5.8mm wide angle -- ugh! at DVinfo.net

Bill Edmunds · November 11th, 2007, 07:37 AM

This camera was looking great until I saw the 5.8mm wide angle setting. That's a real disappointment to me. That's not nearly wide enough IMO. I was seriously thinking of selling my HVX200 and buying this unit, but now I'm really reconsidering. The HVX200 has a 4.2mm wide angle -- MUCH wider than the Sony. I really dislike using WA attachments as well. Why did Sony go with such a limiting setting? A lense limitation?

Erwin van Dijck · November 11th, 2007, 07:48 AM

Bill,

You must take in consideration that the SONY EX has a different size image sensor compared to the HVX. That makes a direct comparison impossible.

The HVX200 has 1/3" image sensor and the EX 1/2". Therefore it is an idea to recalculate to the equivalent of a 35mm still camera:

HVX: 4.2mm would be 32.5mm (in a 35mm photocamera)
EX: 5.8mm would be 31.4mm

So the difference is not that bad at all.

Regards,
Erwin

John M. Graham · November 11th, 2007, 07:51 AM

Bill,

The EX has 1/2 inch chips as opposed to the HVX's 1/3 inch chips. That means the EX will have a wider view than a 1/3 inch camera at the same focal length. In order to compare on the same playing field, each lens/sensor size combination needs to be converted into the 35 mm equivalent. I don't know the formula to convert 1/2" and 1/3" sensor cameras into 35mm though, but I would assume the 5.8mm of the EX would be very close to the 4.2mm of the HVX.

A good example of this would be take a full-size sensor DSLR like the Canon 1Ds-Mark III and a Rebel XTi and fit the with the same lens, say a 50mm fixed. If you had them on tripods right next to each other, the 1D will have a much wider viewing angle than the Rebel at the same focal length. The reason is because the Rebel (and other more affordable DSLRs) usually have the APS-C sized sensor, which is smaller than a full size 35mm sensor. They have a 1.6x magnification factor. So to match the 50mm of the 1Ds, you would have to fit a 31.25mm lens.

John M. Graham · November 11th, 2007, 07:52 AM

Erwin beat me to it - and with the correct conversion! ;o)

Bill Edmunds · November 11th, 2007, 08:41 AM

Quote:

Originally Posted by Erwin van Dijck

The HVX200 has 1/3" image sensor and the EX 1/2". Therefore it is an idea to recalculate to the equivalent of a 35mm still camera:

HVX: 4.2mm would be 32.5mm (in a 35mm photocamera)
EX: 5.8mm would be 31.4mm

I had no idea! So the Ex is actually about the same or even wider?

Tim Polster · November 11th, 2007, 08:44 AM

31mm on a 35mm frame is not that bad for wide angle.

Steven Thomas · November 11th, 2007, 08:44 AM

Quote:

Originally Posted by Bill Edmunds

I had no idea! So the Ex is actually about the same or even wider?

Correct. Thanks to the 1/2" sensors.

Ray Bell · November 11th, 2007, 08:47 AM

Just to toss in the Wide Angle Converter figures.... I think I read it was a
x .8

So with the WA adaptor in place the wide side of the lens would be 25mm
that is if you want to use a WA....

I have also heard that with the larger battery, the WA converter balances the camera better.......

This could become a consideration as the cam is not a shoulder mount

Eric Pascarelli · November 11th, 2007, 11:30 AM

Yes, the EX1 is slightly wider than the HVX. You can skip over the 35mm conversion (which applies to the "8-perf" still camera format and not the "4-perf" motion picture camera format) and just convert between the two cameras.

The math is simple - since 1/3" is .333" and 1/2" is .5", divide one by the other to get the ratio.

The conversion ratio between the two cameras is 1.5 : 1.

So the 5.8mm lens on the Sony is equivalent to a (nonexistent) 3.86mm on the Panasonic.

Put a different way, the Sony goes more than 8% wider in terms of field of view than the Panasonic. And this is before attaching the wide angle converter.

Steven Thomas · November 11th, 2007, 11:44 AM

Does anyone know the calculation at a given f-stop and match for field of view (focal length) on how much tighter DOF is on a 1/2" vs 1/3" sensor camera?

I realize this answer would be the science and may not match 100%, but would be close.

Paul Ramsbottom · November 11th, 2007, 11:53 AM

This should help

http://www.panavision.co.nz/main/kba...alcFOVform.asp

Steven Thomas · November 11th, 2007, 12:49 PM

Thanks Paul.

