Thursday, 11 July 2013

RAW vs JPEG demo video

This video shows the difference between RAW and JPEG captures.

Nikon D80 or D7000 set on RAW+JPEG, images viewed in iPhoto.

Good quality screen and internet connection are needed to see the difference.
RAW capture has more shadow detail, less saturation and contrast, and smoother tones in the highlights. Check out the sun ball and the deep under ledge shadow areas.

For evenly lit open scenes and macro JPEG works well giving a pleasing image straight out of the camera. But for scenes with deep shadows, sun balls or large areas of mid-toned background water, RAW is best.

Of course the idea with RAW is that it's just the starting point. Adjustments to exposure, contrast, saturation and sharpness are most likely needed. But you can make these adjustments with less degradation than if you started with the JPEG.

By degradation I mean visible banding in the graduated tones of the background water, and digital noise or speckling in the darker areas.

Thursday, 27 June 2013

2 camera solo video drysuit dive

In this video, shot with Nikon D7000 and GoPro HD2, I don a drysuit unaided, show the beach entry at Cottage Reef and meet some of the local marine life.

Shooting with a second camera like a GoPro can add an interesting cutaway viewpoint to the final edit. But some post processing of the auto exposure and white balanced GoPro footage is necessary.

Saturday, 1 June 2013

Video via towed diver

This info is mainly for my own future reference.

I have occasionally needed to record video along underwater transects (that's a scientific term for straight lines running across an area of interest). For transects of 100m or so it's OK to swim it (on scuba), but for longer distances I have been towed behind a boat. A scooter would be the best option but not within the budget.

For the video to be useable towing speeds need to be very slow. Firstly so the diver can hang on and have some depth control and secondly so the image is not moving too fast.

In the past a Panasonic Lumix LX3 has given reasonable results, but this time I tried the Nikon D7000. I wasn't using lights so did a Manual WB measurement off the sand, and that worked well. Max depth was only 4m.

Camera setup was Tokina 10-17mm at 17mm to reduce the fisheye distortion, pointing down and slightly angled forward about 1m off the bottom. 1/50th sec Shutter priority -0.3EV and ISO 400.
Here's an example of the footage captured.

Better results would be achieved with a faster shutter speed (so that single frames would be usable), say 1/125th, slower towing speed, 0EV, more distance to the bottom, say 1.5m, and/or angling the camera 45ยบ forward.

It was interesting to see thousands of Elysia viridis? slugs over the entire area we surveyed.

Friday, 19 April 2013

Tasselled Anglerfish

Blairgowrie Marina is the best site to find this rare and cryptic fish.

I have dived at Blairgowrie 26 times over the last 6 years and this is the first unaided sighting for me.

The camouflage mimics red algae closely so the only way to spot them is by finding the mouth, eye or lure.

My next challenge is to find one in a more photogenic pose, just have to keep returning.

Wednesday, 27 March 2013

Rapid Bay dive trip - Days 2,3,4

The wind eased overnight so it was just a matter of waiting for the water to clear up a bit. We checked the jetty first thing but the swell was still up and vis about 1/2m.
Checked again in the afternoon and conditions had just improved enough to jump in. Swell was still enough to make entry a little tricky with a bulky camera setup but vis had improved to 3m. Lucky we did dive because this would be our only break in the weather for the whole 4 days.

The trip from the dirt carpark to the entry platform is much easier with trolleys. It's shorter than it used to be walking right out to the end of the old pier and could be done without trolleys if you don't have heavy camera gear. We locked the trolleys and camera bag to the pier railings with a bike cable lock, but the fishos seemed friendly enough. It gets very crowded on weekends.

From the entry platform a row of metal stakes lead west straight across to the old pier in about 6m. Another row heads out north west toward the end of the old pier then does a dog-leg back to meet the main pier. The stakes must be about 5m apart, we couldn't see from one to the next.
The area between the two rows of stakes is called Leafy Gardens, there are 5 resident leafies here.

