Help me understand "fractional" sensor size

[vindibona1]

Math isn't my strong suit and I'm having trouble wrapping my head around the censor size notations in fractional inches with decimals. In this case it would be much clearer if done in millimeters. But it is what it is. And why do non US companies use inches anyway?

I was comparing the sensor in the Mini 2 vs the Autel Nano Plus. The Nano plus has a1/1.28 Inch CMOS Sensor while the Mini 2 has a 1/2.3-inch CMOS sensor. The Nano's (non Plus) censor has a more straight forward listing of 1/2", which is easily understood. What's with the fractions after the slash (division mark) with a Mini 2 or Nano Plus? How is that calculated? While we're at it, explain how 4/3rds censors are calculated for area. TIA

Please help unconfuse me?

 

[Meta4]

Please help unconfuse me?

That might not be possible as the names for sensor sizes are very confusing and don't refer to any of the dimensions of the sensor.

This explains how the names were derived:

Blog - Machine Vision and Automation - Scorpion Vision

Find the latest news and updates from Scorpion Vision and from across the industry of automation and machine vision.

www.scorpionvision.co.uk

There is a large table with actual sensor dimensions at the bottom of this article:

Image sensor format - Wikipedia

en.wikipedia.org

 

[MaximusCZ]

Everyone measures it in inches because that's what everyone is accustomed to.

Fractions is division: 1/2 = 1 ÷ 2 = 0.5

The number in front of slash dividend, and the number after the slash is divisor.
The higher the dividend is, the higher the resulting number.
The higher the divisor is, the smaller the resulting number.

1/1.28 = 1 ÷ 1.28 = 0.78125
1/2.3 = 1 ÷ 2.3 = 0.43478
4/3 = 4 ÷ 3 = 1.33333

The resulting number is the diagonal of the sensor in inches

EDIT:
Ah, so to get to correct answer you always have to multiply the whole division by another 0.63

4/3 inch sensor then 1.3333 -> 1.3333 * 0.63 = 0.8399 actual diagonal inches

As "sar104" noted: That is approximately correct for most sensor sizes.

 

[sar104]

I would start by taking a look at this:

Image sensor format - Wikipedia

en.wikipedia.org

 

[vindibona1]

Everyone measures it in inches because that's what everyone is accustomed to.

Fractions is division: 1/2 = 1 ÷ 2 = 0.5

The number in front of slash dividend, and the number after the slash is divisor.
The higher the dividend is, the higher the resulting number.
The higher the divisor is, the smaller the resulting number.

1/1.28 = 1 ÷ 1.28 = 0.78125
1/2.3 = 1 ÷ 2.3 = 0.43478
4/3 = 4 ÷ 3 = 1.33333

The resulting number is the diagonal of the sensor in inches

There is somewhat clarifying. The question came up in my mind as I was comparing the new Autel nano plus versus the DJI mini 2.

 

[brett8883]

1/(the smaller this number is the bigger the sensor). This is only helpful to compare size these numbers don’t equate to anything meaningful

Everyone measures it in inches because that's what everyone is accustomed to.

Fractions is division: 1/2 = 1 ÷ 2 = 0.5

The number in front of slash dividend, and the number after the slash is divisor.
The higher the dividend is, the higher the resulting number.
The higher the divisor is, the smaller the resulting number.

1/1.28 = 1 ÷ 1.28 = 0.78125
1/2.3 = 1 ÷ 2.3 = 0.43478
4/3 = 4 ÷ 3 = 1.33333

The resulting number is the diagonal of the sensor in inches

It’s easy to see why people think that but that isn’t true. A 1” sensor has a 16mm diagonal ie ~0.63 inches.

The name 1” sensor is short for 1 inch tube equivalent digital sensor. It doesn’t have anything meaningful to do with the inches that are on a ruler

 

[Meta4]

There is somewhat clarifying.

It wasn't really.
He's given you an incorrect answer.

 

[MaximusCZ]

1/(the smaller this number is the bigger the sensor). This is only helpful to compare size these numbers don’t equate to anything meaningful


It’s easy to see why people think that but that isn’t true. A 1” sensor has a 16mm diagonal ie ~0.63 inches.

The name 1” sensor is short for 1 inch tube equivalent digital sensor. It doesn’t have anything meaningful to do with the inches that are on a ruler

Ah, so to get to correct answer you always have to multiply the whole division by another 0.63?
Is the following correct?

4/3 inch sensor then 1.3333 -> 1.3333 * 0.63 = 0.8399 actual diagonal inches

Does it apply the same way for any sensor size?

 

[sar104]

Ah, so to get to correct answer you always have to multiply the whole division by another 0.63?
Is the following correct?

4/3 inch sensor then 1.3333 -> 1.3333 * 0.63 = 0.8399 actual diagonal inches

Does it apply the same way for any sensor size?

That is approximately correct for most sensor sizes.

 

[jeff Voigt]

Everyone measures it in inches because that's what everyone is accustomed to.

Fractions is division: 1/2 = 1 ÷ 2 = 0.5

The number in front of slash dividend, and the number after the slash is divisor.
The higher the dividend is, the higher the resulting number.
The higher the divisor is, the smaller the resulting number.

1/1.28 = 1 ÷ 1.28 = 0.78125
1/2.3 = 1 ÷ 2.3 = 0.43478
4/3 = 4 ÷ 3 = 1.33333

The resulting number is the diagonal of the sensor in inches

EDIT:
Ah, so to get to correct answer you always have to multiply the whole division by another 0.63

4/3 inch sensor then 1.3333 -> 1.3333 * 0.63 = 0.8399 actual diagonal inches

As "sar104" noted: That is approximately correct for most sensor sizes.

Well defined. Well said.

 

[MavicAir2Marc]

This is how Wendy's shelved the 1/3 pound burger because people actually thought Mc Donald's 1/4 pound burger was bigger.