A dark place

Having dried inside-out overnight, I was about to turn my wetsuit right again this morning when my eyes detected some movement in the suit. As I carefully checked, out came some weird but innocent looking insect. Too small. Still suspicious, I slowly bent some more neoprene, thereby revealing the actual alert tripping culprit: a small scorpion (2cm not counting its bent up tail). Welcome to Mexico!

Pickup truck fully loaded with three sets of gear & doubles, Richie, Gosia & I agreed to pay Jailhouse a visit, Richie absolutely wanting to show us the Swiss Syphon, despite my stated reluctance for dark places. I never felt at ease in Sistema Naranjal and suppose I never will, its stained walls absorb all light and extrude a somber mood.


With three Ts, a jump and another T it's a rather complex left-right-right-left-right path line to get to the sub-halocline Swiss Syphon, but the salt water passages there are quite something to behold indeed.

On the way back from the cenote, Richie spotted Gunni sitting in a roadside café, so of course I jumped out of the truck to greet my former boss of Aktun Dive Center, now fully into kite board surfing.

CamOne+aquapixs in Chan Hol

Great 90' cave dive in Chan Hol led by Jeff, who carried an extra video light for your visual pleasure. Chan Hol has some really cool tunnels, the perfect place for a staged lighting configuration.

Today I actually trusted my CamOne into my self modified DiveBox, i.e. the one with a flat lens prototype in stead of the original dome lens. This flat lens prototype was kindly sent to me for trial at my own risk by aquapixs, the German company that also makes the GoForFocus flat lens replacement for the popular GoPro. Whether they'll commercially produce flat lenses for the CamOne I don't know?

The two main advantages of this solution are that you don't need to change the CamOne's factory set focus and you can shoot both above and below water in Full HD. More about pros & cons in another post.


For the record: Importing & converting the 25 Full HD clips at only a 1/4 of their original resolution into iMovie 08 took 1h, for about 3.3 GB of raw material I collected this morning. Followed by about 90' of editing. Exporting the quickly cut together 2'48" selection of passages at 960x540 only required 6'. Uploading to & processing by YouTube demanded another 39' of patience for this 82.5 MB teaser.

[ 19.12.2018 ] new 1080p video uploaded to Youtube

Cave crawling

After three long days of room rest, another cave dive at last. Not just in any cenote, this time we went to my favorite: Kalimba. Upon entering & exiting the dry cavern to check the entrance pool I got tapped upon the shoulder by two bats, which I took for a good omen.

With me again to record the action: my tiny CamOne infinity in its original DiveBox, its optics now turned about 95° counter-clockwise for a small lets-try-it change, but I don't think its better than 90°?


The CamOne infinity, snuggly fitted in its DiveBox, was mounted on a Sea&Sea tray together with two TillyTec LED 2000 VIDEO lights.

Richie led for 50' into darkness, going left at the T, before I gave the turn-around sign with still more than 2/3 left of my nitrox mix, and headed back towards daylight. This shallow cave section, part of Sistema Sac Actun, gets tight here and there, requiring some finger crawling and precise maneuvering to get one's body & tanks positioned as required to fit through the various restrictions. Cozy indeed. I like!

Santa Fe

CamOne in Aktun Ha and Dos Ojos

Joined a cavern tour today to try out my CamOne below water, using the original DiveBox with domed lens, meaning I had to manually re-adjust the camera's focus by rotating its optical element, about 90° counter-clockwise, so as to get relatively sharp underwater footage.

Note that with this solution you can't have it both ways, it's either sharp above or below. Evaluating the Full HD clips I'd say I haven't quite hit the optimum setting yet, but it's hard to tell due to grain.

Playa Maya

Third beach session in a week's time, that's a personal record! Only to experiment with my CamOne's time-lapse mode of course. I wouldn't want to get a tan, I'm here as a daylight shunning cave diver after all.

Cuzan Nah

Private 99' cave dive in Sac Aktun lead by Richie, Robbie's jr. brother, whom we also met there with two swedish cave divers. We almost closed the beautifully decorated Cuzan Nah loop, but I had to call the dive shortly before. Coming out with more than 100 bar at the end.

Room of Tears

Upon arrival at Aktun Ha, a.k.a. Carwash, we're greeted in watchful silence by a small (<1m) but apparently well fed lagarto, enjoying a warmup sunbath by the cenote's edge.


