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Old Aug 30, 2007, 4:54 PM   #1
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hello guys!

i need your help badly:?with exposure! and ive got a few question to ask as well.

1. when i compare shots with manual and auto, i noticed that the photo shot withauto is brighter than the one shot on manual with the same settings. thats y when i shoot manual i always put +1 on the ev acale just to compensate or make it closer to the photo shot with auto. y is it like that?

2. how do u really use a greycard? i bought 1 just to help me get the xposure right, followed the instructions and still got a result of either over or under expose specialy under a bright sun. i use spot meter to get a reading from the greycard so i dont have to come closer to the subject. i put it up vertically to get a reading. some r saying it has to be hold in a 45 deg angle.

and when u get a reading from a grey card do you set the ev scale to "0" and aelock it? coz sometimes the moment i point my camera to the grey card it gives me an initialreading on the ev scale of +1, sometimes +1/3..+2. what i do is set what aperture i want and try to set the shutter and then look at the ev scale. if its under or over i set it to "0" and lock it (this is while my camera is still pointinigthe card) then i recompose the shot.

any ways to get around this? thanks alot and more power!

giddy
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Old Aug 30, 2007, 6:47 PM   #2
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Post some sample images and I'm sure members would be happy to comment and make suggestions.

By not getting "closer to the subject", you may be misjugdging the difference in lighting and/or you are not taking metering behavior into consideration (since every model's metering tends to be somewhat unique).

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Old Aug 31, 2007, 5:14 AM   #3
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JimC wrote:
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Post some sample images and I'm sure members would be happy to comment and make suggestions.

By not getting "closer to the subject", you may be misjugdging the difference in lighting and/or you are not taking metering behavior into consideration (since every model's metering tends to be somewhat unique).

thanks jimc!

what do u mean by metering behavior? the subject is thesame just on diff backgound or location.

here r some of the photos i took of my wife when we went to legoland windsor and stonehenge 2 days ago. i used the kit lens 18mm to 70mm DT of my alpha.

1. stonehenge : f8 1/60 @ 35mm, iso 100, manual, spot metering, sunshine, no flash, with nd grad filter 0.6

this is a bit overexpose. i used a greycard. zero it then add +1/3 and locked it.

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Old Aug 31, 2007, 5:27 AM   #4
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2. legoland windsor : f8 1/60 @35mm, manual, spot, awb, 1so 100

grey card used. ev scale set to "0" then add +1/3. then locked. nd grad filter used 0.6.

this is also overexpose.
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Old Aug 31, 2007, 5:34 AM   #5
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this is f8 1/60 @18mm, manual, spot, awb, iso 100

it looks like underexpose. i didnt use a grey card on this shot and no filter as well.
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Old Aug 31, 2007, 5:41 AM   #6
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this is f8 1/125 @26mm, manual, spot, iso100, sunshine

grey card was used and ev scale +1/3. nd grad filter 0.6 was also used.


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Old Aug 31, 2007, 5:47 AM   #7
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f8 1/250 @28mm, manual, spot, sunshine, iso 100

grey card used and ev scale set to 1/3

style="BACKGROUND-COLOR: #000000"just noticed that it seems that theres a color overcast on this photo. yellow or green not sure.

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Old Aug 31, 2007, 5:51 AM   #8
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f8 1/50 @ 35mm, manula, spot, sunshine, iso 100

greycard used then +1/3 on the ev scale. nd grad filter 0.6 used.
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Old Aug 31, 2007, 7:21 AM   #9
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Personally, I think you're probably making it harder than it needs to be.

If you use a gray card for setting exposure, it's going to need to be in exactly the same spot, at the same angle to the light, as your subject. For example, one of your photos was of a backlit subject (as you can tell by the shadows coming towards the camera). Was the gray card in that exact same spot and also backlit? ;-) Of course, if the lighting changes, that reading is no good anyway (and lighting does vary a lot outdoors with clouds moving back and forth and more, when the human eye may not detect the change as a camera would).

Here's a tutorial on one way to approach it:

http://www.luminous-landscape.com/tu.../dig-exp.shtml

Your subjects reflectivity will also play a role, as does dynamic range (the camera has a limited range of bright to dark that it's going to be able to capture, so it's not always possible to get everything in the same image correctly exposed). Lighting also has a tendency to change pretty often, especially on a partially cloudy day. Here's a page on understanding exposure and incident light:

http://www.robert-barrett.com/photo/exposure.html

I don't use a gray card for setting exposure, although in a studio setting, that kind of thing can be useful.

I rarely use spot metering either, unless the lighting is very difficult, and you have to be very careful of what you meter on when you do use it (because it's only taking that exact spot into consideration for exposure). So, if you meter on something darker than the rest of the scene, you'll get an overexposed image. If you meter on something brighter than the rest of the scene, you'll get an underexposed image.

