Tip of the week: Keep it in focus
Have you ever had your image refused for being out of focus?
From time to time as editor I see mostly new users having focusing issues and images being refused for that particular reason. I will try to give you some advices how to take sharp images.
Well, let's begin with refusal reason itself.
"Image is out of focus or too much of the subject is out of focus (DOF too shallow or DOF not justified) / Image is shaken. Use a faster speed or a tripod. Please check the files at 100% zoom before submitting them."
DOF stands for Depth Of Field. It is the distance from point you focused on where objects appear acceptably sharp in the image.
DOF depends on many factors. It depends from the distance between object and sensor plane, focal length used and aperture of the lens. Note that closer you are to the subject you are focusing on DOF will be shallower and vice versa. Next thing is focal length that affect DOF. The longer the focal length of the lens, the shallower DOF will be on same aperture and same distance. And last one - aperture. The bigger aperture you use DOF will be shallower, closing it down will increase DOF resulting more of image will be in focus. Yes, yes I know images on large apertures look more appealing when you separate subject from distracting background, but also note that some lenses are not really sharp wide open and shallow DOF can be sometimes hard to maintain while keeping your subject in focus. Stopping down aperture for 1 or 2 stops can improve results (from f 1.4 to f 2 for instance).
Next thing to pay attention to is shutter speed. There is one rule that can be used, and was shown to be quite correct for static subjects in most cases. That rule connects shutter speed with focal length being used. It goes like this: shutter speed = 1/focal length. For instance when shooting on full frame camera with 50mm lens, minimal shutter speed should be 1/50 second. With a crop camera you just multiply focal length with crop factor (Nikon x1.5, Canon x1.6, Olympus x2). For action shooting you must adjust your shutter speed according to the subject you are shooting. The faster the subject moves the shorter exposure need to be to keep it sharp.
When to use tripod? Well, whenever you are in situation that you need longer shutter speed and want your photos sharp at maximum quality. When shooting static scenes such as cityscapes, landscapes, architecture tripod is a must have. It will allow you to maintain longer exposures without camera shake and use of low iso which will bring out most of the quality of the taken photo your camera can give you.
Also keep in mind that technically good photos have more sales potential, and will probably generate more income over time. Some customers have demand on high resolution photos that are required to be sharp at 100% magnification.
And the one last thing: Please check the files at 100% magnification before submitting them.
Focus on the focus and have a nice day :)