Monday April 14, 2008

Underwater photography in the Channel Islands

Just before this year's CSUN conference (blog trip report to come), I went diving with my "friend in the news" Mark Epstein for two days with Truth Aquatics in the Channel Islands off of Santa Barbara. I brought my new Canon G9 camera (bought in part because I thought it'd make a great underwater housed camera), and a new underwater lighting rig: the Brightstar Darkbuster diving torch mounted on their camera arm set.

You can see the photos at this slideshow of my Truth Aquatics dive trip.

The typical underwater digital camera is a housed camera with a flash and perhaps a focusing light (as is shown in this photo of Mark with my old rig + his HID light). The best underwater photos these days are taken with SLR cameras in special custom housings with multiple large flashes. Such a setup can cost more than $10,000! This gets you something like a Canon 5D, a housing for it, and then strobes and arms (ideally 2 strobes!).

For this dive trip, I tried to put together an effective setup at 1/10th the cost. I went with the Canon G9 in order to have something small, but with a bright 3" LCD screen and pretty fast focusing. And then the big experiment: going with the new and incredibly bright 24W HID light from Darkbuster in "video light" configuration (plus diffuser) in the place of a flash. Going this route allowed me to save on buying a bright and expensive flash (the cheapest good underwater flash is more expensive than the Darkbuster!), and meant that I didn't need an electrical sync cord (which requires a more expensive housing and significantly increases your chances of getting a leak) or a fiber optic flash trigger cord (which I haven't found to work that well and getting the right amount of light is always more of a challenge).

I'm pretty pleased with the results, especially for macro photography (check out all of the nudibranch photos). So long as I took the time to adjust the light, and made sure to zoom in a tad so that all of the photo was within the cone of light from the Darkbuster, I got pretty good results. If I do a lot more of this, I'll probably get a second Darkbuster in order to achieve more even lighting results (and use my makeshift "lens cap" - PVC pipe end fitted over the light with holes drilled in for water cooling - to cover one for more dramatic side-lighting - like in this shot). The biggest challenge will still be dealing with surge underwater, which combined with even 1/10th of a second of shutter delay means a high percentage of slightly-out-of-focus photos. My old housed film camera never had this problem... (2008-04-14 21:00:04.0) Permalink Comments [1]

Saturday September 01, 2007

Too Much Fun at ThunderHill

One of the things I like to go is go fast (at least in controlled, safe places...). Last weekend, going fast was accomplished (with our own cars) at Thunderhill, a racetrack owned by the San Francisco chapter of the Sports Car Club of America. I went there with my 18 year old step-son, as part of a High Performance Driving Event put on by the Golden Gate Chapter of the BMW Car Club of America.

We spent an entire weekend at Thunderhill - getting nearly 4 hours of actual "track time" (and 3 hours of classroom instruction). There were around 120 of us, divided into 4 "run groups". Group A is made up of the "nearly ready to start racing" folks. Group B is for folks who think they are hot stuff but really still have a bunch to learn. Group C folks have some experience (and retain a sense of humility). Group D is where folks new to racetracks go. With about 30 folks at a time on a nearly 3 mile track, there is plenty of room to find an empty area and focus on honing your skills (vs. working on passing/being passed techniques).

This was something like my 8th weekend of going fast at a race track (in addition to Thunderhill, I've been to Sears Point [er, Infineon] and Laguna Seca). The first half of the first day was about getting reacquainted with the track, its turns, and how to handle my car on them. Just after lunch turn 2 became my friend again. Also around that time I got back into a good groove with turns 10 & 11. Sunday morning I got a new instructor, and he helped me dial in turns 14 & 15 (the most important on the track, because they lead into the longest straight on the track). I also found his suggestions for 7 and 8 to be very helpful. Finally, his turn-in point for 5 made sense to me, and I found it very comfortable (it is almost an early apex, but since the left is immediately followed by an off-camber, downhill right, it makes sense).

In the A group they had been operating with a set of "relaxed passing rules" - with the exception of turns 1, 5, 8, 9, 14, and 15, you could pass at any time (with a point by from the car you were passing). On the second day they extended this to the B group, and after a little concern, I found it worked quite well (and was passing & being passed in turns 2, 3, and 5a quite comfortably, in addition to the "normal" parts of the track). With good speed carried through turns 14 & 15, I found myself heading into turn 1 at nearly 110mph. I was approaching 100 at turn 14, and just over 90 going into turn 9 (which is up a hill).

