Dallas Texas HABS / HAER / HALS Photography
Photographer/Author Marfa Flights: Aerial Views of Big Bend Country (Texas A&M University Press)
Petroleum Oil Pics
Maybe I start with my 90mm and see whats shakin' handheld, then add my gyro. I think with my 90mm, Im worried about vignetting dark toward edges. That being said, I can get a good angle of view with a 28mm on FF/35 from a Cessna. It just clears the landing gear, strut, and tail. Strut to tail is biggest issue, so I think that the horizontal angle of view is my primary consideration. So a 90mm may be more realistic. Also if I go wide, better to use helicopter.
I need to test with my existing lenses before I add more glass to be dedicated for this.
Dallas Texas HABS / HAER / HALS Photography
Photographer/Author Marfa Flights: Aerial Views of Big Bend Country (Texas A&M University Press)
Petroleum Oil Pics
Dallas Texas HABS / HAER / HALS Photography
Photographer/Author Marfa Flights: Aerial Views of Big Bend Country (Texas A&M University Press)
Petroleum Oil Pics
Some aerial photos were made hand-held. Surf and ye shall see. Keep in mind that expectations of image quality with non-stabilized hand-helds were low compared to today.
The military stuff we worked with in the Sixties were stabilized in a number of ways. In some cases merely having ~9" (or 5x5") stereo negatives, and panning reflective surfaces (imagine long three sided mirrors) gave visual integrity regardless of aircraft movement and some vibration.
No gyro. Agiflites and predecessors shot 6x6 on 70 mm film. They were basically cine cameras, had huge rotating sector shutters. The USCGS kits had two lenses, 150/2.8 Sonnar and 350/5.6 TeleTessar. See, e.g., https://www.flightglobal.com/FlightP...20-%204466.PDF
This source is basically an AGI press release. The Agiflite is an improved F.139. The F.139 is a Williamson F.134 with the F.134's spring motor replaced with an electric one. AGI took over production of Williamson cameras after Williamson went bust. F.134s and F.139s flew with a variety of lenses, mostly TTH. 4"/2, 12"/4 are the most often seen, there were others. So did early F.95s. When TTH left that market Vinton got most of the F.95's lenses from Elcan, AGI got lenses from Zeiss. The TTH lenses for both lines are super.
For a variety of reasons, Agiflite lenses are very hard to repurpose. The 4"/2.0 TTH, which covers 2x3, is just usable on a 2x3 Speed Graphic. The 12"/4 tele just covers 4x5, can be used on Speed Graphics.
If someone uses a quality 50mm f/2 lens on a 35mm camera, he can use a higher shutter speed than with most 150 lenses on 4x5 to reduce apparent shake. The 4x5 may be more stable handheld. I'd still go with the smaller camera.
I'm aware that there are various overlaps used for [aerial] stereo photography, so for trivia's sake I'll confirm that the RF-4B (and I believe the RF-4C as well) has two settings for overlap: 56% and 12% (the latter being twice the interval time). We used to use 56% almost exclusively. Oh, standard sidelap for us was 40%. As for formation work, I don't believe we ever operated cameras in formation as a photo mission, but there was a little-used technique that involved being in formation to a point at which each aircraft would turn onto a specified track after a different time past that point to result in the formation flying parallel lines (40% overlapped) and thereby getting a large area done quickly. Sorry...now back to the original topic :-).
Last edited by Mfagan; 12-Jan-2018 at 16:25. Reason: algebra error and failure to proofread before posting
Randy I worked for an aerial research company in the late 60's into the early 70's. We shot tons of 9x9, 70mm and analog IR line scanning. Most images were shot with overlap for stereo viewing and plotting. We flew 1 9x9 camera and up to 5 Hasselblad EL bodies or Superwides mounted in a special mount in a port in the belly of the aircraft. In the 70mm we typically shot 4 or 5 different emulsions including aero ektachrome, aero color IR, aero color neg ( don't remember the designation), aero plus x and occasionally a super high res B&W film ( I think it was Eastman 1111 or might have been 1515) with no actual name. It was on ultra thin estar and we could bet around 200 frames in a cassette. We used either a Douglas DC3 or a Piper Aztec.
I probably have in excess of two thousand hours of pilot in command and or photographer. I continue to do aerial work to this day after nearly 50 years.
I'm not aware of anyone shooting overlapping 9x9 from two aircraft. Consider the cost of operating two aircraft as well as each aircraft pitching, rolling and yawing independently of eachother. You'd never have perfect stereo pairs. Aerial work is often flown in lines and the pilot will turn fro one line and fly the oposite direction in a parallel line. Imagine two aircraft turning together, trying to line up on the same pair of lines and fly a consistent series. It's virtually impossible.
To the OP, you're going to have a lot of problems shooting 4x5 from a 172. As I previously mentioned you stand a high probability of ripping the bellows out of your camera. Just get it in the edge of the slipstream and it's gone. Also how do you plan to precisely frame? Most press type cameras don't have very precise viewfinders. A 90 is way too wide. You'll get wing struts, door and window in your shots. There too much parralax between the VF and the view from the lens in that tight a quarters. Have you actually been in a 172? Shooting digital is a different world than shooting 4x5 aerials from a 172.
As to your question, tje amount of motion depends on altitude, aircraft speed and how stable you can handle the camera while bouncing through the sky in rough air. Even a helicopter has its issues. The air coming down from the rotor is moving about 150 mph and any forward motion adds a horizontal component to that flow of air. Unless you have a helicopter like a Hughes 500 you'll have problems with extended hovering due to transmission overheating.
There are a lot of factors influencing the stability of any aircraft. The main one is thermal heating of the air. As the day progresses solar heating increases turbulent conditions. The closer to sunrise and sunset you fly, generally the smoother. Although turbulence occurs from wind conditions and other weather events. I live in an area where wind sheer is common and even rotors ( horizontal tornados). You can't see them but they'll freak you out when you get into one.
I'd love to see you make some nice images but you're going about it all wrong. Good luck and fly safe!
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