HDRI Digest, Vol 70, Issue 5

hdri
1

I have one more question regarding the calibration:

I am doing daylight research in an office area with alternative shadings (artificial lighting is off during the study).
Is using the Illuminance calibration with the help of handhold illuminance meter a correct way of calibrating the HDR photos In my case?

V. Kumaragurubaran and M. Inanici have proposed this method for special cases such as sun and sky capture.

Dear Lars:Thank you for your proposed alternatives. Webhdr is a great, user friendly tool and I was not aware of that.

Thanks Greg. I've tried to make it short.

Regards
Fatemeh
M.ARCH
UNIVERSITY PUTRA MALAYSIA

2

Hi Fatemeh,

It is possible to calibrate HDR images against the illuminance at the
lens. I have found, however, that calibrating against the luminance
of an object that's in the image is more reliable.

See page 9 of my presentation from the 2012 Radiance workshop:
http://radiance-online.org/community/workshops/2012-copenhagen

the columns labelled CF_lumi and CF_illu list the calibration factors
for that scene, a photo of which is on the previous page. You can see
that luminance-based CFs are much more consistent.

The story might change for sky capture, but I am not familiar with the
methodology proposed by Kumaragurubaran and Inanici.

Regards

Axel

ยทยทยท

On 22 April 2014 04:59, gs33070 <[email protected]> wrote:

I have one more question regarding the calibration:

I am doing daylight research in an office area with alternative shadings
(artificial lighting is off during the study).
Is using the Illuminance calibration with the help of handhold illuminance
meter a correct way of calibrating the HDR photos In my case?

V. Kumaragurubaran and M. Inanici have proposed this method for special
cases such as sun and sky capture.

Dear Lars:Thank you for your proposed alternatives. Webhdr is a great, user
friendly tool and I was not aware of that.

Thanks Greg. I've tried to make it short.

Regards
Fatemeh
M.ARCH
UNIVERSITY PUTRA MALAYSIA

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