[Digikam-devel] Fwd: [Digikam-users] Dark Images for 16-bit raw and reconstructed highlights

[Gilles Caulier]

Forwarded to mailing list, to be sure

Gilles


---------- Forwarded message ----------
From: Alex Tutubalin <lexa at lexa.ru>
Date: 2009/5/7
Subject: Re: [Digikam-users] Dark Images for 16-bit raw and
reconstructed highlights
To: Gilles Caulier <caulier.gilles at gmail.com>, paul at waldoware.com
Cc : digiKam - Home Manage your photographs as a professional with the
power of open source <digikam-users at kde.org>


Hi,

I'm not  digikam-users@ member, so this message will be rejected from
list. Hope, you'll receive personal copies.

LibRaw do _all_ processing in 16 bit. 16->8-bit conversion is made on
final output stage. So, you should not see any difference (plus-minus
8/16 bit quality issues) for 8/16 bit modes.

On the other side, highlights recovery WILL darker entire image:  you
lower highlights values (to see details instead of clipped pixels), so
you need to lower all other tones to preserve tonal correlations


Gilles Caulier wrote:
>
> This is a technical question for libraw athor. I CC him (:=)))
>
> Paul please, you forget to mention which camera raw file you use...
>
> Gilles Caulier
>
> 2009/5/6 Paul Waldo <paul at waldoware.com>:
>
>>
>> Hi all,
>>
>> I have been trying to figure out why my 16-bit raw image conversions are
>> going dark on me: if I use "Highlights: Solid White", I get a decent image.
>>  If I use "Highlights: Reconstruct", the image is significantly darker and
>> the details are not as sharp.
>>
>> I have looked at the dcraw man page, Digikam documentation and the Oracle of
>> Google, but I can't find any mention of why highlights would cause an image
>> to be dark.  If this is documented somewhere, please help me with a link.
>> How do you process raw files where you want to rebuild the highlights?  Any
>> help would be appreciated!
>>
>> Paul
>>
>> _______________________________________________
>> Digikam-users mailing list
>> Digikam-users at kde.org
>> https://mail.kde.org/mailman/listinfo/digikam-users
>>
>>
>>
>
>
>
>


--
Alex Tutubalin
Web: http://blog.lexa.ru
mailto:lexa at lexa.ru