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how to avoid noise at higher iso?

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Anonymous
April 3, 2005 3:55:06 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

What are some tips to reduce noise at high iso settings? Mostly I'm
interested in methods other than dedicated noise reduction post processing
programs. I own a D70. I've heard the following:

Shoot with exposure compensation +1
Don't use high iso for pictures with uniform areas, only busy pictures.
Downsize the photo (will this just help with computer screen viewing - or
printing too?)
Does shooting in raw as opposed to jpeg do anything?

Does anyone have other suggestions? Any comments appreciated .

More about : avoid noise higher iso

Anonymous
April 3, 2005 3:55:07 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

larrylook wrote:

> Does shooting in raw as opposed to jpeg do anything?

Algorithms in them so this will give you more control of the noise
level vs. sharpness then just taking the jpg that the camera produces,
it is of course a bit mroe work as well.

Scott
Anonymous
April 3, 2005 3:55:07 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

"larrylook" <noemail@email.com> wrote in message
news:7J6dnWU-TuJXjM3fRVn-qw@comcast.com...
> What are some tips to reduce noise at high iso settings? Mostly I'm
> interested in methods other than dedicated noise reduction post processing
> programs. I own a D70. I've heard the following:
>
> Shoot with exposure compensation +1
> Don't use high iso for pictures with uniform areas, only busy pictures.
> Downsize the photo (will this just help with computer screen viewing - or
> printing too?)
> Does shooting in raw as opposed to jpeg do anything?
>
> Does anyone have other suggestions? Any comments appreciated .

You might try uploading some curves into the camera to brighten things up a
bit (have to use Capture). Or, why fight it? With a bit of software
tweaking you can make noise look just like film grain. It can actually add
to the picture, IMHO.
>
>
Related resources
Anonymous
April 3, 2005 4:20:20 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

larrylook wrote:

> What are some tips to reduce noise at high iso settings? Mostly I'm
> interested in methods other than dedicated noise reduction post processing
> programs. I own a D70. I've heard the following:
>
> Shoot with exposure compensation +1

Why? Does everything you shoot come out to zone VI?

The D70 has a rep for under expsosure perhaps (or over metering), but
once you know what that offset is it should be applied to the metering
of your scene, not as a default for every scene. As the D70 has a spot
meter, using it will permit you to expose accurately.

You can always, for a given scene, shoot manual exposure once you've
determined the correct highlight exposure via the histogram. This way
you will get greater consistency in your exposures as you won't be
subjecting the meter to variation.

> Don't use high iso for pictures with uniform areas, only busy pictures.

Heh? Generally, use the lowest ISO that allows for the required shutter
speed. This isn't perfect, but will go a long way.

> Downsize the photo (will this just help with computer screen viewing - or
> printing too?)

Sure. But you should be shooting for outcome, not reducing images until
defects are hidden.

> Does shooting in raw as opposed to jpeg do anything?

Yes.

>
> Does anyone have other suggestions? Any comments appreciated .

Learn more about exposure and metering including a basic appreciation of
the first part of the zone system.

Cheers,
Alan

--
-- r.p.e.35mm user resource: http://www.aliasimages.com/rpe35mmur.htm
-- r.p.d.slr-systems: http://www.aliasimages.com/rpdslrsysur.htm
-- slr-systems FAQ project: http://tinyurl.com/6m9aw
-- [SI] gallery & rulz: http://www.pbase.com/shootin
-- e-meil: Remove FreeLunch.
Anonymous
April 3, 2005 5:54:49 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

On Sun, 3 Apr 2005 11:55:06 -0400, in rec.photo.digital.slr-systems
"larrylook" <noemail@email.com> wrote:

>What are some tips to reduce noise at high iso settings? Mostly I'm
>interested in methods other than dedicated noise reduction post processing
>programs. I own a D70. I've heard the following:
>
>Shoot with exposure compensation +1

No shoot to properly expose the image without blowing highlights out. You
may wish to push this a bit, but don't blow any highlights off. Make use of
the in camera histogram to help. Just remember this is only the luminance
channel, so if you have extreme reds you need to be a bit careful pushing
things to the right.

>Don't use high iso for pictures with uniform areas, only busy pictures.

As Alan said, use the lowest iso that allows an appropriate shutter speed
for what you're trying to shoot. For instance shooting birds you want as
high a shutter speed as possible to capture the details of fine feathers
which my be moving slightly in the breeze.

>Downsize the photo (will this just help with computer screen viewing - or
>printing too?)

Yes, but then you have to deal with the reduced size image. Better to use
noise filtering software, imo.

>Does shooting in raw as opposed to jpeg do anything?

It can, as there is more data to work with. To take advantage of this
you'l need to use a more sophisticated conversion program than PP, NV or
the supplied plugins.

>Does anyone have other suggestions? Any comments appreciated .

