Hallöchen! Matthias Andree writes:
> Am 09.12.2016 um 07:33 schrieb Torsten Bronger: > > [...] > > Assume I have an ultra-wide angle lens, such as 16 mm onto a 24x36 > mm² sensor. This covers 107° across its diagonal. So in real > photography, this means the light in the corners if the senor > arrives from 53.5° from the lens axis. > > The close-to-the lens diffuser changes that and destroys this > spatial property, and the light in the corners of the sensor > arrives "from everywhere". I wonder what that does to the natural > cos^4 illumination roll-off, it appears we're skewing that a bit, > too. If the lens is perfectly clean, the corner pixels get photons only from the 53.5° direction. And if the diffusor a perfecly uniform light emitter, the measurement will be accurate. But the latter is difficult to achieve if you cannot put the diffusor tightly on the lens to avoid reflection of stray light. Tschö, Torsten. -- Torsten Bronger ------------------------------------------------------------------------------ Developer Access Program for Intel Xeon Phi Processors Access to Intel Xeon Phi processor-based developer platforms. With one year of Intel Parallel Studio XE. Training and support from Colfax. Order your platform today.http://sdm.link/xeonphi _______________________________________________ Lensfun-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/lensfun-users
