Hello, first things first, I am a beginner and self-taught. I learned what I know so far through tutorials just like this and fiddling around myself with Photoshop so I appreciate your vote of confidence in me by going through these tutorials. So thank you.
Down to the good stuff.
Creating a new Photoshop document.
Select file>New from the upper left hand corner, or (CRTL + N) on PC, or (Command + N) on Mac
A box opens up that looks like this
In this box you have many options. You can select a Preset from the drop down menu by clicking on the arrow in that option, this will give you option for standard sized documents used for web, and print.
You can also set a custom Width and Height for your document by manually typing in the dimension you want. You can also change the type of measurement used by using the drop-down menu beside both Width and Height.
As you can see you have a few options for the unit of measure you use and each one has a different number that displays as Width and Height. Inches, Centimeters and Millimeters are all pretty self-explanatory. The new document is merely measured used the standard unit for each one. I will take a moment however to define: Pixels, Points, Picas and Columns.
Pixels: The basic definition of a pixel is a tiny point of color within an image that together with many others make up a complete electronic image. This means that the screen you are looking at right now has thousands of pixels each with their own bit-depth that make up what you see on the screen. I will get into Bit-Depth a little later in the tutorial. As you can see in the two images above the original 8.504 inch by 11 inch image has now changes to 1063 Pixels by 1375 Pixels.
Points: This refers to the point system that determines the size of text within the computer. Basically the calculation is this; Per every inch there are 72 Points. When you have a layer of text, if you set is point value to 72 it will print out at exactly one inch. The same goes for the document sizing every grouping of 72 points will equal an inch.
Picas: A Pica is a typesetting unit of measurement commonly used for measuring lines of type. One pica equals 12 points. There are 6 Picas to an inch. This is just another way of defining a document size but not that commonly used unless you are making a specifically type oriented document.
Columns: The columns option is only for the width of a document. There are 2.65 Inches to 1 Column.
The next option is for Resolution it can be displayed as either Pixels/Inch or Pixels/cm. The number in the resolution box determines the amount of pixels per the given unit of measure. This will also effect the overall size of the document, as in how many Megabytes the document will late up on your hard drive.
Color Mode and a drop down menu that consists of 5 options: Bitmap, Greyscale, RBG Color, CMYK Color and Lab Color. Depending on what the intended purpose of the image you are creating is will depend on the color mode you choose.
Bitmap: Is the true black and white image as it only contains those two shades. Each pixel can be either black or white. This color mode is good for making patterns in which a strong definition between the lines is needed. However Greyscale offer a wider range of options.
Greyscale: As its name implies the image that is shown is in the scale from black to white and all the shades of grey in-between. This is mistakenly what we refer to as a black and white image when we see it. This Color Mode can be used for print or web as it is easily replicated by both computer monitors or print.
RBG Color: This is a color mode used by computer monitors to display color. It stand for Red, Green, Blue. Basically a mixture of any of these three colored lights will result in the visible spectrum. When the colors are at full intensity it results in white and when they are at no intensity they result in black, everything else falls in-between. This mode is best used for images for the web or non-print images.
CMYK Color: This color mode is used by printing devices and represents the colors in a printer ink cartridge. It stands for Cyan, Magenta, Yellow, and Black (K). This color mode is best suited for images you wish to be printed as it somewhat limits the RGB colors displayed by your computer screen to colors that are available for printing.
Lab Color: Lab Color is like RBG Color in that it uses the addition of colored light to create new ones except that Lab only uses two channels for color and one other channel for luminosity. This means that the one Channel for luminosity is used to create the lightness or darkness of a color channel. Your best option for this one would be to play around between RBG and Lab and see how each one interacts differently.
Understanding the different type of color mode will help you choose the right one for the type of image you are working on. Next up is bit-depth.
Bit-depth: is the amount of colors that can be represented on any given pixel. For example an 8-bit image contains 256 (8x8x8) possible colors as each channel (Red, Green, Blue) has 8 possible colors in can be. The higher the Bit-depth the more colors you have to play around with and thus the clearer your image could be. 16 bit = 4,096 different colors and 24 bit or “true color” = 16,777,216. as you can imagine the high the bit-depth the larger your overall file size will be as well.
One of the last basic option is for background color, this can be changed to white, transparent, or whatever the last background color you had in the color picker was. The other advanced options of color profile and pixel aspect ration don’t need to be set but you have the option of not color managing your document which simply mean that it will not be preset to a specific type of device. The pixel aspect ratio is always set to square unless you set it to a different option from the menu which will mean that instead of tiny square that make up you image you will have tiny rectangles.
As you can see your image size is displayed in the bottom, that is not to be confused with the file size. It represents how many pixels are in you new document. You also have the option of saving the preset. This means that if you have a specific size that you often work within you can save the setting and use it over and over by selecting it from the presets menu.
Thank you so much for getting through the first tutorial and I hope you learned a bit.