What Is The Iris Diaphragm Aperture

Olympus SP-610UZ Review

Announced earlier this year, the Olympus SP-610UZ is the successor to last year’s SP-600UZ, sporting a 14-megapixel sensor and a new 22x ultra-zoom lens. Also on board is Olympus’ sensor-shift image stabilisation system, a range of Art Filters and a feature that allows the camera to combine two separate photos into a single 3D image stored in MPO format. The new model carries over the 720p HD video recording functionality that was already present in its predecessor, and also has a mini HDMI port that allows users to hook the camera up to an HDTV via an optional HDMI cable. Powered by 4 AA batteries, the Olympus SP-610UZ is a remarkably affordable entry into the world of superzoom cameras, with retail pricing hovering around the £160/$200 mark in the UK and the US, respectively. But does it deliver? Find out in our in-depth review.

As you pick up the Olympus SP-610UZ for the first time you immediately know it's a budget product, betrayed by a decidedly plastic feel in the hand. On the plus side, it is quite comfortable to hold courtesy of a well-sculpted and relatively big right-hand grip, which also houses the four AA batteries that power the camera. The design is, unsurprisingly, dominated by the large 22x zoom lens that provides an extremely versatile focal range of 5-110mm, or 28-616mm in old money. While this isn't quite as big as the class-leading 35-36x zooms of the Canon Powershot SX30 IS and the Nikon Coolpix P500, in real-world use it provides enough width and enough reach to satisfy most photographers' needs. Superzooms have always had a reputation for having a high "fun factor", and the SP-610UZ is no different. The ability to quickly go from wide angle to ultra-telephoto is something that has to be experienced in order to be fully appreciated. It certainly gives you a kind of freedom you do not feel with any other type of camera.

For its size, the SP-610UZ's lens is also respectably fast, with maximum apertures of f/3.3 at 28mm and f/5.7 at 616mm. As the lens lacks an iris diaphragm, there is no aperture control of any kind - whether automatic or manual - available on the camera. In very bright light, the SP-610UZ engages a built-in 2.5-stop neutral density filter in order to prevent overexposure, but this obviously has no effect on depth of field. The camera comes with a large lens cap, which can be secured to the body with the included tether.

APERTURE | Photography Terms

Hole in the front of the camera to give way to light. Usually circular, except in very basic cameras of variable size to control the amount of light passing through the lens and reaching the film. Effective aperture is called the diameter of the beam passing through the anterior lens element along the axis. Except in the rare instruments in which the opening is ahead of target, the effective aperture is slightly larger than the real one, because the light refractaal through the first lens and the beam is narrow, however the effective aperture varies proportionally to the real diameter must be amended through an iris diaphragm. The aperture is the ratio between the lens focal length and effective aperture. So if the lens has a focal length of 50 mm. and the effective aperture is 25 mm., the relative will be 50/25 = 2, a result that is usually expressed as a number f, f2 in this case, the higher f-number, the lower opening. The opening set of values ​​normally recorded in the objectives is 2, 2.8, 4, 5.6, 8.11, 16 and 22, each step is (approximately) half of the previous light or twice as the next. Some targets exceeded upper or lower limits of range, if maximum aperture is greater than it is said that the aim is rapid, because the large amount of light which leads allows you to use a higher shutter speed, very appreciated quality when working in dimly lit areas or when circumstances, sports photography, for example, advise the use of high shutter speeds. Considering fast depends on the state of design goals at any time, at present, 50 mm. f2.8 more than can be described as such. The higher the speed (or brightness) of the target, the more difficult it is to manufacture and therefore high price.

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