Correct LCD viewing angle for accurate exposure at DVinfo.net

James Emory · December 14th, 2004, 10:25 AM

Although it is an inherent property of LCD monitors, is there a correct way that the PD-150 or any LCD should be pitched or angled for the operator to get the absolute true image to ensure correct exposure? When using the PD-150, I have noticed that when the LCD is pivoted downward the image is darker and when pivoted upward it becomes lighter. What, if any, is the correct or best orientation to determine accurate exposure.

Mike Rehmus · December 14th, 2004, 10:30 AM

The bad news is you cannot use the LCD to determine exposure. You have to use an external field monitor or the Zebra patterns generated in the camera.

Boyd Ostroff · December 14th, 2004, 10:51 AM

Of course Mike is right, but there are a couple things you can do to help a bit. Personally, I think the "correct" angle is the one which gives the most contrast, not the brightest image.

Connect the camera via firewire to your computer, and put some NTSC color bars up. These need to be the real NTSC bars, not the ones the camera generates. Now compare the image on the LCD to a properly calibrated monitor and adjust as well as possible. The real thing you're looking for is the level of the PLUGE bars. This tutorial may help: http://www.videouniversity.com/tvbars2.htm.

The other very important thing is to make sure that ambient light is comparable to your expected shooting conditions when you do this excercise. You could also record the bars to tape or as a still to memory stick and try this in the field.

While it is no substitute for a real monitor, I've found this can help. Using the zebra, as Mike suggests, is a better way to judge exposure however.

James Emory · December 14th, 2004, 11:11 AM

A field monitor's accuracy would be nice to have but this is run and gun reality and the only available monitor is the flip out. I was told by another reputable shooter that adjusting the LCD lightness/darkness level down until 2 blocks are left is the most accurate depiction of the image. I guess that's personal preference. I keep mine in the center. I've always used zebra for a reference for whites and glare but the LCD monitor's brightness setting can make a huge difference as well.

Boyd Ostroff · December 14th, 2004, 03:41 PM

<<<-- Originally posted by James Emory : I was told by another reputable shooter that adjusting the LCD lightness/darkness level down until 2 blocks are left is the most accurate depiction of the image. -->>>

It's impossible to generalize about this sort of thing. The amount of ambient light hitting the LCD will determine how bright to set it. BTW, you might want to invest in an LCD hood, they really help outdoors and are quite inexpensive.

But you are not going to find the "perfect setting" for the LCD be it either the center or two clicks from the end. If you're trying to gauge brightness then calibrate it to the PLUGE bars as described above using the ambient light conditions on site.

James Emory · December 14th, 2004, 04:55 PM

Yes. I do use a hood for the LCD. It doesn't matter where you are, indoor or outdoor. If you keep your head and eyes at a constant position and slowly pivot that LCD up and down, the picture will change from dark to light. You could have the absolute correct exposure set with the iris, but if you adjust by what you see in the LCD when it is pitched a certain way you could over or undercompensate because of it's properties of viewing at an angle.

Assume that the camera is set for the correct exposure:

If the LCD is pivoted up, the picture will get darker and you may compensate for that and open the iris because you think the image is too dark when it really isn't. The opposite happens when the LCD is pivoted down.

The orientation of the LCD could make an operator not used to LCDs incorrectly expose depending at what angle they see the LCD whether it's shaded or not.

Boyd Ostroff · December 14th, 2004, 05:52 PM

<<<-- Originally posted by Boyd Ostroff : Personally, I think the "correct" angle is the one which gives the most contrast, not the brightest image. -->>>

That is what I believe, and what I do when shooting. I pivot the screen until I see the greatest contrast. But LCD's just aren't very good for determining exposure, which seems to be what you're saying anyway...

Tom Hardwick · December 15th, 2004, 01:04 PM

Another nice plus point for the Hoodman is that (because of the tunnel formed by the box) it keeps your eye perpendicular to the screen at all times. If it's not you get instant picture cutoff as a warning.

tom.

December 14th, 2004, 10:25 AM	#1
James Emory Regular Crew Join Date: Aug 2002 Location: Atlanta, Georgia Posts: 1,892	Correct LCD viewing angle for accurate exposure Although it is an inherent property of LCD monitors, is there a correct way that the PD-150 or any LCD should be pitched or angled for the operator to get the absolute true image to ensure correct exposure? When using the PD-150, I have noticed that when the LCD is pivoted downward the image is darker and when pivoted upward it becomes lighter. What, if any, is the correct or best orientation to determine accurate exposure.