Toward the end of the day, I had demonstrated enough consistency and prudence at speed (and good awareness when folks were approaching me from behind and wanting to pass), that I was "signed off". I drove the final 30 minute session solo. A glorious ~13 laps at an average of around 70mph. I brought a video camera with me, mounted inside the car, to help review how I did (and remind myself of things if I return to Thunderhill sometime in the future). I've uploaded a video of that first solo lap for your viewing (and listening) pleasure. [you can also watch the Thunderhill official in-car video and their official on-motorcycle video]. (2007-09-01 18:46:51.0) Permalink

Wednesday July 04, 2007

Vacation!

For the first time in far too long, I took a vacation. My wife and I went to Hawaii. We went diving in Kona with Dive Tek Adventures, snorkeling in Hanauma Bay on Oahu, and we explored the results of Pele's wrath in Puna on the Big island. Here is a brief travelogue, with lots of photos!

We dove with Dive Tek for two days. They were incredibly accommodating, moving their normal 7:30am departure time to to 9am so that we could drive in from Naalehu without having to get up at 0-dark-30 in the morning. They also got us special steel tanks - 116cuft for my wife, and 92cuft for me (as opposed to the normal sized aluminum-80s). This meant our typical dive lasted over an hour (being in 78-82 degree F water, with 3mm full wetsuits helped too).

On our first day of diving with Dive Tek we went to "Hoovers", a site named John P. Hoover, author Hawaii's Sea Creatures and Hawaii's Fishes and a number of other great books. Our dive started with a Eagle Ray encounter, followed by a pair of dolphin sightings. We saw an incredible school of fish. We saw them coming, we saw them up close, and then we saw them swiming away. This was followed by a large cornet fish. In addition to the fish, there was a lot of neat stuff on the sea floor. A careful scan turned up this sea star. While we didn't see any nudibranchs on this dive, we came across the most amazing egg rose of a Spanish dancer. If you look closely you can see the individual eggs. Also among the rocks were eels. We saw both a white mouth eel (here is another photo, up close), and a moray eel. And while we didn't see any whales, we did see what one had left behind...

On our second day with Dive Tek, we started our day with a dive in Octopus Garden Cove. At about 80' depth, you see off in the blue a garden of eels, waving in the water. If you are still and wait long enough lying on the bottom, the closer ones will start to come out of their holes. Just incredible! On this dive we saw a bunch of Crown of thorns starfish. They would grasp a rock like some giant, spiked hand. In fact, their thorns/spikes are quite long and pointy! I love this fish photo, with our dive guide Jeanine in the background. Jeanine warned us that some of the sea slugs would spew a sticky mucus if disturbed. Unlike the previous day, on this dive we saw some amazing nudibranchs, including this divided flatworm. In this cool series of pictures we see another nudibranch that is rapidly heading down a rock. He was reaching toward this pencil urchin. Also hiding in crevices in the rocks was this moray eel. As I got close, the eel backed away from me. One of the other folks diving with us shined his HID light on this frogfish - an amazing end to a fabulous dive!

On our final dive with Dive Tek, we went to a spot called High Rock (which is an underwater pinnacle just 40' below the surface). There isn't a lot of soft corals in Hawaii, but I came across this neat white soft coral at the start of the dive. Soon after, this Butterfly fish appeared. One great thing about diving with Jeanie, she would point out neat stuff to us throughout the dive. Moray eels are common in Hawaii, and High Top was no exception. I had trouble with the flash on my camera (the external Sea and Sea YS-90DX that I use with my Canon PowerShot S50 in it's WP-DC300 underwater housing decided it didn't want to turn on). But I managed to use the built-in flash on the camera, through the housing, to get some light on the eel. Unfortunately the built-in flash isn't adjustable, so the lighting wasn't even. That same uneven lighting effect can be seen here, lighting the rocks that this soft coral was growing from (it is truly amazing just how much red is present, but not visible underwater without a bright light). On this dive my wife found a nudibranch, and you can tell that the rock it is traveling on is quite red (assuming you have a flash...). This dive also ended on a high point, as another diver called us over to see an octopus hiding in the rocks. And with that, we made our way to the stairs that Dive Tek kindly put out for us.

I also took a bunch of photos during our day of snorkeling at Hanauma Bay. Being nor more than 10' under water, there was plenty of sunlight penetrating the water. Unlike diving, however, as a snorkeler, I was much less a natural part of the environment, and fish would commonly swim away from me when I dove down to take their picture. Sometimes I would get lucky from a distance. And then there was this fellow who got all curious about me. He kept close to me, and hung around me for much of my snorkeling trip. In the middle-outer bay, I came across a cleaning station (the small blue & white fish is cleaning the others, who are all hanging out waiting their turn). I mentioned that a lot of light penetrates at this shallow depth, as is evident from the colors on this fine fish. As I started heading back in to the beach, I saw another colorful guy, but he was bashful and didn't want his picture taken. He was briefly joined by his smaller, colorful friend. But it was getting late, and so we headed in hoping to make it to Legend Seafood for Dim Sum. Unfortunately, the fabulous fish had been too tempting, and we missed our lunch...

