Alright, the dress code would be preferably jeans and long sleeve tops. If no long sleeve, then bring more insect repellent, be prepared to get drenched in the repellent. And no blue tops, blue jeans at least ok since there won't be any exposed areas for the bottom. You will definitely regret big time if you dress in blue for your top. No bright colours.
Since the grp is large, try to keep very quiet. This is not a talk-c*ck joking session which you can try for portrait or fireworks photoshoots. Quiet stealthy movement through the trails and if you wanna shoot a bird, no sudden movements. Switch HP to silent mode since you will be getting 2 or 3 SMSes when you walk near the Malaysian side, esp with such a big group.
Try not to wear cologne. If scared of armpit smell, deodorant (not cologne/perfume).
Try to bring at least 300ml of water.
Insect repellent.
Tripod/monopod for your tele lenses.
Near IR filter if you have. CL-PL can too. Ultra wide angle. Macro.
Flash. (if got sync cord, bring too.....Nikon can use CLS for off-cam).
Personally, 8AM at SBWR is already on the late side. But i guess bo bian for this.
Enjoy yourself guys.