For jpg shoot P,A,S,or M not Auto or any of the scene modes and turn off
all in camera processing effecting contrast, color, sharpening, etc.
----------
Ed Ruf Lifetime AMA# 344007 (Usenet@EdwardG.Ruf.com)
See images taken with my CP-990/5700 & D70 at
http://edwardgruf.com/Digital_Photography/General/index...
Anonymous
April 3, 2005 6:26:33 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

Merritt Mullen <mmullen8014@mchsi.com> writes:

> In article <7J6dnWU-TuJXjM3fRVn-qw@comcast.com>,
> "larrylook" <noemail@email.com> wrote:
>
>> What are some tips to reduce noise at high iso settings?
>
> Buy a Nikon? <grin>
>
> Mostly I'm
>> interested in methods other than dedicated noise reduction post processing
>> programs. I own a D70. I've heard the following:

Um, the D70 *is* a Nikon. Oops!
--
David Dyer-Bennet, <mailto:D d-b@dd-b.net>, <http://www.dd-b.net/dd-b/&gt;
RKBA: <http://noguns-nomoney.com/&gt; <http://www.dd-b.net/carry/&gt;
Pics: <http://dd-b.lighthunters.net/&gt; <http://www.dd-b.net/dd-b/SnapshotAlbum/&gt;
Dragaera/Steven Brust: <http://dragaera.info/&gt;
Anonymous
April 3, 2005 9:58:05 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

In article <7J6dnWU-TuJXjM3fRVn-qw@comcast.com>,
"larrylook" <noemail@email.com> wrote:

> What are some tips to reduce noise at high iso settings?

Buy a Nikon? <grin>

Mostly I'm
> interested in methods other than dedicated noise reduction post processing
> programs. I own a D70. I've heard the following:
>
> Shoot with exposure compensation +1
> Don't use high iso for pictures with uniform areas, only busy pictures.
> Downsize the photo (will this just help with computer screen viewing - or
> printing too?)

I'm no where near an expert, but this is my understanding (someone
correct me if I am wrong). Digital imaging (at least on the D70) has more
latitude on the underexposed side than when overexposed. In other words,
underexposing will darken the image, but little visual information is
lost, so that can be corrected in post-processing. On the other hand,
over-exposure blows out the highlights, losing visual information which
can not be recovered. So underexposing to avoid using excessively high
ISO may be a good strategy.

> Does shooting in raw as opposed to jpeg do anything?

Again, my understanding, but aren't you always SHOOTING in RAW? The image
becomes a JPEG by processing after it is shot. The processing can be done
in the camera or in a computer after the RAW image is downloaded from the
camera. Clearly, you will have more options for image manipulation if you
do it in your computer, rather than let the camera do it. Of course, that
assumes you know how to get the best out of your image processing software.

I am a newbie to digital photography, so I hope someone will correct me if
I have made any misstatements above.

Merritt
Anonymous
April 3, 2005 9:58:06 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

On Sun, 03 Apr 2005 17:58:05 GMT, in rec.photo.digital.slr-systems Merritt
Mullen <mmullen8014@mchsi.com> wrote:


>I'm no where near an expert, but this is my understanding (someone
>correct me if I am wrong). Digital imaging (at least on the D70) has more
>latitude on the underexposed side than when overexposed. In other words,
>underexposing will darken the image, but little visual information is
>lost, so that can be corrected in post-processing. On the other hand,
>over-exposure blows out the highlights, losing visual information which
>can not be recovered. So underexposing to avoid using excessively high
>ISO may be a good strategy.

Not quite. Yes, you don't want to blow out the highlights. But you want to
expose the rest of the image as much as possible. The noise levels at a
given iso are constant. You want to maximize the signal-to-noise ratio,
which means maximizing the signal. If you underexpose and then lighten in
post processing you'll have greater noise in the shadows.
----------
Ed Ruf Lifetime AMA# 344007 (Usenet@EdwardG.Ruf.com)
See images taken with my CP-990/5700 & D70 at
http://edwardgruf.com/Digital_Photography/General/index...
April 3, 2005 10:22:24 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

"larrylook" <noemail@email.com> wrote in message
news:7J6dnWU-TuJXjM3fRVn-qw@comcast.com...
> What are some tips to reduce noise at high iso settings? Mostly I'm
> interested in methods other than dedicated noise reduction post processing
> programs. I own a D70. I've heard the following:
>
> Shoot with exposure compensation +1
> Don't use high iso for pictures with uniform areas, only busy pictures.
> Downsize the photo (will this just help with computer screen viewing - or
> printing too?)
> Does shooting in raw as opposed to jpeg do anything?
>
> Does anyone have other suggestions? Any comments appreciated .
>
>

If all else fails and you have to use noisy high ISOs then try Neatimage,
www.neatimage.com
Anonymous
April 4, 2005 5:19:31 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

In article <6rd051hf5ojgsbniuk1qm8jq9246jff2f6@4ax.com>,
Ed Ruf <egruf_usenet@cox.net> wrote:

> On Sun, 03 Apr 2005 17:58:05 GMT, in rec.photo.digital.slr-systems Merritt
> Mullen <mmullen8014@mchsi.com> wrote:

> >I'm no where near an expert, but this is my understanding (someone
> >correct me if I am wrong). Digital imaging (at least on the D70) has more
> >latitude on the underexposed side than when overexposed. In other words,
> >underexposing will darken the image, but little visual information is
> >lost, so that can be corrected in post-processing. On the other hand,
> >over-exposure blows out the highlights, losing visual information which
> >can not be recovered. So underexposing to avoid using excessively high
> >ISO may be a good strategy.

> Not quite. Yes, you don't want to blow out the highlights. But you want to
> expose the rest of the image as much as possible. The noise levels at a
> given iso are constant. You want to maximize the signal-to-noise ratio,
> which means maximizing the signal. If you underexpose and then lighten in
> post processing you'll have greater noise in the shadows.

