Digital Camera World » standard zoom lens

Sigma 18-35mm f/1.8: first-ever zoom lens with f/1.8 constant aperture unveiled

jmeyer — Thu, 18 Apr 2013 10:22:54 +0000

The Sigma 18-35mm f/1.8 DC HSM announced today is the first ever zoom lens to achieve a wide constant aperture of f/1.8 throughout the zoom range. Find out all the key specs of this new Sigma lens.

A Sigma 18-35mm f/1.8 price and release date were not available at the time of writing.

Sigma has revealed a new 18-35mm zoom lens with a constant aperture of f/1.8.

The new Sigma 18-35mm f/1.8 DC HSM is the first ever zoom lens to achieve a maximum aperture of f/1.8 throughout the zoom range, according to Sigma.

The previous widest aperture a zoom lens has been able to achieve throughout the zoom range has been f/2.8.

Designed for DSLRs with APS-C size sensors, the Sigma 18-35mm f/1.8 offers a focal range equivalent to 27-52.5mm in 35mm format.

Sigma says the new 18-35mm lens has been designed as a standard lens which is capable of shooting landscapes, portraits, still life photography, even studio photography.

The faster aperture throughout the zoom range will eliminate the need for photographers to keep fixed focal length lenses in their camera bags for brighter images, Sigma says.

The new Sigma 18-35mm lens also incorporates a wide glass-moulded aspheric lens and Special Low Dispersion glass, the latter which compensates for various aberrations as well as field curvature at the widest angle.

The Sigma 18-35mm f/1.8 also features Super Multi-Layer Coating to reduce flare and ghosting, and boost contrast, while a supplied petal type hood provides extra protection.

A Hyper Sonic Motor provides a silent AF function, Sigma says, while the 18-35mm f/1.8 offers a minimum focusing distance of 28cm and a maximum magnification ratio of 1:4.3.

Other features include a 9-blade rounded diaphragm, brass bayonet mount and a newly developed USB Dock that plugs into your computer and attaches to your lens, allowing you to update the lens firmware and adjust parameters such as focus.

Sigma 18-35mm f/1.8 Key Specifications

How different types of lenses ‘see’ the world

jmeyer — Fri, 29 Jun 2012 01:00:11 +0000

There are many different types of lenses available to photographers, as we all know, and the type of lens you choose to fit on your SLR will determine how your end results will look.

The main consideration is focal length. Focal length is the distance between the optical centre of a lens and the sensor, but it’s easier to think in terms of how this affects subject size when compared with a standard lens. For a camera with a full frame sensor, a standard lens is 50mm.

The types of lenses with focal lengths shorter than 50mm are known as wide-angles, while lenses with focal lengths longer than 50mm are referred to as telephotos.

Which type of lens you need will depend on the subject you are shooting, but most focal lengths offer creative potential with all subjects.

Below we’ve broken down the different types of lenses for you to choose from and explain what they’re typically used for and the effects you can expect from them.

We’ve also included images taken with each of these types of lenses to show you the many different effects they produce when shooting the same subject.

At the top left of this page we’ve also included an infographic combining the effects from all the types of lenses into one cheat sheet. The graphic shows the effects of shooting the same subject with different types of lenses. To download the larger version of this cheat sheet, simply drag and drop it on to your desktop.

And if you liked this, you can click here to find more from our photography cheat sheet series.

Shot with a fisheye lens

Fisheye lenses
Fisheye lenses (8-16mm) differ from conventional lenses in that they produce images with a slightly curved or bowed appearance, and a field of view that covers up to 180 degrees.

Shot with an ultra wide-angle lens

Ultra Wide-angle lenses
Ultra wide-angle lenses fall in the 10-24mm range and have a very wide angle of view, which allowsyou to work very close to your subject and stillinclude it all in the frame.

Shot with a wide-angle lens

Wide-angle lenses
A typical wide-angle lens falls between 24-35mm, and is often incorporated into a wide-angle kit lens in the 18-55mm range, or it can be a fixed focal length prime lens.

Shot with a standard lens

Standard lenses
A standard lens is 50mm for DSLRs with a full frame sensor. The equivalent focal length for crop-sensor cameras lies in the 28-35mm range, dependingon the camera model.

