Friday, 26 August 2011

Photoflying in Belgium: Part 2. Getting cameras and photographers ready.


This is the second post in my series on Photoflying in Belgium. Note that further pictures are available on Pbase.

Parts of this series

Photographic techniques.
The Academy itself started on with a couple of talks about Air-to-Air photography. Daniel Rychick from Poland and Tom Houquet from Belgium gave these, with excellent sample photographs. The key messages seem to be straightforward commonsense for anyone who has ever photographed propeller aircraft before.

·                It is important to show the propeller in motion, so never go beyond 1/400 sec in shutter speed, and use shutter priority mode. It should be possible to get full prop rotations going to lower shutter speeds (longer than 1/100 sec), but correspondingly with a lower keeper rate. Different aircraft will require different shutter speeds to give the appearance of full prop discs: the prop has to turn 360° x 1/(the number of blades on the prop) to give the appearance of a full disc. So, a two-bladed prop has to turn 180° to give the effect, a five-bladed one 72°. In any case, the rate of rotation varies between aircraft types. The advice was to get your safety shots in first at a faster shutter speed, and only then go for the longer shutter speeds. In the event, I used speeds between 1/320 (gave me a high proportion of sharp pictures, with moderate prop rotation) and 1/60 (attempting to get full discs, but with a much lower proportion of sharp pictures).

Shutter speed effects. Click the image to see it larger.

·                The aircraft formate quite close to the photoship, so a standard zoom (equivalent to a 24-105 mm on full frame) will be fine for the majority of shots, but in addition a 70-210mm on a second body would be very useful. It is important to take two bodies if you can, because once in flight, safety dictates that there is no changing lenses: more on that later.
·                Shoot Raw. That is easy -- I do that anyway. I asked Daniel about whether it is important to be able to shoot at high speed (e.g. 6 fps) or whether it would be better to shoot higher bit depth raw files: my D300 slows from 6.5 fps to about 2 fps when shooting 14 bit NEFs. His reply was that his major concern is that the buffer on his camera doesn't fill up, and the rate of shooting is really not the issue since the subject aircraft stay behind the photoship for several minutes each. My standard airshow setting is continuous high (CH mode) and 12 bit NEFs, so I started with that, but quickly -- as I mention below -- decided to go to single shot (S) mode once in the air. In future, I think I'll be happy shooting 14 bit files at lower speed.
·                Exposure compensation: it is advisable to set a negative exposure compensation (e.g. -1 stop) to hold the highlights. This was at first a little counterintuitive to me: I have been a long-standing adherent to the "expose to the right" philosophy, but Daniel's advice makes sense here. Very often aircraft have white areas or strongly reflective surfaces on the upper side:  these can fool metering because the majority of what the camera sees is the much less bright ground below. In the event I found myself checking the histogram and blinkies on the rear screen frequently to ensure the right exposure in flight, and dialling in compensation accordingly.
·                White balance: the photoship flies in figures of 8, which means that the quality of light on the subject varies continuously as the angle relative to the sun changes. Using auto white balance would result in a different setting for almost every exposure, and if it does not look right, this means that every picture as to be individually adjusted. Daniel recommends a fixed cloudy white balance which gives a pleasantly warm feeling to the images. I took Daniel's point, but decided to stick with my standard fixed daylight white balance of 5260 K in the first instance. That is something I have worked with since finding David Noton's recommendation to use fixed daylight white balance. I also have little experience of how fixed cloudy white balance works on my D300, so I felt more comfortable sticking with 5260 K. In the event, working with my fixed white balance gave consistently reasonable results every time, depending on the exact lighting. In Lightroom I have found myself putting a cloudy white balance on some of the pictures, so Daniel's recommendation looks fine anyway. (The other thing I’ll mention in passing is the importance of choosing the right Camera Calibration setting in ACR or LR3. I’ve been iterating between Camera Standard (my usual default), Camera Landscape and D2X Mode 3).

One other thing to mention is the use of a gyroscopic stabilizer. This should allow a much higher rate of keepers at slow shutter speeds, providing the subject aircraft stays in one position, and doesn’t move too quickly relative to the photographer. Tom Houquet showed us one of these, and it is very impressive. It is a large black device that mounts under the camera, and when your hand moves, the gyro acts to minimize movement. I’m not sure which one Tom showed us, but it looked like one of these. One of the participants had one, and he used it with a D2X on top and (I think) a Sony NEX camera mounted on top of that for video: very cool.

Safety in flight and planning
Later, we had an extensive session on safety in the air. This was uppermost in my mind because of the Skyvan's open rear door! Two points are key: stopping the photographer falling out of aircraft, and stopping FOD falling out of the aircraft that might be hazardous to the subject aircraft (of course, in this sense, the photographer is the biggest FOD hazard!)

To stop photographers falling out of the photoship, they are strapped into a harness, which is fastened to a safety lead attached to the floor of the aircraft. Photographers closest to the edge get double safety leads.