Good points, thanks. It does sound like it is better to err on the side
of underexposure (if you have to err at all). You may have noise in the
darker portions, but if you overexpose, you have nothing at all in the
highlights.

Merritt
April 4, 2005 12:34:06 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

Merritt Mullen wrote:

> In article <6rd051hf5ojgsbniuk1qm8jq9246jff2f6@4ax.com>,
> Ed Ruf <egruf_usenet@cox.net> wrote:
>
>
>>On Sun, 03 Apr 2005 17:58:05 GMT, in rec.photo.digital.slr-systems Merritt
>>Mullen <mmullen8014@mchsi.com> wrote:
>
>
>>>I'm no where near an expert, but this is my understanding (someone
>>>correct me if I am wrong). Digital imaging (at least on the D70) has more
>>>latitude on the underexposed side than when overexposed. In other words,
>>>underexposing will darken the image, but little visual information is
>>>lost, so that can be corrected in post-processing. On the other hand,
>>>over-exposure blows out the highlights, losing visual information which
>>>can not be recovered. So underexposing to avoid using excessively high
>>>ISO may be a good strategy.
>
>
>>Not quite. Yes, you don't want to blow out the highlights. But you want to
>>expose the rest of the image as much as possible. The noise levels at a
>>given iso are constant. You want to maximize the signal-to-noise ratio,
>>which means maximizing the signal. If you underexpose and then lighten in
>>post processing you'll have greater noise in the shadows.
>
>
> Good points, thanks. It does sound like it is better to err on the side
> of underexposure (if you have to err at all). You may have noise in the
> darker portions, but if you overexpose, you have nothing at all in the
> highlights.


Shooting in RAW allows you to capture a bit more of the blown
highlights. For low contrast scenes you can overexpose significantly &
darken when converting for less noise but that costs light/time so
there's no free lunch.
Anonymous
April 4, 2005 5:34:56 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

On Sun, 3 Apr 2005 11:55:06 -0400, in
<7J6dnWU-TuJXjM3fRVn-qw@comcast.com>, "larrylook" <noemail@email.com>
said:

>What are some tips to reduce noise at high iso settings? Mostly I'm
>interested in methods other than dedicated noise reduction post processing
>programs. I own a D70. I've heard the following:
>
>Shoot with exposure compensation +1

You might as well drop down one ISO step.

>Don't use high iso for pictures with uniform areas, only busy pictures.
>Downsize the photo (will this just help with computer screen viewing - or
>printing too?)

Both.

>Does shooting in raw as opposed to jpeg do anything?

It does help with Canon. You can shoot at a lower ISO & post-adjust a
stop of exp compensation. I have no idea whether this technique is
suitable for RAW on the D70 though.

>Does anyone have other suggestions? Any comments appreciated .

Yeah, buy a Canon DSLR. ;) 

(Sorry, couldn't resist.)

--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------
Anonymous
April 5, 2005 3:06:02 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

In message <d2qcfi$vrb$0@pita.alt.net>,
Lionel <nop@alt.net> wrote:

>On Sun, 3 Apr 2005 11:55:06 -0400, in
><7J6dnWU-TuJXjM3fRVn-qw@comcast.com>, "larrylook" <noemail@email.com>
>said:
>
>>What are some tips to reduce noise at high iso settings? Mostly I'm
>>interested in methods other than dedicated noise reduction post processing
>>programs. I own a D70. I've heard the following:
>>
>>Shoot with exposure compensation +1

>You might as well drop down one ISO step.

I almost always choose the higher ISO with the + EC. Low S/N ratios and
posterization are the real causes of visible noise, moreso than ISO per
se. It really depends on how I judge that the scene will meter with the
particular camera.
--

<>>< ><<> ><<> <>>< ><<> <>>< <>>< ><<>
John P Sheehy <JPS@no.komm>
><<> <>>< <>>< ><<> <>>< ><<> ><<> <>><
Anonymous
April 6, 2005 11:02:08 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

On Sun, 3 Apr 2005 11:55:06 -0400, "larrylook" <noemail@email.com>
wrote:

>What are some tips to reduce noise at high iso settings?

In low light situations I set my D60 at 1000 and underexpose one or
one and a half stops. Using plus gamma adjustment and adding a little
contrast The resulting file will print an accepable 8X10-inch image...
as good as most film in the same lighting.

>Mostly I'm interested in methods other than dedicated noise reduction post processing
>programs. I own a D70. ....

If I need an 11X17-inch print of the low light image I use the program
NoiseWare, on the default setting, for results of zero grain with very
little lose in resolution. I have a freeware copy of NoiseWare, with
limited featurs, but it works well for the few times i'm in a "black
cat in a coal bin" type situation.

Dave
East Englewood
-----------------------
The proof is in the print.
Anonymous
April 6, 2005 11:11:08 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

On Wed, 06 Apr 2005 19:02:08 GMT, dave6134@verizon.net wrote:

>On Sun, 3 Apr 2005 11:55:06 -0400, "larrylook" <noemail@email.com>
>wrote:
>
>>What are some tips to reduce noise at high iso settings?
>
>In low light situations I set my D60 at 1000 and underexpose one or
>one and a half stops. Using plus gamma adjustment and adding a little
>contrast The resulting file will print an accepable 8X10-inch image...
>as good as most film in the same lighting.

