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 http://www.palaeoart.com (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.

Reflectance Transformation Imaging - Dome construction

Today my Cree LEDs and Arduino-type board arrived in the post, closely followed by the 600mm diameter acrylic dome.

Let the build begin....

600mm acrylic dome with flange, 4mm.

Arduino clone

Cree LEDs. I've gone for 4v through the hole for this initial prototype, sacrificing shorter exposure times since I understand the primary constraining factor will be the speed at which the camera will save pictures in RAW format.

Marking the dome up. This dome will have 48 LEDs, so there are four rows of lights. From the top 8, 12, 16 and 12 in the bottom row.

All 48 holes marked up.

This is the clone wired up to the bread-board with three LEDs to test my programming skills! Wired to the board, the jack end of the remote (now cut in two) successfully focuses and then triggers the shutter whilst each LED is lit in turn. I plan to use the remote switch to a) start the sequence or b) manually advance through the sequence.

LEDs and resistors soldered to boards.

Drilling holes into the dome. A jig is used to obtain the correct angle.

Soldering the ground...

And the live wire

Ta-da! Camera hole cut and first coat of black.

Wired up, painted and the clone is in a case... Next step is to test (and debug I expect).