PDA

View Full Version : Okay aerial guru's: question about film size, focal length, and the jitters



pchaplo
12-Jan-2018, 08:54
This is somewhat hard to express accurately in my question. Let me give a barnyard example: lets say that i can easily hand-hold a 50mm lens in a Cessna effectively and get clear (non camera-motion blurred) aerial images on FF digital camera. If I use a 150mm lens on a 4x5 camera, under the same conditions, can I expect the same results?

In short, does a normal-ish angle-of-view lens "shake" any more on 4x5 compared to 35mm? By "shake" I mean "create blur caused by camera/lens movement."

Givens: Pretend that both cameras are perfect and I hold them exactly the same for this little experiment; the aircraft vibration, wind, altitude, everything other than the lens and the film/sensor size are the same. Also, I am not referring to the relative motion of the target below the aircraft due to the speed of the plane.

I use 50mm for 35mm, and 150mm for 4x5 as that is what I have in real life. I dont want to argue about 'what is normal.'

I understand re: gyros and I have one. Its just that I will shoot using 3 cameras and to have a gyro on 1 gets unwieldy in the cockpit. Therefore, I am simply exploring the relationship, if any, between focal length, angle of view, film/sensor size, and image blur due to motion caused by camera-lens movement (rather than the speed of the aircraft over the target).

Dan Fromm
12-Jan-2018, 09:04
From the sensitized surface's point of view, image motion is image motion regardless of cause. Shake and the platform's movement are equivalent. All that matters is magnification. If small format and large format images are taken at the same magnification, they'll have the same blur.

Randy Moe
12-Jan-2018, 09:37
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.

Pere Casals
12-Jan-2018, 09:51
This is somewhat hard to express accurately in my question. Let me give a barnyard example: lets say that i can easily hand-hold a 50mm lens in a Cessna effectively and get clear (non camera-motion blurred) aerial images on FF digital camera. If I use a 150mm lens on a 4x5 camera, under the same conditions, can I expect the same results?

In short, does a normal-ish angle-of-view lens "shake" any more on 4x5 compared to 35mm? By "shake" I mean "create blur caused by camera/lens movement."

Givens: Pretend that both cameras are perfect and I hold them exactly the same for this little experiment; the aircraft vibration, wind, altitude, everything other than the lens and the film/sensor size are the same. Also, I am not referring to the relative motion of the target below the aircraft due to the speed of the plane.

I use 50mm for 35mm, and 150mm for 4x5 as that is what I have in real life. I dont want to argue about 'what is normal.'

I understand re: gyros and I have one. Its just that I will shoot using 3 cameras and to have a gyro on 1 gets unwieldy in the cockpit. Therefore, I am simply exploring the relationship, if any, between focal length, angle of view, film/sensor size, and image blur due to motion caused by camera-lens movement (rather than the speed of the aircraft over the target).


Well, having the same normal angle of view, you cannot allow the same shake in a 35mm camera than in a 4x5 camera.

Let me explain that, imagine that a 35mm film camera or DSLR resolves some 20Mpix, well, we can calculate the amount of shake (linear or angular) that do not degradates that 20 Mpix Image quality (let me speak in the nasty Mpix terms).

But the 4x5 can deliver 400 Mpix (optimal conditions) in film, perhaps 200 scanned in practice, the amount of shake that not degradates those 300 Mpix is some 1/3 of the shake that do not degradates the 35mm film image. , with similar angle of view. How I calculate that 1/3 ? Easy, the 35mm film image has a 36mm side, say 1.5 inches, while the 4x5 has 5 inches in the long side, hence the 1:3 relationship about allowed shake

If in general you have shake enough then it is not worth the larger format, if at the end the shake allows 20 Mpix you better shot 35mm film, as you will end with same IQ for 1/8 the money.

If you want to test easy, just take the DSLR, disconnect VR and use and use the same actual (not equivalent) focal length than with the 4x5. The amount of shake that not degradates the DSLR image with a 150mm focal it won't degradate the 4x5 image from the 4x5 camera with the 150mm. This is if lenses had same performance.

As we can guess a lower ultimate lens performance for the 4x5 lens then you may test with a 100mm in the DSLR (without VR), to know the amount of shake that will start degradating IQ in the 4x5 case with the 150.

Mark Sampson
12-Jan-2018, 09:52
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.

Randy Moe
12-Jan-2018, 10:06
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 was working from memory of an old film on PI. Found this fascinating link just now that clears my cobwebs. I agree you are correct.

https://gizmodo.com/spies-in-the-skies-how-aerial-surveillance-tipped-the-1592113832

Pfsor
12-Jan-2018, 11:02
This is somewhat hard to express accurately in my question. Let me give a barnyard example: lets say that i can easily hand-hold a 50mm lens in a Cessna effectively and get clear (non camera-motion blurred) aerial images on FF digital camera. If I use a 150mm lens on a 4x5 camera, under the same conditions, can I expect the same results?


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.

Dan Fromm
12-Jan-2018, 12:04
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.

pchaplo
12-Jan-2018, 12:20
Shake and the platform's movement are equivalent.