You *under*-expose?

I get less noise if I nudge the D70 to *over*-expose slightly. This is
partly due to its (and many other DSLR's) natural tendency to
underexpose anyway) and partly because noise is present in the darker
areas of the image first, something that would only be made worse by
underexposing.

--
Owamanga!
http://www.pbase.com/owamanga
Anonymous
April 6, 2005 11:12:01 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

On Wed, 06 Apr 2005 19:11:08 GMT, Owamanga
<owamanga(not-this-bit)@hotmail.com> wrote:

>On Wed, 06 Apr 2005 19:02:08 GMT, dave6134@verizon.net wrote:
>
>>On Sun, 3 Apr 2005 11:55:06 -0400, "larrylook" <noemail@email.com>
>>wrote:
>>
>>>What are some tips to reduce noise at high iso settings?
>>
>>In low light situations I set my D60 at 1000 and underexpose one or
>>one and a half stops. Using plus gamma adjustment and adding a little
>>contrast The resulting file will print an accepable 8X10-inch image...
>>as good as most film in the same lighting.
>
>You *under*-expose?
>
>I get less noise if I nudge the D70 to *over*-expose slightly. This is
>partly due to its (and many other DSLR's) natural tendency to
>underexpose anyway) and partly because noise is present in the darker
>areas of the image first, something that would only be made worse by
>underexposing.

....hold on, ignore me. You mean you under expose rather than pushing
the ISO above 1000. This makes sense.

My point is that if I am forced to choose a high ISO, I am careful not
to underexpose.

--
Owamanga!
http://www.pbase.com/owamanga
Anonymous
April 7, 2005 6:14:41 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

In message <qed8511n89me45grqf2p8n5h4vkukpurjo@4ax.com>,
Owamanga <owamanga(not-this-bit)@hotmail.com> wrote:

>...hold on, ignore me. You mean you under expose rather than pushing
>the ISO above 1000. This makes sense.

.... only if the highest analog gain is only available up to 1000.

>My point is that if I am forced to choose a high ISO, I am careful not
>to underexpose.

You don't always have a choice, unless what you choose is not to shoot
at all when the S/N drops below a certain ratio.
--

<>>< ><<> ><<> <>>< ><<> <>>< <>>< ><<>
John P Sheehy <JPS@no.komm>
><<> <>>< <>>< ><<> <>>< ><<> ><<> <>><
Anonymous
April 7, 2005 12:20:53 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

larrylook wrote:

> What are some tips to reduce noise at high iso settings? Mostly I'm
> interested in methods other than dedicated noise reduction post processing
> programs. I own a D70. I've heard the following:
>
> Shoot with exposure compensation +1

Now think about that for just a second... if you're shooting ISO 1600
with EV+1, and you find there's too much noise, why not just shoot at
ISO 800 and be done with it?
April 7, 2005 12:23:01 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

Matt Ion wrote:

> larrylook wrote:
>
>> What are some tips to reduce noise at high iso settings? Mostly I'm
>> interested in methods other than dedicated noise reduction post
>> processing
>> programs. I own a D70. I've heard the following:
>>
>> Shoot with exposure compensation +1
>
>
> Now think about that for just a second... if you're shooting ISO 1600
> with EV+1, and you find there's too much noise, why not just shoot at
> ISO 800 and be done with it?


If you aren't going to blow highlights with the +1 it should improve the
image more for being pushed into the better capture range in the light
end. The improvements for moving into the highlights should be more
important than the ISO noise addition because there is so much more data
in the highlights. Theoretically.
Anonymous
April 7, 2005 4:17:36 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

One way to eliminate noise on longer
exposures is to chill the camera down.
Put it in a fridge for a couple hours
then take the shots. But, longer
exposure noise is dark current, I'm not
sure if ISO related noise is the same.
-Rich
Anonymous
April 8, 2005 3:41:16 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

In message <APydnYTeOYnKzcjfRVn-3w@speakeasy.net>,
paul <paul@not.net> wrote:

>If you aren't going to blow highlights with the +1 it should improve the
>image more for being pushed into the better capture range in the light
>end. The improvements for moving into the highlights should be more
>important than the ISO noise addition because there is so much more data
>in the highlights. Theoretically.

Works in practice, too, if you dig into the shadows. Posterization can
destroy shadows more than amplifier gain.
--

<>>< ><<> ><<> <>>< ><<> <>>< <>>< ><<>
John P Sheehy <JPS@no.komm>
><<> <>>< <>>< ><<> <>>< ><<> ><<> <>><
Anonymous
April 9, 2005 11:22:06 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

On Thu, 07 Apr 2005 08:20:53 +0000, Matt Ion wrote:

> larrylook wrote:
>
>> What are some tips to reduce noise at high iso settings? Mostly I'm
>> interested in methods other than dedicated noise reduction post processing
>> programs. I own a D70. I've heard the following:
>>
>> Shoot with exposure compensation +1
>
> Now think about that for just a second... if you're shooting ISO 1600
> with EV+1, and you find there's too much noise, why not just shoot at
> ISO 800 and be done with it?

That's two stops less exposure than shooting at 1600 with +1 exposure comp.

Why anyone would want to use exposure compensation with a DSLR is beyond
me. Do they not know how to use PhotoShop?

