Archive for the ‘Guest Contribution’ Category

Richard Chesher joined 360Cities.net in 2007 and has posted 288 images of New Caledonia, Vanuatu and Australia. He is an Expert Pro and his images have had over 1.5 million views. He has contributed to the blog before on how to take Underwater 360 Panoramas: This blog is about how to expand the impact of your panoramas with themes and descriptions.

By Richard Chesher, Ph.D.

 

 Trekking New Caledonia Dumbea River Pool

 

I love sphere images. For me, a sphere image is a memory bubble; a perceptive memory of a focal point that can be shared with thousands of people all over the world – thanks to 360Cities.net and Google Earth. Using the metaphor of a memory bubble has some real advantages (to me) when I am planning an image, or looking for the perfect place to set up my camera.

Think of it like this: Memory bubbles allow viewers to extend their perception through time and space and, from that vantage place, look out and turn their own perception in any direction they wish. So when you create a memory, it will be more effective, more interesting, if the viewer knows more about what they are looking at – so they can share the memory.

I Was Here Style Memory Bubbles

The vast majority of images on 360Cities.net are “I was here” images – landscapes, seascapes, aerial images, monuments – documenting that location. It’s what Google Earth likes and what Street-View has made into a viewable interactive model of many cities in the world.

These memory bubbles allow people to locate places they want to visit and, if the images are taken with care, reveal our planet’s beautiful, special, unique places, creatures and events as clear, sharp, delightful memory bubbles; captured from just the right angle, just the right light, when they are looking their finest.

 

 Ouvea Paradis Beach Footprints

 

The above memory bubble from Ouvea shows a pair of lover’s footprints along one of the most beautiful beaches in the world – the footprints vanished with the next tide but they remain in the matrix, available for anyone to experience.

By providing the viewer with a written description of what the image means to you, the creator of the memory, you help shape the viewer’s enjoyment of the moment. Locations and moments like this are very few and far between, and precious to record. My wife and I waited two weeks to get the light, beach, water, and sky just right to make this memory bubble reveal the beach looking just right.

Themed Memory Bubbles

Memory bubbles become more interesting if they reveal a story, and not just a place or a thing. This is important because it gives the memory bubble an added depth of meaning. One of my favorite themes for memory bubble stories is life in the tropical Lagoon. I make memory bubbles showing behavior of sea creatures; not a photo of a reef or a fish or a shark, but the interacting behavior one senses when actually percieving the moment.

 

Coral Reef Fish New Caledonia

 

These brilliant yellow fish form dense schools over the coral reefs during the day – but they move away if a diver approaches to photograph them. To tell the story of these snoozing fish I had to think of a way of moving the focal point of my memory bubble right into their midst – a place they would not let me actually go.

So I anchored the underwater camera in the center of their usual schooling area with a little motor to turn it around. After I swam away and got back in my dinghy the fish resumed to their normal behaviour and the robot camera captured them undisturbed. Getting the image took 6 months of tinkering from the time I first decided I wanted to take it.

 

Water Sports Noumea New Caledonia

 

Sometimes a story happens by surprise – like when a sea turtle appeared while I was taking photographs of starfish gathering to spawn in a marine reserve. Surprise opportunities mean you have to be quick to get the shot. Again a description of the surprise adds an important element to the memory bubble – revealing why the girl in the image (my wife) is laughing.

 

 Bird Fish Feeding Frenzy New Caledonia

 

The ideal memory bubble image would tell the story without any written comment at all. Like this image recording a mad feeding frenzy of sea birds and fish. – every fisherman will know right away what’s going on here. But not everyone is a fisherman and a description can make all the difference in the world to the viewer’s ability to share the memory.

 

 Triton Attacks Crown Of Thorns Starfish

 

Very few people in the world would know what this memory bubble is about – or why it is an important story about the survival of coral reefs in many parts of our world. I wrote a really long description of that memory because it was, for me, quite a stellar day in my life. As with all of my descriptions I write in the first person – this is happening to me – to help re-create the memory bubble in the mind of those who will, in the future, revisit this moment in time.

