A "Wow" moment, but why?

M38A1 · February 28, 2011

I've been shooting my D90 for a year or so. I have a firm grasp of the ISO/Shutter speed/Aperture triangle, and have been shooting mostly Aperture mode. Up until a few days ago, I was fairly pleased with the results.

But then on a whim, I decided to go full Manual. First shot out of the camera was a bit overexposed, so I dialed back the shutter speed. Hmmm.... results look considerably better then before. So I start playing with shutter speeds and apertures in "M" mode and that's when I went "Wow".

I would have assumed if using the same ISO across all modes of experimentation, I would have the same results if the shutter speeds and apertures matched. But that's not the case. Manual mode seems to be much 'richer' in color saturation.

Unfortunately, I don't have all the test images to show EXIF information.

So what's going on in the camera? I assume the final image isn't going through some sort of comparison process and it's literally sensing the image "as-is".

Thoughts?

.

moose135 · February 28, 2011

Are you shooting Raw or JPEG? Do you have any in-camera adjustments (sharpening, saturation, etc.) turned on - without realizing it - that are different between modes?

M38A1 · February 28, 2011

Always have shot RAW so that's not changed across the images...

To my knowledge I don't have any options turned on. At least I haven't done it on purpose.

I've just spent a lot of time looking at others EXIF information, and many shoot manual so I gave it a try and was impressed with how they were different in a good way.

ziggy53 · February 28, 2011

Comparative sample images with full EXIF would go a long way in helping to understand what's going on.

M38A1 · February 28, 2011

ziggy53 wrote: »

Comparative sample images with full EXIF would go a long way in helping to understand what's going on.

Oh, I fully recognize that fact......

Yet, all things being equal (ISO or example), shouldn't a shot done in aperture mode be identical to that done in manual using the same settings?

Rob Pauza · March 1, 2011

M38A1 wrote: »

Yet, all things being equal (ISO or example), shouldn't a shot done in aperture mode be identical to that done in manual using the same settings?

Yes.

Weird... I'm not sure what's going on other than what has been previously suggested about the color profiles being set differently between modes... if you can even do that.

M38A1 · March 1, 2011

Is it possible that what I was doing manually was actually getting a better (ie: more realistic) exposure combination than the camera was calculating possibly based on what metering mode I had selected?

I'll try and get a couple examples up if I can undelete the ones I culled prior to the change.

pathfinder · March 1, 2011

ISO 100, f 4, 1/100th is the same exact exposure whether shot in Manual Mode, Av mode, or Tv mode. If you shoot a grey card, at a light intensity such that ISO 100, f4, 1/100th is correct for the Manual mode, shooting either Av or Tv should give an identical match with the subsequent file. Now, how the jpg will come out of your raw processor depends on what settings you choose in the raw processing steps, of course. If in camera jpgs, you need to carefully make sure what the camera is doing in its raw rendering into jpgs.

ziggy53 · March 1, 2011

M38A1 wrote: »

Oh, I fully recognize that fact......

Yet, all things being equal (ISO or example), shouldn't a shot done in aperture mode be identical to that done in manual using the same settings?

Seeing the images "plus" the EXIF can give us several clues as to what's going on.

For instance, the camera might have an EV bias set in the aperture priority program mode. Manual mode generally does not accept an EV bias, except for the manual exposure compensation that you choose. That simple difference of an EV bias can cause the exposure shift you describe. (I've accidentally left an EV bias on before myself. It can get confusing.)

You might have also changed the metering program. Metering a scene in aperture priority and spot metering will give potentially greatly different results to metering a scene in manual mode with evaluative metering engaged. Again, been there, done that.

Lots of other causes too, so that combination of looking at the picture results plus the EXIF can be pretty definitive as to cause and effect.