--
The good old days start now.
Anonymous
April 9, 2005 7:16:58 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

In message <pan.2005.04.08.18.13.21.498000@home.com>,
Roxy d'Urban <not@home.com> wrote:

>On Thu, 07 Apr 2005 08:20:53 +0000, Matt Ion wrote:

>> Now think about that for just a second... if you're shooting ISO 1600
>> with EV+1, and you find there's too much noise, why not just shoot at
>> ISO 800 and be done with it?

>That's two stops less exposure than shooting at 1600 with +1 exposure comp.

No, that's exactly the same exposure on the sensor. The only difference
is the way it is digitized during readout. The dynamic range of the
subject will be represented by twice as many levels in the RAW data at
1600 and +1, as opposed to 800. 1600 and +1 is a *better* 800 than
straight 800, provided that desired data doesn't clip.

>Why anyone would want to use exposure compensation with a DSLR is beyond
>me. Do they not know how to use PhotoShop?

You seem to be at the foothills of the digital learning curve.

Photoshop will make the noise brighter, along with the signal, and you
will have more posterization, as well.

You need to maximize exposure at the time of the capture, while
saturating the RAW levels, for the highest quality images; even if it
means raising the camera ISO to saturate the RAW data.
--

<>>< ><<> ><<> <>>< ><<> <>>< <>>< ><<>
John P Sheehy <JPS@no.komm>
><<> <>>< <>>< ><<> <>>< ><<> ><<> <>><
Anonymous
April 9, 2005 11:37:48 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

<JPS@no.komm> wrote:

> 1600 and +1 is a *better* 800 than straight 800, provided that desired
> data doesn't clip.

And provided it's a real 1600, and not 800 with a digital push.

--
Jeremy | jeremy@exit109.com
Anonymous
April 10, 2005 8:17:59 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

In message <115gboc1kuhb5@corp.supernews.com>,
Jeremy Nixon <jeremy@exit109.com> wrote:

> <JPS@no.komm> wrote:
>
>> 1600 and +1 is a *better* 800 than straight 800, provided that desired
>> data doesn't clip.
>
>And provided it's a real 1600, and not 800 with a digital push.

In that case they'd be the same, except of course, the 800 would have a
stop more of highlights.
--

<>>< ><<> ><<> <>>< ><<> <>>< <>>< ><<>
John P Sheehy <JPS@no.komm>
><<> <>>< <>>< ><<> <>>< ><<> ><<> <>><
Anonymous
April 10, 2005 6:50:45 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

On Sun, 10 Apr 2005 04:17:59 GMT, JPS@no.komm wrote:

>In message <115gboc1kuhb5@corp.supernews.com>,
>Jeremy Nixon <jeremy@exit109.com> wrote:
>
>> <JPS@no.komm> wrote:
>>
>>> 1600 and +1 is a *better* 800 than straight 800, provided that desired
>>> data doesn't clip.
>>
>>And provided it's a real 1600, and not 800 with a digital push.
>
>In that case they'd be the same, except of course, the 800 would have a
>stop more of highlights.

a question: is the noise fundamental to all light channels; or more
prevelent in a particular color? I ask becuse of a previous thread
regarding color'd filter attachments and they're touted optimisation
/balancing of a particular channel.

I'm familiar with a flaw frame approach (which of course involves post
production - not this thread).

If this question is not relevant, my apologies.

rgds
Ken
Anonymous
April 10, 2005 10:11:03 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

In message <gkei519u00jje87i2bd6ovqgprudjlbl6f@4ax.com>,
Ken Ellis <kenellis@nycap.rr.com> wrote:

>On Sun, 10 Apr 2005 04:17:59 GMT, JPS@no.komm wrote:
>
>>In message <115gboc1kuhb5@corp.supernews.com>,
>>Jeremy Nixon <jeremy@exit109.com> wrote:

>>>And provided it's a real 1600, and not 800 with a digital push.

>>In that case they'd be the same, except of course, the 800 would have a
>>stop more of highlights.

>a question: is the noise fundamental to all light channels; or more
>prevelent in a particular color? I ask becuse of a previous thread
>regarding color'd filter attachments and they're touted optimisation
>/balancing of a particular channel.

The green channel is what the ISO setting of the camera is set to. The
blue and red channels are scaled to a different exposure index by the
raw converter, while performing color balancing. When the camera is set
to ISO 100, the EI of the red channel might be 180, and the blue channel
might be 140 (for sunlight). For incandescent, it might be 90 for the
red, and 400 for the blue. On the Canon DSLRs, this is done
mathematically after the A2D conversion. Allegedly, on the Nikons (or
some of them), it is done during the A2D.

--

<>>< ><<> ><<> <>>< ><<> <>>< <>>< ><<>
John P Sheehy <JPS@no.komm>
><<> <>>< <>>< ><<> <>>< ><<> ><<> <>><
Anonymous
April 11, 2005 3:24:38 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

On Sat, 09 Apr 2005 07:22:06 +0200, Roxy d'Urban <not@home.com> wrote:
>
> Why anyone would want to use exposure compensation with a DSLR is beyond
> me.

A scene with a lot of white will underexpose without exposure
compensation. That can be dealt with in Photoshop, yes, but it
won't look as good as a picture that was properly exposed in the
first place. Don't take my word for it -- try it yourself.

