Last week I wrote about shutter speed, that mechanical opening in the camera that for a specific time will stay open to allow light to come in to make your exposure or image. Fast shutter speeds like 1/250 of a second or higher will freeze action while lower shutter speeds of 1/4 or slower will let more light in or allow the image to show blur for that artsy look.
There is a second part of exposure for the control of light that does add an artistic look and that is the F stop or aperture in the lens. It looks like an iris of an eye and by making the hole bigger or smaller allows a set amount of light through the lens before it gets to the shutter. Some liken it to a window blind that depending on how much it is open or closed controls the amount of light in a room.
The reason it is important is since the shutter is opened for a set piece of time you do not want too much or too little light coming through since that would make the image too light or too dark. The balance of F stop and shutter speed contribute to the correct exposure. There is one other part of a good exposure which is the ISO or sensitivity of the chip/film that I will also blog about later. But I don’t want your head to explode with too much info for now.
So how do you balance the shutter speed and F stop? Well the good news is that with many of the newer cameras they do most of the heavy lifting for you. If you are in the creative or programed modes this is done by the camera saying to it self “Ok, the shooter wants us to be more on a fast shutter mode so we are going to need more light. Let’s open up the F stop to make a bigger hole to let more light in.” Of course this is all done in a split second and with fancy camera speak but you get the idea.
However there is also a creative aspect to F stop. All those crazy numbers of F 4, F 5.6, F 11 and such can be used to give different looks to your images. For example a low number like F 2.8 or F 4 will give a shallow depth of field (DOF). Depth of field is the part of the image that is in focus. A shallow DOF means just part of the image is sharp, like a person or flower, and the background is all blurry. A good long lens or being zoomed out to the high numbers will help in giving this effect.
At the other end numbers like F 8, F 11, or F 22 will give a huge DOF of sharpness. These are the F stops that most landscape photographers will use so all is in focus. Those flowers in the front, that tree about 50 yards out and the mountains in the background.
Here is the trade off, the low number F stops of F 4 and smaller make the iris a big hole so a lot of light is coming in. A faster shutter speed would be needed to hold back the light. The bigger numbers of F 8 and higher is a much smaller hole so the shutter speed has to be much slower to let enough light in for a good exposure. A slower shutter speed could also mean camera shake which is also why many landscape photographers also use a tripod or some kind of steady surface for the camera to rest on.
So there are two parts of the three parts of good exposure. Shutter speed that can either freeze or allow motion blur into an image and F stop which controls the light and the depth of field. Next time I will talk about the third part ISO and how all three can be used both creatively and to get those must have shots.
In photography there is a principle of what is called the Trinity of Exposure. This Trinity is the three parts that make up a well exposed image. If one of these parts are off the image will be too dark or too light. Get one of the parts way off and you end up with black image or white out conditions. With digital photography and smarter cameras we think that all of this is in the past but this is not true. While a lot of cameras can give a good exposure even set in the point and shoot or Green dial mode setting you can miss out on better or more creative shots.
So lets look at one part of this trinity, Shutter Speed. Inside of the camera is a little slit in a movable curtain that travels in front of the sensor chip which allows the image from the lens to be captured. Since all photography is light hitting some recording surface this shutter is there to only let that fraction of second of light to come in. So in a literal blink of an eye what you see in the camera’s viewfinder is captured.
Depending on the lighting conditions this shutter speed can be very fast, (1/250 to 1/4000 of a second) or very slow, (1/4 of a second to even 30 minutes or longer) . In bright light the shutter doesn’t need to be open very long. In fact it is said that any camera can capture a good image in bright sunlight. It is when the light is low that the shutter will need to be open longer to let in enough light to make an exposure. These lower light conditions can be shade to inside at a sports game, church, or even a birthday party. So why worry about a slower shutter speed if you have a whiz bang new digital camera. Well if the digital camera is thinking that the light is too low it may decide to keep the shutter open longer for more light. A longer shutter speed can also mean camera shake or a blurry photo. This is why you see many pros with tripods for their cameras when they are working in low light. That steady support means they can shoot with shutter speeds of ¼ of a second and get a razor tack sharp image.
Also if you are the creative type you may want to change up the shutter speed for different effects. A super-fast shutter speed can do a much better job of freezing the action of a basketball or soccer game than what is called for in a point and shoot. Also if you like to hike in the woods and want that water fall or stream to look really cool a slower shutter speed will give the water that angel hair or milky look.
Keep in mind I have just given you one part of the Trinity of Exposure and with any change there are advantages and drawbacks. The other two parts are for another day.
Many of the books and podcasts on Photoshop will always have the term Key Board Shortcut in it. What these are are keyboard combination to do is perform certain functions like copy and paste. For a lot of people just starting in Photoshop it is enough to remember where the commands are in the menus let alone obscure key combos.
