Nothing special, I use a Panasonic GF1 (Micro-FourThirds-Kamera) with a LEICA DG Macro-Elmarit 45 mm. These pictures where made with indirect sunlight.
But that´s only one part for getting pictures with such a big depth of field, especially because I work with a aperture of 5.4 to 8.
Since you are in Penang do you get to see a lot of barbatum for sale (that may have been wild plants?).
Playing around on the internet I saw a photo from somebodies orchid shopping spree in Penang, and they had an assortment of barbatum that ranged all over the board from pale to dark.
Kind of makes you think the variability in color intensity is pretty high in this species.