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

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?

On a different subject, why aren't there any flash units that use CR123
batteries. The voltage is higher, the batteries are smaller and lighter
than AAs and rechargeables are available. Couldn't someone make a
smaller hot shoe flash unit that would be suitable for smaller cameras
with those batteries. My Canon 550ex is bigger than the Powershot G9.
It's even a monster on my G2. I end up holding the flash and not the
camera when it is attached. Even if such a unit took longer to charge or
didn't have as many flashes, the trade-off in size would seem attractive
for smaller cameras with hot shoes.

I have an LED flashlight that takes two CR123s and is considerably
brighter than my huge (by comparison) 4 D-Cell Maglite. The LCD bulbs
last forever (near enough) and use much less power to put out the same
amount of light, why no LED flash units? Maybe there is a technical
reason to prevent it, but, if not, why not? Surely color temperature is
now a non-issue with digital photograpy which could automatically adjust
the color balance to the flash when one is being used.

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.

End rant.

Eric Miller
www.dyesscreek.com

They offer a 500 f/4.5 at $5400 MSRP ($4200 street price).

Not something you would go out and purchase on a whim, but not out of
reach if you save up for it.


I guess that illustrates my curiosity as well as exposing my hyped final
quoted question. There is a wide range in price and quality between the
available 500 f/6.3 zooms and the 500 f/4.5 prime. At $4,200, any lens
is out of my price range and it has little to do with saving up or not
saving up; I simply cannot justify spending that much on a lens. I could
however manage what I imagine a 400 f/5.6 IS L lens would cost and
perhaps even what I imagine a 500 f/5.6 OS/IS lens might cost, but maybe
my imagination is running wild on the latter. Perhaps the difference in
price is simply not enough to justify building one.

Eric Miller
www.dyesscreek.com

On Sat, 02 Feb 2008 23:13:32 -0600, Eric Miller
wrote in
:

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?

Probably not enough demand.

On a different subject, why aren't there any flash units that use CR123
batteries. The voltage is higher, the batteries are smaller and lighter
than AAs and rechargeables are available. Couldn't someone make a
smaller hot shoe flash unit that would be suitable for smaller cameras
with those batteries. My Canon 550ex is bigger than the Powershot G9.
It's even a monster on my G2. I end up holding the flash and not the
camera when it is attached. Even if such a unit took longer to charge or
didn't have as many flashes, the trade-off in size would seem attractive
for smaller cameras with hot shoes.

What matters is energy density, not voltage.

I have an LED flashlight that takes two CR123s and is considerably
brighter than my huge (by comparison) 4 D-Cell Maglite.

Apples and oranges. LED with D-cells would be just as bright.

The LCD bulbs
last forever (near enough) and use much less power to put out the same
amount of light, why no LED flash units?

Apples and oranges again. The Maglite flashlight uses an incandescent
bulb.

Maybe there is a technical
reason to prevent it,

The flash uses a far more efficient flash tube, and LEDs aren't (yet at
least) capable of anywhere near the same light intensity.

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.

I'm guessing it would be a near impossible design challenge (with
current technology at least), given differences in attached lenses, not
to mention a limited market.

--
Best regards,
John Navas
Panasonic DMC-FZ8 (and several others)

In article , Eric Miller
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?

nikon used to have a 400/5.6 long ago. f/5.6 isn't that fast and i
guess they figure anyone wanting a 400mm fixed focal length lens is
willing to pay a premium for f/4, especially since most zooms covering
that range are f/5.6 already.

On a different subject, why aren't there any flash units that use CR123
batteries. The voltage is higher, the batteries are smaller and lighter
than AAs and rechargeables are available. Couldn't someone make a
smaller hot shoe flash unit that would be suitable for smaller cameras
with those batteries. My Canon 550ex is bigger than the Powershot G9.
It's even a monster on my G2. I end up holding the flash and not the
camera when it is attached. Even if such a unit took longer to charge or
didn't have as many flashes, the trade-off in size would seem attractive
for smaller cameras with hot shoes.

taking longer to recharge and having fewer flashes is a very serious
drawback.

I have an LED flashlight that takes two CR123s and is considerably
brighter than my huge (by comparison) 4 D-Cell Maglite. The LCD bulbs
last forever (near enough) and use much less power to put out the same
amount of light, why no LED flash units? Maybe there is a technical
reason to prevent it, but, if not, why not? Surely color temperature is
now a non-issue with digital photograpy which could automatically adjust
the color balance to the flash when one is being used.

many cellphone cameras have led flash. it's fine for a few feet, but
that's about it.