December 14th, 2004, 10:30 AM	#2
Mike Rehmus Wrangler Join Date: May 2002 Location: Vallejo, California Posts: 4,049	The bad news is you cannot use the LCD to determine exposure. You have to use an external field monitor or the Zebra patterns generated in the camera. __________________ Mike Rehmus Hey, I can see the carrot at the end of the tunnel!

December 14th, 2004, 10:51 AM	#3
Boyd Ostroff Wrangler Join Date: Dec 2002 Location: Mays Landing, NJ Posts: 11,787	Of course Mike is right, but there are a couple things you can do to help a bit. Personally, I think the "correct" angle is the one which gives the most contrast, not the brightest image. Connect the camera via firewire to your computer, and put some NTSC color bars up. These need to be the real NTSC bars, not the ones the camera generates. Now compare the image on the LCD to a properly calibrated monitor and adjust as well as possible. The real thing you're looking for is the level of the PLUGE bars. This tutorial may help: http://www.videouniversity.com/tvbars2.htm. The other very important thing is to make sure that ambient light is comparable to your expected shooting conditions when you do this excercise. You could also record the bars to tape or as a still to memory stick and try this in the field. While it is no substitute for a real monitor, I've found this can help. Using the zebra, as Mike suggests, is a better way to judge exposure however.

December 14th, 2004, 11:11 AM	#4
James Emory Regular Crew Join Date: Aug 2002 Location: Atlanta, Georgia Posts: 1,892	A field monitor's accuracy would be nice to have but this is run and gun reality and the only available monitor is the flip out. I was told by another reputable shooter that adjusting the LCD lightness/darkness level down until 2 blocks are left is the most accurate depiction of the image. I guess that's personal preference. I keep mine in the center. I've always used zebra for a reference for whites and glare but the LCD monitor's brightness setting can make a huge difference as well.

December 14th, 2004, 03:41 PM	#5
Boyd Ostroff Wrangler Join Date: Dec 2002 Location: Mays Landing, NJ Posts: 11,787	<<<-- Originally posted by James Emory : I was told by another reputable shooter that adjusting the LCD lightness/darkness level down until 2 blocks are left is the most accurate depiction of the image. -->>> It's impossible to generalize about this sort of thing. The amount of ambient light hitting the LCD will determine how bright to set it. BTW, you might want to invest in an LCD hood, they really help outdoors and are quite inexpensive. But you are not going to find the "perfect setting" for the LCD be it either the center or two clicks from the end. If you're trying to gauge brightness then calibrate it to the PLUGE bars as described above using the ambient light conditions on site.

December 14th, 2004, 04:55 PM	#6
James Emory Regular Crew Join Date: Aug 2002 Location: Atlanta, Georgia Posts: 1,892	Yes. I do use a hood for the LCD. It doesn't matter where you are, indoor or outdoor. If you keep your head and eyes at a constant position and slowly pivot that LCD up and down, the picture will change from dark to light. You could have the absolute correct exposure set with the iris, but if you adjust by what you see in the LCD when it is pitched a certain way you could over or undercompensate because of it's properties of viewing at an angle. Assume that the camera is set for the correct exposure: If the LCD is pivoted up, the picture will get darker and you may compensate for that and open the iris because you think the image is too dark when it really isn't. The opposite happens when the LCD is pivoted down. The orientation of the LCD could make an operator not used to LCDs incorrectly expose depending at what angle they see the LCD whether it's shaded or not.

December 14th, 2004, 05:52 PM	#7
Boyd Ostroff Wrangler Join Date: Dec 2002 Location: Mays Landing, NJ Posts: 11,787	<<<-- Originally posted by Boyd Ostroff : Personally, I think the "correct" angle is the one which gives the most contrast, not the brightest image. -->>> That is what I believe, and what I do when shooting. I pivot the screen until I see the greatest contrast. But LCD's just aren't very good for determining exposure, which seems to be what you're saying anyway...

December 15th, 2004, 01:04 PM	#8
Tom Hardwick Inner Circle Join Date: Mar 2003 Location: Billericay, England UK Posts: 4,711	Another nice plus point for the Hoodman is that (because of the tunnel formed by the box) it keeps your eye perpendicular to the screen at all times. If it's not you get instant picture cutoff as a warning. tom.