SD15曝光問題請益

Monte920

16916分

樓主

Monte920

個人積分：16916分

文章編號：36795451

WanBanDrow wrote:
同意傑夫大的觀點這些...(恕刪)

曝光過度是我們大家都早已知道的現象, 現在的問題是, 為何SD15在大太陽下快門會太慢造成過曝? 這是SD15會有的現象? 還是我這台SD15的測光有問題? (沒有用閃燈喔!)

我認為並非快門廉的問題, 因為在陰天或室內中並不會過曝. 拍來拍去總覺得我這台SD15在太陽下的測光有問題.

以下是前面那張女生採果的EXIF, 請Jeff大參考. 下面那段是我在SPP中修改的: (我曝光和highlight都盡量調低, 但救不回來了!)
File Name: SDIM0483.jpg
File Type: JPEG
Image Dimensions: 18.6 MP (5280 x 3520)
File Size: 3.88 MB
Location: E:\Pictures\SD15\SDIM0483.jpg
Capture Date: 6/22/2012 9:55:20 AM
Exposure Mode: A - Aperture Priority AE
Exposure Compensation: +0.0
ISO Setting: 100
White Balance Setting: Auto
Color Mode: Neutral
Flash: Off
Shutter Speed: 1/100s
Aperture Value: F9.0
Metering Mode: Evaluative Metering
Focus Setting: AF-S - Single Auto Mode
Focal Length: 28 mm (17-70)
Resolution: HI
Drive Mode: Single Frame Shooting
Camera: SIGMA SD15 1002651
Firmware Version: 1.04.0.000
Image Unique ID 30313030323635310841E44F32394445

Modified: 6/23/2012 3:44:00 PM
Exposure: -1.1
Contrast: +0.0
Shadow: +0.0
Highlight: -0.5
Saturation: +0.1
Sharpness: +0.2
X3 Fill Light: +0.0
Color Adjustment: 0
Color Space: sRGB
JPEG Quality: 8
Adjustment Mode: Custom: Current Unsaved Setting

Monte920

16916分

樓主

Monte920

個人積分：16916分

文章編號：36796395

大概發現問題了, 今天回家再拍, 發覺是SD15的權衡測光(evaluative metering)在作怪, 而且曝光的差異極為巨大! 至於用ISO200固定來拍, 似乎沒有特別大的幫助.

我同樣的景用SD15的四種測光各拍一張來比較: 權衡測光, 平均測光, 中央偏重測光, 點測光. 我都用jpg直出來拍, 所得的曝光就是它的原始曝光, 沒有再經過修改, 得到的結果如下: 並且順便附上EXIF值.

權衡測光: (嚴重過曝)

File Name: SDIM0566.JPG
File Type: JPEG
Image Dimensions: 4.6 MP (1760 x 2640)
File Size: 1.49 MB
Location: G:\Temp\SDIM0566.JPG
Capture Date: 6/25/2012 5:02:17 PM
Exposure Mode: A - Aperture Priority AE
Exposure Compensation: 0
ISO Setting: 200
White Balance Setting: Auto
Color Mode: Standard
Flash: Off
Shutter Speed: 1/250s
Aperture Value: F5.6
Metering Mode: Evaluative Metering
Focus Setting: AF-S - Single Auto Mode
Focal Length: 38 mm (17-70)
Resolution: HI
Drive Mode: Single Frame Shooting
Camera: SIGMA SD15 1002651
Firmware Version: 1.04.0.000
Image Unique ID 30313030323635319999E84F31343144
Modified: 6/25/2012 5:02:17 PM 1.04.0.000000000
Exposure: +0.0
Contrast: +0.0
Shadow: +0.0
Highlight: +0.0
Saturation: +0.0
Sharpness: +0.0
X3 Fill Light: +0.0
Color Adjustment: 0
Color Space: sRGB
JPEG Quality: FINE

平均測光 (仍然過曝)