Of course, there is more to see in Hawaii than what is under water. While we didn't get to see flowing lava on this trip, we did spend time in Puna on the Big Island, where there is a lot of amazing "new land" to check out. Here in this forest of trees and other things we came upon a lava tree. During a lava flow some time back, the lava surrounded a still-standing tree, which then died from within, leaving a hollow lava tree shell. Elsewhere in Puna, we could see coconut impressions left in the cooling lava. We went to Kalapana where a lava flow in 1990 wiped out the town and the beach. While only 17 years old, this new land is already sprouting life. Walking through the black moonscape of the lava field, we would frequently come upon ferns growing in the cracks of the brittle, glass-like lava. As we approached the Ocean's edge, we saw a field of newly planted coconut trees in the distance, behind a small thicket of ficus. Incredibly, in this thicket of ficus we found a gecko and a salamander (the green gecko is barely visible, hiding along the horizontal branch toward the left side of the photo).

Our trip to Hawaii was amazing, if too short. I hope we manage to return soon... (2007-07-04 20:46:17.0) Permalink Comments [1]

Tuesday November 14, 2006

Strč prst skrz krk

If it is Tuesday, I must be in Prague (Praha)...

Today was World Usability Day 2006, and as they did last year, the Sun Prague user interface design team helped host the Prague edition of World Usability Day - with a full agenda of speakers (text in Czech). I was a last minute supplement to my boss Harry Burks' keynote talk. He and I co-delivered our presentation (I got to do all the fun demos).

Being as I had a sore throat from all of my travels (first DC for the second TEITAC meeting, then a brief 25 hours in Denmark, and now Prague), I rather felt as if I had stuck my finger through my throat, and so began my remarks accordingly...

Prague is a beautiful old city, and I would be remiss if I didn't share some of my photos. The Charles Bridge (Karlův most) over the Vltava River is spectacular at night. Above it is the St. Vitus Cathedral (Katedrála svatého Víta) and Prague Castle (Pražský hrad). Alfons Mucha's work is visible everywhere in Prague, but perhaps nowhere more strikingly than in a stained glass window in St. Vitus Cathedral. No photo collection of Prague would be complete without the astronomical clock of Old Town Hall (Staroměstská radnice). And finally, I wanted to share with you one of the incredibly detailed marionette figures (available for sale to tourists and folk art aficionados). (2006-11-14 15:21:40.0) Permalink

Monday April 24, 2006

The Gate

Sun maintains a "Hot Blogs" list which I've appeared on occasionsly (like when slashdot referenced my Massachusetts ODF blog (and which my teammate Rich Burridge is often at the top of). Following a suggestion Rich made, I started tracking my blog via StatCounter. To my surprise, I found that most of the hits to my blog weren't to accessibility postings, but rather to the individual photos from my trip to Coventry, UK, and specifically to Warwick Castle.

Then, earlier today I get an e-mail asking permission from the Christian rock band The Gate for permission to use their modification of a photo I took of the Warwick Castle gate. Cool!

Of course I said yes. Perhaps they'll give me a photo credit when they become famous and release an album or something... (2006-04-24 23:03:45.0) Permalink

Thursday July 15, 2004

European Summer Tour 2004, part 5

As mentioned earlier, I'm in Coventry, UK for a few days. At the rental car agency, the car I'd asked for wasn't available, so I wound up with this car instead. Driving on the left side of the road - with the gear shift in my left hand, the rear-view mirror on the left, and cars wizzing by me on the right - is a somewhat mind-bending experience for this Yank. Add to it trying to read a fax of a screenshot of a JPG map image while coming off a round-about onto the motorway with the trumpet allegro of the William Tell Overture playing on BBC 3, and you have the making of a truly surreal experience!

Having successfully managed to find my hotel, I was able to do a bit of sightseeing before my meetings. There is a lot to see in the beautiful English countryside. I spent the day at Warwick Castle. They have a massive gate which, as can be seen in cross-section is unlikely to yield to medieval weaponry. Inside the castle grounds is a peacock garden, whose occupants are only too happy to show off.

(2004-07-15 10:44:37.0) Permalink Comments [1]

Tuesday July 13, 2004

European Summer Tour 2004, parts 2 and 3 and 4

If it's Wednesday, then we have a lot of catching up to do...

Two weeks ago was the excellent GUADEC conference in Kristiansand Norway (as seen from the air). Wonderful long days (and nights - thanks to a latitude of 58.17 N at the height of summer), and not enough sleep.