After taking our time to gear up, Richi and I step straight into the cenote's refreshing 24°C water, perform a mutual equipment check, slowly descent to about 4m for some safety drills, then head for the cavern's entrance, where RIchi starts laying a continuous line towards the cave's permanent main line. About 20' later we pass Luke's Hope, another small cenote, now completely cleared from overhanging vegetation, thus letting in a lot more daylight than before. Then off we jump into a small hole and through a narrow tunnel in order to reach the Room of Tears, still as wonderful as ever. Having almost used 1/3 of my nitrox mix, I give the turn around signal after 37'.


Back in the cenote's entrance pool I tried to find the small alligator but couldn't see it. Maybe later? The good news is that my modified DiveBox remained dry this time, after having replaced the first flat lens prototype with the second one I got. So there's still hope indeed.

Tulum playa

After breakfast and a copious amount of sun lotion I grabbed myself one of Villa Matisse's Beach Cruisers and headed for la playa, even against a moderate wind an easy 25' ride, now that there's a nicely paved bicycle path all the way to the T-junction, where I turned left, following the road till a public beach section, used by local fishermen as anchoring site for their lanchas.

Having nothing to do I tried to shoot a time-lapse with my CamOne infinity securely wrapped around a washed up tree log using a small Gorillapod, thereby forcing me to stay at least half an hour in the blazing sun. Most of it turned unusable though due to fogging up of the housing's domed lens…

Temperature quickly rising and there being no free shade in sight, I soon saddled up again, biking back to el pueblo in only 20', now aided all the way by the refreshing sea breeze.


It's actually possible to go by foot, but only if you're crazy like a loco. By taxi, the official tourist price is 50 Pesos one way, i.e. about 3€.

Solo check dive in Aktun Ha

Went to Xibalba this morning to set up my gear. To my dismay my backup second stage, a Scubapro S550, is not functioning, despite having been serviced recently by Gerda's Dive Shop. Had to swap it with my R190, brought for stage diving. So much so for german Gründlichkeit. As you can imagine, I'm quite disappointed :o/

After lunch a taxi drove me to Aktun Ha, where to my surprise I got greeted by Miguel surfacing from a photo dive as I was about to splash in. Miguel was my cave guide four years ago. Small world indeed :o)

Friendly surface chat over, I took my time slowly diving around the shallow open water area, still clear of algae, just getting used to being underwater again with plenty of gear all over, before lining my way into the cavern zone to check my lights and also drop a little deeper to pressure check my two DiveBoxes. The original remained dry down to 18m, but the modified housing alas leaked, from the looks of it, through the hand-glued prototype lens :o(

At 4pm my driver picked me up again and brought me back to the dive center for 180 Pesos return, i.e. only 100 more than for mexicans.

DIY lens replacement

Replacing my secondary DiveBox's standard dome lens with a flat lens prototype took 25', carefully following the german manufacturer's step-by-step instructions. Now I just need to test my modified box's waterproofness, before trying it out with a camera inside.


Using a DiveBox with flat lens should allow me to shoot in Full HD (i.e. with a FOV of 127°) both above and below water, without needing to manually re-focus my CamOne infinity for each medium, as would be required with the original dome lens.

Note that this flat lens solution causes heavy vignetting in all photo modes (3|5|8MP) and in 170° videos (480p & 720p), at least in air!

---

UPDATE: My modified DiveBox failed its first test, from the looks of it the prototype lens leaked :o( The original remained dry down to 18m.

UPDATE: Yesterday I replaced the first flat lens prototype with the second one I got in about 15'. And today I'm happy to write that this one passed its first 70' submersion down to 18m.

Room #5

Sonthofen - Tulum

Door to door a 20h journey, leaving home around 7:40 to catch the 8 o'clock train (25€) to Munich's airport, arriving there three hours later as planned. Check-in, passport-control & security-check. Slightly delayed take-off and landing about 12h later, a little after 6pm local time in Cancun, after a rather long flight w/o personal entertainment system. Immigration stamp, luggage pick-up & customs control. Uneventful shared shuttle transfer (60$) to Tulum in about two hours.

51kg packed to roll

Last day delivery

Twelve days ago I unexpectedly received two flat lens prototypes for trial, upon which I immediately ordered a second DiveBox (30€) for my CamOne infinity directly from ACME, these not being readily available yet in online shops. Today, less than 24h before departure, DPD delivered the box at last, together with a spare battery (25€).

