos...
A telephoto lens one had to wait more than five years to buy would not
do well in the market. Furthermore, an AP telephoto would not have a
performance advantage or a price advantage over the superb Canon and
Nikon lenses in this range.
Davoud
--
usenet *at* davidillig dawt com
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Date: 09 Jun 2007 22:40:08
From: Kevin M. Vernon
Subject: Re: AP should be making ultra-high quality telephoto lenses
|
Davoud <star@sky.net > wrote:
>Rich wrote:
>
>> If they made super high end 300mm-800mm telephotos...
>
>A telephoto lens one had to wait more than five years to buy would not
>do well in the market. Furthermore, an AP telephoto would not have a
>performance advantage or a price advantage over the superb Canon and
>Nikon lenses in this range.
>
>Davoud
Maybe Takahashi should try it.
Oh wait - they already do. The camera lenses they make say "Canon" on
them.
Or rather, it's more the other way around - I understand that Canon
makes Tak's glass for them.
-Kevin in Indy
To reply, remove (+spamproof+) from address........
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