If you take the time to do the image correctly it obviously means more to you than just the scene. So share the story, too.

Photo by Amypalko

 

 

We’ve just created a new category for blog posts created by you, the awesome panoramic photographers who make up our community. The category is called “Guest Contributions” and we hereby invite you to share your insights about techniques, technical improvements, or the story behind panoramas that you’ve uploaded to 360cities.net.

Please send your ideas to blog@360cities.net. Write “Guest Contribution” in the subject field. We’ll get back to you to discuss and agree on next steps, the goal being to turn as many ideas as possible into interesting blog posts.

The 360Cities Team

This is last fifth part of the 360° underwater panorama tutorial series by Richard Chesher. Read Part 1, Part 2, Part 3 and Part 4.

Here is an image of a school of reef fish taken with the robot I mentioned in part 4:

And here is one taken very close to a school small tropical fish

A 3 Volt Hankscraft “Display” motor rotates the camera rig at 1 rpm. I put the motor in a PCV housing with the shaft going through a 1/8″ o-ring sealed camera control fitting. I made a hook mount on the shaft and a bracket to attach to the camera bracket on the other end. There is also a switch and a battery holder (2 AA cells) inside the case (photo below).

Underwater panorama rotator robot

The upper end is attached to the lower end of a section of a pool noodle float – just enough so there remains about 1kg of negative buoyancy for the whole rig. I use the robot as shown in photo 4 for shots close to the bottom or add a length of aluminium strap to raise the camera off the bottom if required.

A GentLED Auto time lapse module triggers the camera.  The camera fits snugly in the Ikelite camera housing and there is no room to place even such a tiny control module as the GentLED Auto. James Gentled was so kind as to make a special GentLED Auto unit with the LED on a short wire extension so I could fit it into the Ikelite housing. I attach the GentLED Auto using a sticky clay-like goo purchased in a stationary store (photo below). I turn on the timer, but not the camera, just before getting into the water and then seal the camera case. The control is set to trigger the camera once every 3 seconds, giving some 20 photos per 360 degrees.

When I have the camera in place I turn it on and check to be sure it is taking photos. Then Freddy and I swim off and spend 15 to 20 minutes taking photos with our other cameras. 20 minutes gives the fish time to get back to their normal behaviour and yields some 400 images. When I return I unhook the float and the motor housing and attach these to each other. Freddy swims off with them and I take the down and up images with the liberated camera.

Post processing becomes a challenge when you have to select 12 to 14 images out of 400 – especially when they contain constantly shifting schools of fish. Unlike land photos, you can’t control the rotational angle of each image because the camera is always moving from wave surge and currents. Sometimes a wave surge will move the camera rapidly – sometimes the focus isn’t correct – and you need an overabundance of images to select from.

Once I have my prime series selected I do all of the color, lighting and contrast corrections to each image in Photoshop before stitching. I save the processed RAW images in TIFF format.

I have tried both PTGui and AutoPano for stitching the underwater panos. I found AutoPano was the easiest and best for stitching these complex images. It works wonders – usually stitching the pano on the first try with practically no adjustments needed. It’s anti-ghosting feature is excellent and I rarely have any half-fish – a big issue when there are hundreds of fish in the image. It also adjusts for color and lighting variations so the end result looks great. After stitching I save the image as a TIFF file and correct any problems in Photoshop. Next I convert the image to cube faces using Pano2VR. I de-fisheye the down shot, open the bottom cube face in Photoshop and cover the nadir with the down shot, carefully matching it with the rest of the bottom view. (I rarely can get the bottom to stitch well in the original image because it is difficult to reposition the camera at exactly the same location). Then I fill in zenith hole in the top cube face and reassemble the cube faces back into a rectilinear image in Pano2VR.

This is last fifth part of the 360° underwater panorama tutorial series by Richard Chesher. Read Part 1, Part 2, Part 3 and Part 4.

