Home > Photoshop Basics > Photoshop Basics

Photoshop Basics

With digital SLR cameras your RAW file is your digital negative.  Your digital negative and for that matter any image you see on a computer or tv screen is made up of Pixels.  (side not the word Pixel was made up by combining the words Picture and Element).

The size of the image your camera can take is your MP which stands for Mega Pixels.  For example a camera that can take 12MP images produces an Image, a Digital Negative made up of 3000 by 4000 grid of pixels, that is 12 million pixels.

Here is the RAW file of Yoda (click here to download).

The original shot was shot at f/11 at 180th of a second shutter speed, ISO200 at 55mm and using a flash as a fill light.

As shot, the image size is 3872 pixels wide by 2592 pixels tall.  At 240 PPI the document size is 16.133 inches wide by 10.8 inches tall.

As shot whatever white balancing options you have set your camera will be applied if you shot in JPG or TIFF mode, but if you shot in RAW mode  if you open up the RAW file in photoshop you will notice that in Photoshop you can apply whatever White Balance option you want.  Play around with the different white balances to see the difference.  Ultimate since I used the flash to fill in my subject Flash white balancing looks best.  But you also have the option to adjust the Temperature of the light using the temperature scale.   Notice how the lower (more to the left) the temperature gets the bluer the image, and the higher (to the right) the temperature gets the warmer and yellower the overall tone of the image.

You can also adjust the tint of the overall image.  Your exposure, this will help if you have an image that is sligthly over or under exposed but will not work miracles.  If you severely over or underexposed the image using Exposure may only add noise to your image.  You can also play with the fill light and with the Blacks.  The Blacks option will for the most part only affect the black areas of your image where ass Brightness will affect the overall brightness level of the entire image evenly.  Same goes for Contrast.

Once you know how to use the RAW options you can use them to adjust your image for some interesting effects.

.

.

.

.

.

.

.

Below is the original image unadjusted in RAW format with Flash White Balancing.

Below is the same image as above, but with the RAW settings adjusted with some creative license.

However, all of these changes are done to the RAW file, sot that when you open it you wont be able to get the image back as you shot it if you save over the RAW file.  Instead close this and Open the RAW file and only change the White Balancing so the image looks natural.  Before we go on and talk about adjustment layers and how to adjust an image without damaging the or making permanent changes to the file we should talk about image size.

The document (physical) size is determined by  you PPI, Pixels Per Inch.  A computer monitor can only display at 72 PPI, that is 72 Pixels Per Inch.  If I were to post this image online at its original size, the image would be huge on your computer monitor.  Below is a small version of the actual size of the image.

To post this on the web I would open the original image in Photoshop go to the Image menu and then image size.

.

.

.

.

.

.

Then when the prompt comes up make sure Scale Styles, Constrain Proportions and Resample Image is set and change the Pixel Dimensions if the Width to 600.  Since we have Constrain Proportions checked the image size will be contrained to the orginal proportions the image was shot in.  Also notice how the original size of 28.7 Megabytes went down to 706 Kylabytes.

.

.

.

.

.

.

Below is the resized image.

This image looks good on your computer monitor.  It is optimized for the computer screen.  However since the image resolution is 72 PPI (pixels per inch) when printed this image, specially the text, will look awful.  It will look blurry and any detail that we can perceive on the computer screen will be fuzzy on paper.  If your final output will be a printed you should keep your image resolution at or above 200 Pixels Per Inch.  300 is ussually a good image resolution to have if you are printing.

With the image open in RAW file, lets look at the different options you have to adjust an image in Photoshop.

Your tool bar will have all the tools you can use to adjust your image.  If you dont see your toolbar go to the Windows menu at the top horizantal menu and make sure Tools has a check mark next to it.  Within the toolbar you will notice that certain tools have a triangle on the bottom right corner.  This triangle indicates that there are multiple versions of the tool.  Press and hold on the tool and the other versions of the tool will become visible.  I did this with the Lasso Tool and you can see you have the Lasso Tool, the Polygonal Lasso Tool and the Magnetic Lasso Tool.

Select the Lasso Tool and you can see what it does.  It allows you to select pixels within your image.

