As a general rule, more optical zoom is good, but this comes at an increased price and increased weight. If you are intending to photograph or film wildlife or sports, then go for at least 10x optical zoom, but even up to 50x optical zoom would be ideal. If you are photographing your family or landscapes, then you can often get away with as little from 3x optical zoom up to 8x optical zoom.
You might think that more optical zoom means a much more expensive camera, but there are excellent cameras under $300 that have 30x or even 60x optical zoom. See the linked article for more details.
Figuring out how much zoom do I need for a specific situation can be tricky if you are not well versed in camera terminology.
You should first understand that the level of optical zoom itself is not really relevant on its own – you also need to know the focal length of the lens to understand something like a 10x optical zoom distance, for example.
Optical Zoom and Focal Length
Focal length refers to the distance that light must travel between the end of the lens, where it first enters your camera, and the sensor in your camera, where the light is recorded as an image.
The zoom lens above shows a focal length of 55 – 250 mm. The optical zoom level is then the largest number divided by the smallest number – in this case 250 / 55 = 4.5.
Therefore, the optical zoom for the above lens is 4.5x.
You will have realized that because the optical zoom level is a function of the focal length, this means that optical zoom level alone is not sufficient to understand the field of view that your lens will give you.
For example, the lens below has a focal length of 24 – 105 mm. This gives an optical zoom amount of about 4.4x.
But, this lens will give you a much tighter field of view and will therefore show a much more zoomed in image, when used on the same camera.
So, it is not really appropriate to state something like “a 30x optical zoom distance is 100 feet”, because this will depend on the focal length and camera.
How to Choose the Best Optical Zoom
Although the zoom level is not independent of focal length, it is still useful to understand what situations you want to use your camera in, to give you a general idea of the lens or camera that you should use.
Remember that it is always better to use optical zoom vs digital zoom, as the latter degrades your image quality, while the former maintains it.
Do you want to take pictures of sports at sporting events?
You need a lot of optical zoom to take sports photos (along with a lens that has a wide aperture so that you can have a fast shutter speed). Ideally, you should be looking at at least 10x optical zoom, but 30x optical zoom would be better. Essentially, more zoom is better in this situation.
Do you want to photograph wildlife, birds or something very far away?
This generally requires the most optical zoom of any, as you generally want close up images of wildlife that fills the frame, but you cannot get close. At least 10x zoom is needed, but 50x optical zoom or even more is better. Many professional wildlife photographers go for very long lenses that enable them to photograph wildlife from a significant distance. If you can’t afford a lens with a long focal length, then a high zoom range is what you should go for.
Do you want to make pictures of landscapes and the natural world?
Landscape photography is a discipline that requires you to shoot wide angle views that encompass an entire scene. This means that you generally want a low zoom range, with a 5x optical zoom probably the most that you will ever use. If you think that you will want to zoom into details, like waterfalls or tree details, you may want more, but even 8x optical zoom is overkill.
Do you want to photograph your family, or people up close?
You shouldn’t need much zoom to photograph people up close – usually 2x or 3x optical zoom is enough. This is because it is generally better to get up close to people to photograph them, rather than shooting from a distance with a long zoom lens. This will also be beneficial for large groups shots where you want multiple people in the frame at once. Macro lenses also tend to only have a small range of magnification.
Do you want to take photos indoors, or in tight spaces?
If you are in a tight space, then zoom cameras start to become unusable, as they require a larger minimum distance to focus. This means that a short zoom is better, such as 2x optical zoom or 3x, but a wide angle lens is even better.