This was followed by a quick trip to Stockholm Sweden - both to hook up with my wife Anneli and also to drop by the good folks at Sun Sweden to talk up accessibility. Stockholm is a beautiful city, and I had some time for sightseeing. There is a great statue of St. George slaying the Dragon which I enjoyed. And of course I had to visit the Vasa Museum. I took lots of photos of the Vasa, with its amazing carved prow, the many gunports - see the gunport detail - the experimental restoration work, and the amazing carved rear of the ship. We also found time to visit one of the nearby small castles.

After Stockholm, it was off to Bordeaux for the Libre Software Meeting, and some more sightseeting. The fountain in downtown Bordeaux. One side of the fountain has two men at the base representing sin. The other side has a trio of babies representing industry, a a baby riding a porpous with a couple swiming, while a woman looks on. On both sides of the fountain there are fantastical horses spewing water out of their nostrils. We of course visited the main cathedral with a stunning interior. We also checked out the Beaux Arts museum. At first glance there appeared to be a child lying on the floor, but it quickly became apparent that this was an exhibit-inside-an-exhibit. We also took a brief side-trip to St. Emilion and sampled some of their fine wines, and purchased some lovely congac.

Now I'm in Coventry, UK for visits with Sun UK, and also a bit of sightseeing here as well. I'm looking forward to heading home soon... (2004-07-13 08:45:56.0) Permalink

Sunday June 27, 2004

European Summer Tour 2004, part 1

If it is Sunday, it must be Frankfurt Flughofen...

This past week I've been in Heidelberg, visiting with the good folks at BAUM (makers of many fine products for the blind and visually impaired, including the open source Gnopernicus screen reader/magnifier for UNIX and GNU/Linux desktops running GNOME), in advance of the GUADEC conference in Kristiansand. We met in the delightful Schloss Langenzell, just outside of Heidelberg (not to be confused with Schloss Heidelberg). Bill Haneman and Marc Mulcahy, and I had several enjoyable and productive days of engineering meetings with the BAUM Gnopernicus engineers.

In our four days of meetings, we talked about some of the new technologies available in GNOME for working with Bonobo and AT-SPI from a high level language like Python, as well as debugging strategies for dealing with some of the nastier bugs that affect Gnopernicus. We also looked at some of the new magnification technologies that will soon be available in the Xorg server -> DAMAGE, XFIXES, and COMPOSITE. DAMAGE will allow the Gnopernicus magnifier (aka gnome-mag) to know when the source pixels are dirty and respond immediately (it's actually a much more sophisticated interface than that description suggests; but for the low-vision user, this is the key thing). XFIXES fires events when the mouse cursor changes, and also will provide the actual pixels that make up the mouse cursor image, so a magnifier can magnify them. Finally, COMPOSITE will allow a brand new way of doing magnification, and one that promises to be dramatically faster!

All UNIX and Windows full-screen magnifiers (as well as those for for OS/2, and for Macintosh OS 9 and prior) required two sets of bitmaps in order to do magnification: the unmagnified source screen bitmap (stuffed into a RAM buffer), and the physical screen memory bitmap. Virtually all also have a third bitmap: one containing the full magnified image. This means that to do 3x magnification of an entire 1280x1024 screen at 16-bits (minimum for GNOME to look good), 2621440 bytes for the original copy (2.5MB), and another 23592960 bytes (22.5MB) for the 3x magnified view, in addition to the 2.5MB allocated on the video card. And then for every pixel an application draws onto the screen that is also rendered to the magnified view, there is the first draw command (generally to system RAM, not video RAM), a scaled/copy to the 3x magnified view (again generally in system RAM), and then a final copy to the video display. There are additional steps if the magnifier is doing image smoothing (desired by many low vision users), and of course there are things like mouse cursor magnification and full-screen crosshairs.

All of this conspires to slow down the magnifier (especially as stock X isn't particularly good about copying pixels to/from system RAM). It would be nice if we could just stretch a magnified X window on top of the entire screen, but still be able to get the pixels that would be underneath that magnified window. It would also be nice if we could overlay things like crosshairs at will, rather than having to composite them ourselves...

These things, and more, are given to us directly by the new COMPOSITE extension! Now all we need to do is figure out exactly how to best make use of it to support magnification!

We also used the time in Germany to hook up with a number of blind and low vision users/testers, and helped them configure their systems to use Gnopernicus. After seeing experimental magnification with XFIXES and DAMAGE, one low vision Gnopernicus user got quite excited, and told us he was looking forward to retiring his Windows screen magnifier to move full time to GNU/Linux.

And so ends part 1. Next up: Kristiansand (2004-06-27 18:15:52.0) Permalink