True, but can control aircraft motion over the ground with airspeed and, in a relative sense, vector toward target and altitude. Thats why I'm just wanting to consider blur resulting from imperfect operator hand-held effects.

Did I get that right?

pchaplo
12-Jan-2018, 12:22
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 :)


As we can guess a lower ultimate lens performance for the 4x5 lens then you may test with a 100mm in the DSLR (without VR), to know the amount of shake that will start degradating IQ in the 4x5 case with the 150.

pchaplo
12-Jan-2018, 12:24
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


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.

Pere Casals
12-Jan-2018, 12:29
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.

pchaplo
12-Jan-2018, 12:37
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.

pchaplo
12-Jan-2018, 12:39
Agiflight cameras were handheld? Did they have gyro? Wow those are some long lenses! Tell me more, tell me more...


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.

Jac@stafford.net
12-Jan-2018, 12:53
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.

Dan Fromm
12-Jan-2018, 13:54
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/FlightPDFArchive/1979/1979%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.

Jim Jones
12-Jan-2018, 14:25
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.

Mfagan
12-Jan-2018, 16:21
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 :-).

Randy Moe
12-Jan-2018, 16:28
The parallel formation is what I remembered from perhaps a British documentary. It was stressed as very difficult navigation.

Thanks for the memory jog!


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 :-).

Don Dudenbostel
12-Jan-2018, 21:29
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!

pchaplo
12-Jan-2018, 21:34
Dan, thanks, I read that Agi article with great interest. I like the Agi camera controls and “gun site.”


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/FlightPDFArchive/1979/1979%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.

pchaplo
12-Jan-2018, 22:21
Good points. Thanks. Yes I’ve been in 172 a few times. For FF digital, I usually shoot with a 28mm on one camera and a 50mm (or a 28-70mm zoom) in the other. The window is a non-issue. My fav personal images are shot the 28mm, and yes, I can clear the strut, landing gear (prefer fairings off), tail, and wing with a good pilot. Does that imply that I can clear the obstructions with a 90mm on 4x5? I can go longer if needed but I love to see the horizon and the earth wrapping below me in a wider shot. 120mm and gyro might be a more realistic compromise.

Back to my question, I was wondering about focal length. I’m shopping for a field camera then will test with my Ken-Lab gyro. It can all be solved.

I’m also concerned about the parallax of 4x5 viewfinder, too. Perhaps there is a solution - makes me wonder how I can mount viewfinder perhaps to just clear the strut. Or I can get a wider optical viewfinder and mark it with a reference for the strut, etc.

I’m an aviation fanatic so I love all these interesting tangents!

adelorenzo
12-Jan-2018, 23:56
Here is how Bradford Washburn managed to do it with an 8x10 camera: https://goo.gl/images/N1whhB

Don Dudenbostel
13-Jan-2018, 07:40
Have you noticed aerial cameras don't have bellows. There's a reason because you get it in the slipstream and they're ripped from the camera.

Personally I think a 90 is too wide. Possible a 135 and get the pilot to cross control the plane and roll it to the left. Of course in that configuration you can't fly slow or you'll stall. By cross control I mean right rudder and left aileron or vice versa depending on what side of the aircraft your on.

You might see if you can get access to a 172RG. The RG has retractable gear. Even better is the 177RG Cardinal. It's basically a 172 RG with retractable gear, no wing strut and a slightly bigger window. Many have constant speed props allowing for more flexibility in flying.

I'd forget the gyro. Those are mainly for motion picture and will only get in the way. Actually I'd forget 4x5 and shoot a Pentax 6x7.

Mfagan
13-Jan-2018, 08:06
A couple of points that may be useful... last photos I took from a 172 were in the late 70s so maybe the design has changed, but the door windows could be opened in flight, and if the one screw restricting the opening angle is removed, the window will open and stay open up against the underside of the wing. I have shot with a SG keeping the bellows out of the wind. Secondly, when operating from an aircraft carrier (not the 172 of course :-)), we had a cardboard box of Topcons with a 100mm lens ó loaded with TechPan in the ready room. Just grab one on way out to man up for the flight and photo any shipping seen, mission permitting. So, I will guess we would go about 300-350 knots along side a ship at about 500 feet. The purpose of the photos was no doubt different than the OPís, but the images were sufficient for their purposes (shooting through a quite optically imperfect canopy.

Don Dudenbostel
13-Jan-2018, 09:45
I'm assuming these are similar to what you're going to shoot but in a rural area?

I shot these in 1980 from an Instrom F-28 Helicopter with a 4x5 Pacemaker Crown Graphic and 135 Xenar. I used TX film packs because there's not much room for a bag of holders. It was a very hazy day with clouds in the sky.

pchaplo
13-Jan-2018, 13:21
Hi Don, Thanks for sharing these delightful 4x5 aerials shot Pacemaker Crown Graphic. Love those! You handheld 135mm Xenar? What shutter speed and f-stop were typical, do you remember?

173666


I'm assuming these are similar to what you're going to shoot but in a rural area?