While helpful they can be daunting. There are over 278 different official keyboard shortcuts and another two dozen that seem to pop up at will. Some of these seem to have more fingers and functions than on a human hand. This including the undocumented Ctrl + Alt + Shift + K (for Mac Cmd + Opt + Shift + K) which brings up the key board short cut menu in Photoshop.
However I do use about a dozen KBS (Keyboard Shortcuts though you would think the abbreviation would have been shorten to just KS) which are helpful in everyday Photoshop operations. If you only play in Photoshop once a month then don’t worry but if you are working in it everyday then they can be time saver.
Ctrl + Z (Mac Cmd + Z) for a one step undo. The most helpful KBS of all and functions in other programs too. Add Alt or Option with this and it will step back about 20 times.
Ctrl + C (Mac Cmd + C) for copy. When you an image or text selected this KBS will copy the contents to clipboard which runs in the background. Will stay there untill you copy something else or turn off the computer.
Ctrl + V (Mac Cmd + V) for paste. Yes I know why isn’t this Ctrl + P for paste but that is setup for printing. So I quess it stands for Very Sticky.
All three of these KBS will also work in word processing programs and some other graphic programs too.
So now for some of the Photoshop centric KBS which are helpful.
Ctrl + J (MAc Cmd + J) for new layer. With nothing selected this will make a new blank layer above the layer you are currently on. Here is what is cool, if you do have selection made this KBS will copy that selection to a new layer. Then you can just start working on only it for Transforming or special effects.
And speaking of Transforming Ctrl + T (Mac Cmd + T) will give you a free transform box around your selection. This is when you see a box around your selection with the eight handles, four in the corners and four on each side. Clicking on these boxes will let you shrink or skew your image. To keep the image in the correct ratio hold down the Shift key and move the corners. Add the Alt or Option key and the box will move toward the center.
One last one for Layers, it is a handful but only on the left side of the keyboard. Ctrl + Alt + Shift + E (Mac Cmd + Opt + Shift + E) will make a merged copy of all the layers without flattening the layers. What this makes helpful is for those times when you need a flatten copy of all the layers but still want all the layers in case you want to go back and re-adjust or want to click and drag this layer to a new image. Go to the top of your layers and do the left hand keyboard shuffle of these keys and it is done. Now with this new merged layer you can apply sharpening to it and change the mode to Luminosity. By over sharpening this layer with the mode change will reduce the halo effect and a reduction of the opacity to taste gives you more control over the look. You can also add a layer mask and bring back some of the original softness.
One more I promise, Using the ALT or Option key when clicking on the Layer Mask Icon at the bottom of the Layer Pallet. This will make a Layer Mask but it will filled with Black to hide the effect instead of White which shows everything. Lets say you copied the whole image into a merged layer and applied a soften filter to it for the smooth skin look. The soften filter will soften everything and not just the skin. Well with an all black layer mask this effect is hidden. Now with a soft edge brush and the color white you can paint the soften look on just the skin. Plus you can play with the opacity of the layer for the best look.
When you have a great image and want to share it what if you have a parent or relative who does not have the internet or you would just like a print of your work, is it easier or harder than it used to be? There are a lot of choices for making prints. A number of local one hour printers from the chain drugstore to big box shops like Costco and Sam’s Club are out there. Some make it easy with computer setups that you just have to put your camera card in and with some minor corrections and cropping you are done.
But if you like to use Photoshop and Photoshop Elements (why else would you buy them?) what happens if you work on an image or a group of images and now want prints. There are a number of horror stories about lousy prints or bad color and while many of these stories are true but they don’t have to be.
First and foremost you should check if your monitor is giving you good color. I will cover this in some future post in more detail to talk about calibration vs the 80% method.
For now lets say you got a good system and want some prints. You don’t want to use your desktop printer but a local lab. If you haven’t done a lot to the image in the way of color correction or major cropping you can just save the file as a jpeg and take it right to the lab. It is almost the same as the camera’s image. Even if you have done some cloning or added text the size of the image is the same.
If you have worked on a number of images and want to have a lot of prints there are few things to keep in mind. First local labs can only print Jpeg images. This means you will have to save the images to a disk or jump drive. I like to use the Save for Web under File for making the copies into a new folder on the desktop. This will save the image and convert it to the right color space for jpeg. You should be saving them at the maximum or highest jpeg setting with the least amount of compression. It may seem strange but the highest quality setting is 12.
If you are planning on cropping try to not to crop too much or if you have to then do not expect Photoshop to save you in making larger prints. Cropping reduces the number of pixels in an image so enlarging too much will give you pixelation. That jagged edge look from pixels being stretched to their limit.
Lastly since many of the local printer are not professional labs if you have a problem with a image do not be afraid to ask them to reprint it, FOR FREE. Sometime they will make a mistake with the chemicals or paper and try to hope you would not notice. It is cheaper for them to reprint than refund.