Re: ISO

Thanks Mel. It's not devastating that I have to stick with 200 ISO. Just odd, really that Nikon
would start at that setting. Thanks so much for answering my question.

Cheers,
Ian

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--- In Nikon-D70%40yahoogroups.com">Nikon-D70yahoogroups.com, "io2006io" <ioneill...> wrote:
&gt;
> Thanks Mel. It's not devastating that I have to stick with 200 ISO.
Just odd, really that Nikon
> would start at that setting. Thanks so much for answering my question.
>
> Cheers,
> Ian

>From what I have read, 200 ended up being the optimum base sensitivity
for the sensors Nikon chose for the D70. I believe the D300 and the
D3 both have a base of 200 as well. Although in those two cameras,
there is an option that allows shooting at "Lo 1", an ISO 100
equivalent. But stil, 200 is the optimum.

It is a whole new world.

Mel

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.

Hello Mel,

How are you?

Would you or anybody else be able to explain WHY Iso 200 is the
optimum. And what is exactly optimum? IS it that they could not make
sensors less sensitive? Other technical problems? I mean, we know now
that high-end cameras are 'going back' to a full-frame solution, so
why is there no possibilty to have an Iso 100 or even less as that,
for example Iso 50, Iso 25, etc.....?

Regards,

Louis

On 3/24/08, Mel Hughes < mellh_50%40yahoo.com">mellh_50yahoo.com> wrote:
&gt;
>
>
&gt;
>
>
>; --- In Nikon-D70%40yahoogroups.com">Nikon-D70yahoogroups.com, "io2006io" <ioneill...> wrote:
&gt; >
>; > Thanks Mel. It's not devastating that I have to stick with 200 ISO.
>; Just odd, really that Nikon
&gt; > would start at that setting. Thanks so much for answering my question.
> >
>; > Cheers,
> > Ian
>
> From what I have read, 200 ended up being the optimum base sensitivity
> for the sensors Nikon chose for the D70. I believe the D300 and the
> D3 both have a base of 200 as well. Although in those two cameras,
> there is an option that allows shooting at "Lo 1", an ISO 100
> equivalent. But stil, 200 is the optimum.
>
>; It is a whole new world.
&gt;
> Mel

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.

Here are some guesses, many can't be proved, are only common sense based.
First, the sensor itself has only a base ISO! All the other ISO are obtained
using amplifiers, so increasing the sensor internal noise too. These are
facts, not guesses!
The amplifiers are not ideal things, they has their internal noise, the
bigger the gain, the bigger the noise.
Starting for a given base ISO, and a given limit of amplifier gain due to
noise, we have the maximum ISO we can obtain before starting to apply noise
reduction.
Now comes the guesses...
People WANT BIG ISO ! This hype is also pushed by marketing depts...
So, to increase maximum ISO, we must to increase base ISO.
Also, the sensors manufacturers found that under a certain ISO, there is no
gain in IQ to worth develop lower ISO sensors.
Other fact, mass market doesn't care about ISO 50/25... this is only for
"noise in shadow&quot; obsesed or "smooth silky water"; effect, which are a
minority, they don't count
So we arrived to ISO 200 as the best balanced base ISO to please everybody.

A question for the veterans: wasn't this trend already present in the film
before DSLR becoming mass?
I remember myself shooting in the 90s almost only ISO 200 because I find it
more versatile to cover all my needs.

Renato

----- Original Message -----
From: "Louis Weyl" < lbweyl%40gmail.com">lbweylgmail.com>
To: < Nikon-D70%40yahoogroups.com">Nikon-D70yahoogroups.com>
Sent: Tuesday, March 25, 2008 08:26
Subject: Re: [Nikon-D70] Re: ISO

