How does ISO 400 in Digital Rebel compare to ISO 400 film?

On Sun, 15 Aug 2004 17:23:03 +0200, "Bart van der Wolf"
wrote:


"Veggie" wrote in message
m...
I read that the Digital Rebel can do ISO 100 thru 1600. Are they
comparable to good film at the same ISO points?

The method used in the ISO standard defining photosensitivity ratings
for digicams, is aimed at getting comparable numbers for film and
digicams. However, there may be a small difference due to the noise
characteristics or the dynamic range of the camera electronics.

So roughly comparable. Image quality is something entirely different,
but that wasn't the question.

I believe the ISO rating is one of time to expose to mid grey for a
given AV/TV... or something like that... it doesnt actually specify
the "noise" or grain levels.

I've found that on the whole Digital is slightly better than film
"noise" wise.

1600 is almost a no-no in film or digital unless there is no other
option if you want a reasonable shutter speed... that said, when I use
1600 it is in dark small live venue gigs, and concidering the love of
red and yellow lights in such places the noise tends to enhance the
"roughness" of the photo... I try to keep away from flash totaly in a
live music venue or night club as you loose all the atmosphere... and
sometimes I cheat by grey scaling the photo, then replacing the "grey"
colours with say red (or the most predominant original colour) which
works quite well.

I've not used neat image, but I believe it tends to give a plasticy
feel if used incorrectly... I would love to see an original 1600
"noisy" shot processed with neat image to as close as possible a
no/low-noise image just to see it work.


Bart

--
Jonathan Wilson.
www.somethingerotic.com

On Sun, 15 Aug 2004 17:23:03 +0200, "Bart van der Wolf"
wrote:


"Veggie" wrote in message
m...
I read that the Digital Rebel can do ISO 100 thru 1600. Are they
comparable to good film at the same ISO points?

The method used in the ISO standard defining photosensitivity ratings
for digicams, is aimed at getting comparable numbers for film and
digicams. However, there may be a small difference due to the noise
characteristics or the dynamic range of the camera electronics.

So roughly comparable. Image quality is something entirely different,
but that wasn't the question.

I believe the ISO rating is one of time to expose to mid grey for a
given AV/TV... or something like that... it doesnt actually specify
the "noise" or grain levels.

I've found that on the whole Digital is slightly better than film
"noise" wise.

1600 is almost a no-no in film or digital unless there is no other
option if you want a reasonable shutter speed... that said, when I use
1600 it is in dark small live venue gigs, and concidering the love of
red and yellow lights in such places the noise tends to enhance the
"roughness" of the photo... I try to keep away from flash totaly in a
live music venue or night club as you loose all the atmosphere... and
sometimes I cheat by grey scaling the photo, then replacing the "grey"
colours with say red (or the most predominant original colour) which
works quite well.

I've not used neat image, but I believe it tends to give a plasticy
feel if used incorrectly... I would love to see an original 1600
"noisy" shot processed with neat image to as close as possible a
no/low-noise image just to see it work.


Bart

--
Jonathan Wilson.
www.somethingerotic.com

On Sun, 15 Aug 2004 17:23:03 +0200, "Bart van der Wolf"
wrote:


"Veggie" wrote in message
m...
I read that the Digital Rebel can do ISO 100 thru 1600. Are they
comparable to good film at the same ISO points?

The method used in the ISO standard defining photosensitivity ratings
for digicams, is aimed at getting comparable numbers for film and
digicams. However, there may be a small difference due to the noise
characteristics or the dynamic range of the camera electronics.

So roughly comparable. Image quality is something entirely different,
but that wasn't the question.

I believe the ISO rating is one of time to expose to mid grey for a
given AV/TV... or something like that... it doesnt actually specify
the "noise" or grain levels.

I've found that on the whole Digital is slightly better than film
"noise" wise.

