Wide comparison of 4x3 vs. 16x9, DSR-450/390

Dave Hall · December 29, 2005

Here is the second of my still tests for the Sony DSR-450WS and the DSR-390. I didn't actually fathom the difference between 16x9 and 4x3 as far as how wide of a shot (angle of view) you can get, until I had my hands on both. I have the equivalent lens on each camera, which is a very wide Canon YJ12X6.5 on the 2/3" DSR-450, and a YH12X4.8 on the 1/2" DSR-390. The bottom line people should know is that when using a 16x9/4x3 switchable camera, the 4x3 view is not nearly as wide as you would hope it to be (which is why the lens companies offer a .8X crossover.) For framing, I used the top of the wall as the top of my safe area in the viewfinder, and from left to right centered on the clock. Lenses set as wide angle as possible. Here are the results:

DSR-450 in 16x9 mode

DSR-450 in 4x3 mode

DSR-390 in 4x3 mode (the only option)

Peter J DeCrescenzo · December 30, 2005

A curious thing happened when I went to check related info using the Angle of View / Field of View / Depth of Field calculator on the Panavision New Zealand website:

http://www.panavision.co.nz/main/kbase/ref...calcFOVform.asp

Am I misunderstanding how the following math works, or is there a bug in their calculator? (I'm not a math wizard, so I suspect the former.)

Using their calulator, if I enter a Subject Distance of 50 feet, a focal length of 50mm, set the format to 1/2" 4:3 video CCD, and set all the units of measurement to feet, the resulting horiz. AOV is 5.5 degrees and the FOV is 6.4 feet.

If I enter a Subject Distance of 50 feet, a focal length of 50mm, set the format to 2/3" 16:9 video CCD, and set all the units of measurement to feet, the resulting horiz. AOV is 6.2 degrees and the FOV is 9.6 feet.

If I subtract 20% from the AOV and FOV of the 2/3" 16:9 results above to get approx. values for what happens when you switch the _camera_ (not the lens) to its 4:3 mode, the resulting AOV is 4.96 degrees and the FOV is 7.68 feet.

I believe it's correct that a 16:9 cam loses about 20% of it AOV when you switch the _cam_ to 4:3. At least, that's my understanding of what Fujinon is describing here:

http://www.fujinonbroadcast.com/vformat.shtml

... but then why the difference in width (in feet) between "4.96 degrees = 7.68 feet" compared to "5.5 degrees = 6.4 feet" as shown above? I mean, the wider AOV degrees should equal a wider FOV in feet, right?

I'm sure it's because of something simple, but my small brain isn't grasping it. Or is the calculator wrong? I'd appreciate it if someone could shed some light on this for me.

EDIT: Hmmm ... am I making an "apples & oranges" comparison?

Edited December 30, 2005 by Peter DeCrescenzo

Brian Drysdale · December 30, 2005

Using the 4 x 3 mode in a camera that can also shoot 16 x 9 means you don't use the full width of the CCD. This means that for the same focal length you'll have a narrower angle of view in 4 x 3 than 16 x 9. Some video lenses have a selectable optical element (found with the x 2 range extender bulge) that shortens the focal length of the lens in use, so that you can keep the same angle of view in both aspect ratios.

Edited December 30, 2005 by Brian Drysdale

Dave Hall · December 30, 2005

Some video lenses have a selectable optical element (found with the x 2 range extender bulge) that shortens the focal length of the lens in use, so that you can keep the same angle of view in both aspect ratios.

That's the 0.8X crossover I mentioned in the original post. Having one would get you back to the wide angle you would expect. I've got to imagine it adds a lot of weight to the lens, and it will eventually be obsolete in the magical world of 16x9.

Brian Drysdale · December 30, 2005

That's the 0.8X crossover I mentioned in the original post. Having one would get you back to the wide angle you would expect. I've got to imagine it adds a lot of weight to the lens, and it will eventually be obsolete in the magical world of 16x9.

Yes, I haven't seen one for sometime, nearly everything in the UK is now shot 16x9. It does add a bit of extra weight to the lens, however, it's not so much that you'd notice it (it looks like there are two range extenders fitted). It's worth having if you're shooting a lot on both aspect ratios.