Questions from manual at DVinfo.net

Kent Dammand · November 27th, 2004, 02:01 PM

Questions from manual

1. "* if you have no external ND filter, use Tv mode and set a high shutter speed or use Av mode and set a small aperture value"

Does this mean if you have no matte box + filter or no lens with filter I.E provided 20x lens.

2. "Turning On/Off the ND filter changes the apertature setting. Readjust the aperture in Av mode as required."

Why does it say in Av mode, what is the realtionship to Av mode and the filter?

Also, why does using the filter adjust the aperture? Is the ND filter a true filter or is it just setting the aperture differently.

A. J. deLange · November 27th, 2004, 02:52 PM

1. With or without an external ND filter setting a high shutter speed in Tv mode will require a larger lens opening (smaller f/ number) to achieve the correct exposure. Setting a larger aperture (smaller f/ number) in Av mode will require a longer shutter speed which will be selected automatically.

2. If you enable one of the internal (or add an external) ND filter in Av mode the amount of light reaching the CCD will be reduced and the aperture will open automatically in Tv mode to restore the same level as before the filter was added. In Av mode the aperture will stay the same but the shutter speed will increase. As the object here is, apparently, to increase the aperture (for reduced DOF I assume) one must, in this mode, manually increase the aperture. If the aperture is opened to admit as much extra light as the neutral density filter attenuates the shutter speed will stay the same.

Kent Dammand · November 28th, 2004, 12:33 PM

Does anyone here actually use av or tv mode or mainly manual mode?

I still dont see the reason for using it.

A. J. deLange · November 28th, 2004, 01:20 PM

If you want a particular shutter speed (because, for example, you want to eliminate the blur in a rapidly moving object) AND you want the camera to follow changing light levels for you automatically you use Tv mode.

If you want a particular aperture (because, for example, your lens is sharpest at f/8) AND you want the camera to follow changing light levels automatically you use the Av mode.

If you don't want automatic exposure control, you use manual. Personally, that's my preference for most applications because I don't like watching the background change when someone moves from light to shadow. In the real world the background stays the same and the person becomes harder to see when he moves into a shadow. But that's just my preference and not all the time. If the light change is rapid and tricky and you want the subject properly exposed, then you may find that auto can do it better than you can. Note that the auto modes will also change the gain.

Kent Dammand · November 28th, 2004, 03:45 PM

Thanks, thats very clear now

November 27th, 2004, 02:01 PM	#1
Kent Dammand Regular Crew Join Date: May 2004 Posts: 80	Questions from manual Questions from manual 1. "* if you have no external ND filter, use Tv mode and set a high shutter speed or use Av mode and set a small aperture value" Does this mean if you have no matte box + filter or no lens with filter I.E provided 20x lens. 2. "Turning On/Off the ND filter changes the apertature setting. Readjust the aperture in Av mode as required." Why does it say in Av mode, what is the realtionship to Av mode and the filter? Also, why does using the filter adjust the aperture? Is the ND filter a true filter or is it just setting the aperture differently.

November 27th, 2004, 02:52 PM	#2
A. J. deLange Major Player Join Date: Jun 2004 Location: McLean, VA United States Posts: 749	1. With or without an external ND filter setting a high shutter speed in Tv mode will require a larger lens opening (smaller f/ number) to achieve the correct exposure. Setting a larger aperture (smaller f/ number) in Av mode will require a longer shutter speed which will be selected automatically. 2. If you enable one of the internal (or add an external) ND filter in Av mode the amount of light reaching the CCD will be reduced and the aperture will open automatically in Tv mode to restore the same level as before the filter was added. In Av mode the aperture will stay the same but the shutter speed will increase. As the object here is, apparently, to increase the aperture (for reduced DOF I assume) one must, in this mode, manually increase the aperture. If the aperture is opened to admit as much extra light as the neutral density filter attenuates the shutter speed will stay the same.

November 28th, 2004, 12:33 PM	#3
Kent Dammand Regular Crew Join Date: May 2004 Posts: 80	Does anyone here actually use av or tv mode or mainly manual mode? I still dont see the reason for using it.

November 28th, 2004, 01:20 PM	#4
A. J. deLange Major Player Join Date: Jun 2004 Location: McLean, VA United States Posts: 749	If you want a particular shutter speed (because, for example, you want to eliminate the blur in a rapidly moving object) AND you want the camera to follow changing light levels for you automatically you use Tv mode. If you want a particular aperture (because, for example, your lens is sharpest at f/8) AND you want the camera to follow changing light levels automatically you use the Av mode. If you don't want automatic exposure control, you use manual. Personally, that's my preference for most applications because I don't like watching the background change when someone moves from light to shadow. In the real world the background stays the same and the person becomes harder to see when he moves into a shadow. But that's just my preference and not all the time. If the light change is rapid and tricky and you want the subject properly exposed, then you may find that auto can do it better than you can. Note that the auto modes will also change the gain.

November 28th, 2004, 03:45 PM	#5
Kent Dammand Regular Crew Join Date: May 2004 Posts: 80	Thanks, thats very clear now