--
Ben Rosengart (212) 741-4400 x215
Sometimes it only makes sense to focus our attention on those
questions that are equal parts trivial and intriguing.
--Josh Micah Marshall
Anonymous
April 11, 2005 11:59:28 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

On Sat, 09 Apr 2005 15:16:58 +0000, JPS wrote:

>>That's two stops less exposure than shooting at 1600 with +1 exposure comp.
>
> No, that's exactly the same exposure on the sensor. The only difference
> is the way it is digitized during readout. The dynamic range of the
> subject will be represented by twice as many levels in the RAW data at
> 1600 and +1, as opposed to 800. 1600 and +1 is a *better* 800 than
> straight 800, provided that desired data doesn't clip.

Apologies, I got mixed up (again).

>>Why anyone would want to use exposure compensation with a DSLR is beyond
>>me. Do they not know how to use PhotoShop?
>
> You seem to be at the foothills of the digital learning curve.

He-he. Well, I've only been doing it on a part-time pro basis since 2001.

> Photoshop will make the noise brighter, along with the signal, and you
> will have more posterization, as well.

Photoshop, my friend, will do anything I tell it to do.

> You need to maximize exposure at the time of the capture, while
> saturating the RAW levels, for the highest quality images; even if it
> means raising the camera ISO to saturate the RAW data.

When shooting with a DSLR, underexposing the shot and fixing it in PS will
provide you with all the data you need to produce an image of high
quality. Of course you have to know what you're doing in Photoshop.

--
The good old days start now.
Anonymous
April 11, 2005 5:32:39 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

On Mon, 11 Apr 2005 07:59:28 +0200, Roxy d'Urban <not@home.com> wrote:
snip
>
>When shooting with a DSLR, underexposing the shot and fixing it in PS will
>provide you with all the data you need to produce an image of high
>quality. Of course you have to know what you're doing in Photoshop.

I read an article in DigPhotog. which agreed with this shoot dark
approach. Maybe not every single shot..but in general. I often do
this myself - i find it's easier to deal with colors other than white
in post capture processing..eg., theres something there to process.

I don't think there's a simple rule for this one though. Sometimes, a
plus exposure is the way to go. Casual observation.
rgds
Ken
Anonymous
April 11, 2005 6:29:27 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

On Mon, 11 Apr 2005 13:32:39 GMT, Ken Ellis <kenellis@nycap.rr.com>
wrote:

>On Mon, 11 Apr 2005 07:59:28 +0200, Roxy d'Urban <not@home.com> wrote:
>snip
>>
>>When shooting with a DSLR, underexposing the shot and fixing it in PS will
>>provide you with all the data you need to produce an image of high
>>quality. Of course you have to know what you're doing in Photoshop.
>
>I read an article in DigPhotog. which agreed with this shoot dark
>approach. Maybe not every single shot..but in general. I often do
>this myself - i find it's easier to deal with colors other than white
>in post capture processing..eg., theres something there to process.
>
>I don't think there's a simple rule for this one though. Sometimes, a
>plus exposure is the way to go. Casual observation.

It's generally a good approach to avoid blown highlights yes. But the
OP was about how to avoid noise. Underexposing isn't going to avoid
noise. It'll lower the signal, the noise stays the same (okay, I
simplified this a bit) and photoshop adjustments will tend to amplify
the noise with the signal when the exposure gets corrected. End
result: A noisy image.

--
Owamanga!
http://www.pbase.com/owamanga
Anonymous
April 11, 2005 9:52:19 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

On Sun, 10 Apr 2005 18:11:03 GMT, JPS@no.komm wrote:

>In message <gkei519u00jje87i2bd6ovqgprudjlbl6f@4ax.com>,
>Ken Ellis <kenellis@nycap.rr.com> wrote:
>
>>On Sun, 10 Apr 2005 04:17:59 GMT, JPS@no.komm wrote:
>>
>>>In message <115gboc1kuhb5@corp.supernews.com>,
>>>Jeremy Nixon <jeremy@exit109.com> wrote:
>
>>>>And provided it's a real 1600, and not 800 with a digital push.
>
>>>In that case they'd be the same, except of course, the 800 would have a
>>>stop more of highlights.
>
>>a question: is the noise fundamental to all light channels; or more
>>prevelent in a particular color? I ask becuse of a previous thread
>>regarding color'd filter attachments and they're touted optimisation
>>/balancing of a particular channel.
>
>The green channel is what the ISO setting of the camera is set to. The
>blue and red channels are scaled to a different exposure index by the
>raw converter, while performing color balancing. When the camera is set
>to ISO 100, the EI of the red channel might be 180, and the blue channel
>might be 140 (for sunlight). For incandescent, it might be 90 for the
>red, and 400 for the blue. On the Canon DSLRs, this is done
>mathematically after the A2D conversion. Allegedly, on the Nikons (or
>some of them), it is done during the A2D.

Thanks for the explaination. It leads me to ask, does the noise vary
consitent with the individual channel iso...eg ., if iso 100, where
red channel is 180, and blue maybe 140..is the noise higher
in the red channel respectively? Beyond the reactivity of the
camera elements at any given time, it would appear (reasonably)
that the source light(incandeesent, sun, etc) factors
into this dynamic....so the white balance comes into play.
Presumably the camera logic factors all this in. How would i
know..with a 20d, which setting was best to avoid noise in
low light...For example..an 800 iso with the wb set to tungsten - just
as a hypethetical.