The 16:9 1/2" sensor was not listed as an option, so I based the info from using the 4:3 1/2" and 1/3" sensors.

Of course it's all about FOV (Field Of View). Since the 1/2" is wider at a given focal length, the 1/3" would have to go wider (hence more DOF) to maintain the same FOV as the 1/2" camera.
If the same distance from the subject using the 1/2" and 1/3" cams are maintained, the 1/3" cam would have to increase its focal length by 25% to match the 1/2" cam FOV. As a result the 1/3" cam would also increase its DOF by 25%.

So does this result seem correct? It shows a 25% improvement for tighter DOF (at the same FOV and f-stop) over the 1/3" cams.

Eric Pascarelli · November 11th, 2007, 02:42 PM

Steven,

Another way to look at DoF among different formats is to think of equivalents.

Using the same lens conversion factor of 1.5, it works out that the DoF of a 1/3" camera at a certain stop is the same as a 1/2" camera at that stop number x 1.5, at equal fields of view.

As an example, a 1/3" camera at 10mm at f/4 is the same as a 1/2" camera at 15mm at f/6. So a 1/2" camera at the same stop, f/4 has less DoF than a 1/3" camera with the same field of view.

Since each f/stop is an increase in number by a factor of approximately 1.4, it can be said that the 1/2" camera has about one stop less depth of field than a 1/3" camera, at a given field of view.

All of the above assumes that the circle of confusion spec is also proportional to the lens/chip conversion factor, which it pretty much is in a typical depth of field calculation.

It also assumes that the sensor sizes really are what they say they are and are in a 1 : 1.5 proportion - I cannot find the actual measurement spec for the active area of the 1/2" 16x9 chip used in the Sony, nor have I ever found a reliable spec for the HVX (2/3" is widely published as 9.6x5.4mm, for example). If anyone has those exact specs I can revise my numbers.

Steven Thomas · November 11th, 2007, 02:58 PM

Quote:

Originally Posted by Eric Pascarelli

Since each f/stop is an increase in number by a factor of approximately 1.4, it can be said that the 1/2" camera has about one stop less depth of field than a 1/3" camera, at a given field of view

Thanks Eric, that's good information.

November 11th, 2007, 07:37 AM	#1
Bill Edmunds Major Player Join Date: Aug 2003 Location: Conway, NH Posts: 574	5.8mm wide angle -- ugh! This camera was looking great until I saw the 5.8mm wide angle setting. That's a real disappointment to me. That's not nearly wide enough IMO. I was seriously thinking of selling my HVX200 and buying this unit, but now I'm really reconsidering. The HVX200 has a 4.2mm wide angle -- MUCH wider than the Sony. I really dislike using WA attachments as well. Why did Sony go with such a limiting setting? A lense limitation?

November 11th, 2007, 12:49 PM	#12
Steven Thomas Trustee Join Date: Sep 2005 Location: Gilbert, AZ Posts: 1,896	Thanks Paul. The 16:9 1/2" sensor was not listed as an option, so I based the info from using the 4:3 1/2" and 1/3" sensors. Of course it's all about FOV (Field Of View). Since the 1/2" is wider at a given focal length, the 1/3" would have to go wider (hence more DOF) to maintain the same FOV as the 1/2" camera. If the same distance from the subject using the 1/2" and 1/3" cams are maintained, the 1/3" cam would have to increase its focal length by 25% to match the 1/2" cam FOV. As a result the 1/3" cam would also increase its DOF by 25%. So does this result seem correct? It shows a 25% improvement for tighter DOF (at the same FOV and f-stop) over the 1/3" cams. Last edited by Steven Thomas; November 11th, 2007 at 01:41 PM.

November 11th, 2007, 02:42 PM	#13
Eric Pascarelli Major Player Join Date: Nov 2007 Location: Los Angeles, CA Posts: 498	Steven, Another way to look at DoF among different formats is to think of equivalents. Using the same lens conversion factor of 1.5, it works out that the DoF of a 1/3" camera at a certain stop is the same as a 1/2" camera at that stop number x 1.5, at equal fields of view. As an example, a 1/3" camera at 10mm at f/4 is the same as a 1/2" camera at 15mm at f/6. So a 1/2" camera at the same stop, f/4 has less DoF than a 1/3" camera with the same field of view. Since each f/stop is an increase in number by a factor of approximately 1.4, it can be said that the 1/2" camera has about one stop less depth of field than a 1/3" camera, at a given field of view. All of the above assumes that the circle of confusion spec is also proportional to the lens/chip conversion factor, which it pretty much is in a typical depth of field calculation. It also assumes that the sensor sizes really are what they say they are and are in a 1 : 1.5 proportion - I cannot find the actual measurement spec for the active area of the 1/2" 16x9 chip used in the Sony, nor have I ever found a reliable spec for the HVX (2/3" is widely published as 9.6x5.4mm, for example). If anyone has those exact specs I can revise my numbers. Last edited by Eric Pascarelli; November 11th, 2007 at 03:41 PM.

