Panoramas of London from a Helicopter with a 100Mpixel Phase One XF and 40-80 LS Lens

August 15, 2017  •  1 Comment

When Sky Sports commissioned me to photograph the backdrop to their Sunday Supplement TV programme, I presumed it would involve a similar process to the previous year: a lot of research, find a tall building with a view of the relevant stadium and city, create a super-high-res panorama using my existing Phase One IQ260 on a DF+ camera mounted on a tripod.

2016 Season Set Design - Sky Sports 'Sunday Supplement' with Leicester City FC and Leicester image as backdrop. Each season, the image used is from the winners of the previous season's football Premiership. 2016 was Leicester City FC, 2017 was Chelsea FC. After pounding the streets of Chelsea, poring over maps and many calls and emails to hotels, councils and other property owners, it became obvious that there are NO suitable buildings in Chelsea.

The client then suggested we could use the Sky News helicopter to get the shots. OK, well that's an interesting development! I'd been wanting to try open-door aerial shooting for a while but the opportunity hadn't arisen. I was also not convinced that the IQ260 and DF+ camera would be suitable for this work as fast shutter speeds and high ISO's were going to be necessary.

The size of the image on the set is 7m x 3.5m. That is a very large print and with 4K TV, the highest possible image quality would be needed. On a tripod, stitching multiple images, this would be no problem. I hadn't heard of many people stitching panoramas from helicopters, but single shots would not be sufficient, no matter which camera I used. 

So, big megapixels, at least 1000th/sec shutter speed, ISO400-800, wide-angle zoom lens.... only one possibility: the Phase One XF with the IQ3100 digital back and 40-80LS lens, though I had no idea if this was going to work. Using an entirely unfamiliar and untested camera for an entirely new shooting situation would normally be a recipe for disaster. The excellent guys at Teamwork and Phase One assured me that all would be well.

Picking up the XF/IQ3100 with the 40-80 zoom for the first time at Teamwork was a laugh-out-loud moment. It is huge! And heavy... at nearly 4Kg, it weighs more than a Canon 1DX with 300F2.8 lens. In the shop, it felt OTT, especially compared with the Sony A7R I use as a backup! However, this heft became a positive advantage in the air: hanging out of a helicopter, being buffeted by winds and downdraft, the camera shrank in the hand to a very manageable size and its weight greatly increased stability. It felt reassuringly solid.

V11F1  Aerial View of Houses of Parliament and The Thames, Westminster, London, UKV11F1 Aerial View of Houses of Parliament and The Thames, Westminster, London, UK Open door helicopter flights have some specific requirements. In the first instance we had to pay a hefty premium on our insurance for that one flight. We had to provide a full risk assessment and method statement. Then there was the weather. The level of unpredictability in forecasts has now reached a high level - it's increasingly difficult to plan with certainty. Then the news agenda went crazy. Multiple events requiring aerial coverage, day after day, meant the helicopter wasn't available and then had to go in for a service. Then I had to make sure every piece of gear - including me - can be tethered to the airframe of the aircraft. I used camera tethers for attaching to the camera neckstrap loops and tool lanyards with karabiners for attaching to the airframe, a 3-point body-harness for me, a head strap for my glasses, a bungee cord with karabiners for the camera case, and a beanie hat to keep the hair out of my eyes. Lens caps should also be removed and under no circumstances can there be any changing of lenses! So if you want a different view, keeping a second camera round your neck is essential.

I felt paranoid about items falling from the aircraft on to people below. I decided not to use the metal lens hood on the 40-80 lens after seeing an online video about them working loose and potentially falling. This was a mistake as a lot of shots were ruined by flare. Instead I could have just taped the lens hood on: one for future flights. 

In the tortuous drive out of London towards Redhill Aerodrome, the afternoon I had planned to get acquainted with the camera disappeared and I was left with 20 minutes before the flight to do LCC's, check the settings, and try to get a feel for it. It is testament to Phase One that it just worked - I set it to manual, 1/2000 sec/ISO 800/F11 and AF on and had zero problems - though many of the shots were a stop or more underexposed as clouds came across the Sun. The only things I changed were the orientation of the camera between portrait and landscape and the zoom.

 After a quick discussion with the pilot about flight plan, a safety briefing, attaching all the straps and safety checks, we finally had lift off! It's an easy 10 minute flight into central London - the envy of commuters - with the door closed. As we got to the location, I opened the door as I'd been shown in the safety briefing: wow, a 1250ft drop with no safety barrier! I was wearing both a harness that's secured to the airframe, and a seat belt so it actually felt really secure. Although we finally had perfect weather, we had to circle Stamford Bridge stadium for a few minutes to wait for my old frenemies the clouds to clear the sun.

Once we had the light, I asked the pilot to hover in the right spot so I could take a series of overlapping images for a stitched panorama. Hovering is not easy for helicopters: even a moderate wind moves them around so the panoramas were a bit all over the place. I had to compensate by taking more shots with more overlap than normal. Hence needing 1/2000 sec shutter speed. With such high resolution, even the slightest camera shake in one of the images could ruin a panorama.