Or more directly put, I can WB bracket on the cam. Is there anyway to
know which colors to supress and which to enhance for the purpose
of noise reduction. Is this even relevant? Geeezums. Duuuuuh.

Anyway.. i suppose i should go off some where and look this stuff up.

rgds
Ken
Anonymous
April 11, 2005 9:57:38 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

Ken Ellis <kenellis@nycap.rr.com> wrote:
> On Mon, 11 Apr 2005 07:59:28 +0200, Roxy d'Urban <not@home.com> wrote:
>
>> When shooting with a DSLR, underexposing the shot and fixing it in PS will
>> provide you with all the data you need to produce an image of high
>> quality. Of course you have to know what you're doing in Photoshop.
>
> I read an article in DigPhotog. which agreed with this shoot dark
> approach. Maybe not every single shot..but in general. I often do
> this myself - i find it's easier to deal with colors other than white
> in post capture processing..eg., theres something there to process.
>
> I don't think there's a simple rule for this one though. Sometimes, a
> plus exposure is the way to go. Casual observation.

Underexposing and then fixing it in Photoshop will result in lower
image quality than getting the exposure right in the first place.
This isn't just a general guideline; it is something that will be
true 100% of the time.

The above is extraordinarily bad advice. If you just want to get
a shot, and don't care about the best possible quality, you could
spend a lot less money and effort and just use a point-and-shoot
camera.

--
Jeremy | jeremy@exit109.com
Anonymous
April 11, 2005 10:09:02 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

On Mon, 11 Apr 2005 17:57:38 -0000, Jeremy Nixon <jeremy@exit109.com>
wrote:

>Ken Ellis <kenellis@nycap.rr.com> wrote:
>> On Mon, 11 Apr 2005 07:59:28 +0200, Roxy d'Urban <not@home.com> wrote:
>>
>>> When shooting with a DSLR, underexposing the shot and fixing it in PS will
>>> provide you with all the data you need to produce an image of high
>>> quality. Of course you have to know what you're doing in Photoshop.
>>
>> I read an article in DigPhotog. which agreed with this shoot dark
>> approach. Maybe not every single shot..but in general. I often do
>> this myself - i find it's easier to deal with colors other than white
>> in post capture processing..eg., theres something there to process.
>>
>> I don't think there's a simple rule for this one though. Sometimes, a
>> plus exposure is the way to go. Casual observation.
>
>Underexposing and then fixing it in Photoshop will result in lower
>image quality than getting the exposure right in the first place.
>This isn't just a general guideline; it is something that will be
>true 100% of the time.
>
>The above is extraordinarily bad advice. If you just want to get
>a shot, and don't care about the best possible quality, you could
>spend a lot less money and effort and just use a point-and-shoot
>camera.

Good point.
rgds
Ken
Anonymous
April 11, 2005 10:58:59 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

On Mon, 11 Apr 2005 17:52:19 GMT, Ken Ellis <kenellis@nycap.rr.com> wrote:
>
> Thanks for the explaination. It leads me to ask, does the noise vary
> consitent with the individual channel iso...eg ., if iso 100, where
> red channel is 180, and blue maybe 140..is the noise higher
> in the red channel respectively?

If the sensor is recording less signal in a given channel, hence
having to apply more gain to that channel, then I'd expect to see
more noise in that channel.

I had some experience with this shooting concert photos in low,
reddish light. I blew out the red channel but underexposed the
green and blue channels.

In conversion to B&W, I would've liked to just use the red channel,
but since it was blown out, I had to use the other channels for
highlight detail. And being underexposed, they brought a fair
amount of noise with them.

A good illustration of all that noise:

http://narcissus.net/SandaWeigl/pages/doug-wieselman.ht...

> Beyond the reactivity of the
> camera elements at any given time, it would appear (reasonably)
> that the source light(incandeesent, sun, etc) factors
> into this dynamic....so the white balance comes into play.
> Presumably the camera logic factors all this in. How would i
> know..with a 20d, which setting was best to avoid noise in
> low light...For example..an 800 iso with the wb set to tungsten - just
> as a hypethetical.

Eh, just shoot RAW, and worry about the WB at your leisure.

> Or more directly put, I can WB bracket on the cam. Is there anyway to
> know which colors to supress and which to enhance for the purpose
> of noise reduction. Is this even relevant? Geeezums. Duuuuuh.

I'm no expert on this stuff, but my best guess is that the most
significant thing you can do to reduce noise is to expose as far to
the right as you can without blowing out desired highlight detail.
If your final image is going to be monochrome, then you should look
at the characteristics of each channel. (Unfortunately, AFAIK, only
the really high-end DSLRs give you per-channel histograms.)

--
Ben Rosengart (212) 741-4400 x215
Sometimes it only makes sense to focus our attention on those
questions that are equal parts trivial and intriguing.
--Josh Micah Marshall
Anonymous
April 11, 2005 11:07:27 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

On Mon, 11 Apr 2005 17:52:19 GMT, Ken Ellis <kenellis@nycap.rr.com> wrote:
>
> Thanks for the explaination. It leads me to ask, does the noise vary
> consitent with the individual channel iso...eg ., if iso 100, where
> red channel is 180, and blue maybe 140..is the noise higher
> in the red channel respectively?

If the sensor is recording less signal in a given channel, hence
having to apply more gain to that channel, then I'd expect to see
more noise in that channel.

