From: ASAAR on
On Sun, 31 Aug 2008 19:20:34 GMT, David J Taylor wrote:

> If you feel I have not backed up my opinions sufficiently, I will try and
> expand or explain.

No, I don't believe that you will. You have only to examine the
quotes in your own replies to see the issues you've avoided
addressing. That goes for this latest reply of yours. You've had
many opportunities to expand or explain, but it's not even a matter
of backing up your opinions sufficiently. You have yet to make a
reasonable start. It means nothing to you to have me repeatedly say
that Fuji doesn't provide full resolution 12MP shots at its highest
ISOs, and Fuji makes this clear on their website, in their catalogs
and in their manuals. You continue to state that you wouldn't trust
a company that offers those high ISOs with 12mp shots, when even the
most clueless dummy knows by now that Fuji doesn't and has never
offered that in any of their cameras. You're quick to see insults
before they materialize, yet you don't mind tarnishing your own
reputation with what now can only be described as your own
incorrigible behavior, which continues year after year. You can
only play "rope-a-dope" for so long before everyone catches on.

From: John McWilliams on
David J Taylor wrote:
> John McWilliams wrote:
> []
>> RAW files can be converted to a viewable format by non-linear or
>> linear, gamma corrected, or not, depending on the software and
>> settings of the user.
>>
>> Saying JPEGs have more dynamic range is simply wrong.
>
> To clarify, John, I was talking about the JPEG files which come straight
> from the camera, not those from a RAW to JPEG conversion.
>
> Given the class of camera under consideration (Fuji F100fd and Nikon
> Coolpix 610), would you like to name one which uses a linear rather than a
> gamma corrected representation in the JPEG? I would be very surprised if
> any did.

I am not familiar with either camera, but in any event, it's irrelevant
to my statement: JPEGs do not have inherently more dynamic range than
the RAW from which it's processed.

--
john mcwilliams
From: Shon Kei Picture company on
John McWilliams wrote:
> David J Taylor wrote:
>> John McWilliams wrote:
>> []
>>> RAW files can be converted to a viewable format by non-linear or
>>> linear, gamma corrected, or not, depending on the software and
>>> settings of the user.
>>>
>>> Saying JPEGs have more dynamic range is simply wrong.
>>
>> To clarify, John, I was talking about the JPEG files which come
>> straight from the camera, not those from a RAW to JPEG conversion.
>>
>> Given the class of camera under consideration (Fuji F100fd and Nikon
>> Coolpix 610), would you like to name one which uses a linear rather
>> than a gamma corrected representation in the JPEG? I would be very
>> surprised if any did.
>
> I am not familiar with either camera, but in any event, it's irrelevant
> to my statement: JPEGs do not have inherently more dynamic range than
> the RAW from which it's processed.
>

It's not your misunderstanding of a camera's dynamic range that matters
as much as whether or not you can display it all in a single picture.

If you consider 3 stops to the left of centre will produce an image from
a RAW file that has detail in white and near white areas and 3 stops to
the right will produce detain in dark areas... It is *impossible* to
display a picture with both the left and right detail *IF* the central
portion is correctly displaying the dynamic range of the sensor.

Where David is (seemingly) unable to elaborate on his statement is when
you and the idiot from the frozen wastes of Canada jumped in and try to
discredit him with twisted bullshit about what you perceive the dynamic
range to be.

Well here's some information for you two, that I suspect neither of you
would prefer to read.

The Dynamic range of a camera is that point at which detail in
highlights and shadows in a correctly exposed image cease - *not* an
image tampered with in Photoshop.

When the detail stops being displayed in light areas and detail stops
being available in dark areas, the dynamic range has been exceeded.

It is entirely possible to manipulate the dynamic range during
processing. The resulting JPEG developed from a RAW file may well exceed
the dynamic range of the camera by a considerable amount - but that is
tampering with the image, not a description of the true dynamic range of
a camera.

When (most) Digital cameras save a JPEG file, it will have had some post
processing done to it by the camera's computer and it *will* exceed the
dynamic range of the camera and therefore the dynamic range of an
unprocessed RAW file. Not enough for those people who refuse to consider
ND filters to control contrast and believe they need a $1000 program to
do it after the shoot.

The fact you may be able to extend the dynamic range of a photo further
that the range of the camera with manipulation of the RAW (or JPEG)
image during development, does not change the fact a RAW file - straight
from the camera - has less dynamic range than a JPEG file - straight
from the camera.

Further to this; Instead of trying to extend the dynamic range of the
camera, it is entirely practical to *compress* the dynamic range in the
camera and avoid the need to post process entirely... Unless of course
you actually enjoy this sort of stuff. I prefer to use Photoshop to
produce art photos rather than recover disasters that could have been
avoided with knowledge of photography.
From: David J Taylor on
Alan Browne wrote:
[]
> JPG's 8 bits/color is compressed DR, not more DR. The 'loss' is in
> graduation 'tween colors. JPG cannot contain an expression of more
> information than the original raw, compressed or otherwise.
>
> The key point is that in-camera JPG leaves you with much less in terms
> of options than post-processed raw.

With an 8-bit linear coding, the ratio between maximum and minimum signal
level is 255:1.

The typical RAW data is 12-bit or 14-1bit, having a ratio of max/min of
4095:1 or 16383:1.

With JPEG, taking 2.2 as the typical gamma correction, the ratio is
255^2.2:1, or about 200,000:1.

Agreed that JPEG compromises on the accuracy with which any particular
brightness can be represented, but the range of values which can be
represented is greater with JPEG than RAW.

Cheers,
David


From: David J Taylor on
John McWilliams wrote:
[]
> I am not familiar with either camera, but in any event, it's
> irrelevant to my statement: JPEGs do not have inherently more dynamic
> range than the RAW from which it's processed.

Of course not, but on its own, JPEG has the greater dynamic range. See my
earlier post for the numbers.

David