"...the behaviour of most present day humans remains moderated by magical thinking-type mental processes (lack of integration between the left prefrontal cortical areas and memory), underwritten by sub-optimal cause and effect perception."

Robert G. Bednarik, An aetiology of hominin behaviour, Homo, 2012

Thursday, 10 December 2015

Reflectance Transformation Imaging - Update 2

Finally! The marbles arrived, sphere detection worked and I have created my first RTI....

Some snapshots

Using the HSS Fitter with specular enhancement

And then with the PTM algorithm....

Static Multi Light

Coefficient Unsharp Masking

Image Unsharp Masking

I've uploaded a couple of ptm files to my website (beware they are large files) for anyone interested in seeing the end result. Additionally the first eight or so pictures were rendered from PTMs and then cut out in Adobe Photoshop.

I have also reduced the overall processing time by using only PTMfitter in conjunction with a single 'lp' (light profile) file. I am quietly pleased with the dome - it does everything I wanted it to do.

Finally, a photo of the finished dome - with protective covering.

Monday, 7 December 2015

Reflectance Transformation Imaging - Update

Finally working. Some issues tackled in the process, including:

The Canon EOS Utility doesn't work on my Windows 10 platform (it appears that I am not alone in this experience). I eventually resigned myself to finding an alternative piece of software to capture and control images directly from the camera.

I made a bracket that I plan can be modified if I use a different camera. 

I changed the configuration of the LEDs slightly. Originally evenly spaced at 10, 30, 50 and 70 degrees, I've moved the top row down to 65 and the bottom row up to 15 - according to CHI the optimum angles at which to set exposure and aperture settings. The picture below shows the dome after these mods.

I did a trial run and found that sphere detection in the Builder process wouldn't work.... Presumably because the black sphere (a pool ball) was too big relative to the highlights. I will test this assumption when the black marbles I have ordered arrive.

Back soon.