Dome1 – Ashmolean

Dome1 was our first “quarters” split portable RTI imaging dome produced in the AHRC project for the Ashmolean museum in Oxford. It  used 76  3W white LEDs (~400 lumen  Bridgelux BXRA-N0402-00000 LEDs) driven with a constant current source.  A grid cross-over technique is used to power each in turn using our custom usb controller, plus a Nikon D3x camera controlled via its USB connector. These LEDs have a “neutral white” colour temperature of around 4100K. We rely on a short (< 5s) exposure to avoid heating effects and the need for a heatsink.

here you can see the "feet" which not only stand the dome off the table but hold the quaters together
here you can see the “feet” which not only stand the dome off the table but hold the quarters together
Here is Dome1 being testsed in the University of Oxford
Here is Dome1 being tested in Oxford
a "lab-jack" was used to raise the objects slowly into focus in the centre of the dome
a “lab-jack” was used to raise the objects slowly into focus in the centre of the dome

You can see a time-lapse video of the dome construction on Vimeo. The two domes of this design are in Archaeology in Southampton and in Oxford. The camera frame is the first version and not as stable as the one designed for domes 4,5,6.

dome2 bridgelux spectrum

This is the spectrum of the LEDs – showing the characteristic blue spike around 450nm (taken from datasheet).

2 thoughts on “Dome1 – Ashmolean

  1. What LED’s did you use in Dome4 ? How big is the dome and what is the largest object that can be imaged?

    Thank you,
    John

    1. Hi – the latest LEDs we are using are Bridgelux BXRA-N0402-00000. About 300 Lumens.

      The dome diameter is 1m – so upbjects up to about 20 to 30cm are a maximum size recommended.

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