The concept of bolting a huge zoom lens to the back of a smartphone isn’t new. Samsung has already had a couple of tries and must be hoping it’s third time lucky with the Galaxy K Zoom.

This smartphone looks like a hybrid of the Galaxy S4 and S5, and on the back is a 10x optical zoom lens.

In 35mm terms, it’s equivalent to 24 to 240mm, which means a nice wide-angle setting as well as decent telephoto. The 20.7Mp sensor is the type you’d find in a budget compact camera, and it’s physically larger than a normal smartphone would have.

It can shoot Full HD video at 30 or 60 frames per second, and you get the same choice at 720p resolution. There’s optical stabilisation to help avoid blurry shots at full zoom and a continuous shooting mode which takes three photos per second when using autofocus.

There’s a proper slimline flash and an autofocus assist lamp on the rear. You get a dedicated shutter button and you can use the touchscreen to choose separate focus and exposure points.

As a smartphone the Galaxy K Zoom has a 4.8in Super AMOLED screen with a 1280x720 resolution. You get 8GB of internal storage, but you’ll want to pop in a microSD card to add up to 64GB extra for storing all those photos and HD videos.

There’s a front camera as well but at 2Mp, it’s not great for selfies.

Inevitably, there are some compromises if you want a whacking great zoom lens in your smartphone. At 200g, the K Zoom is heavy and at more than 20mm thick, it’s not going to slip easily into a trouser pocket.

The dimpled plastic panel unclips so you can remove the battery. This would be useful if you could easily buy spares, but at the moment, they’re hard to come by. If you’re going to be taking photos and video all day, you’ll probably want to keep a portable USB battery handy for charging up the K Zoom.

The phone runs Android KitKat and has the usual Samsung adornments and software. The camera app is easy to use and lets you choose picture and movie sizes.

It’s fine to leave it in Auto mode, but there are other modes including a manual mode which gives you control over shutter speed, aperture, exposure correction and ISO.

An unusual Pro Suggest mode lets you pick camera settings saved by other users, these are displayed only after you’ve half-pressed the shutter button and the scene has been analysed.

Galaxy K Zoom: Performance

Apart from the screen resolution, which is lower than we’d like, the K Zoom has a great screen. Colours are vivid and viewing angles are great. As long as you're not outdoors in bright sunlight composing photos and shooting videos is a treat because you can easily see whether they’re in focus or not.

In terms of performance Android runs smoothly, apart from the occasional stutter. Gaming performance is acceptable, but it's not as good as the best smartphones.

Photo and video quality is more important, of course and, overall, it’s not bad at all, especially when compared with the current batch of mid-range (and even flagship) smartphones. Photos look great on even the biggest screens, but they don’t stand up to close scrutiny in Photoshop where you'll find a lack of detail and smudgy textures because of noise reduction.

The image stabilisation system does its job pretty well and autofocus is quick, too. Given that this is a smartphone, it takes a couple of seconds to fire up the camera app - it’s a shame you can’t launch the app using the shutter button.

Video is sharp enough with good detail levels, and sound quality is good too. You can zoom in and out when filming, too.

Galaxy K Zoom: Verdict

By no means the  perfect combination of a smartphone and zoom lens, the K Zoom isn’t half bad. It’s capable of great photos and videos in the right conditions.

This isn’t a device for everyone, but if the “zoom camera with a built-in smartphone” concept appeals to you and you don’t mind the size and weight, it’s currently your best option.

 See also: the 32 best smartphones you can buy in 2014