I want a 400/500 f/5.6 IS/OS non-zoom lens . . .

In article <Ahipj.38525$4w.20127@pd7urf2no>,
Matt Ion <soundy106 RemoveThis @gmail.com> wrote:

> Now look at your Maglite - the end of the barrel rotates to adjust the
> reflector position to focus the beam. With the big 4-D model you can
> light something a block away. This is partly due the fact that the
> incandescent bulb produces light fairly evenly out all sides, rather
> than just forward. Put an LED in its place, and you get almost no
> "spillage" light to focus.

Matt-

You haven't gone shopping for a Maglite flashlight lately, have you? I
have a 3-D Cell Maglite flashlight that came with a 3 Watt LED bulb.

It came with a "spare" incandescent bulb stored in the end cap. When I
tried it with the incandescent bulb, it was clearly not as bright as the
LED bulb when focused to a spot. I didn't notice, but it may have had a
better flood setting when intentionally de-focused.

(They also sell genuine Maglite LED replacement bulbs to retrofit your
old flashlight.)

I think the real reason the LED isn't being seriously used for
photography, is that it has to be focused to obtain the needed
brightness. Therefore, several would be needed to light a wide area.
As someone else mentioned, it would only take 3 Volts but many Amperes
to do the job!

Perhaps the development of small many-Farad low voltage capacitors will
enable the use of multiple LEDs, just as a high voltage capacitor is
used with a xenon flash tube. The 3 Volt battery would charge the
capacitor slowly, but the LED would discharge it quickly. The trick
will be development of an efficient high current switching device!

Fred
 >> Stay informed about: I want a 400/500 f/5.6 IS/OS non-zoom lens . . . 

Eric Miller wrote:

> but the battery size of CR123s would allow for a much
> smaller flash.

It really comes down to:
-how much energy is in the battery
(eg: is it better than say a AA with 2000 mA-h @ 1.5 V)?

-how fast can it deliver the power to the flash capacitor (NiMH and
NiCd are great at this; but NiCd are fragile from several POVs).

As there are probably no great packaging advantages in CR123 over AA for
a given chemistry, I doubt there is a case for change.

CR123's are 3 V batteries and come in about 700 mA-h. (highest capacity
I found, rechargeable, Li-ion)

Energy:
CR123: 3 V x 0.7 A x 3600 seconds = 7560 joules
AA: 1.5 V x 2.0 A x 3600 seconds = 10800 joules

Volume:
CR123: 32.5 x 16.5 (dia)= 1685 mm^3
AA: 43 x 8.5 (dia) = 1148 mm^3

Energy/Volume
CR123: 4.5 joules/mm^3
AA: 9.4 joules/mm^3

So, an NiMH AA seems to have higher energy storage by volume than a
Li-ion CR123.

In the end, if a CR123 in NiMH exists, I would expect its energy/volume
efficiency to be similar to AA (perhaps a little less as it would have
to be two back to back 1.5 V batteries in the same volume).

Cheers,
Alan

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 >> Stay informed about: I want a 400/500 f/5.6 IS/OS non-zoom lens . . . 

Alan Browne wrote:
> Eric Miller wrote:
>
>> but the battery size of CR123s would allow for a much smaller flash.
>
> It really comes down to:
> -how much energy is in the battery
> (eg: is it better than say a AA with 2000 mA-h @ 1.5 V)?
>
> -how fast can it deliver the power to the flash capacitor (NiMH and
> NiCd are great at this; but NiCd are fragile from several POVs).
>
> As there are probably no great packaging advantages in CR123 over AA for
> a given chemistry, I doubt there is a case for change.
>
> CR123's are 3 V batteries and come in about 700 mA-h. (highest capacity
> I found, rechargeable, Li-ion)
>
> Energy:
> CR123: 3 V x 0.7 A x 3600 seconds = 7560 joules
> AA: 1.5 V x 2.0 A x 3600 seconds = 10800 joules
>
> Volume:
> CR123: 32.5 x 16.5 (dia)= 1685 mm^3
> AA: 43 x 8.5 (dia) = 1148 mm^3
Oops:
that should have been:
CR123 = 6949 mm^3
AA: 2440 mm^3
>
> Energy/Volume
> CR123: 4.5 joules/mm^3
> AA: 9.4 joules/mm^3

Which means:
CR123: 4 j/mm^3
AA: 4.43 j/mm^3

>
> So, an NiMH AA seems to have higher energy storage by volume than a
> Li-ion CR123.
if only by about 10%

> In the end, if a CR123 in NiMH exists, I would expect its energy/volume
> efficiency to be similar to AA (perhaps a little less as it would have
> to be two back to back 1.5 V batteries in the same volume).
 >> Stay informed about: I want a 400/500 f/5.6 IS/OS non-zoom lens . . . 

nospam wrote:
> In article <47a5f8b8$0$29962$4c368faf@roadrunner.com>, Pudentame
> <no.one.RemoveThis@no.were.invalid> wrote:
>> From Digital Photography Now review of 2007 PMA show
>> (http://dpnow.com/3623.html)
>>
>>> Why did Sigma produce such a behemoth of a lens? Apparently there is
>>> demand from specialist sports photographers who need an extra bright
>>> telephoto lens for covering night time sports events under the far
>>> from ideal lighting situations.
>
> so why is it that awful shade of green? it seems like they're
> targeting the wildlife photographer, not the sports photographer.
>

My guess is so it'll stand out amongst a sea of white. ;-D


>>> Indeed, there is apparently an immediate and ready demand for the
>>> lens and it isn't even needed to be made to order. It will be
>>> available in Canon, Nikon and Sigma DSLR mounts later in the year.
>
> there's a market for the sigma mount?