I shot these in 1980 from an Instrom F-28 Helicopter with a 4x5 Pacemaker Crown Graphic and 135 Xenar. I used TX film packs because there's not much room for a bag of holders. It was a very hazy day with clouds in the sky.

pchaplo
13-Jan-2018, 13:26
Bradford Washburn is my inspiration! Thanks for the link. I met his nephew about a year ago perhaps at Sierra club.


Here is how Bradford Washburn managed to do it with an 8x10 camera: https://goo.gl/images/N1whhB

pchaplo
13-Jan-2018, 13:35
Slippery analogy: some vertical photography that approximately satellite views is more like high-altitude precision bombing, low-altitude obliques are more like strafing.

Randy Moe
13-Jan-2018, 15:39
This thread has me looking at lots of interesting sites.

'Big' Wild Heerbrugg which is also an interesting name. Massive Stereo and complicated. History in the link. Seems the A8 was the best machine for 3 decades. Must still be Top Secret with no picture included.

I'm a big camera nut, but you knew that. The 1937 Model R3 shooting camera image shows the 2 tilted planes using one massive lens. Scroll way down.


http://www.wild-heerbrugg.com/photogrammetry1.htm

Don Dudenbostel
13-Jan-2018, 16:36
I'm assuming these are similar to what you're going to shoot but in a rural area?

I shot these in 1980 from an Instrom F-28 Helicopter with a 4x5 Pacemaker Crown Graphic and 135 Xenar. I used TX film packs because there's not much room for a bag of holders. It was a very hazy day with clouds in the sky.

I did hand hold them. It's not that difficult in s helicopter as long as you keep the camera out of the rotor wash. It's been 38 years since I shot these. The were for planning purposes for the 1982 worlds fair. Just a guess I'd say I shot at 1/250 but I remember some overcast at times an haze and don't remember if I had a K2 filter on it or not. I might have because of the haze. The f stop, ???.

If you're really serious about 4x5 I'd buy an old wooden body crown or speed graphic. A 127 Ektar would be good and I'd get some aluminum and build a cowling around the bellows and just past the front standard. I said wooden body because I'd secure the cowling on the camera with screws. Then I'd run the front standard out to exactly infinity, pot epoxy on the rails and then secure the rails at infinity focus wit a screw. It's just too easy for things to move up there. I'd then use the wire sports finder on the camera and figure out what the lens sees vs the view through the wire finder. Usually theses finders aren't very accurate so you might even need to fabricatecone.

If you really want a fun adventure, find someone with a J3 Cub. The strut is farther forward than the 172 and you can fly with the door open. The J3 originally didn't have an electric start so you had to pull the prop by hand. Folks would get behind the prop, crack the throttle, prime the engine, switch on the magnetos then pull the prop and jump in because there was no way to engage the breaks. I flew a 7AC Aeronca Champ that I had to pull the wooden prop on to start it but the door was different and the strut too far back to do that. I had to have someone hold the breaks because I had to start it from in front of the prop. It's a little in needing the first time.

J3 pilots are usd to flying from the back seat as that's where you have to fly from when there's only one person aboard. It's duecti center of gravity, CG. Fly solo from the front and you become a lawn dart.

The J3 other than being really small is it's cheap cheap to fly and Slooooow. It's like the champ, I know from experience in cold dry weather it would fly at 25-30 mph. If you're a flying nut, these old vintage aircraft are a hoot to fly in. The Champ I flew was built in 1946, 2 years before me. Uncomfortable seats, pulling a wooden prop by hand to start it and flying with a stick. Everything's cool until you encounter a large hawk that wants to take you down.

Maximize your fun. Get someone to fly you that's an instructor and use it as a flying lesson too. That's what I do when I use a helicopter. The flying service I use has two Schweitzer 300's and the pilot in an instructor. I've got enough hours in rotor now that I do all the flying frongvthecairport to the shoot site and back. It's on my clients dime too.

pchaplo
13-Jan-2018, 17:41
Don, I’ve collected hours, too ;) 300c’s and R-22’s mostly. Those darn hawks (and buzzards in Texas) always seem to dive when near don’t they? I like your idea of building a cowling and was brainstorming that today. J3 hand-start wow that’s old school! No mid-air restart option? Yikes! I’ve been in one:( Back to the cowling I might even use black foam core —then I saw this - see below. Looks WW1 era. Fits my bailing twine and duct tape aesthetic :)
173667

Don Dudenbostel
13-Jan-2018, 19:38
Foamcore won't stand up to the wind. Build a mockup and have someone take you out to a deserted road in their car and get you up to 100 mph and then stick it out the window. If it'll hold up then it'll be ok in the air. But I would bet money a foamcore and gaffer tape cowling won't stay together. I'd use a pretty rigid aluminum popriveted together then screwed securely into the body of the camera.

I'm a big nut about sAfety. Remember anything that fall to earth is a potential reason for a lawsuit. Any property damage or injury is serious. All someone needs to do is get your N number or track you through ATC.

Jac@stafford.net
21-Jan-2018, 17:16
In my modest opinion the only acceptable aerial camera is one with no bellows and minimal body.
.