Verdict
Pros
- Multi-format image coverage
Cons
- Very poor image quality at 300mm
Key Specifications
- Review Price: £159
Sigma’s 70-300mm has an impressive list of features but it also calls forth the warning that if something sounds too good to be true, then maybe that’s exactly what it is. Its 70-300mm focal-length range may be more than many users will really need in an everyday tele-zoom but there is nothing wrong with having a little bit of extra power – provided, that is, nothing more essential has to be sacrificed along the way.
The wide zoom ring has a very comfortable feel but its quarter-circle throw is quite highly geared and the lens extends by more than 50mm. Coupled with a close-to-camera hold 
on the lens, the considerable extension increases the risk of camera shake. It is not possible to steady the lens with a further-forward grip because the entire front section of the lens rotates during focusing – and the instruction book specifically warns against obstructing this movement. Using the lens at its 300mm setting is therefore very difficult indeed. All of this is a huge shame because the 70 -300mm has an image circle big enough to accommodate full-frame sensors and the lens even includes an infrared focusing mark for those who need it. There is also a very useful ‘macro’ capability that, while not being fully deserving of the term, manages a very creditable 1:2 reproduction ratio.
Image Quality
Unfortunately, MTF testing reveals that the 70-300mm is lacklustre at best, climbing above the critical 0.25 cycles-per-pixel value only between about f/8 and f/22 for short-to-medium focal length settings. It fails to get anywhere near the magic figure at any point when set to 300mm.
Sample images
Verdict
The trouble with this lens is that it tries to do too much: it’s very versatile but it doesn’t shine in any department. It offers so much that it cannot possibly meet all of its promises at such a low price-point. Its resolution figures start low and never climb as high as other comparable lenses either and its crucial 300mm performance is particularly poor. The lens is also hard to handle given its considerable extension and the fact that its barrel rotates during focusing.
Trusted Score
Score in detail
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Value 8
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Design 9
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Image Quality 7
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Features 9
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Professional conduct
We also expect our journalists to follow clear ethical standards in their work. Our staff members must strive for honesty and accuracy in everything they do. We follow the IPSO Editors’ code of practice to underpin these standards.
Editorial independence
Editorial independence means being able to give an unbiased verdict about a product or company, with the avoidance of conflicts of interest. To ensure this is possible, every member of the editorial staff follows a clear code of conduct.
Professional conduct
We also expect our journalists to follow clear ethical standards in their work. Our staff members must strive for honesty and accuracy in everything they do. We follow the IPSO Editors’ code of practice to underpin these standards.
