be a great scanning
discussion group but I get these kind of post cluttering my mail box. Makes
me want to unsubcribe right now!!!
- Original Message -
From: Austin Franklin [EMAIL PROTECTED]
To: [EMAIL PROTECTED]
Sent: Friday, August 09, 2002 10:35 AM
Subject: [filmscanners] RE: IV ED
Basically, what it comes down to is that if you want more signal and
less noise, then contribute signal, not noise. If you are here to watch
and listen you are certainly welcome, but you cannot dictate policy or
content.
Hi Arthur,
I agree with what you said, and I'm sure you know
This is going to be my last on-forum comment on this.
I HAVE provided definitions, clear, concise definitions. I have also
clearly provided my assertions etc. I said I would write-up something,
I
never made any PROMISE to do so, nor stated any time frame for doing so.
I accept that you
Julian,
Julian now replies:
Hmmm. Here is the draft ISO spec, from
http://www.pima.net/standards/iso/tc42/wg18/WG18_POW.htm . It is
entitled
Photography Electronic scanners for photographic images
Dynamic range
measurements. Perhaps there is another ISO spec from which you are
---direct quote from Proposed ISO standard---
7.2 Scanner dynamic range
The dynamic range is calculated from the Scanner OECF by:
DR = Dmax - Dmin(7.2)
DR = Scanner Dynamic Range
Dmax = Density where the Signal to noise ratio is 1
Dmin =
on 8/9/02 10:29 AM, Austin Franklin wrote:
You will notice, it is exactly as I have described it, a RANGE.
I do not see ANYWHERE where it says dynamic range is a range. It shows
the RESULT of a calculation WITHIN A RANGE (Dmax), divided by the noise
(Dmin), but the result is NOT a range.
the media under test, while a scanner captures light entering
through its lens aperture.
-Original Message-
From: Clark Guy [mailto:[EMAIL PROTECTED]]
Sent: Thursday, August 08, 2002 3:08 PM
To: [EMAIL PROTECTED]
Subject: [filmscanners] RE: IV ED dynamic range... DYNAMIC RANGE!
HI
Hi Toodd,
Ouch. Sigh. Dynamic range:
1. The difference, in decibels, between the overload level and
the minimum
acceptable signal level in a system or transducer.
snip
5. The difference between the maximum acceptable signal level and the
minimum acceptable signal level.
Peter,
Some time ago you promised us a paper setting out your definition,
derivations and sources.
I HAVE provided definitions, clear, concise definitions. I have also
clearly provided my assertions etc. I said I would write-up something, I
never made any PROMISE to do so, nor stated any
Message-
From: Kapetanakis, Constantine [mailto:[EMAIL PROTECTED]]
Sent: Thursday, August 08, 2002 9:58 AM
To: Clark Guy
Subject: [filmscanners] RE: IV ED dynamic range... DYNAMIC RANGE!
You are right. The max optical density of our ss120 scanner as an example is
about 3.6~3.7. We measure
Hi Arthur,
Based upon the discussion which occurred here recently regarding the
use of density range, dynamic range, etc., it seems fairly hopeless.
Partially speaking, this is because there have not been agreed upon
definitions or standards within the industry.
Actually, that's not true.
: [filmscanners] RE: IV ED dynamic range... DYNAMIC RANGE!
Hi Laurie,
The whole damn thing turns on the phrase, acceptable signal level.
Austin, if I read him correctly, holds that acceptability is defined as
being above the noise level at the low end;
If you read the definitions used, both terms
Arthur Entlich wrote:
Partially speaking, this is because there have not been agreed upon
^^
definitions or standards within the industry.
That was supposed to read Practically speaking...
Art
I am only posting two replies to what has been posted during my
overnight. This one is a short response to the nitty gritty of Austin's
argument. The other includes replies in a single post to other points by
everybody.
There are two points I am addressing in this post:
1. Dynamic range is
Julian Robinson [EMAIL PROTECTED] wrote:
1. Dynamic range is a range, not a resolution
No, it's a ratio; a value measured in dB. As such, it implies a resolution,
namely the number of divisions it makes sense to divide (quantize) the range
into.
2. Dynamic range is the range that the
This is composed into a single post because I know that this topic is
overexposed and frustrates many people. It frustrates me too, but it would
be wrong not to try to correct misinformation which is propagated with such
authority that it has succeeded in hijacking the moral and technical high
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