This Saturday I made a last minute decision to head for the Clifton Suspension Bridge after looking at the sky and realising late on that something special might happen! High cirrus and a gap on the horizon had me thinking of pink skies and so I cancelled my shopping plans and headed for the bridge.
After a short drive and run I was at one of the classic viewpoints of Clifton Suspension Bridge just as the sky became colourful. In my rush to leave home I left without my wide-angle lens (I usually have my gear ready but not this time!). This turned out to be a blessing in disguise and forced my hand into shooting an ultra high resolution panoramic.
Armed with my Canon 5DmkII, 50mm 1.4 and tripod the only way I could capture a full view of the bridge was to shoot a panoramic of vertical frames.
When shooting panoramic it is important to ensure that the tripod is not only stable, but also level. This is so that as you pan the camera the horizon position doesn’t move vertically around the frame. If you want to shoot a panorama in vertical orientation it helps to have an L-plate as well (I have never got on with the slots on ballheads for changing camera orientation!)
Once the tripod is in the right location you can start to figure out your exposures. Usually at sunset you will either have to use graduated filters or exposure blending. I tend to prefer the exposure blending option due to its flexibility. In this case the highest contrast was on the right side of the image. The Avon Gorge was in shadow, providing the darkest tones, whilst the sky above it wasn’t far from the sun and so was significantly brighter than the rest of the sky.
When shooting panoramas it is best to shoot in manual mode since otherwise the camera is likely to vary the exposure as you pan the camera. Using live view and a timer I fired off 3 bracketed shots towards the right side of the final image to determine my exposure. The 3 shots generated had a total range of 3 stops and captured the full tonal range. I fired another set of exposures to the left side of the image just to double check that the exposure was correct. I double checked my focus, stopped down to f13 and then waited for the clouds to become more colourful.
As the pinks developed in the clouds over the Clifton Suspension Bridge I shot a series of bracketed panoramas. Generally it’s best to have massive overlaps and take more shots than you need, this makes a good stitching result more likely. I generally try to get 50% overlaps. In total the final image was produced from 5 bracketed sets of frames (5×3).
The 15 frames were combined into 3 separately exposed panoramas using PTGui and the same settings (I will do a tutorial on this process at some point but essentially the geometry of each panoramic exposure must be the same otherwise the blend will never work!).
I copied the 3 panoramas onto separate layers on a Photoshop file, cropped the image to the final composition and set to work creating the exposure blend. Again, I wont go into details here of how the blend was achieved but it was a relatively simple process. One slight complication came in areas where there were streaks on the road from cars where I was mixing the two brightest exposures. This created an unpleasant ghosting effect. The only way around this was to show the brightest layer at 100% opacity in that local region, and then locally darken it to match the brightness of the blended exposures. This might be hard to understand so take a look at the Photoshop file!
Once the blend was done I started making adjustments to the image. I almost exclusively use curves and hand painted masks to correct my images. In this case the priority was improving the clarity of the image by removing a magenta cast and setting a true black point. Once this was achieved I started editing the local brightness and contrast of the image to reveal the full detail of the scene, its true colour and create balance between the bright cliff side on the left, and the dark side of the gorge on the right.
Some lazy masking lead me to tweak the image a few times but I am now pleased that the result captures the full potential of the scene.
The cropped panorama is 11000×5000, 55mp. At 300ppi this will allow a print of 37″ and would produce outstanding detail at this size. I have no doubt that a 60″ image would look excellent up close.
This image is one of the highest quality images I have ever taken in terms of sharpness and detail, rivalling medium format. The composition is classic but still successful, the light was of course wonderful and I was even lucky enough that it happened to be high tide! . The only slight niggle I have is the scaffolding, what a shame!