Location

If you're ever wondered how wide the Amazon river actually is, then have a look at how far away the opposite bank is on this photo.
Technically speaking, this isn't actually the River Amazon. This is the Rio Negro which comes down from the North. Around 12 km down river from this spot it meets the Rio Solimões, a river which carries with it the melt water of the Andes and starts in Peru. The Peruvians actually call this river the Amazon, but to Brazilians the Amazon river doesn't start until it meets the Rio Negra, the river in this photograph.

When the two rivers meet, their different colours (the Negro is black and the Solimões a muddy brown) run side by side before mixing. It's a strange sight which occurs because there is a 6ºc difference in temperature between the two rivers. Holding your hand in the water as you cross across the two different flows is a really strange experience.

This shot was taken from a floating pier at the beach (there are lots of beaches on the Amazon) called Ponta Negra, a suburb to the west of Manaus.

We arrived here in the afternoon and had to catch our boat deeper into the rainforest from this pier at 6am. During the evening I decided to have a go at taking a shot of the sunset, and this is the result.

Technique

The hardest part of making this image was the fact that the pier was floating, so every disturbance in the water rocked the pier up and down, blurring the far bank.
I had to wait until there were no boats passing to get the shot, and by this time the sun had dipped below the horizon.

I was fascinated by the beautiful glowing blue of this rope, and the flaking paint on the wooden planks of the pier, so to focus the eyes on them I chose a long exposure which would smooth out the water and blur the sky, giving the foreground textures more prominence in the image.

I wanted an exposure of around 2 minutes, and used a 9 stop filter to enable me to get that with the camera's aperture at f13.

The camera was secured on a tripod low to the pier to bring the foreground as close to the lens as possible, and I used two 3 stop neutral density graduated filters placed along the horizon to hold the sky back and stop it from burning out.

All of the composition, focusing and alignment of the ND grads had to be done first, before I added the ND400 9 stop filter, as it's impossible to see through the viewfinder with this on the camera.

I then used a cable release to open the shutter, and timed 2 minutes using my watch while sitting very still as any movement would have disturbed the pier.
With this filter, the camera does tend to underexpose and I wanted to give it a little more time, but there was a boat approaching and I didn't want the waves it created to disturb the pier. The boat is actually within the frame of this shot, but it was moving fast enough so that it didn't record in the exposure.
I closed the shutter a few seconds before the waves started to rock the pier.

The sun sets so quickly at this latitude that I knew I would only get one chance at such a long exposure...I was lucky that everything worked first time.

Post Processing

Almost nothing has been done to this shot and it's pretty much as it came out of camera on the RAW file. The blue of the rope really was that saturated.
The image was a little noisy in the shadows, so I ran it once through Neat Image (an amazing little plug-in) and used the healing brush to remove a few dust spots on the sensor.

The image was then resized, sharpened a little and then I added the frame and title before converting to JPEG and saving it.

Metadata

Taken at Ponta Negra, Manaus, The Amazon, Brazil
Nikon D80 | Sigma 10-20mm | Nikon Cable release
Manfrotto 190XProB w/ 322RC2 ballhead
Hoya ND400 (9 stop) | Lee 0.9 (3 stop) hard GND | Cokin ND8 (3 stop) soft GND
137.5 seconds | f13 | 10mm

Workflow in Apple Aperture. Frame and title in PS