Could be. They're selling a few DSLR bodies; makes sense to offer their
product to fit their own cameras.
 >> Stay informed about: I want a 400/500 f/5.6 IS/OS non-zoom lens . . . 

In article <47a640fa$0$8660$4c368faf@roadrunner.com>, Pudentame
<no.one RemoveThis @no.were.invalid> wrote:

> >>> Indeed, there is apparently an immediate and ready demand for the
> >>> lens and it isn't even needed to be made to order. It will be
> >>> available in Canon, Nikon and Sigma DSLR mounts later in the year.
> >
> > there's a market for the sigma mount?
>
> Could be. They're selling a few DSLR bodies; makes sense to offer their
> product to fit their own cameras.

obviously, they have to support their own mount. it would look bad if
they didn't.

it's just that so few sigma cameras are sold that the potential
customer base is already minescule. however, since the sigma mount is
basically a clone of the canon ef mount (exact same electrical
interface, just a different mount plate), they could probably pop the
back plate off as needed in the event someone wants it in the sigma
mount.
 >> Stay informed about: I want a 400/500 f/5.6 IS/OS non-zoom lens . . . 

Eric Miller <millereric_nospam_.RemoveThis@bellsouth.net> wrote:

>Why doesn't anyone make one of these? Canon's 400 f/5.6L is a great
>lens, and I have it, but IS would be so sweet in that lens. Sigma is now
>going to make a 500mm optically stabilized zoom with a 6.3 minimum
>aperture at 500mm - and a 500mm f/2.8, why no 500mm prime that
>individual, non-millionaire photographers can actually afford?

<snip>

>Finally, how about an IS teleconverter? They are already made for video
>cameras, why not 35mm? Surely Sigma could sell a load of these in Canon
>and Nikon mounts; something like a "APO 1.2x Tele Converter EX OS" or
>some such creature. I'd drop $500-600 on one of those tomorrow were such
>a thing available.


Have you considered a 70-200mm f/2.8 L IS and a 2X teleconverter?

That would give you 400mm f/5.6 at the long end and I assume (please
someone correct me if I am wrong) that the IS would still work ...
 >> Stay informed about: I want a 400/500 f/5.6 IS/OS non-zoom lens . . . 

On Sun, 03 Feb 2008 12:16:25 -0500, Alan Browne
<alan.browne.DeleteThis@Freelunchvideotron.ca> wrote in
<fo4st9$qq6$1@inews.gazeta.pl>:

>Chris Malcolm wrote:

> > A flash tube has comparable efficiency to an LED. May even be more
> > efficient.
>
>I don't believe so. Flash tubes do heat up (try 10 full power pops as
>fast as your unit will reload and fire) so conversion to visible light
>is not close to 100%.

Correct. Actually pretty low. (My prior post was incorrect.)
http://en.wikipedia.org/wiki/Luminous_efficacy
What flash tubes do well is very high intensity for very brief periods.
The highest efficiencies are from sodium gas discharge lamps.

>Recent (and I mean very recent) LED's are very
>efficient in energy to visible light.

Light efficiency of LED isn't as high as is often assumed --
fluorescents are often as much or even more efficient:
* Current LED methods allow for a maximum of 60-70 lumens per watt.
* Modern fluorescent bulbs produce between 60-110 lumens per watt.
The latest LED technology is claimed to go as high as 130 lumens per
watt, but isn't reflected in current readily available and affordable
products AFAIK. http://www.otherpower.com/otherpower_lighting.html

--
Best regards,
John Navas
Panasonic DMC-FZ8 (and several others)
 >> Stay informed about: I want a 400/500 f/5.6 IS/OS non-zoom lens . . . 

["Followup-To:" header set to rec.photo.digital.slr-systems.]
Mark B. <mbohntrash54.RemoveThis@comcast.net> wrote:
> "Eric Miller" <millereric_nospam_.RemoveThis@bellsouth.net> wrote in message

>> Why, based upon your market studies? And, no doubt, there is tons of
>> demand for a 200-500 f/2.8?

> Between the 35 lb weight and the cost of at least $20,000 US there's very
> little demand. Sigma did that more for bragging rights than anything.

And it does not even have an image stabilizer![1]
You'd have thought a new $20k lens with it's own batteries would
have IS.

Now, I don't think I could handhold a 35lb lens for very long
(even if very is in the single digit seconds range), IS or not,
but ... IS helps even on beanbags, monopods, tripods (unless they
are all-granite 10ton, fuzed to the earth --- and no truck nor
train passing near!) and does help a lot with stabilizing the
image in the viewfinder.