November 11th, 2007, 07:48 AM	#2
Erwin van Dijck Regular Crew Join Date: Nov 2007 Location: Hoofddorp, The Netherlands Posts: 75	Bill, You must take in consideration that the SONY EX has a different size image sensor compared to the HVX. That makes a direct comparison impossible. The HVX200 has 1/3" image sensor and the EX 1/2". Therefore it is an idea to recalculate to the equivalent of a 35mm still camera: HVX: 4.2mm would be 32.5mm (in a 35mm photocamera) EX: 5.8mm would be 31.4mm So the difference is not that bad at all. Regards, Erwin

November 11th, 2007, 07:51 AM	#3
John M. Graham Regular Crew Join Date: Oct 2006 Location: Fort Worth, Texas Posts: 83	Bill, The EX has 1/2 inch chips as opposed to the HVX's 1/3 inch chips. That means the EX will have a wider view than a 1/3 inch camera at the same focal length. In order to compare on the same playing field, each lens/sensor size combination needs to be converted into the 35 mm equivalent. I don't know the formula to convert 1/2" and 1/3" sensor cameras into 35mm though, but I would assume the 5.8mm of the EX would be very close to the 4.2mm of the HVX. A good example of this would be take a full-size sensor DSLR like the Canon 1Ds-Mark III and a Rebel XTi and fit the with the same lens, say a 50mm fixed. If you had them on tripods right next to each other, the 1D will have a much wider viewing angle than the Rebel at the same focal length. The reason is because the Rebel (and other more affordable DSLRs) usually have the APS-C sized sensor, which is smaller than a full size 35mm sensor. They have a 1.6x magnification factor. So to match the 50mm of the 1Ds, you would have to fit a 31.25mm lens.

November 11th, 2007, 07:52 AM	#4
John M. Graham Regular Crew Join Date: Oct 2006 Location: Fort Worth, Texas Posts: 83	Erwin beat me to it - and with the correct conversion! ;o)

November 11th, 2007, 08:44 AM	#6
Tim Polster Inner Circle Join Date: Dec 2004 Location: Arlington, TX Posts: 2,231	31mm on a 35mm frame is not that bad for wide angle.

November 11th, 2007, 08:47 AM	#8
Ray Bell Regular Crew Join Date: Nov 2004 Posts: 1,414	Just to toss in the Wide Angle Converter figures.... I think I read it was a x .8 So with the WA adaptor in place the wide side of the lens would be 25mm that is if you want to use a WA.... I have also heard that with the larger battery, the WA converter balances the camera better....... This could become a consideration as the cam is not a shoulder mount

November 11th, 2007, 11:30 AM	#9
Eric Pascarelli Major Player Join Date: Nov 2007 Location: Los Angeles, CA Posts: 498	Yes, the EX1 is slightly wider than the HVX. You can skip over the 35mm conversion (which applies to the "8-perf" still camera format and not the "4-perf" motion picture camera format) and just convert between the two cameras. The math is simple - since 1/3" is .333" and 1/2" is .5", divide one by the other to get the ratio. The conversion ratio between the two cameras is 1.5 : 1. So the 5.8mm lens on the Sony is equivalent to a (nonexistent) 3.86mm on the Panasonic. Put a different way, the Sony goes more than 8% wider in terms of field of view than the Panasonic. And this is before attaching the wide angle converter.

November 11th, 2007, 11:44 AM	#10
Steven Thomas Trustee Join Date: Sep 2005 Location: Gilbert, AZ Posts: 1,896	Does anyone know the calculation at a given f-stop and match for field of view (focal length) on how much tighter DOF is on a 1/2" vs 1/3" sensor camera? I realize this answer would be the science and may not match 100%, but would be close.

November 11th, 2007, 11:53 AM	#11
Paul Ramsbottom Regular Crew Join Date: Jan 2006 Posts: 85	This should help http://www.panavision.co.nz/main/kba...alcFOVform.asp