I had some experience with this shooting concert photos in low,
reddish light. I blew out the red channel but underexposed the
green and blue channels.

In conversion to B&W, I would've liked to just use the red channel,
but since it was blown out, I had to use the other channels for
highlight detail. And being underexposed, they brought a fair
amount of noise with them.

A good illustration of all that noise:

http://narcissus.net/SandaWeigl/pages/doug-wieselman.ht...

> Beyond the reactivity of the
> camera elements at any given time, it would appear (reasonably)
> that the source light(incandeesent, sun, etc) factors
> into this dynamic....so the white balance comes into play.
> Presumably the camera logic factors all this in. How would i
> know..with a 20d, which setting was best to avoid noise in
> low light...For example..an 800 iso with the wb set to tungsten - just
> as a hypethetical.

Eh, just shoot RAW, and worry about the WB at your leisure.

> Or more directly put, I can WB bracket on the cam. Is there anyway to
> know which colors to supress and which to enhance for the purpose
> of noise reduction. Is this even relevant? Geeezums. Duuuuuh.

I'm no expert on this stuff, but my best guess is that the most
significant thing you can do to reduce noise is to expose as far to
the right as you can without blowing out desired highlight detail.
If your final image is going to be monochrome, then you should look
at the characteristics of each channel. (Unfortunately, AFAIK, only
the really high-end DSLRs give you per-channel histograms.)

--
Ben Rosengart (212) 741-4400 x215
Sometimes it only makes sense to focus our attention on those
questions that are equal parts trivial and intriguing.
--Josh Micah Marshall
Anonymous
April 11, 2005 11:30:07 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

On Mon, 11 Apr 2005 19:07:27 +0000 (UTC), Ben Rosengart
<br+rpdss@panix.com> wrote:

>On Mon, 11 Apr 2005 17:52:19 GMT, Ken Ellis <kenellis@nycap.rr.com> wrote:
>>
>> Thanks for the explaination. It leads me to ask, does the noise vary
>> consitent with the individual channel iso...eg ., if iso 100, where
>> red channel is 180, and blue maybe 140..is the noise higher
>> in the red channel respectively?
>
>If the sensor is recording less signal in a given channel, hence
>having to apply more gain to that channel, then I'd expect to see
>more noise in that channel.
>
>I had some experience with this shooting concert photos in low,
>reddish light. I blew out the red channel but underexposed the
>green and blue channels.
>
>In conversion to B&W, I would've liked to just use the red channel,
>but since it was blown out, I had to use the other channels for
>highlight detail. And being underexposed, they brought a fair
>amount of noise with them.
>
>A good illustration of all that noise:
>
> http://narcissus.net/SandaWeigl/pages/doug-wieselman.ht...
>
>> Beyond the reactivity of the
>> camera elements at any given time, it would appear (reasonably)
>> that the source light(incandeesent, sun, etc) factors
>> into this dynamic....so the white balance comes into play.
>> Presumably the camera logic factors all this in. How would i
>> know..with a 20d, which setting was best to avoid noise in
>> low light...For example..an 800 iso with the wb set to tungsten - just
>> as a hypethetical.
>
>Eh, just shoot RAW, and worry about the WB at your leisure.
>
>> Or more directly put, I can WB bracket on the cam. Is there anyway to
>> know which colors to supress and which to enhance for the purpose
>> of noise reduction. Is this even relevant? Geeezums. Duuuuuh.
>
>I'm no expert on this stuff, but my best guess is that the most
>significant thing you can do to reduce noise is to expose as far to
>the right as you can without blowing out desired highlight detail.
>If your final image is going to be monochrome, then you should look
>at the characteristics of each channel. (Unfortunately, AFAIK, only
>the really high-end DSLRs give you per-channel histograms.)

Thanks for taking the time to advise Ben. RAW..and get the best
exposure you can (right). Sounds saged to me

rgds and grat
Ken
Anonymous
April 12, 2005 1:34:22 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

On Mon, 11 Apr 2005 17:57:38 +0000, Jeremy Nixon wrote:

> Underexposing and then fixing it in Photoshop will result in lower
> image quality than getting the exposure right in the first place.
> This isn't just a general guideline; it is something that will be
> true 100% of the time.

Agreed, but Photoshop is capable of some extraordinary remedies. I use the
curves with the eye-dropper tool to sample blacks, greys and whites. The
results are eye-popping.

> The above is extraordinarily bad advice. If you just want to get
> a shot, and don't care about the best possible quality, you could
> spend a lot less money and effort and just use a point-and-shoot
> camera.

That's a bit extreme.

--
The good old days start now.
Anonymous
April 13, 2005 2:07:49 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

In message <pan.2005.04.12.07.34.20.108000@home.com>,
Roxy d'Urban <not@home.com> wrote:

>> The above is extraordinarily bad advice. If you just want to get
>> a shot, and don't care about the best possible quality, you could
>> spend a lot less money and effort and just use a point-and-shoot
>> camera.
>
>That's a bit extreme.

Not really. It may be worth under-exposing in some situations, to
preserve very bright highlights, to make a blanket policy of
under-exposing reduces image quality and especially editability.
--

<>>< ><<> ><<> <>>< ><<> <>>< <>>< ><<>
John P Sheehy <JPS@no.komm>
><<> <>>< <>>< ><<> <>>< ><<> ><<> <>><
!