Unfortunately a recent head cold had left me with an unsuspected clogged up frontal sinus. Below 5m I was getting a bad headache above my right eye. This was the first time ever for me, very frustrating. I then spotted 2 leafy sea dragons down at 6m but was unable to get down to photograph them. I flashed Bruce with my strobes and there was much rejoicing, although he wondered why I wasn't down there shooting. I think he interpreted my headache signals as clenched fist type celebrations.

Eventually I managed to get down the extra 1m by going very slowly, or it might have been the adrenaline masking the pain, and started shooting dragons. What an experience, they are the most bizarre and beautiful creatures. They swim very slowly rocking up and down, often swimming in unison with a mate. In fact the rocking motion is how I spotted them initially, and they are slightly brighter yellow than the weed.

We stayed down for over an hour finding one more seadragon, a few big spider crabs and a little cuttle.
While we were down the wind and swell had increased making the exit a little too exciting but nothing could dampen the exhilaration of finding these spectacular and rare seadragons. Leafies are only found in a limited stretch of southern Australia, nowhere else in the world.

We were looking forward to subsequent dives with better conditions but sadly the wind picked up and prevented any more diving over the next 2 days. We could have headed over to Victor Harbour and calmer water but the vis wouldn't have been any better.

Here's a 4 min video of the trip

One issue with diving at Rapid Bay is that there are no dive shops on the Fleurieu Peninsula. The closest dive shop is Southern Diving 70min drive north at Christies Beach. All the closer dive shops have closed down. So we took 3 tanks each and intended to do the 2 1/2 hr round trip for fills after dive 3. Maybe next time.

On our last walk along the jetty we came across an instructor and student from NB Scuba in McLaren Vale. He told us these were the worst conditions he'd seen in 6 months! He also said he has a compressor at home and does fills and is closer than Christies Beach. Good to know.
It was interesting to see the dive instructors wearing shark shields, maybe it's a workplace safety requirement.

More underwater and kite aerial photos here

Thursday, 21 March 2013

Rapid Bay dive trip - Day 1

Bruce T and I are in Second Valley, South Australia for a 4 day leafy seadragon photo trip.

Thu 21st March 2013

Got bogged trying to drive out of Randalsea, our holiday rental house at Second Valley. Had to enlist a passing 4WD to tow us out. The drive is very steep, short and dusty. Too steep for a wagon loaded with dive gear.

Wild weather arrived overnight Storm force NW wind, rain, lightning the works.

Diving not possible in 4m swells and it will take a while to clear up. Bad start.

Saturday, 9 February 2013

Lumix Coolpix Triggerfish

Whenever we do the yearly Bluescope seagrass monitoring trip to Westernport I take the tweaked Coolpix 5000 housing with the Lumix LX3 fitted. Jan always likes to spice up her report with some photos of the colourful marine life under the wharfs.

It's not worth taking the SLR rig and I think the compact setup is better for the difficult conditions. Currents and terrible vis are the norm.

I have been using the Inon S2000 strobe with fibre optic sync cord but that presents some problems. Because the strobe always copies the camera strobe it always gives 2 flashes. That means you cant use full or half power because the strobe can't recharge in time for the second flash.

Using the Triggerfish slave sensor with a wire sync cord and Inon Z220 means I can use the full range of flash power and have total control. The triggerfish can be programmed to fire on the first or second flash. The Inon's dials are much easier to read and operate too.

I also added a focus torch mount using Locline which matches the one on my SLR housing.

Tuesday, 1 January 2013

Dive site aerial photos

Mixing two hobbies, UW photography and Kite Aerial photography, results in aerial photos of dive sites.

On a recent dive to Popes Eye in Jan's boat I decided to sling in the KAP bag just incase the wind was nice. I was a little concerned about disturbing the gannets and kite line tangles. Shouldn't have worried as we were the only boat at the site and the gannets are such good flyers and they tended to come in just skimming the water surface.

I used the Pilot 2m2 parafoil which stuffs into a small bag and the GoPro in its waterproof housing. Wind was just right, light and steady. Next time I'll aim to capture the whole rock circle.

Underwater the blue-throat wrasse were up for some posing and the water was clear enough for some decent shots.

Now my dive site requirements are calm clear water with just enough wind to lift a KAP rig. Unfortunately all subsequent dives have been in perfect diving weather with no wind at all.