Rule #1     Never Throw Away Data

Rule #2     Save, Save, Save.

Rule #3     Backup, Backup, Backup

Rule #4 Rename the Keepers

Rule #5 Never Assume

WORKING WITH YOUR Keeper PICTURES

When you load a picture into PhotoShop or other image editing program of choice
Immediately save it using the "SAVE AS" command
(File/Save as)  and select .tif  format

or Process all your keepers at one time in PhotoShop Elements changing the file format from .jpg to .tif

Process Multiple Files (Batching) in PhotoShop Elements
renaming and changing file names via Menu item
File/Batch Processing (in photoshop Elements 2.0)
or File/Process Multiple Files (in photoshop Elements 3.0)

The batch converter in PhotoShop Elements 2.0 is different and easier to use that the one in Photoshop 7 or CS

PhotoShop Elements 2.0	PhotoShop Elements 3.0

Or follow the following procedure...
If you have loaded a .jpg picture you can change the picture file format to .tif  using Save As...

You need to do this as .jpg is a "lossy" format. Every time you save a .jpg picture you will loose data.

You might want to re-name the "save as" picture with an added number
eg. PamBeijing-01.tif
Every time you make a change you can increment the number by one
PamBeijing-02.tif
PamBeijing-03.tif
etc.
Or just continue using the save command (File/save) When you are done editing the picture you can rename again Using Save As to
PamBeijing-Final.tif

AFTER you verify that the Final Picture has been saved without corruption you can delete the other copies.

Save often, and ALWAYS VERIFY.

When you are all done BACKUP your FINAL KEEPER pictures to a CD Disk

Light Meter Reading ---Finding Mid Gray.

Real Time Camera Histogram in Record Mode	recorded Histogram in Display mode

When your camera does a meter reading, it is trying to determine what is mid­gray (18% gray) in the view and place the mid gray in the middle of the dynamic range of the light falling on the sensor.

In a photograph, If you plot horizontally, brightness levels from dark at 0 (black) to bright at 255 (white), and vertically the number of pixels at each light level, you would have a graph that is called an histogram.

"There is no such thing as a bad histogram."

The Vertical axis
shows the number of pixels
at each level of brightness

The Horizontal axis has a scale of 0 - 255
(left to right) with 0 = black and 255 = white.

Thus on a histogram, mid gray would have a value of 128. Almost all cameras can display the pictures histogram in playback mode, some can show histograms in record mode. There is no such thing as a good or bad histogram, but one that shows most of the pixels in the middle is a better exposure that one that has the pixels clumped toward the black or white end of the plot.

A Normal Histogram	An histogram of an underexposed picture	An Histogram of an overexposed picture
Just right	Not Enough	To much

With a little practice, you will be able to tell if your photo has good exposure values by looking at its histogram. But, the digital information we really need to know about a picture when we are image processing is What pixels are white, What pixels are mid gray, and What pixels are black.

An Introduction to PhotoShop Image Processing

In PhotoShop or PhotoShop Elements 2.0 or 3.0

2. Set the eye dropper:

sample size to 3 by 3 Average

The eye dropper is found in the tool bar. In the options bar click the check mark and choose 3 x 3 Average

3. Setting values for layers

Under the Enhance menu select Adjust Lighting/Levels

(Keyboard shortcut on th PC is Control L, Mac it's Command L)

To set the black point

double click the Black eye dropper

• Change
• R setting to 10
• G setting to 10
• B setting to 10

then click okay

To set the White Point

double click the White Eye Dropper

• Change
• R setting to 240
• G setting to 240
• B setting to 240

then click okay

To set the Gray Point

double click the Grey Eye Dropper

• Change
• R setting to 128
• G setting to 128
• B setting to 128

then click okay

Now click okay in the Levels dialog box.

A requester will pop up that asks if you want to "save the new target colors as defaults?"

Click Yes

Now were ready to Image Process.

Rule : Do not assume...

that if the picture doesn't turn out, you can fix it in Photoshop,  ImageFX or some other image processing software. You will be sorely disappointed! Remember, with a digital camera, you don't use film... you can shoot until you run out of storage memory and you can always delete failed pictures.

Some Image Processing Rules:

Absolute Rule: Do Not Throw Away Data

• Use contrast and brightness controls carefully and sparingly as these tools changes whole pixel values... you actually wind up throwing away information when you save the result. In other words, the data you changed using contrast and brightness is a one way street...there is no way to get back to the original data set. 
• Use color balance controls:  R, G, B, or Hue / Saturation, or CYMK
  • These functions control or manipulate data in the colour look up table, only changing their values not not throwing them away. You can reset or revert the "color look up data" back to its original state, even after you have saved the changes.
• Do Not Throw Away Data 
  • Never change image resolution.
• Do Not Throw Away Data
  • Crop the picture, only if it is absolutely necessary.

 Using "Levels" to adjust color settings

The test picture was shot in Guadalajara, Mexico on a dark sunless street using a Nikkormat FT2 with a Vivitar f/2.8 28 ­ 90mm lens on KodaChrome 64 slide film.

The fix is to work with the mid grays. this is done using the "Levels" function and the sliders under the histogram's bell curve. 

The "Levels" Dialogue box 

Using the Eye dropper... (Classroom Demo)

x. Don't forget to flatten and save the "enhanced" picture.

For a quick tutorial on using PhotoShop go here...

This picture below captured from digital video shot at the Beijing Opera in Beijing, China.

Because it is a video capture, the resolution is only 720 x 480 pixels. There is a lot of detail in the picture, especially in the headdress and the eyes of the subject... to improve the detail in the headdress I sharpened the picture, using a function called convolving.

Convolve allows you to mathematically manipulate the data, that is the pixel value of each pixel in the picture. This is accomplished by using a matrix grid that overlays the picture. The under lying pixels are then processed or enhanced.

To sharpen a picture you use a convolution matrix with the unlikely name of Unsharp Mask

If you over do Unsharp Masking you'll start to see white fringing around parts of the image... so use this function sparingly and avoid the white fringing. If your software allows you to use LAB Mode (not available in PhotoShop Elements), sharpen in the luminance or lightness layer...

Interestingly enough, today's digital cameras do this unsharp masking in the camera when you save the picture in Tiff or Jpg format.... Some cameras even allow you to set the level of sharpening. But, if you save your picture data in RAW format, no image processing takes place at all and you must do the sharpening later in the computer with your image processing software.
Always do sharpening last just before you print the picture.

How to fix an OVER EXPOSED or an Under Exposed Photograph

Overexposed Instructions