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Earth rotation limits in-body image stabilization to 6.3 stops (2020)

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Re: Earth rotation limits in-body image stabilization to 6.3 stops (2020)

#71

Post by Filligree »

thrdbndndn wrote: post #67
SamBam wrote: post #45

Earlier quoted context omitted.

Imagine the camera were floating just above the surface of the Earth, and also that it had perfect image stabilization. This image stabilization would keep the camera always oriented in the same direction. Same direction relative to what? To the rest of the universe. So if it was pointing right at a star, it would continue pointing directly at that star as it went around and around the Earth. From our perspective on…

> Same direction relative to what? To the rest of the universe By this logic, the Earth's revolution would also cause similar issue, and even worse. But in reality only the rotation does. I think at least some part of your explanation does not calculate.

The Earth's revolution around the sun? What makes you think it doesn't? It's just that the effect is 1/365 the size, on the same axis as the rotation.

Re: Earth rotation limits in-body image stabilization to 6.3 stops (2020)

#72

Post by _ph_ »

thrdbndndn wrote: post #69
_ph_ wrote: post #66

Earlier quoted context omitted.

The relevant "speed" is the change of the direction you are pointing at. The Earth rotates around itself in 24 hours, but around the Sun in 365 days, so the daily rotation is 365x as fast. We also rotate around the center of the Milky Way every couple of hundreds of millions of years.

Ah, so the angle (orientation?) is what actually matters? It makes sense now. Thanks!

At least with respect to the influence of the Earths rotation. With respect to compensating actual camera shake, the modern systems correct 5 axis's. 3 for rotation around the 3 space axis's, and 2 translational, which leaves only motion towards or away from the motive uncorrected for (which usually only expresses itself in the need of refocussing, but that usually is far beyond camera shake, except for macro photography).

Re: Earth rotation limits in-body image stabilization to 6.3 stops (2020)

#73

Post by zamalek »

thrdbndndn wrote: post #65
zamalek wrote: post #29

Earlier quoted context omitted.

Per my other comment: Earth isn't attached to the sun, the sun isn't attached to the galactic center (they are orbiting). They are independent rotational frames of reference. They are also gyroscopes in their own right. As far as taking pictures of other things on Earth, at least. Taking a picture of another planet/star/galaxy would also face similar challenges.

What's the difference between our "attachment" to Earth compared to Earth's attachment to the Sun? Aren't both doing circular motion due to gravity (in us-Earth's case, gravity + support force from the ground) and inertia?

The Earth is in freefall above the sun. We are not in freefall. https://en.wikipedia.org/wiki/Free_fall

Re: Earth rotation limits in-body image stabilization to 6.3 stops (2020)

#75

Post by cesaref »

This is analogous to astro-photography problems with keeping stars as points rather than as blurred lines in long exposures. If you think about it, if a long exposure at night has a static landscape but moving stars, the IBIS equivalent would have static stars and a moving landscape :)

Re: Earth rotation limits in-body image stabilization to 6.3 stops (2020)

#76

Post by SamBam »

thrdbndndn wrote: post #67
SamBam wrote: post #45

Earlier quoted context omitted.

Imagine the camera were floating just above the surface of the Earth, and also that it had perfect image stabilization. This image stabilization would keep the camera always oriented in the same direction. Same direction relative to what? To the rest of the universe. So if it was pointing right at a star, it would continue pointing directly at that star as it went around and around the Earth. From our perspective on…

> Same direction relative to what? To the rest of the universe By this logic, the Earth's revolution would also cause similar issue, and even worse. But in reality only the rotation does. I think at least some part of your explanation does not calculate.

It does. A perfect gyro will remain on a single axis relative to the rest of the universe while the Earth goes around the sun, and while the galaxies swirl around.

I'll leave it to you to figure out how "perfect" it would need to be, and what the actual error that the stabilizer would need to account for if the gyroscope is accurate enough to detect the motion of the Earth around the sun, compared with the error created by the Earth's rotation.

Re: Earth rotation limits in-body image stabilization to 6.3 stops (2020)

#77

Post by jjk166 »

labcomputer wrote: post #57
Rinzler89 wrote: post #35

Earlier quoted context omitted.

> Inertial navigation systems in aircraft (which use very stabilised platforms with a lot of math involved) worked before GPS was available. Inertial measurement units for aircrafts and submarines cost as much as a house in California. Good luck putting those in a phone.

Well, that, and there's no such thing as a "solid state laser gyro". I believe the GP is confusing MEMS solid-state gyros and laser-ring gyros (which can use a solid state laser, but AFAIK aren't ever called "solid state laser gyro"). MEMS gyros have too much bias drift (both on a unit basis due to fab processes and on a temperature basis) to be practically useful here. You can measure the earth's rotation with a MEM…

Laser ring gyros are referred to as solid state laser gyros.

Re: Earth rotation limits in-body image stabilization to 6.3 stops (2020)

#78

Post by sib »

Nikon claims 8.0 stops of "VR image stabilization" for their Zf camera (released late in 2023).

https://www.nikonusa.com/p/z-f/1761/overview

("Based on CIPA standards; when using the telephoto end of the NIKKOR Z 24-120mm f/4 S" - for clarity, that lens does not have optical VR in the lens itself, so this is all based on in-body stabilization.)

Re: Earth rotation limits in-body image stabilization to 6.3 stops (2020)

#79

Post by Karellen »

Filligree wrote: post #71
thrdbndndn wrote: post #67

Earlier quoted context omitted.

> Same direction relative to what? To the rest of the universe By this logic, the Earth's revolution would also cause similar issue, and even worse. But in reality only the rotation does. I think at least some part of your explanation does not calculate.

The Earth's revolution around the sun? What makes you think it doesn't? It's just that the effect is 1/365 the size, on the same axis as the rotation.

The same axis of rotation? Pretty sure they're about 23° off.
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