Qarik · March 1, 2011

when you say "richer" in color I assume it means more saturated. This maybe because you are judging the exposure with your eyes on the LCD instead of letting the camera choose? When you do that you maybe choosing exposures that are slightly underexposed wrt to the camera meter. If your D90 was slightly overexposing, the colors get a bit washed out and as you "meter" with your eye, the colors saturate. That's my guess. Examples would be good though.

M38A1 · March 2, 2011

First off, these are not stellar pictures. They came from my culled images and have had no post done on them. In a nutshell, I have generally always shot aperture mode allowing for me to select DOF and let the camera do the rest. It's sort of easy that way. But I recall seeing a lot of exif info that showed manual mode on peoples shots so I decided to try it.

A couple things I think come into play here to include:
1) The setting sun may have had an affect, but I don't think much in the time I shot.
2) The theory on metering and being washed out sounds quite valid to me and going manually I was underexposing them to compensate in the LCD screen.
3) The two examples aren't apples to apples. They are somewhat different angles and different settings. If I did my calculations right, I did in fact underexpose the 'richer' one a stop or so.

So here goes:

Shot in aperture mode as most images were done before going to manual:
Filename - 2011Terlingua 7033.NEF
ImageWidth - 160
ImageLength - 120
BitsPerSample - 8 8 8
Compression - 1 (None)
PhotometricInterpretation - 2
Make - NIKON CORPORATION
Model - NIKON D90
StripOffset - 124224
Orientation - Top left
SamplesPerPixel - 3
RowsPerStrip - 120
StripByteCount - 57600
XResolution - 300
YResolution - 300
PlanarConfiguration - 1
ResolutionUnit - Inch
Software - Ver.1.00
DateTime - 2011:02:25 18:15:10
ReferenceBlackWhite - 0
ExifOffset - 480
DateTimeOriginal - 2011:02:25 18:15:10
ExposureTime - 1/1000 seconds
FNumber - 5.60
ExposureProgram - Aperture priority
ISOSpeedRatings - 200
DateTimeOriginal - 2011:02:25 18:15:10
DateTimeDigitized - 2011:02:25 18:15:10
ExposureBiasValue - 0.00
MaxApertureValue - F 2.83
MeteringMode - Center weighted average
LightSource - Auto
Flash - Not fired
FocalLength - 24.00 mm
UserComment -
SubsecTime - 00
SubsecTimeOriginal - 00
SubsecTimeDigitized - 00
SensingMethod - One-chip color area sensor
FileSource - Other
SceneType - Other
CustomRendered - Normal process
ExposureMode - Auto
White Balance - Auto
DigitalZoomRatio - 1 x
FocalLengthIn35mmFilm - 36 mm
SceneCaptureType - Standard
GainControl - None
Contrast - Normal
Saturation - Normal
Sharpness - Normal
SubjectDistanceRange - Unknown

GPS information: -
GPSVersionID - 2.2.0.0

Maker Note (Vendor): -
Data version - 0210 (808595760)
ISO Setting - 200
Image Quality - RAW
White Balance - AUTO
Focus Mode - AF-S
Flash Setting - NORMAL
Flash Mode -
White Balance Adjustment - 0
White Balance RB - 730
Exposure Adjustment - 68608
Thumbnail IFD offset - 13954
Flash Compensation - 67072
ISO 2 - 200
Lens type - AF-D G
Lens - 974
Flash Used - Not fired
Bracketing - 0
Contrast Curve - I0
Noise Reduction - OFF
Total pictures - 13029