-Wolfgang
 >> Stay informed about: I want a 400/500 f/5.6 IS/OS non-zoom lens . . . 

Annika1980 <annika1980.TakeThisOut@aol.com> wrote:
> You could always buy a gyro. Then all your lenses would be stabilized.

> http://www.ken-lab.com/stabilizers.html

So you get to carry:
35 lb lens
2-4 lb camera, hand/battery grip
10+ lb tripod with head

PLUS

20.5 lb 4 Admiral KS-8[1]
2+ lb braces to fit said KS-8
2 lb quad-output inverter
44 lb 600WH in lead-acid --- about enough for a 10 hour
shoot, unless you stand down the KS-8s in between
and wait for a couple of minutes when they spin
up again. [2]

Sheesh, instead of 50lb, now you need something like 120lb, and
all that because someone stinted on the IS! Not that the gyros
and the IS would hinder one another, on the contrary, they _help_
each other ...

-Wolfgang

[1] one can stabilize 8-12 pounds. 8-12lb *3 = 24-36lb ---
just not enough for lens and camera.
Note that you get 30°/s panning ... not more. Takes 5 seconds
to just turn around ...
[2] You need overproportionally more for shorter shoots,
thanks to
http://en.wikipedia.org/wiki/Peukert's_Law
 >> Stay informed about: I want a 400/500 f/5.6 IS/OS non-zoom lens . . . 

On Sun, 03 Feb 2008 16:41:17 -0500, Alan Browne
<alan.browne.DeleteThis@Freelunchvideotron.ca> wrote in
<fo5ce8$512$1@inews.gazeta.pl>:

>Eric Miller wrote:
>
>> but the battery size of CR123s would allow for a much
>> smaller flash.
>
>It really comes down to:
> -how much energy is in the battery
> (eg: is it better than say a AA with 2000 mA-h @ 1.5 V)?

AA NiMH are now available up to 2900 mAh.
http://www.thomas-distributing.com/accupower-2900mAh-rechargeable-batteries.htm

--
Best regards,
John Navas
Panasonic DMC-FZ8 (and several others)
 >> Stay informed about: I want a 400/500 f/5.6 IS/OS non-zoom lens . . . 

nospam wrote:
> In article <47a640fa$0$8660$4c368faf@roadrunner.com>, Pudentame
> <no.one DeleteThis @no.were.invalid> wrote:
>
>>>>> Indeed, there is apparently an immediate and ready demand for the
>>>>> lens and it isn't even needed to be made to order. It will be
>>>>> available in Canon, Nikon and Sigma DSLR mounts later in the year.
>>> there's a market for the sigma mount?
>> Could be. They're selling a few DSLR bodies; makes sense to offer their
>> product to fit their own cameras.
>
> obviously, they have to support their own mount. it would look bad if
> they didn't.
>
> it's just that so few sigma cameras are sold that the potential
> customer base is already minescule. however, since the sigma mount is
> basically a clone of the canon ef mount (exact same electrical
> interface, just a different mount plate), they could probably pop the
> back plate off as needed in the event someone wants it in the sigma
> mount.

It's a Pentax K-mount bayonet rotated 120 degrees.
 >> Stay informed about: I want a 400/500 f/5.6 IS/OS non-zoom lens . . . 

John Navas wrote:
> On Sun, 03 Feb 2008 16:41:17 -0500, Alan Browne
> <alan.browne.DeleteThis@Freelunchvideotron.ca> wrote in
> <fo5ce8$512$1@inews.gazeta.pl>:
>
>> Eric Miller wrote:
>>
>>> but the battery size of CR123s would allow for a much
>>> smaller flash.
>> It really comes down to:
>> -how much energy is in the battery
>> (eg: is it better than say a AA with 2000 mA-h @ 1.5 V)?
>
> AA NiMH are now available up to 2900 mAh.
> http://www.thomas-distributing.com/accupower-2900mAh-rechargeable-batteries.htm


More the reason. I just used 2000 mAh as a reference. See my amended
v. as I screwed up the volume calc on the first v.

I can't find any NiMH in CR123 format, probably 'cause as 3V they would
need to be 2 NiMH in series which makes for poor recharging.

Cheers,
Alan


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 >> Stay informed about: I want a 400/500 f/5.6 IS/OS non-zoom lens . . . 

Alan Browne wrote:
> Paul Coen wrote:
>
>> Oddly enough, when you go to the sonystyle.com camera page, the link
>> for the lenses is a picture of the 500mm Reflex. I would have figured
>> they'd use one of the Carl Zeiss lenses.
>
> I don't think Carl Zeiss are much into really long FL's, and esp. not
> CAT's.
>

They're not - I'm commenting on the odd choice of an image of the 500mm
reflex as the image for the "lenses" category in general. I would have
expected them to use an image of one of the snazzy new lenses.
 >> Stay informed about: I want a 400/500 f/5.6 IS/OS non-zoom lens . . .