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.

it's possible, but not that practical. interestingly, there is a nikon
teleconverter that adds autofocus to manual focus lenses.

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?

Probably not enough demand.

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


I have an LED flashlight that takes two CR123s and is considerably
brighter than my huge (by comparison) 4 D-Cell Maglite.

Apples and oranges. LED with D-cells would be just as bright.

But my LED light with CR123s is much, much, much smaller - and
considerably brighter - that combination being my intended point. In
fact, 3 volt LEDs are starting to approach the brightness of 6 volt
incandescents for an even greater size advantage, the light output of a
4D Cell incandescent from an LED light on your keychain that is about
the same length or shorter and just a little thicker than a AA battery.


The LCD bulbs
last forever (near enough) and use much less power to put out the same
amount of light, why no LED flash units?

Apples and oranges again. The Maglite flashlight uses an incandescent
bulb.

Apples and oranges is the point. This question is about flash units, not
Maglite flashlights.


Maybe there is a technical
reason to prevent it,

The flash uses a far more efficient flash tube, and LEDs aren't (yet at
least) capable of anywhere near the same light intensity.


But they are much smaller and thus, presumably, more than one LED could
be used to compensate for the higher output of the flash tube and still
use less power.

Eric Miller
www.dyesscreek.com

In article , Eric Miller
wrote:

And, no doubt, there is tons of demand for a 200-500 f/2.8?

that thing is ridiculously impractical and nothing more than bragging
rights. it doesn't even have to be any good, yet there are numerous
news stories about it and countless threads on dpreview discussing it.

nikon has a 200-400mm f/4 stabilized lens that's only one stop slower
and 100mm shorter, yet it's $20k cheaper and 30 pounds lighter. guess
which one i'd rather have on a safari.

The flash uses a far more efficient flash tube, and LEDs aren't (yet at
least) capable of anywhere near the same light intensity.

But they are much smaller and thus, presumably, more than one LED could
be used to compensate for the higher output of the flash tube and still
use less power.

leds are nowhere near as bright as a flash tube.

"John Navas" wrote in message
news
On Sat, 02 Feb 2008 23:13:32 -0600, Eric Miller
wrote in
:

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?

Probably not enough demand.

On a different subject, why aren't there any flash units that use CR123
batteries. The voltage is higher, the batteries are smaller and lighter
than AAs and rechargeables are available. Couldn't someone make a
smaller hot shoe flash unit that would be suitable for smaller cameras
with those batteries. My Canon 550ex is bigger than the Powershot G9.
It's even a monster on my G2. I end up holding the flash and not the
camera when it is attached. Even if such a unit took longer to charge or
didn't have as many flashes, the trade-off in size would seem attractive
for smaller cameras with hot shoes.

What matters is energy density, not voltage.

I have an LED flashlight that takes two CR123s and is considerably
brighter than my huge (by comparison) 4 D-Cell Maglite.

Apples and oranges. LED with D-cells would be just as bright.

The LCD bulbs
last forever (near enough) and use much less power to put out the same
amount of light, why no LED flash units?

Apples and oranges again. The Maglite flashlight uses an incandescent
bulb.

Maybe there is a technical
reason to prevent it,

The flash uses a far more efficient flash tube, and LEDs aren't (yet at
least) capable of anywhere near the same light intensity.

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.

I'm guessing it would be a near impossible design challenge (with
current technology at least), given differences in attached lenses, not
to mention a limited market.

Yes.....The market is certainly there, but I doubt if such a thing is
possible....The elements that "float" in an IS lens are not the ones that
exist in teleconverters.

On Sun, 03 Feb 2008 00:23:48 -0600, Eric Miller
wrote in
:

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?

Probably not enough demand.

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

Based on lack of such a product. If there were demand, and if it were
practical, then there would probably be such a product. That's how the
market works.

I have an LED flashlight that takes two CR123s and is considerably
brighter than my huge (by comparison) 4 D-Cell Maglite.

Apples and oranges. LED with D-cells would be just as bright.

But my LED light with CR123s is much, much, much smaller - and
considerably brighter - that combination being my intended point.

LED with D-cells would be just as bright.
LED with C-cells would be just as bright.
LED with AA-cells would be just as bright.
LED with AAA-cells would be just as bright.

Size of the battery relates to capacity, not brightness.

