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Old May 6, 2008, 1:00 PM   #1
csd
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In reviewing some photos I took recently with my D80 - I noticed in the Exif data some of the photos have Exif data that says "Contrast = Hard" while most are "Contrast = Normal". I changed no settings between taking many of these photos other than focal length and in some cases rotating a Circular Polarizer.
Does anyone know what causes the camera to choose between these settings?
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Old May 6, 2008, 4:28 PM   #2
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Are you sure you weren't changing modes between photos? Many camera models have mode specific settings for image processing parameters like Contrast, Sharpness and more.

What you're seeing could also be the way a given EXIF reader is interpreting the data Nikon is storing, by reading the proprietary "Maker Notes" section of the image's metadata. This information is proprietary to a camera manfacturer is is mostly undocumented. So many EXIF viewers and editors are reverse engineering the data to try and give you the camera settings used (looking at what data in the image is changing when settings or images change, to try and figure out what the manufacturer is storing in the metadata).

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Old May 6, 2008, 5:06 PM   #3
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I was in Apperture Priority the entire time - and shot a bunch of consecutive shots changing only lens' zoom and refocussing so I'm sure I didn't change mode or any settings. I am wondering if the camera is making some processing decisions (I was not in RAW - was in JPEG Fine).
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Old May 6, 2008, 5:51 PM   #4
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I'd downsize an image to around 640 pixels wide and post an example if you want members to take a look for anything obvious in the metadata causing it (for example, I could see what a couple of different EXIF readers say about the proprietary makernotes section).

Make sure to use software that's not going to strip out or modify the EXIF for downsizing.

I'd suggest using something like the free Irfanview

After you open an image using File>Open, go to Image>Resize/Resample. Leave the box checked to retain the original aspect ratio (dimensions of width to height), and make the longest side abvout 640 pixels. That will be fine for checking settings. Then, Save it to a new filename (so you don't overwrite your original) using File>Save As (picking a folder that you want to keep it in).

Set the jpeg quality to around 80% and leave the boxes checked to retain EXIF (you'll see a box pop up with a jpeg quality slider when you use the Save As choice and select jpeg as the file type).

As long as it's not too large (dimensions or file size), then you can attach a photo using the browse button you'll see at the bottom of your entry screen when typing a new post.

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Old May 6, 2008, 7:39 PM   #5
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JimC,
Thanks for the suggestions. I was viewing the "Hard" contrast using Photoshop Elements 6.0 Organizer. It looks like the "number" is set to "2" which is Hard.
Most of my photos this number is set to "0" for normal. I've only had the D80 for a short time so am still getting used to it but am pretty sure I changed no settings (I use the Exif data to see when I changed stuff like exposure value) and when I compare this to other photos I took at the same time, the only change - other than focal distance - is this number.

If you ever opened a photography book - you will likely recognize where I took the photo
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Old May 6, 2008, 7:53 PM   #6
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Interesting. My guess is that because Tone Compensation is set to Auto, it's automatically changing the contrast for the scene. Here's what one EXIF viewer is showing (and I see the hard contrast setting you're referring to).

File name: DSC_5160-640wide.jpg (Standard EXIF Tags)

>>> Photograph Information <<<

Color Filter Array Pattern : 0 2 0 2 1 2 0 1
Color Space : sRGB
Components Configuration : YCbCr
Compressed Bits per Pixel : 4
Contrast : Hard
Custom Rendered : Normal process
Date and Time (digitized) : 2008:04:23 18:30:27
Date and Time (original) : 2008:04:23 18:30:27
Digital Zoom Ratio : 1.0
Exif Version : 48 50 50 49
Exposure Bias : 0
Exposure Mode : Auto
Exposure Program : Aperture priority
Exposure Time : 1/320 s
FNumber : F8
File Source : Digital still camera
Flash : No flash
FlashPix Version : 48 49 48 48
Focal Length : 52.0 mm
Focal Length In 35mm Film : 78.0 mm
Gain Control : None
ISO Speed Ratings : 100
Interoperability IFD Pointer : 3488
Light Source : Unknown
Max Aperture Value : F4.9
Metering Mode : Multi-segment
Pixel X Dimension : 640
Pixel Y Dimension : 428
Saturation : Normal
Scene Capture Type : Standard
Scene Type : Directly photographed
Sensing Method : One-chip color area
Sharpness : Normal
Subject Distance Range : Unknown
White Balance : Auto


>>> Image Information <<<

Date and Time : 2008:05:06 20:19:52
Exif IFD Pointer : 228
Manufacturer : NIKON CORPORATION
Model : NIKON D80
Orientation : top, left
Resolution Unit : inch
Software : Adobe Photoshop Elements 6.0
X-Resolution : 72
YCbCr Positioning : Co-sited
Y-Resolution : 72


