Exposure Lock Qestion... at DVinfo.net

Joseph Andolina · June 4th, 2006, 02:42 PM

I've always been using the Manual selection on the XL2. I've noticed by experimenting the other day, that Exposure lock is not an option in maual mode, but is in all other modes like AV & TV. I was always thinking that if I was in manual, that everything WOULD BE MANUAL, which would include the iris/exposure. But when I pan with the camera, there is a fluctuation in the exposure depending what I'm panning over to.
But, if in the other modes, I'm able to set it to Exposure Lock, and naturally don't notice that problem. So the real question(s) is, why in manual mode, the exposure doesn't lock in, and do I have the same control if I go with one of the other settings such as AV or TV as I would have in Manual? (or which one would be most comprible to Manual Setting) Thanks to anyone ahead of time for any guidance.
Joe

Henry Cho · June 4th, 2006, 06:18 PM

hi joseph...

i'm not sure i understand the problem, but i'll try to help. in manual mode, the iris will not change. are you referring to the exposure meter in the top left of the viewfinder? when panning from one position, with good light, to one with less light, for example, you'd have to ride the iris (or use shutter priority mode) to get proper exposure on both ends of the pan.

shutter priority and aperture priority are auto modes on the camera. with shutter priority, you will lose the ability to manually set the iris (but as you know, gain exposure lock), and in aperture priority, you lose the ability to change shutter speed, as the camera's auto exposure controls take over. manual mode is the only setting on the camera that lets you control everything.

Chris Hurd · June 4th, 2006, 06:36 PM

Quote:

Originally Posted by Joseph Andolina

I was always thinking that if I was in manual, that everything WOULD BE MANUAL, which would include the iris/exposure. But when I pan with the camera, there is a fluctuation in the exposure depending what I'm panning over to.

Are you certain that you have the Gain control set to 0db? If it's left in Auto, then that will affect exposure even when shooting in the Manual program mode.

Joseph Andolina · June 4th, 2006, 07:33 PM

thanks guys for the responses. Well, I guess maybe I'm not sure how to explain what I'm seeing, but I'll give it another stab at it. (and as far as the gain setting, I always keep it to - 0 -, never on auto.) And I'm asuming what I'm seeing is a shift in gain maybe?

So, here goes, Camera set to Manual Mode. Gain on - 0 -. I'm panning my room. On my right is my patio window, to my left is my fireplace, TV, etc...
My walls are white. It's daytime out. Natural light from the patio window ligthing the entire room. I start the camera over to the left of the room. As I pan from left to right, pretty consistant in over all exposure. But a little b4 I reach the window, I notice a shift of exposure (gain?) on the white walls, and then finally get to the window. Now, I understand what would normally happen if I have a camera on automatic, how the light from the window would cause a noticeble shift in the gain. But am I understanding that when the Camera is set to Manual, that I shouldn;t see the shift on the walls, that it should remain consistent?

Henry Cho · June 4th, 2006, 07:42 PM

my guess is it's probably your auto white balance compensating for the shift in color temperature, from indoor to daylight. the shift might be affecting your exposure as it compensates.

Joseph Andolina · June 4th, 2006, 08:33 PM

Quote:

Originally Posted by Henry Cho

my guess is it's probably your auto white balance compensating for the shift in color temperature, from indoor to daylight. the shift might be affecting your exposure as it compensates.

I don;t actually have the white ballance set to auto. I usually manually white ballance with the white ballance knob set to 1.

Greg Boston · June 5th, 2006, 05:14 AM

Quote:

Originally Posted by Joseph Andolina

thanks guys for the responses. Well, I guess maybe I'm not sure how to explain what I'm seeing, but I'll give it another stab at it. (and as far as the gain setting, I always keep it to - 0 -, never on auto.) And I'm asuming what I'm seeing is a shift in gain maybe?