1600 is almost a no-no in film or digital unless there is no other
option if you want a reasonable shutter speed... that said, when I use
1600 it is in dark small live venue gigs, and concidering the love of
red and yellow lights in such places the noise tends to enhance the
"roughness" of the photo... I try to keep away from flash totaly in a
live music venue or night club as you loose all the atmosphere... and
sometimes I cheat by grey scaling the photo, then replacing the "grey"
colours with say red (or the most predominant original colour) which
works quite well.

I've not used neat image, but I believe it tends to give a plasticy
feel if used incorrectly... I would love to see an original 1600
"noisy" shot processed with neat image to as close as possible a
no/low-noise image just to see it work.


Bart

--
Jonathan Wilson.
www.somethingerotic.com

In message ,
Jonathan Wilson wrote:

1600 is almost a no-no in film or digital unless there is no other
option if you want a reasonable shutter speed... that said, when I use
1600 it is in dark small live venue gigs, and concidering the love of
red and yellow lights in such places the noise tends to enhance the
"roughness" of the photo...

Is that with a 10D?

The 10D's "ISO 1600" is just ISO 800 pushed a stop by doubling the RAW
data, so you are better off setting the camera to ISO 800 and -1 stop
exposure compensation. There is absolutely no loss of quality; the
dynamic range captured in "ISO 1600" is of the exact same quality in 800
and -1 EC, but you get a stop more headroom with the latter. That's
with RAW. With JPEG, it may be possible that the compression makes them
slightly different.
--


John P Sheehy

"Jonathan Wilson" wrote in message
...
SNIP
I believe the ISO rating is one of time to expose to mid grey for
a given AV/TV... or something like that... it doesnt actually
specify the "noise" or grain levels.

The ISO rating for digicams is defined by either a level of exposure
that (almost) saturates the potential wells, or by an exposure level
that produces a certain level of noise. Which level is used, depends
on the values found, and a kind of checklist that helps to make the
decision in a consistent, repeatable, manner.

SNIP
I've not used neat image, but I believe it tends to give a plasticy
feel if used incorrectly...

If used incorrectly, yes. However, the art of noise reduction is more
about how much noise to leave in the image, rather than remove all of
it.

I would love to see an original 1600 "noisy" shot processed
with neat image to as close as possible a no/low-noise image
just to see it work.

There is a free demo version of Neat Image available at:
http://www.neatimage.com/download.html . There is a learning curve
though, so I'm willing to process a 1600 "noisy" shot/crop you or
someone else can pick, and I'll adjust it to my liking. It can never
be as good as a low ISO shot because there is less data available to
work with in a higher ISO shot, but NI *will* improve matters.

I've done an earlier NI version correction of an ISO 1000 film scan
for someone:
http://misc.hq.phicoh.net/gem/ngem0.png before noise reduction,
http://misc.hq.phicoh.net/gem/ngem0-NI.png after Neat Image.
It is an extreme blow-up of a handheld ISO 1000 ! film image of a
helicopter in turbulent air that already lacked a lot of sharpness.
The current Neat Image is probably even more capable to tackle the
problem, because it has improved since.

Bart

"Jonathan Wilson" wrote in message
...
SNIP
I believe the ISO rating is one of time to expose to mid grey for
a given AV/TV... or something like that... it doesnt actually
specify the "noise" or grain levels.

The ISO rating for digicams is defined by either a level of exposure
that (almost) saturates the potential wells, or by an exposure level
that produces a certain level of noise. Which level is used, depends
on the values found, and a kind of checklist that helps to make the
decision in a consistent, repeatable, manner.

SNIP
I've not used neat image, but I believe it tends to give a plasticy
feel if used incorrectly...

If used incorrectly, yes. However, the art of noise reduction is more
about how much noise to leave in the image, rather than remove all of
it.

I would love to see an original 1600 "noisy" shot processed
with neat image to as close as possible a no/low-noise image
just to see it work.

There is a free demo version of Neat Image available at:
http://www.neatimage.com/download.html . There is a learning curve
though, so I'm willing to process a 1600 "noisy" shot/crop you or
someone else can pick, and I'll adjust it to my liking. It can never
be as good as a low ISO shot because there is less data available to
work with in a higher ISO shot, but NI *will* improve matters.