File Name: SDIM0567.JPG
File Type: JPEG
Image Dimensions: 4.6 MP (1760 x 2640)
File Size: 1.55 MB
Location: G:\Temp\SDIM0567.JPG
Capture Date: 6/25/2012 5:02:26 PM
Exposure Mode: A - Aperture Priority AE
Exposure Compensation: 0
ISO Setting: 200
White Balance Setting: Auto
Color Mode: Standard
Flash: Off
Shutter Speed: 1/400s
Aperture Value: F5.6
Metering Mode: Average Metering
Focus Setting: AF-S - Single Auto Mode
Focal Length: 38 mm (17-70)
Resolution: HI
Drive Mode: Single Frame Shooting
Camera: SIGMA SD15 1002651
Firmware Version: 1.04.0.000
Image Unique ID 3031303032363531A299E84F31343431
Modified: 6/25/2012 5:02:26 PM 1.04.0.000000000
Exposure: +0.0
Contrast: +0.0
Shadow: +0.0
Highlight: +0.0
Saturation: +0.0
Sharpness: +0.0
X3 Fill Light: +0.0
Color Adjustment: 0
Color Space: sRGB
JPEG Quality: FINE

中央偏重測光 (準確很多)

File Name: SDIM0568.JPG
File Type: JPEG
Image Dimensions: 4.6 MP (1760 x 2640)
File Size: 1.56 MB
Location: G:\Temp\SDIM0568.JPG
Capture Date: 6/25/2012 5:02:35 PM
Exposure Mode: A - Aperture Priority AE
Exposure Compensation: 0
ISO Setting: 200
White Balance Setting: Auto
Color Mode: Standard
Flash: Off
Shutter Speed: 1/500s
Aperture Value: F5.6
Metering Mode: Center Area Metering
Focus Setting: AF-S - Single Auto Mode
Focal Length: 38 mm (17-70)
Resolution: HI
Drive Mode: Single Frame Shooting
Camera: SIGMA SD15 1002651
Firmware Version: 1.04.0.000
Image Unique ID 3031303032363531AB99E84F31343634
Modified: 6/25/2012 5:02:35 PM 1.04.0.000000000
Exposure: +0.0
Contrast: +0.0
Shadow: +0.0
Highlight: +0.0
Saturation: +0.0
Sharpness: +0.0
X3 Fill Light: +0.0
Color Adjustment: 0
Color Space: sRGB
JPEG Quality: FINE

點測光 (最準確, 不過也許偏暗一點)

File Name: SDIM0569.JPG
File Type: JPEG
Image Dimensions: 4.6 MP (1760 x 2640)
File Size: 2.69 MB
Location: G:\Temp\SDIM0569.JPG
Capture Date: 6/25/2012 5:02:44 PM
Exposure Mode: A - Aperture Priority AE
Exposure Compensation: 0
ISO Setting: 200
White Balance Setting: Auto
Color Mode: Standard
Flash: Off
Shutter Speed: 1/1000s
Aperture Value: F5.6
Metering Mode: Spot Metering
Focus Setting: AF-S - Single Auto Mode
Focal Length: 38 mm (17-70)
Resolution: HI
Drive Mode: Single Frame Shooting
Camera: SIGMA SD15 1002651
Firmware Version: 1.04.0.000
Image Unique ID 3031303032363531B499E84F31343836
Modified: 6/25/2012 5:02:44 PM 1.04.0.000000000
Exposure: +0.0
Contrast: +0.0
Shadow: +0.0
Highlight: +0.0
Saturation: +0.0
Sharpness: +0.0
X3 Fill Light: +0.0
Color Adjustment: 0
Color Space: sRGB
JPEG Quality: FINE

通常不同測光模式當然會有一些差異, 尤其是光反差很強的時候. 但這張反差並不會特別強, 整個畫面都在太陽的照射之下, 平均曝光照說不會相差太多, 但唯獨衡量測光卻是這麼嚴重過曝, 還讓人挺驚訝的! 這跟我前面遇到過曝的情況還蠻類似的.