And the manual image:
Filename - 2011Terlingua 7037.NEF
ImageWidth - 160
ImageLength - 120
BitsPerSample - 8 8 8
Compression - 1 (None)
PhotometricInterpretation - 2
Make - NIKON CORPORATION
Model - NIKON D90
StripOffset - 124348
Orientation - Top left
SamplesPerPixel - 3
RowsPerStrip - 120
StripByteCount - 57600
XResolution - 300
YResolution - 300
PlanarConfiguration - 1
ResolutionUnit - Inch
Software - Ver.1.00
DateTime - 2011:02:25 18:18:32
ReferenceBlackWhite - 0
ExifOffset - 480
DateTimeOriginal - 2011:02:25 18:18:32
ExposureTime - 1/60 seconds
FNumber - 19.00
ExposureProgram - Manual control
ISOSpeedRatings - 200
DateTimeOriginal - 2011:02:25 18:18:32
DateTimeDigitized - 2011:02:25 18:18:32
ExposureBiasValue - 0.00
MaxApertureValue - F 2.83
MeteringMode - Center weighted average
LightSource - Auto
Flash - Not fired
FocalLength - 24.00 mm
UserComment -
SubsecTime - 00
SubsecTimeOriginal - 00
SubsecTimeDigitized - 00
SensingMethod - One-chip color area sensor
FileSource - Other
SceneType - Other
CustomRendered - Normal process
ExposureMode - Manual
White Balance - Auto
DigitalZoomRatio - 1 x
FocalLengthIn35mmFilm - 36 mm
SceneCaptureType - Standard
GainControl - None
Contrast - Normal
Saturation - Normal
Sharpness - Normal
SubjectDistanceRange - Unknown

GPS information: -
GPSVersionID - 2.2.0.0

Maker Note (Vendor): -
Data version - 0210 (808595760)
ISO Setting - 200
Image Quality - RAW
White Balance - AUTO
Focus Mode - AF-S
Flash Setting - NORMAL
Flash Mode -
White Balance Adjustment - 0
White Balance RB - 730
Exposure Adjustment - -33485824
Thumbnail IFD offset - 13954
Flash Compensation - 67072
ISO 2 - 200
Lens type - AF-D G
Lens - 974
Flash Used - Not fired
Bracketing - 0
Contrast Curve - I0
Noise Reduction - OFF
Total pictures - 13035

And for grins, here's one about 15 minutes later, no post, shot manual:
Filename - 2011Terlingua 7055.NEF
ImageWidth - 160
ImageLength - 120
BitsPerSample - 8 8 8
Compression - 1 (None)
PhotometricInterpretation - 2
Make - NIKON CORPORATION
Model - NIKON D90
StripOffset - 124588
Orientation - Left bottom
SamplesPerPixel - 3
RowsPerStrip - 120
StripByteCount - 57600
XResolution - 300
YResolution - 300
PlanarConfiguration - 1
ResolutionUnit - Inch
Software - Ver.1.00
DateTime - 2011:02:25 18:36:20
ReferenceBlackWhite - 0
ExifOffset - 480
DateTimeOriginal - 2011:02:25 18:36:20
ExposureTime - 1/90 seconds
FNumber - 16.00
ExposureProgram - Manual control
ISOSpeedRatings - 200
DateTimeOriginal - 2011:02:25 18:36:20
DateTimeDigitized - 2011:02:25 18:36:20
ExposureBiasValue - 0.00
MaxApertureValue - F 2.83
MeteringMode - Center weighted average
LightSource - Auto
Flash - Not fired
FocalLength - 29.00 mm
UserComment -
SubsecTime - 00
SubsecTimeOriginal - 00
SubsecTimeDigitized - 00
SensingMethod - One-chip color area sensor
FileSource - Other
SceneType - Other
CustomRendered - Normal process
ExposureMode - Manual
White Balance - Auto
DigitalZoomRatio - 1 x
FocalLengthIn35mmFilm - 43 mm
SceneCaptureType - Standard
GainControl - None
Contrast - Normal
Saturation - Normal
Sharpness - Normal
SubjectDistanceRange - Unknown

GPS information: -
GPSVersionID - 2.2.0.0

Maker Note (Vendor): -
Data version - 0210 (808595760)
ISO Setting - 200
Image Quality - RAW
White Balance - AUTO
Focus Mode - AF-S
Flash Setting - NORMAL
Flash Mode -
White Balance Adjustment - 0
White Balance RB - 730
Exposure Adjustment - -218035200
Thumbnail IFD offset - 13954
Flash Compensation - 67072
ISO 2 - 200
Lens type - AF-D G
Lens - 974
Flash Used - Not fired
Bracketing - 0
Contrast Curve - I0
Noise Reduction - OFF
Total pictures - 13062

ziggy53 · March 2, 2011

It looks like in the first image the Center-Weighted-Average (CWA) metering was probably reading some of the shadow area as significant in the exposure, tending to over-expose the rest of the scene.