&gt; Hello Mel,
>;
> How are you?
>;
> Would you or anybody else be able to explain WHY Iso 200 is the
> optimum. And what is exactly optimum? IS it that they could not make
>; sensors less sensitive? Other technical problems? I mean, we know now
> that high-end cameras are 'going back' to a full-frame solution, so
> why is there no possibilty to have an Iso 100 or even less as that,
&gt; for example Iso 50, Iso 25, etc.....?
>
&gt; Regards,
>
>; Louis
&gt;
> On 3/24/08, Mel Hughes < mellh_50%40yahoo.com">mellh_50yahoo.com> wrote:
&gt;>
&gt;>
&gt;>
&gt;>
&gt;>
&gt;>
&gt;> --- In Nikon-D70%40yahoogroups.com">Nikon-D70yahoogroups.com, "io2006io" <ioneill...> wrote:
&gt;> >
>;> > Thanks Mel. It's not devastating that I have to stick with 200 ISO.
>;> Just odd, really that Nikon
&gt;> > would start at that setting. Thanks so much for answering my question.
>> >
>;> > Cheers,
>> > Ian
>>
>> From what I have read, 200 ended up being the optimum base sensitivity
>>; for the sensors Nikon chose for the D70. I believe the D300 and the
>> D3 both have a base of 200 as well. Although in those two cameras,
>> there is an option that allows shooting at "Lo 1", an ISO 100
>> equivalent. But stil, 200 is the optimum.
>>
>> It is a whole new world.
&gt;>
&gt;> Mel
>

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.

Hello Renato,

Thank you for your quick and elaborated answer. I tried to understand
all you wrote, and re-read to make sure I did.

Let me see if I understood you every where correctly. If a camera
comes with the minimum of ISO 200 then that is the base. The higher
the ISO on that camera the higher the noise. Right? If higher ISO
(i.e. higher as the lowest ISO e.g. D70 with ISO 200, which YOU call
the base ISO) is done by using an 'amplifier', yes that means more
noise, as we all know and have seen in many test done by Thom and
others... But that still doesn't explain why there are no lower ISO
available in cameras (25-50 or at least 100 ISO). Amplifiers increase
ISO to gain higher ISO. That I understand. That that increases noise I
understand too, because of the limits of this so-called amplifier. On
top of that (if I understand you correctly again) the amplifier has
also internal noise by itself, added to that the working of the
amplifier when increasing the ISO and the result if more and more
noise the higher the ISO.

If I remember correctly from the beginning of this D70 list, many
people 'complaint' about the lack of a LOWER ISO, such as ISO 100. I
still 'crave' for it as I sometimes like to have a F16 with a very
slow shutter time.

You wrote: "the sensors manufacturers found that under a certain ISO,
there is no
> gain in IQ to worth develop lower ISO sensors&quot;. For whatever effect (among them the ones you mentioned) it would be nice to have that possibilty. Marketing Departments can indeed push things in one way, but that's not always what a minority want. Right? Questions: what do you mean by IQ in this sentence? Would there be a technical reason to not have a sensor with lower ISO available? A D300 has, for example, a setting for HDR, double exposure, so why not lower ISO?

In these nineties, I shot mostly ISO 100 for daytime, ISO 200 on
cloudy days and with even less light (very cloudy, evenings, and or
nights) ISO 400. But when being on the beach, or in the snowy
mountains I always dreamed of lower ISO's..... And still do.

Your comments and thought are appreciated. Be well,

Louis

On 3/25/08, Renato Aranghelovici < renato.aranghelovici%40laposte.net">renato.aranghelovicilaposte.net> wrote:

> Here are some guesses, many can't be proved, are only common sense based.
&gt; First, the sensor itself has only a base ISO! All the other ISO are obtained
> using amplifiers, so increasing the sensor internal noise too. These are
> facts, not guesses!
> The amplifiers are not ideal things, they has their internal noise, the
> bigger the gain, the bigger the noise.
&gt; Starting for a given base ISO, and a given limit of amplifier gain due to
> noise, we have the maximum ISO we can obtain before starting to apply noise
&gt; reduction.
> Now comes the guesses...
> People WANT BIG ISO ! This hype is also pushed by marketing depts...
> So, to increase maximum ISO, we must to increase base ISO.
>; Also, the sensors manufacturers found that under a certain ISO, there is no
> gain in IQ to worth develop lower ISO sensors.
> Other fact, mass market doesn't care about ISO 50/25... this is only for
> "noise in shadow&quot; obsesed or "smooth silky water"; effect, which are a
> minority, they don't count
> So we arrived to ISO 200 as the best balanced base ISO to please everybody.
>
&gt; A question for the veterans: wasn't this trend already present in the film
>; before DSLR becoming mass?
&gt; I remember myself shooting in the 90s almost only ISO 200 because I find it
> more versatile to cover all my needs.
&gt;
> Renato

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> Let me see if I understood you every where correctly. If a camera
&gt; comes with the minimum of ISO 200 then that is the base.
Yes, this is the only ISO sensor is capable.