My suggestion for those types of outdoor shots would be to use either Matrix or Center Weighted except for special circumstances where you need to meter on an exact spot. Then, use your camera's histogram as a guide to how your settings are working. Your Sony will even show you blinking highlights and shadows for overexposed and underexposed areas, and you can adjust from there, depending on what you want properly exposed in the image (and you may not be able to get everything properly exposed because of dynamic range limitations).

Most matrix (a.k.a., mult-segment) metering systems (where the entire image is taken into consideration) are going to weight your focus point more heavily, while still taking the entire frame into consideration. So, if using matrix metering, keep focus point in mind.

Center weighted is usually more predictable with most cameras. But, more emphasis is placed on correctly exposing what's in the center of the frame (even though the entire frame is still being taken into consideration), so you may get some brighter areas outside of center overxposed in a high dynamic range scene, and even clothing can impact it (darker clothes may lead to overexposure, lighter clothes may lead to underexposure). Again, you may not be able to properly expose everything in a scene. You'll need to decide what's more important in it.

If you are shooting in non-manual modes, exposure compensation is your friend. If your subject is darker than the rest of the scene (for example, when they are backlit), use a +EV setting with Exposure Compensation so that it takes a brighter exposure than it normally would. Fill flash can also be useful for backlit subjects.

If your subject is brighter than the rest of the scene (for example, direct sunlight on their face), use a -EV setting with Exposure Compensation so that it takes a darker exposure than it normally would. After you become more accustomed to your camera's metering behavior, you'll start to learn when it's needed, even before checking the histogram to see what's properly exposed in the image and making further adjustments as needed.

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Old Aug 31, 2007, 7:48 AM   #10
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JimC wrote:
Quote:
Personally, I think you're probably making it harder than it needs to be.

If you use a gray card for setting exposure, it's going to need to be in exactly the same spot, at the same angle to the light, as your subject. For example, one of your photos was of a backlit subject (as you can tell by the shadows coming towards the camera). Was the gray card in that exact same spot and also backlit? ;-) Of course, if the lighting changes, that reading is no good anyway (and lighting does vary a lot outdoors with clouds moving back and forth and more, when the human eye may not detect the change as a camera would).

Here's a tutorial on one way to approach it:

http://www.luminous-landscape.com/tu.../dig-exp.shtml

Your subjects reflectivity will also play a role, as does dynamic range (the camera has a limited range of bright to dark that it's going to be able to capture, so it's not always possible to get everything in the same image correctly exposed). Lighting also has a tendency to change pretty often, especially on a partially cloudy day. Here's a page on understanding exposure and incident light:

http://www.robert-barrett.com/photo/exposure.html

I don't use a gray card for setting exposure.

I rarely use spot metering either, unless the lighting is very difficult, and you have to be very careful of what you meter on when you do use it (because it's only taking that exact spot into consideration for exposure). So, if you meter on something darker than the rest of the scene, you'll get an overexposed image. If you meter on something brighter than the rest of the scene, you'll get an underexposed image.

My suggestion for those types of outdoor shots would be to use either Matrix or Center Weighted except for special circumstances where you need to meter on an exact spot. Then, use your camera's histogram as a guide to how your settings are working. Your Sony will even show you blinking highlights and shadows for overexposed and underexposed areas, and you can adjust from there, depending on what you want properly exposed in the image (and you may not be able to get everything properly exposed because of dynamic range limitations).

Most matrix (a.k.a., mult-segment) metering systems (where the entire image is taken into consideration) are going to weight your focus point more heavily, while still taking the entire frame into consideration. So, if using matrix metering, keep focus point in mind.

Center weighted is usually more predictable with most cameras. But, more emphasis is placed on correctly exposing what's in the center of the frame (even though the entire frame is still being taken into consideration), so you may get some brighter areas outside of center overxposed in a high dynamic range scene, and even clothing can impact it (darker clothes may lead to overexposure, lighter clothes may lead to underexposure). Again, you may not be able to properly expose everything in a scene. You'll need to decide what's more important in it.

If you are shooting in non-manual modes, exposure compensation is your friend. If your subject is darker than the rest of the scene (for example, when they are backlit), use a +EV setting with Exposure Compensation so that it takes a brighter exposure than it normally would. Fill flash can also be useful for backlit subjects.

If your subject is brighter than the rest of the scene (for example, direct sunlight on their face), use a -EV setting with Exposure Compensation so that it takes a darker exposure than it normally would. After you become more accustomed to your camera's metering behavior, you'll start to learn when it's needed, even before checking the histogram to see what's properly exposed in the image and making further adjustments as needed.
thanks for the info. really appreciated. ill try to experiment with the metering.

btw, on pics # 5, do u think theres something wrong with the wb? it looks like theres a color overcast like yellow or green. or myabe its under expose.
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