This is Part 4 of the 360° underwater panorama tutorial series by Richard Chesher. Read Part 1, Part 2 and Part 3. The last installment will be published next Friday, so watch this blog!

Richard Chesher taking an underwater 360° panorama

Keeping the camera stable relative to the sphere center

Just as on land you need to rotate the camera around the nodal point of the lens and keep it level. The problem is that the camera and the camera case is big and subject to movement by wave action and currents. There is no “nodal ninja” for your underwater work and a tripod can be a hassle when swimming to and from a photo location and getting in and out of a dinghy. Also if you want to use a tripod solid enough to hold your camera steady you need to put heavy weights on the end of each leg to keep it in place. I’ve tried this and quickly decided to do it another way.

There are three “levels” of sphere placement – very close to the bottom (less than half a metre) – near the bottom (about a metre off the bottom) and midwater (more than a metre from the bottom).

Image 1 – Richard Chesher holding his underwater camera housing

I made a bracket for my Ikelite housing out of aluminium. The ends are bent as shown in images above so the attachment holes are located above and below the nodal point for the lens. The upper attachment is next to the shutter release lever so I can hold the upper attachment and trigger the camera manually.

For spheres very close to the bottom or near the bottom I use a monopod – a length of 25-mm wide aluminium – attached to the lower camera bracket with a bolt and wing-nut. I use a 200-mm length for very low level spheres and a folding length 500-mm long for images 500-mm to one metre from the bottom (see image 1). Here is a sphere image taken with the monopod at half a meter from the bottom:

When shooting, I am positioned above and behind the camera rig holding the upper bracket. I turn myself and the camera rig in a 360 circle while taking as many shots as possible (usually 19 to 20) while watching the monopod to be sure it stays relatively perpendicular to the bottom. Before I begin, I take a vertical down shot and a vertical up shot. When I take the up shot I need to hold my breath long enough so the surface is not disturbed and there are no bubbles in the scene.

For mid-water spheres I use a surface float with a string to a small folding anchor.

The float is a swimming pool “noodle”. A surveyor’s chalk line spool with the chalk line replaced with fishing line is attached to one end of the float (see photo above). I hook one fluke of the small folding anchor under a dead coral rock and then roll in the line until the float is about half submerged. Surface waves do not disturb the float because it is in a vertical position. I then swim down and attach the camera at the preferred location by simply looping the fishing line around the bottom and top bracket. Then I position myself behind and above the camera and swim slowly in a circle taking about 20 images per 360 degrees and holding the camera so it stays level and so the line stays vertical (see the photo at the beginning of this blog post). Finally, I carefully note the location of the camera relative to some bottom feature and then remove the camera, roll up the line and give the float to Freddy who swims it out of view while I dive down again to take the down and the up photo.

Both the monopod and the noodle technique can be difficult where there is a current but it still works if you are careful and can compensate for it. Surface waves don’t make much difference as long as they are not too big or causing horizontal surge at your location.

The major problem of both techniques is the monstrous, alien, killer ape (me) smack in the center of the sphere. Except in special reserves where the fish are happy to swim with tourists – like the photo at the Amedee Marine Reserve image above – reef creatures prefer to stay as far away as possible from monstrous alien killers. Even where the fish are not chased, speared or netted, schools of fish are difficult to get close to and refuse to stay around while I set up the camera rig and take the sphere image. So I replaced the monster with a robot (mentioned in the last part of this tutorial series). The robot takes the sphere photos while Freddy and I swim elsewhere.

This is Part 4 of the 360° underwater panorama tutorial series by Richard Chesher. Read Part 1, Part 2 and Part 3. A new installment will be published every Friday, so watch this blog!

This is Part 3 of the 360° underwater panorama tutorial series by Richard Chesher. Read Part 1 and Part 2. A new installment will be published every Friday, so watch this blog!