Bathtub trials

Just as GoPro's standard housing, CamOne's DiveBox suffers from blurry vision when used underwater. Unlike GoPro's HD HERO, it's supposedly possible to manually adjust the CamOne infinity's focus to get sharp underwater images using the original domed housing.

As there's nothing like trying it out one-self, I filled up the bathtub, pre-checked my DiveBox's waterproofness, put in the CamOne and gave both their first plunge together. For the record: with standard housing & factory-set focus, underwater footage is uselessly blurry indeed (screenshot from 1080p clip below to see for yourself).


Corrective action being required, I put on my reading glasses, got out a precision screwdriver, slightly unscrewed the two 1.5mm screws keeping the CamOne's optical element fixed in place and turned the lens counter-clockwise about 60°. Placed the camera snugly into the housing again and went for another dip. To my surprise that little twist already improved image quality quite noticeably, as in usable-if-need-be. Getting good enough focus, at least at close range, required several more twist-plunge-check cycles and, it being an overcast day, some more artificial light to reduce overall graininess.

In the end, I rotated the lens nearly 90° counter-clockwise* from the factory setting, i.e. a quarter turn, in order to obtain a relatively clear underwater image. Note that sharp below means blurry above!


So, definitely possible, but alas rather impractical on the go as this re-focusing involves fiddling with two tiny screws and requires some Fingerspitzengefühl. Whether in the middle of Yucatan's mosquito infested jungle after a sweaty hike, on a rocking salt sprayed boat before rolling back over into the sea, or, you get the picture, pretty anywhere near outdoor action, is not quite the right place nor time to open a housing and start screwing around with a camera. YMMV.

Meaning you have to decide beforehand whether to go for air or water footage, as shooting sharp in both mediums is not possible without giving the lens a spin. While acceptable for a dedicated above- or underwater cam, not being able to obtain mixed footage, not to mention one-take transitions, is IMO a very restrictive limitation.

Enlightened caveman?

Worn in these pictures: stainless steel backplate, harness, pouch with spare mask (not visible), pouch with arrows & cookies, small knife, safety reel, primary light source (TillyTec LED 1000 + Goodman handle + umbilical + Green Force Flexi II NiMH battery pack), two backup torches (TillyTec MPL 500 & 1500) and my video lighting setup (TillyTec LED 2000 VIDEO ×2 + Y-umbilical + TillyTec TT 3 NiMH battery pack). All together about 10kg of gear.

To be added: wings, double tanks, regulators, backup knife, mask, fins, wetsuit, primary reel and housed camera with armed tray.

Steinbock Konstellation

In plain english: underwater camera lighting support constellation (codename "ibex") to be tried out & adjusted as needed on location.

Flat lens prototypes

In my mailbox this morning: an envelope sent by a friendly company with two flat lens prototypes for my CamOne's DiveBox.


To be assembled, tested & used at my own risk. Returnable after review if not wanted. Feedback appreciated. [ to be continued ]

TillyTec MPL 500 & 1500 LED torches

After getting a TillyTec MPL 500 single LED torch as second backup at boot 2012 for my upcoming cave diving trip, I decided to trade in both my old Green Force Tristar Diamond head and TillyTec W30 backup light (plus some cash) for a new TillyTec MPL 1500 triple LED torch.

According to TillyTec the MPL 500/9010 has a 30W halogen equivalent 10° beam, delivering about 9000 Lux or 500>197* Lumen at 5500°K for about 3h at nearly 100% and up to 10h at diminishing output.

The larger MPL 1500/30010 has a 85W halogen equivalent 10° beam, delivering about 30000 Lux or 1500>370* Lumen at 5500°K for ca 1h.

Both torches are of course compatible and can be shortened in lenght from about 20cm (3x AA batteries) down to 12cm (1x 18650 cell).


The MPL 500 & 1500 are meant as hand-held torches, but an optional shaft clamp with velcro strap is available allowing Goodman-handle style finger-free use. And the MPL 1500's larger head actually fits into my TillyTec LED 1000 & 2000 flex-arm clamps, an interesting option especially for video using the 85° wide beam model, e.g. as short wireless version or together with a MPL-1 battery pack connected via umbilical cable for up to 4h of bright light.