So, here goes, Camera set to Manual Mode. Gain on - 0 -. I'm panning my room. On my right is my patio window, to my left is my fireplace, TV, etc...
My walls are white. It's daytime out. Natural light from the patio window ligthing the entire room. I start the camera over to the left of the room. As I pan from left to right, pretty consistant in over all exposure. But a little b4 I reach the window, I notice a shift of exposure (gain?) on the white walls, and then finally get to the window. Now, I understand what would normally happen if I have a camera on automatic, how the light from the window would cause a noticeble shift in the gain. But am I understanding that when the Camera is set to Manual, that I shouldn;t see the shift on the walls, that it should remain consistent?

If you were to use a light meter, you would probably find that the exposure isn't as consistent as you think it is. Remember, when you look across the room, your eyes have auto iris that will change in response making it appear to you that the room has a constant exposure level. The camera is telling you otherwise. What does the exposure meter do as you pan across the room? That will tell you what the camera 'sees' in terms of exposure. In full manual, when you see the exposure meter shifting, you'll have to adjust shutter/iris in response to maintain that level on the meter.

In the scenario you describe, you are panning from a reflected light source more towards the direct light coming through the window. The camera lens also has a more limited view than your eyes and so it's more sensitive to the direction of source lighting.

-gb-

June 4th, 2006, 02:42 PM	#1
Joseph Andolina Regular Crew Join Date: Mar 2004 Location: Everett, WA Posts: 178	Exposure Lock Qestion... I've always been using the Manual selection on the XL2. I've noticed by experimenting the other day, that Exposure lock is not an option in maual mode, but is in all other modes like AV & TV. I was always thinking that if I was in manual, that everything WOULD BE MANUAL, which would include the iris/exposure. But when I pan with the camera, there is a fluctuation in the exposure depending what I'm panning over to. But, if in the other modes, I'm able to set it to Exposure Lock, and naturally don't notice that problem. So the real question(s) is, why in manual mode, the exposure doesn't lock in, and do I have the same control if I go with one of the other settings such as AV or TV as I would have in Manual? (or which one would be most comprible to Manual Setting) Thanks to anyone ahead of time for any guidance. Joe

June 4th, 2006, 06:18 PM	#2
Henry Cho Major Player Join Date: May 2005 Location: NYC Posts: 516	hi joseph... i'm not sure i understand the problem, but i'll try to help. in manual mode, the iris will not change. are you referring to the exposure meter in the top left of the viewfinder? when panning from one position, with good light, to one with less light, for example, you'd have to ride the iris (or use shutter priority mode) to get proper exposure on both ends of the pan. shutter priority and aperture priority are auto modes on the camera. with shutter priority, you will lose the ability to manually set the iris (but as you know, gain exposure lock), and in aperture priority, you lose the ability to change shutter speed, as the camera's auto exposure controls take over. manual mode is the only setting on the camera that lets you control everything.

June 4th, 2006, 07:33 PM	#4
Joseph Andolina Regular Crew Join Date: Mar 2004 Location: Everett, WA Posts: 178	thanks guys for the responses. Well, I guess maybe I'm not sure how to explain what I'm seeing, but I'll give it another stab at it. (and as far as the gain setting, I always keep it to - 0 -, never on auto.) And I'm asuming what I'm seeing is a shift in gain maybe? So, here goes, Camera set to Manual Mode. Gain on - 0 -. I'm panning my room. On my right is my patio window, to my left is my fireplace, TV, etc... My walls are white. It's daytime out. Natural light from the patio window ligthing the entire room. I start the camera over to the left of the room. As I pan from left to right, pretty consistant in over all exposure. But a little b4 I reach the window, I notice a shift of exposure (gain?) on the white walls, and then finally get to the window. Now, I understand what would normally happen if I have a camera on automatic, how the light from the window would cause a noticeble shift in the gain. But am I understanding that when the Camera is set to Manual, that I shouldn;t see the shift on the walls, that it should remain consistent?

June 4th, 2006, 07:42 PM	#5
Henry Cho Major Player Join Date: May 2005 Location: NYC Posts: 516	my guess is it's probably your auto white balance compensating for the shift in color temperature, from indoor to daylight. the shift might be affecting your exposure as it compensates.