Re: Okay aerial guru's: question about film size, focal length, and the jitters
I see. This seems to reduce the issue to simple terms. Thanks. Does everyone agree that this is accurate? a 150mm is a 150mm. I was afraid of that :D
Quote:
Originally Posted by
Pfsor
Pchaplo, take it with common sense. It's not because you add a real estate behind a lens that it will somehow calm it. A longer FL will show more shake than a shorter one regardless of what the size film is behind it. I'm speaking about the shake effect on the film not the final result on a print.
I follow your misery and I think that handholding 150mm lens on a vibration platform is madness. If you don't believe it take a few long distance shots from a train window faring through landscape and see for yourself if you like the result or not.
Re: Okay aerial guru's: question about film size, focal length, and the jitters
Quote:
Originally Posted by
pchaplo
100mm handheld on 35/FF is tough without IS/VR, I know. Maybe I put my gyro on 4x5. I better start working out again :)
One thing, given your subject is pretty far, your concern is only angular camera shake, so the gyro stabilization is the important thing.
Re: Okay aerial guru's: question about film size, focal length, and the jitters
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.
Re: Okay aerial guru's: question about film size, focal length, and the jitters
Agiflight cameras were handheld? Did they have gyro? Wow those are some long lenses! Tell me more, tell me more...
Quote:
Originally Posted by
Dan Fromm
Interesting. Williamson/AGI f.134, f.139 and Agiflite cameras were made to be shot handheld. Before TTH withdrew from that market their standard long lens was a 12"/4 TTH telephoto. It was replaced by a 350 TeleTessar, which was one of two lenses in the standard US Coast Guard Agiflite kit.
The TTH tele was also a standard lens for the Vinten F.95 camera. F.95s were usually mounted in pods but were also shot handheld.
Re: Okay aerial guru's: question about film size, focal length, and the jitters
Quote:
Originally Posted by
pchaplo
Agflight cameras were handheld? Did they have gyro? Wow those are some long lenses! Tell me more, tell me more...
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.
Re: Okay aerial guru's: question about film size, focal length, and the jitters
Quote:
Originally Posted by
pchaplo
Agiflight cameras were handheld? Did they have gyro? Wow those are some long lenses! Tell me more, tell me more...
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.
Re: Okay aerial guru's: question about film size, focal length, and the jitters
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.
Re: Okay aerial guru's: question about film size, focal length, and the jitters
Quote:
Originally Posted by
Mark Sampson
Randy- Aerial photographers got stereo imaging by exposing frames with a 50% image overlap. (i've never heard of flying two aircraft in formation.)
And 9"x9" images on 9-1/2" aerial film was the standard until digital took over 10-12 years back. That does give spectacular resolution- in a past life I used to make 40"x40" color enlargements from 9" aerial color negs. I'm sure that my co-workers at Kodak Aerial would have liked prints even larger, but that was as big as our lab could make.
Back to the OP's question- if the 4x5's shutter speed will be fast enough, you should be ok. Some testing is in order here, though.
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 :-).
Re: Okay aerial guru's: question about film size, focal length, and the jitters
The parallel formation is what I remembered from perhaps a British documentary. It was stressed as very difficult navigation.
Thanks for the memory jog!
Quote:
Originally Posted by
Mfagan
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 half 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% apart) and thereby getting a large area done quickly. Sorry...now back to the original topic :-).
Re: Okay aerial guru's: question about film size, focal length, and the jitters
Quote:
Originally Posted by
Randy Moe
I thought of VR which is just a modern Gyro. I also considered your 35mm and 4x5 choices. We know that 70 years ago High Tech aerial was rolls of 9X9" film shot in stereo from 2 aircraft flying very precise routes. 3D imaging with PI was a game changer for the English and USA.
You won't come close to that tech. Here's a link to the most hated man online.
http://www.kenrockwell.com/nikon/50-comparison/vr.htm He makes some points worth reading.
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!