I could probably have dropped to 1/1000sec and ISO400 - another lesson for next time - but even at ISO800, the files are strong and only show a bit of noise when pushed in the shadows. ISO400 - and even ISO200 at F8 - would work better as the colour and dynamic range (good at 800) would be both be improved. Just for comparison, the IQ260 isn't really useable above ISO140, so this is a remarkable performance for a medium format camera. 

I should say something about the 40-80 lens. This is equivalent to 25-50mm in 35mm format and seems just about perfect for aerial work. If you go much wider, the helicopter blades or skids start to appear at the edges of the frame. With 100MPixels, it's easy to crop to 70 or 100mm equivalent focal length and still have a high resolution shot. The claim for this lens is that it replaces prime lenses and I would have to agree with it: image quality across the frame is outstanding at all focal lengths. Low distortion, no falloff in image quality at the edges of the frame, no chromatic aberrations - these things really matter in architectural work, and especially when photographing entire cityscapes for large-scale reproduction. On the limiting side, the huge 105mm front element means that using filters is not easy - only 150mm filters will work. For aerial work this isn't an issue really - you don't want anything that might catch the wind or become detached so it's best to avoid them. A polariser might be OK for a very bright day and would improve the photos but it's one more thing to have to control - maybe in later shoots. In early research, I thought that optical image stabilisation on 35mm systems might be needed but it doesn't work above about 1/500 shutter speed so it was a non-issue.

For the Sky Sports panoramas, I took both vertical (11,219 pixels resolution vertically) and horizontal (8416 pixels) shots. This was to give the client multiple options for the framing of the stadium against the skyline and differing balance of sky and city. With a lower resolution back, the horizontal framing would not have been high enough resolution. 

We circled the stadium a few times until I was certain we had a good selection: we could have flown a bit lower - though I didn't realise this at the time - and the lower the shooting height, the less 'aerial' the images look. There are strict height restrictions for flying over London and I thought the pilot was keeping to the minimum. Another one for next time! I was then free to take some general London aerials as we had some flight time before flying back. 

V11F8  Aerial View of The City of London, UKV11F8 Aerial View of The City of London, UK We circled the heart of London and the City, which was jaw-dropping from above. An amazing moment came as we flew directly over the Gherkin and I just took my eye away from the camera for a moment and soaked in the view: OK, wow, that's spectacular!

V11F3  Aerial View of The City of London, UKV11F3 Aerial View of The City of London, UK The XF camera really came into its own at this point. I did not stop shooting until the card was full - the one and only time I have filled up a 64GB card, with 500 shots in 20 minutes! The XF didn't flinch, complain, lock-up or draw attention to itself - a big step forward from the DF+. It was also very comfortable in the hand, surprisingly even with the huge 40-80 lens.

V11F14  Aerial View of London, UKV11F14 Aerial View of London, UK The Results
The client chose a horizontal-shot panorama for their set. The high res file is 18287 x 8093 pixels.

Processing
As you can see, the level of detail and overall quality in the images is remarkable, especially considering the ISO800 setting. Bear in mind that when looking at 100% crops, this would give a full size image of 4.1m x 3.1m at 72dpi screen resolution! At any smaller sizes, the files are super-crisp. Capture One makes the best of the files - the highlights and shadows are very controllable and well-isolated so in some shots I've put both sliders at 100 without the image looking unnatural.

Most files needed some work to bring out the best: highlight and shadow recovery, 1 stop more exposure, +20 saturation, noise reduction, horizon straightening, a good slug of clarity and a little contrast to counteract the effects of haze. Virtually every file had the horizon at a slightly different angle.

Conclusions

PROS
- Aerial shooting from a helicopter is addictive. Definitely something I'll be doing more of, especially in cities.
- The XF/IQ3100/40-80LS combination is exceptional and more or less the perfect camera for aerial work.
- The super high resolution gives great detail in the files, with a lot of room for cropping, rotation, keystone correction and options for final output.
- 15 stop dynamic range, low noise and great colour of the IQ3100 back.
- XF camera is robust, intuitive and reliable.
- Aerial panoramas can be done but need careful planning and high shutter speeds.
 

CONS
- Aerial shooting is normally very expensive and requires a lot of preparation including bureaucracy.
- Editing over 650 images is a monster task (inc. A7R files) - especially so many huge 100Mpixel files.
- Weight of the XF/IQ3100/40-80LS is fine for an hour but represents serious weight training if used for longer!
- Can't use filters or polariser easily.
- Lens flare without hood.

Final selection of London aerial shots can be seen here.

Big thanks to Teamwork Digital Ltd. for supplying the Phase One gear and technical support, and to Arena Aviation.


Comments

Max Cottrell(non-registered)
Good work, Richard! And nicely written.
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