[Leica] Re: aerial photography

[henningw at archiphoto.com (Henning Wulff)]

I've done a lot of aerial photography with a wide range of equipment, 
and the basics aren't that hard.

Most of my stuff has been architectural or construction related, and 
has been at altitudes of 500 to 2000m. As other posters have noted, a 
clear, smog-free day is one of the most important ingredients. It's 
surprising how murky the first 200m above the ground are, but it's 
easily seen when you're up in a plane. Avoid days with beautiful 
puffy clouds in the sky, because you'll be in for a rough ride.

I tend to prefer high-wing fixed planes like the Cessna 172 over 
helicopters unless I need to shoot very wide angle shots. I've shot 
with a 47mm SA on 6x12, which is equivalent to a 15mm on 35, but this 
only works from helicopters as the struts and wheel get in the way on 
the Cessna's. If you do use a Cessna, make sure the window does pop 
open all the way, as it's hard to undo the fastener in the air (you 
really have to stand outside!). Also, don't forget that _you_ need 
the window. I once chartered a plane, only to have the pilot say that 
he really wanted to fly from the right hand side, and the window on 
that plane happened to be on the right. Cessnas come with windows on 
the right, left, both or none. Check it out. Once underway, the 
window will stay up of its own accord once you open it due to the 
airflow. I don't take the doors off Cessnas because I don't feel the 
slightly better view is worth the buffeting and increased risk of 
losing somethin.

Helicopters cost 4 to 10 times as much per hour, and if you have a 
lot of ground to cover, the cheaper ones don't get around as quickly. 
It adds up to a lot of money for the client. If you plan your trip, 
you can get a lot done in an hour from a small plane. The other thing 
is that under most circumstances a helicopter vibrates more than a 
Cessna, mostly because it has a lot bigger engine. If you think you 
can ask a helicopter pilot to just hover until you get your shot, 
think again! When hovering, a helicopter vibrates the most. I 
generally only use a helicopter when I need to follow a vehicle on 
the ground, or when the client insists on hiring the aircraft 
himself, and hires a helicopter against my advice. This often happens 
when the client is a government agency (who use 'somebody else's' 
money, ie, ours). One of my scariest moments was when I was in a 
helicopter with a big bulkhead between the pilot and myself, and I 
was sitting on a bench in the back, with both doors left at home. I 
had buckled myself in, as well as the camera bags, and then we went 
flying. As we started circling the site, and the helicopter was 
banking to give me shots straight down, I noticed that the bench I 
was sitting on wasn't fastened to the airframe. I thought for sure 
that I was going for a trip and would have to learn to fly without 
mechanical aids! Fortunately, the seatbelts were fastened to the 
airframe, so now I only had to make sure I hung onto the bench so 
that it didn't fall out the doors until we landed and fastened things 
down again. Obviously, on the last trip the seat had bee taken out to 
enable the 'copter to haul cargo, and the seat hadn't been fastened 
again. Very interesting.

As far as equipment goes, take the 50 and 35 you have. The 35 is nice 
because you can get very nice shots which show a given site below and 
the horizon, which makes it very easy to illustrate a site in 
context. It's hard to use a lens wider than 35 from a Cessna. The 50 
will be good for more detailed shots. Something like a 75 would be 
nice, and then you could leave the 50 at home, but that's really all 
you need. The main thing is to take lots of film, and make sure you 
can change film fast. One of my favourite aerial photo cameras is a 
Mamiya 645 with the 55 and 110mm lenses. Good sharp lenses, and the 
Mamiya allows inexpensive preloaded cassettes to be used. I have 
about 20 of these cassettes, and they are ready on takeoff. I tape 
the distance scales to infinity, the aperture to f/5.6 and set the 
camera on autoexposure (I shoot mostly colour neg on these shoots). 
The film is a high contrast 160 speed material most of the time. I 
usually only use a skylight filter, but sometimes a polarizer. With 
the latter, and in winter, I might use f/4. I try to keep my shutter 
speed around 1/500, but 1/250 works most of the time as well.

I have rented a Kenyon gyro a couple of times, but found it to be 
useful only with quite long lenses (200mm and greater, 35 
equivalent). They are heavy, and can be a pain to re-orient for the 
next shot, and space is limited.

I discuss the flight and communications I use with the pilot 
beforehand. The route is mapped out, and I make sure I can recognize 
the terrain before I get there, because often the pilot will not be 
able to. I don't use headphones when I can help it, because they get 
in the way of the cameras. I use a strap to hold my glasses on. Once 
I forgot it and the wind whipped my glasses off right over City Hall. 
I didn't bother to try to claim them, or find them. It also meant 
that the rest of the flight was an uncertain shoot. Fortunately, 
because focussing wasn't necessary, I did get all the shots. I often 
try to shoot 5 or 6 different sites on one flight; it makes for a lot 
more profit and I can still give the clients an excellent rate.

As far as flying over the sites, I ask the pilots to fly in a square, 
or as close as possible. I use hand signals for direction changes, 
and rate of change of direction, and also when I want the pilot to 
raise the wing tip on my side to that I can get the horizon in. The 
direction changes have to be made sharply and quickly, because 
usually you can't shoot while changing direction and you waste time. 
It's sometimes hard to get pilots to make hard enough turns, because 
many of them do tourist trips or business trips, and on those the 
type of turns I require would lose them their jobs (and lunch). I 
once had a pilot throw up once we came back onto the ground, but that 
is a rarity. Don't take clients on these flights. It's very hard and 
sometimes impossible to refuse them if they insist, as they are 
paying for what they think is a joyride. They almost always turn 
green and twice I've had clients throw up on a flight; once onto 
himself and some of my camera equipment and once on the pilot. I had 
to promise the pilot not to bring a client along again.

If you are going to higher elevations or shoot in the winter, make 
sure you have gloves. I use a glove made of a windstop fleece, 
fingerless but with a mitt 'hood' that I can fold over the 
fingertips. It can get very nippy, but you need the fingertips free 
to load film.

If you have any more questions, e-mail me.

-- 
    *            Henning J. Wulff
   /|\      Wulff Photography & Design
  /###\   mailto:henningw@archiphoto.com
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