Zooms are great. Just ask Stanley Kubrick. Or watch [this video](https://vimeo.com/38828455). A zoom can be used as a storytelling device to add suspense, create a feeling of vastness, or draw attention to a particular element in a scene. Not to mention, they’re great to hone in on details when you’re shooting from afar, and to [add depth](https://vimeo.com/videoschool/lesson/159/adding-depth-to-your-shots) to your shot. When zooming in this digital age, however, an important distinction needs to be made between optical and digital zoom. This difference can be described in terms of mechanics and image quality. But first, take a look at this little video I whipped up on a regular point and shoot camera to demonstrate the difference. Pay close attention to image quality:
Now, let’s zoom in to magnify the details, shall we? **Mechanics and Image Quality** Optical zoom refers to the zooming capabilities of the physical lens itself. A zoom lens (as opposed to a fixed focal length lens, which does not zoom) has moveable lens elements, which allow for the focal length, and thus the field of view, to be varied. Optical zoom does not affect the pixels of the captured image, and therefore maintains the same image quality at all focal lengths. Digital zoom does not depend upon how the lens itself is built, and instead is achieved by digitally magnifying the image captured. It works much like enlarging a certain area of a photo in a digital photo editing program. The problem with this process is that it crops a portion of the image and scales it. Through this process you lose [image resolution](https://vimeo.com/videoschool/lesson/186/the-basics-of-image-resolution), as you end up with an image of the same size, but with less pixels and more image noise. A zoom lens on a consumer level point and shoot camera is described in magnification. For instance, the camera I used magnifies the image 500% optically and 2000% digitally, thus the camera is described as having 5x optical zoom and 4x digital zoom for a combined zoom of 20x. Interchangeable lenses for SLR cameras, on the other hand, are described by the range of their focal lengths, for example 24-70mm or 70-200mm. They are sometimes described by their magnification as well, so a 70-200 lens has a magnification of 2.9. **Usage** When should you use optical zoom, and when would you want to use digital? In my humble opinion, you should always use optical zoom, and never touch digital zoom. The main reason behind this is image quality. You saw the pixellated look of the 20x magnification video footage. It’s just not pretty. In any case, if you find that you really want that extra telefoto effect, but don’t have the lens to back it up, you can always zoom digitally in post. It’s the same effect. You can turn off digital zoom in your camera’s menu settings. Do it now, you’ll thank me later. However if you’re shooting on a mobile device you’ll be limited to just digital zoom since the thin body of a phone can’t accommodate much lens movement. **Other Types of Digital Zoom** Certain digital cameras have a mode that can change the field of view in essentially the same way crop factor does. If you don’t know what that means, I suggest you brush up by reading [this Video School lesson](https://vimeo.com/videoschool/lesson/127/crop-factor). So these modes, when switched on from your camera’s menu settings, utilize a smaller portion of your camera’s sensor, thereby applying a crop factor to your lens. Some cameras only offer this mode when shooting SD video, others offer it in 1080p HD, and others still don’t offer anything of the sort. Here’s a rundown of who offers what: Canon offers a form of digital zoom on some of its prosumer-level cameras, such as the T2i and T3i called **Crop mode**. Crop mode utilizes a smaller portion of the camera’s sensor to create a crop factor. The T3i crop mode produces 1080p footage cropped to 3x magnification. The older T2i produces a crop of 7x, but only works when shooting in 640×480 SD resolution. The higher end Canon cameras, such as the 5D and 7D, do not offer a crop mode. If you like squirrels, or want to check out the T3i crop mode, watch [this test footage](https://vimeo.com/26206617). Nikon offers **DX mode** and **1920×1080 Crop Mode** for its full frame sensor cameras. In Nikon terminology, the FX format refers to a full frame sensor, while DX refers to a smaller sensor. Nikon makes lenses specifically for DX and FX cameras. However, if you put a DX lens on an FX camera, the camera will automatically engage DX mode, which uses a smaller portion of the camer’s usual full frame sensor, and thus applies a 1.5 crop. The 1920×1080 Crop Mode offered by the Nikon D4 applies a 2.7 crop. This is done to avoid vignetting at wide angles, but can also be used to your advantage to get that extra zoom. Engaging these modes renders full 1080p HD footage. If you like the moon, check it out at a 2.7 crop on the Nikon D4 in [this video](https://vimeo.com/41663884). Last but not least, the Panasonic GH2 offers a crop mode they call **Extra Tele Conversion**, or ETC. This mode “crops” the GH2’s 4608×3456 sensor to 1920×1080. The result is 1080p HD footage, cropped to 2.6 magnification. The GH2 already has a crop factor of 2, so when in ETC mode, the crop factor is actually 5.2. So a 100-300mm lens on the GH2 in ETC mode is equivalent to 520-1560mm field of view! If you like the zoo, check out this great [tutorial video and test footage](https://vimeo.com/18827597) from [Eduardo Merille](https://vimeo.com/merille). Boom! There you have it. All about digital vs optical zoom. Remember, when zooming always opt-out of digital and choose optical. However, don’t shy away from crop modes, they might come in handy.
Once your video is ready, but before it reaches the Vimeo player, take advantage of Vimeo’s video editor to perform tasks like trimming clips, merging files, compressing videos, cropping, or even creating GIFs.
