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

[pchaplo]

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]

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.

[Tin Can]

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]

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]

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.

[Tin Can]

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-ski...the-1592113832

[Pfsor]

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]

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]

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]

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.