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 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 > > _______________________________________________ > HDRI mailing list > [email protected] > http://www.radiance-online.org/mailman/listinfo/hdri _______________________________________________ HDRI mailing list [email protected] http://www.radiance-online.org/mailman/listinfo/hdri