Issues related to being underwater

The first and foremost problem of taking sphere images underwater is finding the correct location to center the sphere. This isn’t much different from selecting the center of a sphere on land other than you can’t see a prospective location from more than a few meters away if you are underwater and need to be able to guess at possible locations from aerial photographs or from the surface. The only real solution to this is to get really familiar with an area by exploration and have the camera rig ready to go in the boat when you find what you are looking for.

Your chances of arriving at an unknown destination, leaping in the water and shooting a spectacular sphere image are pretty slim. Local dive guides can suggest great “dive spots” but these may or may not be suitable for a sphere image. For example, dive operators like “drift dives” and “drop-offs” and almost always require swimming with a group that will vanish before you can get your sphere done. So you need to tell the guide you are looking for a dive spot where there is something visible in all directions and preferably not over 4 meters deep; a place where the sea life is abundant and colorful. Tell the guide you need a location where there is not much wave action or current.

The next problem is accessibility to the location. You need to be in a reasonably protected location. Taking a sphere image is difficult if there are significant waves or currents since you and the camera will be moving all over the place – especially in shallow water. You also need to be at the location on a sunny day. Since the wind direction and strength and cloud cover changes from day to day any one location might – or might not – be accessible when you can be there. So if you plan to take sphere images the best location is one you have been to before and can access easily over at least a week in the hope of having at least one day of nice weather.

You also have to be comfortable with the normal difficulties, dangers and pitfalls of diving or snorkelling so you can concentrate on your photography. You are not going to have much luck with a foggy mask half filled with water or fighting to submerge because you don’t have enough weights or inhaling seawater with every other breath. In short, sphere imaging underwater requires that you are completely at home in the sea. It also requires that you have a diving partner that shares this facility. Another consideration is that your diving buddy has to pay attention and when you start taking a sphere he or she has to either get out of the scene or stay in one place. You will be concentrating on the camera and won’t be able to keep an eye on what your dive partner is up to.

This is Part 3 of the 360° underwater panorama tutorial series by Richard Chesher. Read Part 1 and Part 2. A new installment will be published every Friday, so watch this blog!

This is Part 2 of the 360° underwater panorama tutorial series by Richard Chesher. Read Part 1. A new installment will be published every Friday, so watch this blog!

Richard Chesher

Color bias, limited visibility, and low ambient light

Sea water, even when it is tropical clear, is an unforgiving light filter. By the time you are 4 meters deep the ambient light is greatly diminished and most of the red wavelengths are gone. Electronic Flash units or movie floods bring out the wonderful colors of the underwater world – but only very close to the camera. The artificial light is attenuated both on the way to the subject and on the way back so you’ll be lucky if you get nice colors more than two meters from the camera. This is not very useful for a sphere image because the immediate foreground would be beautiful the rest of the sphere would be dark and dismal. Using a pair of big strobes raises additional issues of positioning and rotating the whole rig. So as far as lighting goes I only use ambient light and limit my sphere taking to less than 4 meters – generally less than 3 metres.

When you are in the water your brain corrects for the universal blue cast and colors look wonderful – but your unprocessed images look blue and washed out. The solution is to do your photography in less than 4 meters, shoot in RAW format and correct the images during post processing.

I set the white balance to “shade” or “cloudy” rather than auto-white as this gives a more consistent color balance to start with. Having something white in one of the images helps calibrate the white balance in post processing .

I set the camera on AV and depending on the time of day, water clarity and depth I set the ISO between 200 to 600. The object is to keep the shutter speed above 1/100 sec in the darkest part of the panorama with an F stop between f11 and f16.  This can result in individual frames that are darker or lighter than the others but I adjust them to the same relative values during post processing. My stitching program - AutoPano Giga - does a good job of blending it all together.