To stop more general FOD hazards leaving the aircraft, there are several other precautions. First, camera straps have to pass under the safety harness so that they cannot fly off. Secondly, a separate lead on the harness is attached to the camera so that even if it comes off its own strap, it should not fly out of the aircraft. Lenses, memory cards and batteries are not allowed to be changed in flight. To stop the accidental release of a lens, lenses are gaffer taped onto the body to ensure that even if the lens release button is accidentally pressed, the lens does not come off (yes, this does mean that your expensive DSLR body and lens will be strapped with gaffer tape). Third, anything that might come off in flight is banned: this means that things like baseball caps, sunglasses etc don't go.

Finally, we got down to planning the photo flights. Academy flights were planned for the Friday, Saturday and Sunday. Other optional fights were available for additional fees, including the one I wanted, which was the Warbird flight. The idea of this is to formate with a number of vintage Warbirds (the fee for the Warbird flight is eye-watering, but make sense in the context that it costs about €1000 to get a Warbird off the ground and into the air for 15 minutes). My Academy fight was planned for the Friday, with the Warbird flight to follow on Saturday. As things worked out, the weather put paid to my Academy fight on the Friday, so I did both flights on the Saturday.

After all this, we had an introduction to the Skyvan photoship itself, and a practice with the harnesses. The harnesses are fairly straightforward for anyone who has put on a parachute harness or similar safety harness. The Skyvan itself though is a different matter.

Getting to know the Skyvan

Skyvan cabin. The seats in the centre are positions 6-8, see text.
The Skyvan has two flight crew at the front, and can take 11 photographers at the back. It is not a very large aircraft, so this makes quite ... shall we say ... an intimate setting for the photographers. Three sit cross-legged right next to the open rear (positions 1-3); two sit immediately behind them, again cross-legged, and shoot between the front three (positions 4-5); there are three seats behind them – lightweight aluminium-frame chairs (positions 6-8); and three photographers stand behind them (positions 9-11). Position 1 on the port side is occupied by the photo flight director who communicates with the subject aircraft via the flight crew, and can also give hand signals to the subject aircraft to give positional cues. Photographers in positions 2 and 3 get the best view, although they have to be comfortable with (a) sitting next to an open hatch 2,000ft above the ground, in buffeting wind, cross-legged for an hour and a half, and (b) be not being able to stretch in case their leg (or the rest of them) exits the aircraft. Positions 4 and 5 get a great view too, although they are really unable to move, and suffer the additional discomfort of continually being kicked in the back by people sitting in the seats behind them. Positions 6-8 are probably the most comfortable, but have the most constrained of angle of view, an important consideration when you only have limited time and angles on each aircraft. Those standing in positions 9-11, even though they are farther from the open rear have the advantage that they can move around and swap position in flight if they wish. The downside of positions 9-11 is that tall people are likely to bang their heads on the ceiling, and in the event of turbulence even shorter people are liable to meet the ceiling at speed. In the event, I flew in position 8 (starboard side of the aircraft): this suited me because I don't think it would be safe on other people to expect me to hold a lotus position for an hour and a half, and I'm tall enough to appreciate not having regular encounters with the ceiling.

In flight, and waiting for the subject aircraft to close up. The photographer seated upper right in the image is the photo director, the headset is for communicating with the flight crew.
Getting to know the other photographers
The evening of that Thursday was a good opportunity to meet some of the other participants in the Academy. Among my photographer friends I have a reputation as something of an aviation nut. Relative to the other participants, however, this is simply not the case at all. No way, no how. Just about all the others live, eat, sleep and breathe aviation. Many of them have a professional interest as aviation photographers. For instance, Frank and Sonya were from Irishairpics, an Irish aviation photo-agency. Andy and Serge were from Air Team Images. Just to give a flavour of how committed to aviation photography some of the participants were, one (who shall remain nameless, and is not one of those I have mentioned already) started photographing a fly during a slack period the following day: when asked why he replied "Because it has wings on". In my case, at a personal level I'm a photographer first, and an aviation nut some way down the list; for most of the participants, they are aviation enthusiasts first and foremost, and they enjoy making great images of their passionate interest.

I should also mention that this is not an exclusively male obsession either. I've already mentioned Sonya, and there were several other women on the course too. Whatever genes encode this obsession, they are clearly not all located on the Y chromosome, although the Y probably has some kind of amplifying effect :-).

In the evening that day, the weather got worse and worse. A dreadful storm went through Belgium causing destruction at a festival quite nearby which resulted, tragically, in a number of fatalities. We were spared the worst of it, although the thunder and lightning that evening were quite impressive. The aircraft on the field were all battened down against the weather.

T6 battened down against the storm

2 comments:

  1. Love the effect of the last shot - simply great!! One can imagine the destruction unleashed by the storm by just looking at the sky in this one!!

    ReplyDelete
  2. Nice commentary too on the complete process of photography as well as photoflying.

    ReplyDelete