I've done an earlier NI version correction of an ISO 1000 film scan
for someone:
http://misc.hq.phicoh.net/gem/ngem0.png before noise reduction,
http://misc.hq.phicoh.net/gem/ngem0-NI.png after Neat Image.
It is an extreme blow-up of a handheld ISO 1000 ! film image of a
helicopter in turbulent air that already lacked a lot of sharpness.
The current Neat Image is probably even more capable to tackle the
problem, because it has improved since.

Bart

Veggie wrote in message m...
I read that the Digital Rebel can do ISO 100 thru 1600. Are they
comparable to good film at the same ISO points?

A 6MP mosiac sensor has about 25% of the full color resolution of
color film at the same ISO. Remember with a mosaic you have to
interpolate the information from at least 4 monochrome sensors to
build a single full color pixel, so these are only 1.5MP full color
cameras under ideal circumstances.

At ISO 100 a Direct Image Sensor is comparable to an outstanding
medium format film, or roughly double the full color resolution of ISO
25 35mm film...

http://foveon.com/faq_technology.html#FAQ_tech_13
http://camera-care.com/discover%20on%20foveon.htm

"Georgette Preddy" wrote in message
om...
SNIP
A 6MP mosiac sensor has about 25% of the full color
resolution of color film at the same ISO.

Nonsense, based on deliberate misconceptions.

Remember with a mosaic you have to interpolate the
information from at least 4 monochrome sensors to
build a single full color pixel, so these are only 1.5MP
full color cameras under ideal circumstances.

As I said, you are talking nonsense. CFA sensors are not monochrome as
they capture roughly 1/3rd of the visible spectrum each. The Digital
Rebel produces 6Mp RGB output (after demosaicing the 6M sensors to
RGB), it can even do so in-camera to drop the files of at a printing
kiosk/lab.

At ISO 100 a Direct Image Sensor is comparable to an outstanding
medium format film, or roughly double the full color resolution of
ISO
25 35mm film...

The question was about 400 ISO. Reading comprehension still difficult
for you?

http://foveon.com/faq_technology.html#FAQ_tech_13

Foveon propaganda (unsubstantiated lies) is not a credible source to
support your deliberate misconceptions.

http://camera-care.com/discover%20on%20foveon.htm

An almost 2 years old infomercial (© copyright 2002 The Walt Disney
Company!!!) announcing the SD-9 for US$ 1800 (not including the lens),
is also hardly a credible source with a scientific reputation, unless
you believe Mickey Mouse stories.

Bart

"Georgette Preddy" wrote in message
om...
SNIP
A 6MP mosiac sensor has about 25% of the full color
resolution of color film at the same ISO.

Nonsense, based on deliberate misconceptions.

Remember with a mosaic you have to interpolate the
information from at least 4 monochrome sensors to
build a single full color pixel, so these are only 1.5MP
full color cameras under ideal circumstances.

As I said, you are talking nonsense. CFA sensors are not monochrome as
they capture roughly 1/3rd of the visible spectrum each. The Digital
Rebel produces 6Mp RGB output (after demosaicing the 6M sensors to
RGB), it can even do so in-camera to drop the files of at a printing
kiosk/lab.

At ISO 100 a Direct Image Sensor is comparable to an outstanding
medium format film, or roughly double the full color resolution of
ISO
25 35mm film...

The question was about 400 ISO. Reading comprehension still difficult
for you?

http://foveon.com/faq_technology.html#FAQ_tech_13

Foveon propaganda (unsubstantiated lies) is not a credible source to
support your deliberate misconceptions.

http://camera-care.com/discover%20on%20foveon.htm

An almost 2 years old infomercial (© copyright 2002 The Walt Disney
Company!!!) announcing the SD-9 for US$ 1800 (not including the lens),
is also hardly a credible source with a scientific reputation, unless
you believe Mickey Mouse stories.

Bart