Elena Tresh Foundation Florida
Photoshop Tutorials #1 - Understanding Image Size and
These photoshop tutorials were written by Cressida Goddard.
To start these photoshop tutorials, we will define some terms
- Image Resolution
- The fineness of detail in a digital image.
- Image Size and Resolution
- If the number of pixels stays the same in an image, then, as
the size of the image increases, the resolution (fineness of
- Images which are intended to stay on screen, need to be a low
resolution. Why? Because monitors only have a resolution of 72dpi,
a resolution considerably higher isn’t able to be
- Images which are intended for printing, need to be a high
resolution. The printed image and the on-screen image are
completely different entities. An image printed at 72dpi will be a
low quality image.
- Pixels (image elements)
- The individual dots that are used to display an image on a
computer monitor. The higher the resolution, the more pixels.
- DPI (dots per inch)
- A unit that is used to measure the resolution of a printer or
Dpi is sometimes used to describe the input resolution of a
scanner, but ppi is the more accurate term.
- RAM (Random Access Memory)
- The system memory of a computer that is used for running an
application and processing information, and for temporary
- Zip Disk
- 100 Megabytes
- Floppy Disk
- 1.4 Megabytes
- Approx 600 Megabytes
- File Size
- File size is measured in bytes, kilobytes, megabytes, or
8 bits = 1 byte
1024 bytes = 1 kilobyte
1024 kilobytes = 1 megabyte
1024 megabytes = 1 gigabyte
File Formats used in these photoshop tutorials.
- Photoshop file is the only format in which multiple layers and
layer transparency are available. PSD’s are large files.
- (Joint Photographic Experts Group) A compression method in
photoshop that shrinks a file's storage size, but which can also
cause image degradation as a result of data loss.
- TIFF (Tagged Image File Format)
- A common format that is used for saving a bitmapped image, such
as a scan. A TIFF image can be colour separated and can contain
colour management profiles. Used for magazine, high quality
- Large file, standard windows format, not compressed
- New format, good for alpha channel masking to Flash
- Vector Graphics (lines / circles)
- Used in Illustrator, Corel Draw, Autocad
- Bitmap Graphics (pixels)
- used in Paint programs, Photoshop
This is the end of photoshop tutorials - part 1
[ Photoshop tutorials #2 - scanning ]
The second part of the photoshop tutorials will deal with
- Make sure the scanner is switched on before the computer is
- To start these photoshop tutorials, place image or object in
the scanner, close the lid.
- In Photoshop select File - Import - Twain_32
- The scanning software will appear outside photoshop. When the
preview of the scan comes up;
- Select with the crosshairs the area you want to send to
photoshop. This will greatly reduce the file size of the scan
during these photoshop tutorials.
- Select the image type ie colour drawing, sharp colour photo,
- Check the size of the image and make adjustments.
- Change the resolution depending on the destination of the final
- Send the image to Photoshop
This is the end of photoshop tutorials - part 2
[ photoshop tutorials #3 - Tips for Better Scans ]
The 3rd part of the photoshop tutorials will give further
instructions on gaining better quality images.
- Place the image in the scanner making sure it is straight to
prevent having to rotate it later.
- Try to use a high quality image to scan where possible
- Scan the size you plan to use to avoid scaling in your page
- Check the calibration of your scanner to get the best scan you
can so you can do as little adjustment as possible when in
- When scanning material that has been printed on both sides,
place a black piece of paper behind the page in your scanner. This
will prevent the printing on the back from showing in the
- Make sure you think about where the final image is going (ie
print, web) before starting the scan. This information is essential
for selecting the scan resolution.
- For doing straight reproduction images where faithful colour
reproduction is important, your monitor, scanner and printer all
need to work together to produce the correct image.
- If your scanner or printer tends to put a wash of colour over
the image, notice it and learn to overcome the problem.
photoshop tutorials example:- scan a photo , don’t do
anything to it and then print it , then compare this image to the
original photo .
if there is a yellow tinge to the image for example find a way in
photoshop to override the problem.
- Make adjustments like sharpening later in Photoshop.
- Never use Brightness/Contrast in photoshop to adjust photos as
it destroys too much information, use Curves or Levels instead for
the purposes of these photoshop tutorials.
- File size grows faster than scan resolution. The file size of
an image scanned at 200ppi is four times greater than when it is
scanned at 100ppi.
This is the end of photoshop tutorials - part 3
[ photoshop tutorials #4 - improve your digital photographs
The 4th of the photoshop tutorials will deal with handy hints for
getting the best out of your photoshop image processing.
- Think about composition before taking the photo
- Experiment with different settings taking the same photo.
- Don’t place the subject in the centre of the photo.
- Sometimes it is good to fill the frame with the subject and not
include any background.
- Sometimes it is good to let the background take over and let
the focal point be very small.
- Shoot at the eye level of your subject.
- Compose from different angles.
- For a portrait, think about your subject’s personality
and try to capture it.
- Use a tripod, or don’t use a tripod to get a blurry
- Print on good quality photographic paper from a good quality
printer if possible. Epson papers are good.
- Print at a high resolution eg 300 dots per inch (dpi).
- Take more pictures than you need.
- If compressing the file in JPEG format, use the optimum
- Look carefully at other people’s photographs and the way
they have framed the composition. Be critical, do you think they
work as a composition?
