Recharging Desiccant

I'm just hours away from my next trip... departing to Cozumel, Mexico for a stay of a little over two months! Camera is ready, dive gear (including a whole lotta cave gear) is packed, everything looks good to go. BUT. While packing my desiccant I noticed I hadn't dried it in a while. Probably not since last year's Cozumel trip. Here's some notes on when you should dry your desiccant and how to do it.

I use SeaLife "Moisture Munchers" which come 10 to a pack for about $8. SeaLife part number SL911. The main reason I use these is because they are rechargeable, and have a built-in dye indicator to show their condition. They are bright blue when fully dry, and eventually fade to a dull pink when they are used up. Typically if they are starting to look between purple and pink is when I stop using a Moisture Muncher capsule.

The picture above shows three capsules successfully recharged, and three that blew up probably because their holes were too small to let the rapidly expanding moisture escape. Note the deep rich cobalt blue colour. This is your goal!

To recharge, follow these directions:

• Set oven temperature to 275 F (135 C)
  
• Place used capsules between two pieces of corrugated cardboard, and put the carboard on a baking sheet
  
• Place baking sheet in the middle rack of the oven
  
• Bake for 20-40 minutes, checking every 10 minutes or so for that cobalt blue colour which indicates they are finished
  
• Bake additional 10-15 minutes, to be sure the desiccant in the middle of each capsule is done
  

Important!

• Do not use a toaster oven. They are very bad at regulating temperature and you will either melt the capsules or cause the cardboard to catch on fire!
  
• Do not leave in oven longer than 1 hour
  
• You may need to poke larger holes in some of the capsules especially if they are wet
  
• The reason you use cardboard is to protect capsules from radiative heat and to avoid contact with the metal baking pan. You only want convective heat to remove the moisture. Radiative heat will melt and deform the capsules!
  

In some cases, if the capsules are saturated or you use too high a heat, they will blow up like balloons. If this happens you can still use the capsule (as long as the desiccant isn't leaking out of them) but they may not fit inside your underwater housing anymore. I just throw 'em out if they get deformed. They're pretty cheap and I buy several packets at a time.

Remember! Desiccant is a drying agent, not a sponge. It will absorb small quantities of moisture in ambient air trapped in your housing. It will NOT protect your camera if visible moisture gets in there (such as flooding).

I don't know if there is a limit to how many times you can recharge your desiccant capsules. Probably as long as they recharge to a blue colour they are still usable. I have recharged mine at least 5 cycles now.

Ready for Cozumel (Almost)

Yes! Take a look at this beauty. Looks like a monster, no? It is my new Aquatica Pro Digital housing for the Canon 5D Mark II. Top-of-the-line equipment. And I've fully tricked it out for both still and video use!

I received the housing about 2 weeks ago, just in time to fabricate a slew of parts to retrofit the video lights. The lights themselves were borrowed off my Stingray II video housing, since they still work extremely well. I fabricated a mounting plate for the light arms, and a battery tray for the battery pods. This has taken me about 10 days to do, an hour or two per day. Lots of measuring and adjusting for this custom job.

I also made a carry handle (in blue) to make it easier for deckhands to grab the housing safely when I pass it up at the end of a dive. However, after weighing the whole rig and learning it was about 29 lbs fully loaded, I am thinking that it will need to be moved from water to boat in more than one step. It will weigh closer to 40 lbs if I ever decide to outfit two Ikelite 400's instead of one. Very likely, I'll choose only one mode of shooting for a dive (video or still) and leave the unnecessary hardware at home.

Working with this housing has presented a few new challenges:

There is no eTTL coverter available for the Canon 5D Mark II. I had hoped to use my old Heinrichs-Weikamp eTTL converter but all my tests showed it just doesn't understand what the Canon 5D/II is trying to tell it. The strobes simply don't fire. The Aquatica 5D/II housing has the strobes wired straight, without any converter. This is good enough for manual shooting so I'll have to adapt.

Nobody makes an external color compensation filter for a 5" port. So I'll be doing a lot more manual white balancing. I'm not sure how well this will work for video, however.

Since the Canon 5D/II will not autofocus while shooting video, it would have been great to have a manual focus ring for my lenses. Unfortunately, the focus knob in the flat port is too far away from the focus ring of the lens. Any gear would interfere with the lens rim. This is something I hope to work on when I get back from Coz.

So... what's next? 70 glorious days in Cozumel Mexico where I get to learn how to take stunning 21 megapixel photos with this rig. Add video to that and I'll be very, very busy!

Oops...

Just after the photo shoot, I broke the light arm mounting plate by grabbing one of the arms and pulling upwards. I had made the plate out of plexiglas and apparently the stuff is too brittle for what I'm trying to do. Good thing I learned this now! I still have plenty of time to fabricate a new one out of polycarb, which should be significantly stronger.