>>> Embedded Thumbnail <<<

Compression : JPEG (old-style)
JPEG Interchange Format : 0
JPEG Interchange Format Length : 13245
Resolution Unit : inch
X-Resolution : 300
YCbCr Positioning : Co-sited
Y-Resolution : 300


>>> Interoperability <<<

Interoperability Index : R98
Interoperability Version : 48 49 48 48

Here is the Maker Notes section:

File name: DSC_5160-640wide.jpg (MakerNote EXIF Tags)

>>> Nikon3 <<<

AF Focus Position : Single area; Right-most used
Auto Bracket Release : Manual release
Color Balance 1 : 471/256 320/256 256/256 256/256
Color Balance 2 : 48 50 48 56 1 8 4 5 8 88 72 17 16 42 1 130 128 50 16 34 128 0 128 20 76 32 32 192 148 85 74 64 84 67 14 0 64 41 1 64 80 144 18 3...
Color Mode : COLOR
Color Space : sRGB
Crop High Speed : 0 3904 2616 3904 2616 0 0
Exposure Bracket Comp : 0/6
Exposure Difference : 0 1 12 0
Flash Bracket Comp : 0.0 EV
Flash Comp : 0.0 EV
Flash Device :
Flash Mode : Did not fire
Flash Setting : NORMAL
Focus : (AF-A )
High ISO Noise Reduction : Off
Hue Adjustment : 0
Image Boundary : 0 0 3872 2592
Image Data Size : 3532741
Image Optimization : NORMAL
ISO Settings : 100
ISO Speed : 100
Lens : 18-135mm F3.5-5.6
Lens Data : 48 50 48 50 242 77 118 96 184 111 19 229 194 164 13 72 4 106 149 90 182 70 174 169 116 175 216 241 254 241 214 148
Lens FStops : 5.33333
Lens Type : D G
Light Source : NATURAL
Noise Reduction : OFF
Pointer to a preview image : 2738
Program Shift : 0 1 6 0
Program Variation :
Quality : FINE
Saturation : AUTO
Sensor Pixel Size : 605/100 605/100
Serial Number : 3248763
Sharpening : AUTO
Shooting Mode : (0)
Shutter Count : 4402
Tone Compensation : AUTO
Version : 48 50 49 48
White Balance : AUTO
White Balance Bias : 0

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Old May 6, 2008, 8:14 PM   #7
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The Manual talks about contrast only under the "Optimize Image" settings which I have set to "Normal" (as shown in the Exif data) - but under "Tone Compensation" it does day default is "Auto" and this controls contrast so this must be it. it goes on to say "Lower settings prevent loss of detail in highlights under hard lighting or in direct sunlight. Higher settings preserve detail in misty landscapes and other low-contrast subjects". So many settings on this camera I haven't explored. I was just suprised to see this changing from picture to picture.
Here is one where it stayed "Normal".

Actually, the most SHOCKING thing about the Exif data you are showing me is under "software" it says:
"Software : Adobe Photoshop Elements 6.0"
Is this because you are viewing this in Elements (I presume not) Or because I use it for my organizer and importer it has chosen to put its fingerprint on everyone of my files? (Somehow this doesn't seem right - I never edited the file in Photoshop - so photoshop shouldn't touch the Exif data - it must do it when I import my files into its Organizer - not nice).
JimC - thanks for helping me learn this stuff.
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Old May 6, 2008, 8:29 PM   #8
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csd wrote:
Quote:
Actually, the most SHOCKING thing about the Exif data you are showing me is under "software" it says:
"Software : Adobe Photoshop Elements 6.0"
Is this because you are viewing this in Elements (I presume not)
Nope. Your copy of Elements wrote to the file somewhere along the way. If you used it to modify your images in any way (resizing, etc.), it probably updated the EXIF.


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Old May 7, 2008, 6:10 AM   #9
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I did the modification in Irfanview - but use Elements as my Organizer - it appears to edit the Exif data when you load it into the organizer (without ever making changes, etc.).
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Old May 11, 2008, 10:07 PM   #10
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There is also a free tool from Microsoft called Image resizer in their tweak toys. It will resize an image simply by right clicking on it and choose resize. Then you can choose what size you want 640x480, 800x600 and 1024x 768. or 320x240 for small devices. When you do that it creates a "copy" of the original, with the words, small, medium or large in part of the name. The Exif data is kept intact though.



Is there a way to find out the lens used in the Exif data? I have shot some different lenses and other than photographing a piece of paper with the name on it, I couldn't tell what lens made what shot. Would be nice when you are trying lenses at a camera store and look at the results later when you get back home.


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