> But that still doesn't explain why there are no lower ISO
> available in cameras (25-50 or at least 100 ISO). Amplifiers increase
> ISO to gain higher ISO. That I understand.
Amplifiers has also their own noise that they amplify.
So if the base would be ISO 100, then the highest ISO would be no more 1600,
but something between 800 and 1600, for the same amplifier gain. Want both
100 and 1600, you must increase the gain, so the noise at 1600 will
increase, because at 100 you will have no noise decrease versus ISO 200.

> That that increases noise I
> understand too, because of the limits of this so-called amplifier. On
> top of that (if I understand you correctly again) the amplifier has
> also internal noise by itself, added to that the working of the
> amplifier when increasing the ISO and the result if more and more
>; noise the higher the ISO.
Seems you understand well...

> If I remember correctly from the beginning of this D70 list, many
>; people 'complaint' about the lack of a LOWER ISO, such as ISO 100.
Mostly they complaint believing at 100 they will have an even lower ISO,
without noticing that 200 it is almost noise free.

> I still 'crave' for it as I sometimes like to have a F16 with a
> very slow shutter time.
Minority report ;))

&gt; Questions: what do you mean by IQ in this sentence?
Image Quality

> Would there be a technical reason to not have a sensor with lower ISO
> available?
Technicaly no, is possible.

> A D300 has, for example, a setting for HDR, double exposure, so why not
> lower ISO?
HDR and double expo are software feature, not related to sensor itself in
any way

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I understand that you cannot stretch an amplifier without end. If you
have ISO 100 on your camera then the maximum ISO would be whatever...
say ISO 1600. If you start at ISO 200 you can have the same stretch
but reach higher, say ISO 3200. Better (read stronger) amplifiers
longer reach. Say again ISO 200-ISO 3200 or even 6400. But the more
you stretch the amplifier the more noise. Correct?

If a D70 would have given us the option of ISO 100, it would maybe
have given us the same amount of noise (better the lack thereof)
compared to ISO 200, but it would have given us slower shutter times,
when needed. Wanted....

Obviously, HDR and double expo are software features and not related
to sensor itself in any way. My mistake

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At 09:41 AM 3/25/2008, Hayo Baan wrote:

>and I'm sure the design of the D70 sensor
&gt;doesn't even allow for this)

Essentially the sensor in the D70 is the *same* sensor as in the
D100, with mostly firmware improvements, and an improved metering
system in the D70. It also is a sensor that was probably at least 3
years old (in design) at the time of the release of the original D70.
It was used in the D70 probably because the rip-roaring success of
the D100 made it a very cost-efficient part, as all of the R&D and
manufacturing set-up had already been amortized.

I think it can be said fairly that the D70 was intended for more of a
mass-market audience, for which ISO 400 (in negative films) had long
become the norm, so it made a lot of sense to stick with a base ISO
of 200. I believe Nikon felt (and rightly, IMO) that photographers
wanting a lower effective ISO were skilled enough, and knowledgeable
enough, to use other techniques to achieve similar results.

As already noted, the main part of the market interested in the D300,
and especially in the D3, want *higher* ISO capability, not lower, so
it makes sense to provide a sensor with a base ISO of 200.

Something also to consider is that the D70 (and D100 before it) use a
CCD sensor, while the sensor in the D3 and D300 (and also in the D2X
and D200) are CMOS sensors. Each type has its own particular quirks as to ISO.

Anyway, *digital* ISO is entirely different than *film* ISO --
sometimes you need less, sometimes you need more, exposure with
digital than with a similarly-rated general-purpose film.

Even in the film days, careful practitioners used to do extensive
experimenting and testing to find out the "true* ISO (and ASA before
that ) for their particular film, camera, lens, metering
technique, and choice of developer. The same is true for digital.

I'm guessing a good 80% of the market back in the film-only era, used
to standardize on ISO 400 negative films, and probably at least 50%
of slide film users standardized on films of at least ISO 100 (and
griped that seemed to be the optimum quality film speed, while
wishing for higher... ). I'm leaving Kodachrome pretty much out of
the equation here, because Kodak all but killed it off during the
'80s for all but a relative handful of careful practitioners.

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