.

.

.

.

.

.

.

.

.

With the Lasso Tool selected click and drag around Yoda’s left eye and trace it with your mouse.  When you have it all traced release the mouse and you should see the selction you have just made.  Next we are going go to our Layers menu and we will use this selection to create a mask wich we will use to change the color of only the eye.

If you cannot see your Layers Window, go to Window and make sure Layers has a check mark next to it.

.

With the eye still selected we are going to add an Adjustement Layer so that we change only the color of the eye.  Adjustment Layers are similar to the effects that we used earlier to change the color of the image.  In your Layers Window click on the Circle Icon that is half white and half black.  Select the Color Balance effect.

.

.

.

.

.

This will add another Layer on top of your Background layer. This new Layer will have a Mask.  The Black area represents the Transparent part of the mask, that part that will not be affected by the Color Balance effect, and the white spot will be the opaque part that will be affected by Color Balance effect.  Adjust the sliders to make Yoda’s eye red, or whatever color you want.

.

.

.

.

.

.

If you wanted to change the overall color of the image, you would want to have nothing selected when you add your adjustment layer.  With nothing selected  you will be able to adjust the color of the entire image.  The good thing about using an Adjustment Layer and a Mask is that if at any time you do not like the effect, you can just delete the adjustment layer by clicking on the layer and dragging it to the trashcan, or clicking on the trashcan.

The Magnetic Lasso tool allows you to trace the outline of an object within your image and select it that way. Try it out and trace Yoda’s head and ears.

Another tool that you can use to select certain areas is the Magic Wand tool.  Select it in your tool bar and click on Yoda’s cloak.  The Magic Wand tool allows you to select areas that are alike in color based on whatever tolerance you give it.  The area that it selects won be perfect, but with the tolerance set to its default 32 click on the cloak.

***make sure that on your Layers window you are working on the Background Layer, in other words that the layer that has the image of Yoda is selected in your Layers Menu.

You may notice that there are areas of the cloak that are not selected and that other areas like Yoda’s hair have been selected.  We only want to change the  color of the cloak so we will need to clean this up.  On your toolbar select the Lasso tool.  Now on your image to add to the selection that the Magic Wand gave us hold down the shift button on your keyboard.  To take away hold down the Option/Alt button on your keyboard as you click and drag.

.

.

.

Clean up the selection of the cloak and add another adjustment layer.  This time choose Hue/Saturation and change the Hue and Saturate the Cloak with color.  The color looks a bit unrealistic.  But you can adjust the Opacity and the Blending mode of any layer so that it looks more realistic.

.

.

In your Layers Window, make sure the Hue/Saturation layer is selected and change its opacity to about 60% and check out the different blending modes and see which one you prefer.  I personally liked Overlay. But play around with the different blending modes until you find one that gives you the effect that you want.  Or keep it at Normal if you like how that looks.

.

.

If at any point you do not like how the effects you’ve done or are unsure about them and do not want to delete them, you can hide them.  On your Layers Window click on the little eye that is to the left of the Layer to hide that layer.  Until you check this back on the effect will remain hidden.  As you can see, the eye is back to normal and the cloak is its old natural color.  This is why Adjustment Layers are great.

.

Looking at the image unadjusted it looks flat.  Make sure you have the Background Layer selected and add a Curves adjustment Layer.  You can use Brightness/Contrast or Levels to adjust the contrast of the image, but Curves give you the most control.  As you can see when you add the Curves adjustment Layer you get a picture of your Histogram with a diagnol line going from bottom left to top rigth.

What you can do is that by clicking on the line with your mouse, you can add anchor points and use those to adjust the levels of the lights and the darks.  By adding an anchor point and moving it sligthly up you can adjust the highlights, and by adding another anchor point and moving it slightly down you can adjust the darks.  Below is the Curves adjusted, I have exagerated it a bit to show you the difference but play around a bit and see what you can come up with.  The image below has nice highlights and darks, whereas the image above is flat.

Car Image to fix

Flamingo Image to Fix

Advertisements
Categories: Photoshop Basics
  1. No comments yet.
  1. No trackbacks yet.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: