- I, uh, I said in the last movie that I wasn't going to do any recap of what we covered in the first part of this series, but I just can't help it. I feel like there's one thing that I have to go over again to kick off this chapter, and that is the importance of checking shutter speed to ensure a sharp image. As you should now know, when you half press the shutter button to meter the light in your scene, your camera calculates a shutter speed aperture combination that will yield good, overall brightness. And then shows you those settings in the cameras viewfinder.
Now if you're working in dim lighting, it's possible that the shutter speed that the camera chooses will be too slow to effectively use when you're shooting hand held. When the shutter's open for a longer time, any tiny motion in the camera can cause an overall softening in your image. Now, you may think you have a very steady hand, or that a 30th of a second is still a really fast shutter speed, but it just doesn't take much motion to soften an image. In part one of this series I recommended that once your shutter speed drops below a 60th of a second, you should take action to speed it back up.
And so we looked at using program shift to switch to an equivalent combination of shutter speed and aperture, but an equivalent combination at a faster shutter speed and corresponding wider aperture. We also looked at raising ISO. I also mentioned that there's a guideline you can follow for computing the slowest shutter speed that you can use with a given lens. I covered that guideline in my Photography Foundations: Lenses course. In that course, you'll also learn about the effects of image stabilization and how it can dramatically ease hand held shooting.
Now you might think, I'll just avoid this whole risk of camera shake thing by always trying to keep my shutter speed really high. But as you accelerate your shutter speed, you'll be preventing more light from getting to the image sensor, that will require you to use higher ISOs which will result in your final images having more noise. What's more, faster shutter speeds will require you to use wider apertures, and, as you'll learn in the next chapter, a wider aperture has a huge impact on your final image. One that can cause some parts of your image to go out of focus. So when you go to a wider aperture to prevent motion blur, you've possibly exchanged one sharpness problem for another.
Choosing exposure settings is a balancing act. How much brightness do you want? How much motion? How much ISO noise are you willing to tolerate? And so on. There are a lot of decisions involved, but if you are someone with a tendency towards analysis paralysis, don't worry. Most of the decisions you have to make will be bounded by practicality. I can't shoot with a shutter speed this low because my image will be shaky, or I can't shoot with a shutter speed this fast because I don't want the moving water in that fountain to get frozen, and so on. The more you learn about exposure, the easier it will be to juggle all of these competing creative and practical decisions.
- Shooting sharp images
- Assessing your camera's high ISO options
- How aperture affects depth of field
- Lens speed
- Previewing depth of field
- Depth of field in the real world
- Manual mode
- Controlling motion
- Shooting raw
- Shooting with post-production in mind