- Remember that you don’t have to take photos of
breathtaking landscapes or good looking people, sometimes photos of
objects, which you would never consider, make beautiful
photographs. E.g. a brick wall, the top of someone’s head, a
- Remember Photoshop is very handy for quickly cropping images
and correcting mistakes.
- Break all the rules
This is the end of photoshop tutorials - part 4
[ photoshop tutorials #5 - Photoshop Exercise ]
The 5th of the photoshop tutorials gives you exercises to practice
and enhance what you have learnt during these photoshop
- Open Adobe Photoshop using the shortcut on the desktop.
- In the Photoshop screen choose File - New. Accept the default
settings and you should get a white document on your
- Save your document to the hard drive.
- Have a look at the toolbox on the left-hand side of the screen,
experiment with different tools by clicking on them and using your
mouse to draw on the document.
- When you have finished experimenting, press F12, this will take
you back to the blank document.
- Now choose the paintbrush tool and write your name with the
- Then experiment with filters from the Filter menu.
[ photoshop tutorials #6 - Zooming ]
- Using the zoom tool is very helpful to making accurate
selections and paint work.
- Choose the zoom tool and click on the image to zoom in.
- Choose the zoom tool and press the Alt key while clicking to
- Note: Zooming does not change the image size or anything else
in the image. It is just a temporary viewing option to help you
with selections, painting etc.
[ photoshop tutorials #7 -Selecting an area ]
- Select the Marquee tool and draw a rectangle around the area to
- Press Ctrl / D to deselect.
Selecting By Colour - Magic Wand Tool
- Open an image in the samples folder, which has one solid colour
somewhere within the image.
- Use the Magic Wand tool and click on the area with the solid
- If the whole area is not selected, use the Shift key while
clicking with the mouse to select more of the area.
- On the keyboard press Ctrl/D to deselect the area.
Freehand Selection - lasso Tool
- Using the same image select the Lasso tool
- Trace around part of the image
- Notice how difficult and inaccurate it is.
- Filling a selection
- After making a selection with the magic wand tool, choose Edit
- Open an image from the samples folder.
- Select the Crop tool, which is hidden under the marquee tool.
Then click and drag around the part of the image you want to
- Then press Enter. The image is cropped.
[ photoshop tutorials #8 - Image Adjusting ]
- Open a file you have already been working on.
- Choose Image-Adjust, and adjust the image with a number of the
tools in this menu.
- Then press F12 to revert to the previous image.
- If the brushes palette is not visible, choose Window - Show
- Open a blank document, make sure black is the foreground
- Choose the Paintbrush from the toolbox and experiment with
different brush sizes.
- Experiment with the eraser, airbrush etc... Notice that their
thickness is also controlled by the brushes palette.
- Note: When choosing a tool, if you double-click on it you will
usually get an options palette to give you more control over the
[ photoshop tutorials #9 - Text ]
- Open a new document File-New and accept and the default
- Select the Type tool from the toolbox.
- Click anywhere on the document. A dialogue box appears.
- Select font, font size and colour.
- Type in your name
Cloning part of an image
- Choose the Rubber Stamp tool from the toolbox.
- Alt / Click an area that you want to clone. This copies that
area of the image.
- Then, without pressing the Alt key, use the mouse over the area
you want to clone to.
[ photoshop tutorials #10 - Layers ]
- Open 2 images from the samples folder.
- Select the Move tool, click one image and drag it across to the
- Go to the layers palette on the right hand side of the screen.
Notice that you have a Background layer and a Layer 1.
- Click on the Layer 1 and then adjust the opacity slider in the
palette to 60%.
- Notice that the background layer is now visible underneath
- Make sure Layer 1 is highlighted in the layers palette.
- Choose Layer - Free Transform and reduce the size by clicking
and moving the corner handles.
- Then press enter to remove the box.
Info on layers
- In the Layers Palette you can;
- Temporarily hide layers by clicking the eye icons on and
- You can click and drag layers up and down to change the order
of the layers
- Note. The top layer in the palette is the top layer in the
- You can change the opacity of a layer and change the blending
mode on a layer.
- You can create a new layer by clicking the new layer icon at
the bottom of the palette.
[ photoshop tutorials #11 - Understanding Resolution ]
- Open the two images titled 300dpi and 72dpi.
- Take note of the print size of both images.
- Choose View - Actual pixels for the 300dpi image. This shows
the image at 100%. Notice the image is sharp and appears to be
- Then zoom in on the 72dpi image until it is at the same size as
the 300dpi image. notice how pixelated the 72dpi image
- The number of pixels or dots in an image
- A monitor can only show 72dpi, so when an image has a
resolution larger than 72dpi.
- The monitor can only display the image by enlarging it to fit
in all of the pixels.
- If you were to print both images they would be the same size on
- The only difference being that the 300dpi image would have
- 72dpi is suitable for images which will stay on screen eg web
pages, animation, video.
- 300dpi is suitable for printing quality images.
Display and Screen modes
- Open a file
- By pressing the F key repeatedly you see that there are 3
screens to view your work in.
- Then by pressing the Tab key you will temporarily hide the
toolbox and the palettes.
- To hide or display the palettes only, press Shift /
This ends the photoshop tutorials for now.
Stay tuned for further developments on this front !