In
fact, 3 volt LEDs are starting to approach the brightness of 6 volt
incandescents for an even greater size advantage, the light output of a
4D Cell incandescent from an LED light on your keychain that is about
the same length or shorter and just a little thicker than a AA battery.

Apples and oranges.

The LCD bulbs
last forever (near enough) and use much less power to put out the same
amount of light, why no LED flash units?

Apples and oranges again. The Maglite flashlight uses an incandescent
bulb.

Apples and oranges is the point. This question is about flash units, not
Maglite flashlights.

It makes no sense to compare apples and oranges. You might as well
compare LEDs to sodium vapor lamps.

Maybe there is a technical
reason to prevent it,

The flash uses a far more efficient flash tube, and LEDs aren't (yet at
least) capable of anywhere near the same light intensity.

But they are much smaller and thus, presumably, more than one LED could
be used to compensate for the higher output of the flash tube and still
use less power.

It would take a great many LEDs, thus knocking out your desired size
advantage.

Compare the actual light output of LEDs against a flash tube before
getting too excited.

--
Best regards,
John Navas
Panasonic DMC-FZ8 (and several others)

? "Eric Miller" ?????? ??? ??????
. ..
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?

On a different subject, why aren't there any flash units that use CR123
batteries. The voltage is higher, the batteries are smaller and lighter
than AAs and rechargeables are available. Couldn't someone make a
smaller hot shoe flash unit that would be suitable for smaller cameras
with those batteries. My Canon 550ex is bigger than the Powershot G9.
It's even a monster on my G2. I end up holding the flash and not the
camera when it is attached. Even if such a unit took longer to charge or
didn't have as many flashes, the trade-off in size would seem attractive
for smaller cameras with hot shoes.

Flash works in a total different way, than any incandescent or LED light.It
uses an inverter, to make AC from battery's DC, raises it up to 300V,
rectifies it, and charges a high voltage capacitor, which applies the
voltage across two electrodes of a noble gas tube.There's another excitation
electrode, which is live only when the shutter fires, in the middle of the
tube, and then we have a very bright flash, with a duration of several ms.It
needs large batteries, because all this circuitry is power-hungry.I had a
USSR-vintage flash for my Nikon FM-2, which had no batteries, but took power
from the mains!(It had an U-shaped tube, and was excellent).
I have an LED flashlight that takes two CR123s and is considerably
brighter than my huge (by comparison) 4 D-Cell Maglite. The LCD bulbs
last forever (near enough) and use much less power to put out the same
amount of light, why no LED flash units?
Because for a still photo we need a bright source, for fractions of a
second.A LED light would produce a dimmer light, but continuously.Why not go
all the way, then up to a HQL (metal halide)lamp, but it would be highly
inconvenient to use a 4500 Volt power supply on a camera
Maybe there is a technical
reason to prevent it, but, if not, why not? Surely color temperature is
now a non-issue with digital photograpy which could automatically adjust
the color balance to the flash when one is being used.

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.


--
Tzortzakakis Dimitrios
major in electrical engineering
mechanized infantry reservist
hordad AT otenet DOT gr

In rec.photo.digital.slr-systems Eric Miller wrote:

The LCD bulbs
last forever (near enough) and use much less power to put out the same
amount of light, why no LED flash units?

Apples and oranges again. The Maglite flashlight uses an incandescent
bulb.

Apples and oranges is the point. This question is about flash units, not
Maglite flashlights.

A flash tube has comparable efficiency to an LED. May even be more
efficient.

Maybe there is a technical
reason to prevent it,

The flash uses a far more efficient flash tube, and LEDs aren't (yet at
least) capable of anywhere near the same light intensity.

But they are much smaller and thus, presumably, more than one LED could
be used to compensate for the higher output of the flash tube and still
use less power.

Suppose we're talking about a small pop up flash which produces light
of equivalent intensity to a 2,000 watt incandescent. Suppose we used
overdriven 5watt white LEDs for the flash, then we'd need somewhere
around 100 of them. Doesn't look like a small pop up flash anymore,
and it's going to be technologically difficult to supply the 50A of
current the device will need at around 2.5V.

I could have got my figures wrong, but so far this doesn't sound at
all encouraging :-)

--
Chris Malcolm DoD #205
IPAB, Informatics, JCMB, King's Buildings, Edinburgh, EH9 3JZ, UK
[http://www.dai.ed.ac.uk/homes/cam/]