A sub-£200 optic with Optical Stabilisation and a Hyper-Sonic Motor - too good to be true or an absolute steal?
Jon Tarrant
Nikon AF-S 24-120mm f/4G ED-IF VR Review
An update to an already good performer, is this the ideal all-purpose lens for Nikon bodies?
Image Formation
Drawing on the two previous postings in this 'blog we are now able to create a basic model for image formation. This is not a thorough approach to image formation…
Sigma APO 50-500mm f/4.5-6.3 EX DG OS HSM Review
An impressive 10x zoom range for just over £1100, but has Sigma been a little over-ambitious with this superzoom optic?
How much does light bend?
We have an explanation for why light bends when it moves across a boundary between two different media but is there any predictable pattern to the amount that any given…
Canon EF-S 15-85mm f/3.5-5.6 IS USM Review
With Image Stablisation, UD elements and an Ultrasonic Motor, is this feature-filled objective the perfect kit-lens replacement?
Sigma 85mm f/1.4 EX DG HSM Review
Half the price of the Nikon equivalent, but this optic proves that it can still hold its own
Nikon AF-S 16-85mm f/3.5-5.6G ED VR DX Review
With a second-generation VR system and handy focal range, is this the ideal all-purpose lens for Nikon DX-format bodies?
Nikon AF-S 85mm f/1.4G Review
The price tag might not suit everyone's budget, but this optic's performance is hard to argue with
Canon EF 85mm f/1.8 USM Review
Far cheaper than Canon's f/1.2 equivalent, but still a mighty good performer for a more than reasonable price
Why does light “bend”?
Having covered a couple of real-world observations of the behaviour of light it seems appropriate to look at some of the optics theory that explains how lenses are able to…
Surface Curvature
Most of the effect that a lens has on the light passing through it comes from the surface curvature of its elements. This curvature has to be both precise and…
Reflected Light
Why is some light transmitted and some light reflected at a glass surface? This is a surprisingly difficult question to answer because the nature of reflected light is not as…
Tamron 18-270mm (non-PZD) super-zoom
I've just been testing the new PZD version of Tamron's 18-270mm super-zoom and I've realised that when the review of the non-PZD 18-270mm was published last year it was accompanied…
Nikon AF-S 24-120mm f/3.5-5.6G ED-IF VR Review
With plenty of functionality delivered at a reasonable price, what's not to like about this Nikon optic?
Graham Saxby’s Science of Imaging
Good books on The Science of Imaging are few and far between but Graham Saxby’s is one of the best. For that reason, and also because I’m honoured to be…
Telescope lenses
Why do astronomers use telescopes? The answer is NOT “to make distant things look closer” but rather to make fainter things look brighter. In that respect, telescope lenses are very…
Fixed or Variable Aperture?
You may sometimes have a choice between two similar lenses; one with a fixed aperture, the other with a variable aperture, priced higher and lower respectively. Which is the better…
Pinhole Quality
Some time ago I discussed the optimum size for a pinhole to be used in digital pinhole-camera photography. I’ve now done some practical work, the results of which are presented…
Tamron SP AF 60mm f/2 Di-II LD [IF] Macro Review
Excellent ergonomics and a fast f/2 aperture makes this a serious third-party macro option