Focus is a problem underwater. The low contrast – or complete lack of contrast when the camera is pointing towards deeper water – may prevent the camera from focusing – and triggering. My solution is to either shoot a scene where I am sure there is something for the camera to focus on in every direction or to auto-focus the camera on the closest prime object and then set it on manual focus to shoot the sphere. Despite the excellent depth of focus of the fisheye lens, focus is still a problem when the sphere includes something very close to the camera as well as subjects several meters from the camera. If I want to photograph an object very close to the camera I generally make sure there is something for the camera to focus on in every direction and leave it on auto. Autofocus is necessary when, for example, something swims very close to the camera during an automatic sequence. If I am going to leave the lens on autofocus I check to be sure it is actually taking a photo in the most difficult direction. Originally I used my Canon 7D in the 19 point AF mode but like many 7Ds mine developed a focus error in this mode. I found a fix for this but even so, the AF point expansion mode gets consistently sharper focus – providing there is something to focus on.

This is Part 2 of the 360° underwater panorama tutorial series. Read Part 1. A new installment will be published every Friday, so watch this blog!

 

This is a guest blog post by Richard Chesher, one of the most interesting 360Cities photographers, and a friend of the 360Cities team. Richard has been an active professional photographer for more than 50 years and has been published in National Geographic Magazine, Sports Illustrated, the Encyclopedia Britannica and hundreds of books and magazines, and is an expert in underwater panoramic photography.

1) Richard Chesher with his underwater camera housing

Taking underwater sphere images (360° panoramas – editor’s comment) differs from taking land or aerial sphere images in four ways:

1. Protecting the camera in a watertight housing.
2. Colour bias, limited visibility and low ambient light levels.
3. Issues related to being underwater including breathing, cold, currents, delicate or dangerous creatures to worry about.
4. Keeping the camera in a stable position relative to the subject while rotating through 360 degrees.

Selecting and protecting the Camera

You need a fisheye lens and your choice of camera/lens combination is somewhat controlled by available underwater housings.

The best option is to use a SLR with a full frame sensor – like the Canon 5D with a 10 to 15-mm fisheye lens. But that’s an expensive option for such a risky business. I use a Canon 7D with a Sigma 8-mm lens in an Ikelite Housing with an 8 inch dome and port extension. Photo 1 shows my Canon 7D and Sigma 8-mm lens in an Ikelite Housing with an Ikelite – #5510.45 8″ dome assembly and an Ikelite – #5510.10 8″ port extension. These model numbers would be different depending on your camera and lens.

2) Richard Chesher taking a 360° underwater panorama

There is a wide selection of other housings for Canon and other cameras – whatever you get, make sure you have a fisheye lens that gives you a full 180 degree view and a large diameter dome port (8″) to minimize distortion and maintain your full wide angle view. I’ve used Ikelite housings for 30 years and have only drowned one camera (my own fault) so I have no hesitation recommending Ikelite for your housing. I can also recommend buying it through davidhaas (at) sbcglobal.net. David is an Ikelite dealer and lives near the Ikelite factory. He offers excellent prices but the best part is that David is a well known professional underwater photographer himself and can be a real help with advice and getting spares – especially if you don’t live in the USA.

This gear is big and heavy and expensive so you might be thinking of trying to get something smaller and cheaper. Last year I searched for a more compact solution and tried a Canon S95 in an Ikelite housing with a wide angle “fisheye” adaptor. After a great deal of online research and discussions with other photographers I bought the Dyron Fisheye Adaptor for the S95. The problem with the other adaptors was poor image quality on the edges – both distortion and focus issues. If you zoomed in a bit you got better results but then you didn’t have enough of a wide angle to do a sphere without doing two or more rotations. After a series of trials on the reef I finally had to admit the Dyron fisheye adapter was completely useless for doing sphere images. The photos had vignetting and chromatic aberration for about ¼ of the distance in from the edge – only about 50% of the centre part of the image was OK and even that wasn’t very good. The S95 is, however, a nice little camera and I use it (with no adaptor) to take close-ups and small scenics while the SLR is busy in robot mode. For now I think we are stuck with the big expensive equipment.

This is Part 1 of the 360° underwater panorama tutorial series. A new installment will be published every Friday, so watch this blog!

These images are interactive 360° panoramas / sphere images – click to open:


This is Part 1 of the 360° underwater panorama tutorial series. A new installment will be published every Friday, so watch this blog!