In the second image you came in closer and moved the center of the scene to the wall, still using CWA metering. This time the wall gave you a more accurate exposure, even though you were shooting with manual mode control.

Likewise in the last image where the foliage supplied most of the exposure.

Since ISO and metering program stayed the same, it looks like the difference is the selection of the part of the scene for the CWA is what caused most of the difference.

Moral: Don't use CWA metering against shadow areas unless that is truly your subject. Metering the wall (or foliage in the last case) and setting that for your exposure with the "AE-Lock" in Aperture Priority mode and then recomposing would have worked. "Matrix" metering might have been more appropriate if you were in a hurry and needed full exposure automation.

All that said, since you shot RAW/NEF you might be able to just bring down the exposure and brightness/lightness in a RAW image software processor and gain a more suitable exposure.

M38A1 · March 3, 2011

Ziggy-
Thank you for the analysis. I appreciate it very much. and yet again, continue to learn.

Svennie · March 3, 2011

White balance is set to 'auto'. Did you process the raw files with the same WB setting, or left it on 'as in camera' (photoshop raw plugin)?

M38A1 · March 3, 2011

I've not changed the white balance settings in the camera on any mode. It's always been on AUTO. No post processing has been done other than transfer the files to my computer, view them via Irfanview and save as a .jpg to smugmug in order to post.

I don't think there's a problem with any of this.... I'm just confused as to why my shots looked better using the manual mode. Maybe I just had more fun chimping while going "oh, that's overexposed - let me dial back on the shutterspeed" or something like that.

ziggy53 · March 3, 2011

M38A1 wrote: »

... I'm just confused as to why my shots looked better using the manual mode. Maybe I just had more fun chimping while going "oh, that's overexposed - let me dial back on the shutterspeed" or something like that.

Again, I think it had to do with your using Center-Weighted-Average (CWA) metering and the subject and how the subject was framed in the scene. CWA uses a small central area of the scene on which to calculate most of the metering. Matrix metering uses the whole scene and probably would not have given such varied results.

My recommendation is to use Matrix metering unless you really want to meter a specific region of the scene.

At any rate use the histogram and the highlight "blinkies" to determine relative exposure accuracy, but only after you know what they really represent on your camera.

Svennie · March 3, 2011

M38A1 wrote: »

I've not changed the white balance settings in the camera on any mode. It's always been on AUTO. No post processing has been done other than transfer the files to my computer, view them via Irfanview and save as a .jpg to smugmug in order to post.

I don't think there's a problem with any of this.... I'm just confused as to why my shots looked better using the manual mode. Maybe I just had more fun chimping while going "oh, that's overexposed - let me dial back on the shutterspeed" or something like that.

If it's on auto, WB will change between shots. If you convert them to jpeg, the software will probably use the camera WB.
For example: when I shoot raw+jpg with auto WB, the colors will be 'all over the place' in the JPG. Then I open the raw file in photoshop and set it manually. Usually, when indoors for example or with photo shoots, I set the WB manually in camera and keep it fixed. This way the shots are pretty close to the final results.

Give it a try and let me know what you learn.

Stuart-M · March 10, 2011

The settings are far too different to make any conclusions (look at the aperture values for example, much wider on the AV mode shot). Being in manual mode certainly doesn't make the images better though, if everything else is the same.

A "Wow" moment, but why?

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