HDRI Digest, Vol 70, Issue 3

hdri
1

Thank you guys for your reply:

I think I will go for Greg solution, including a gray card or something whose luminance that I captured the image and use this to correct the output using a scale factor.
I wish there was a Photosphere for windows also.
cheers
Fatemeh

···

On Thu, 17 Apr 2014 12:00:00 -0700, [email protected] wrote:

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Today's Topics:

   1. Re: HDR for Glare Analysis (Lars O. Grobe)
   2. Re: HDR for Glare Analysis (Gregory J. Ward)

----------------------------------------------------------------------

Message: 1
Date: Thu, 17 Apr 2014 12:14:35 +0200
From: "Lars O. Grobe" <[email protected]>
To: High Dynamic Range Imaging <[email protected]>
Subject: Re: [HDRI] HDR for Glare Analysis
Message-ID: <[email protected]>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Hi Fatemeh,

I do not know wether the dynamic range of the raw images you get from
your camera matches the requirements of what you intend to do with those
images. The wide dynamic range in typical daylid scenes led folks here
to use exposure series. About the software, I have some doubts that
Adobe will tell you about the internals of their HDR code. So it will be
difficult to get support or any information about the meaning of pixel
values in the resulting images. Does Adobe claim the resulting HDR
images to have physically correct values?

Cheers, Lars.

Hi there:
I have a question that concerns HDR photo and Glare analysis.

Can I use Adobe Photoshop CC (which has the Camera Raw plugin) to
prepare my HDR images?
after that calibrate it with the use of HDRSCOPE that is proposed by
Mehlika Inanici. Instead of Photosphere?
Regards
Fatemeh
M.Arch
University Putra Malaysia

------------------------------

Message: 2
Date: Thu, 17 Apr 2014 08:37:18 -0700
From: "Gregory J. Ward" <[email protected]>
To: High Dynamic Range Imaging <[email protected]>
Subject: Re: [HDRI] HDR for Glare Analysis
Message-ID: <[email protected]>
Content-Type: text/plain; charset=us-ascii

While you *might* be able to use Adobe's CameraRAW processor to
convert the original images to JPEGs, later to be combined using
hdrgen or similar, Lars is right that Photoshop itself does not
maintain absolute photometric calibration throughout its processing.

Adobe actually hired me to improve their HDR image merge process, so
CS3 and later (I think) derive a camera curve and maintain correct
relative values in the images, similar to Photosphere, but I never
convinced Adobe to include calibration information in their output.
So, you would need to include a gray card or something whose luminance
you measured when you captured the image and use this to correct the
final output using a scale factor. (It is usually a good idea to do
this, anyway.) The procedure for doing this can be found on Mehlika
Inanici's site, and also in other posts to this mailing list.

Cheers,
-Greg

From: "Lars O. Grobe" <[email protected]>
Subject: Re: [HDRI] HDR for Glare Analysis
Date: April 17, 2014 3:14:35 AM PDT

Hi Fatemeh,

I do not know wether the dynamic range of the raw images you get from your camera matches the requirements of what you intend to do with those images. The wide dynamic range in typical daylid scenes led folks here to use exposure series. About the software, I have some doubts that Adobe will tell you about the internals of their HDR code. So it will be difficult to get support or any information about the meaning of pixel values in the resulting images. Does Adobe claim the resulting HDR images to have physically correct values?

Cheers, Lars.

Hi there:
I have a question that concerns HDR photo and Glare analysis.

Can I use Adobe Photoshop CC (which has the Camera Raw plugin) to prepare my HDR images?
after that calibrate it with the use of HDRSCOPE that is proposed by Mehlika Inanici. Instead of Photosphere?
Regards
Fatemeh
M.Arch
University Putra Malaysia

------------------------------

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End of HDRI Digest, Vol 70, Issue 3
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2

Hi Fatemeh,

are you aware of alternatives such as pfstools and webhdr?

Cheers, Lars.