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Sony XDCAM EX Pro Handhelds
Sony PMW-300, PXW-X200, PXW-X180 (back to EX3 & EX1) recording to SxS flash memory.


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Old November 11th, 2007, 07:37 AM   #1
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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?
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Old November 11th, 2007, 07:48 AM   #2
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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
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Old November 11th, 2007, 07:51 AM   #3
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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.
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Old November 11th, 2007, 07:52 AM   #4
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Erwin beat me to it - and with the correct conversion! ;o)
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Old November 11th, 2007, 08:41 AM   #5
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Quote:
Originally Posted by Erwin van Dijck View Post
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?
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Old November 11th, 2007, 08:44 AM   #6
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31mm on a 35mm frame is not that bad for wide angle.
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Old November 11th, 2007, 08:44 AM   #7
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Originally Posted by Bill Edmunds View Post
I had no idea! So the Ex is actually about the same or even wider?
Correct. Thanks to the 1/2" sensors.
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Old November 11th, 2007, 08:47 AM   #8
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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
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Old November 11th, 2007, 11:30 AM   #9
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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.
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Old November 11th, 2007, 11:44 AM   #10
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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.
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Old November 11th, 2007, 11:53 AM   #11
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This should help

http://www.panavision.co.nz/main/kba...alcFOVform.asp
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Old November 11th, 2007, 12:49 PM   #12
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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.
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Old November 11th, 2007, 02:42 PM   #13
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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.
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Old November 11th, 2007, 02:58 PM   #14
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Quote:
Originally Posted by Eric Pascarelli View Post
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.
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