Shot with a short telephoto lens

Short telephoto lenses
Lenses in the 100-200mm range are known as short telephotos. They are used for isolating specific subjects within landscapes, and for portraits and close-up work.

Shot with a long telephoto lens

Long telephoto lenses
Long telephotos typically have a focal length of 300-600mm and have a very narrow angle of view, making them the lens of choice forwildlife and sports photography.

Canon boosts EF lens range with three new models

jmeyer — Tue, 07 Feb 2012 17:13:15 +0000

Canon has announced three new EF lenses to add to its range, a 24-70mm f/2.8 ‘L’ series lens is joined by 24mm and 28mm fixed focal length prime lenses.

First up, the new EF 24-70mm f/2.8 L II USM lens is added to Canon’s professional line and is an upgrade to the previous standard zoom lens.

It features a redesigned optical system which includes two Ultra-low Dispersion (UD) and one Super UD aspheric element which is designed to minimise chromatic aberration and colour blurring.

Super Spectra coatings to reduce ghosting and flare have also been included, along with a fluorine coating to minimise the amount of dust, dirt and fingerprints.

A ring-type Ultrasonic Motor (USM) works in combination with a high-performance CPU for quick and accurate, and silent autofocus. The lens has a minimum focusing distance of 0.38m at all focal lengths throughout the zoom range.

The structure of the lens has been improved to offer enhanced zoom durability along with grater shake and shock resistance within the barrel. The size of the lens has also been reduced by 10mm.

A new zoom lock lever means that photographers can lock the zoom position at the extreme wide end of the lens to prevent damage to the lens in transit, while it is also water and dustproof.

Read more about the new Canon EF lenses, on our sister website, TechRadar.

Tamron unleashes 24-70mm f/2.8 standard zoom

jmeyer — Tue, 07 Feb 2012 11:40:47 +0000

Tamron has announced a new fast, 24-70mm f/2.8 standard zoom lens, which is available in mounts compatible with Sony, Nikon and Canon DSLRs.

The new lens comes equipped with Tamron’s Vibration Compensation (VC) image stabilisation and Ultrasonic Silent Drive, which is designed to help when shooting handheld.

Tamron’s lens also uses special high-grade glass in three LD elements, along with three glass molded aspherical lenses, one hybrid aspherical lens and two XR (Extra Refractive Index) glasses. It also incorporates a rounded diaphragm to enhance out of focus areas, which retains a nearly circular shape even hen taken two stops down from its fully open state.

Full specs for the moisture-resistant Tamron 24-70mm f/2.8:

Model:                        A007
Focal length:                    24-70mm
Maximum aperture:                F/2.8
Angle of view (diagonal):            84°04’ －34°21’ (for full frame 35mm format cameras)
60°20’ －22°33’ (for APS-C format cameras)
Lens construction:                17 elements in 12 groups
Minimum focus distance:            0.38m (15.0 in)
Maximum magnification ratio:        1:5 (at f=70mm: MFD 0.38m)
Filter size:                    φ82mm
Length:                        108.5mm*
Entire Length:                    116.9mm*
Diameter:                    φ88.2mm
Weight:                        825g*
No. of diaphragm blades:            9 (rounded diaphragm)
Minimum aperture:                F/22
Standard accessories:            Flower-shaped lens hood
Compatible mounts:            Canon, Nikon, Sony

Lens Review: Nikon 55-200mm F/4-5.6G AF-S VR DX IF-ED

dcworld — Fri, 22 Jan 2010 14:31:49 +0000

Lens reviews: the Nikon 55-200mm offers some neat tricks, but does it lack reach?

The 55-200mm AF-S VR – Nikon’s closest competitor to Canon’s EF-S 55-250mm IS lens – is a ‘DX’ model for APS-C cameras, though it can also be used in ‘crop’ mode on most full-frame Nikon D-SLRs. There are some notable similarities and diferences to the Canon offering. Firstly, the build quality is pretty much the same, with a reasonably sturdy but plastic construction, including a plastic lens mount.

Also, like the Canon, this Nikon lens lacks a focus distance scale. On this lens the manual focus ring looks almost like an afterthought tacked on to the front end of the lens. As well as its small size, the focus ring has very high gearing, making it diicult to use for accurate manual focusing.

Switch to autofocus and the Nikon fares massively better, with a super-quiet, highly accurate AF-S (AF Silent Wave) system that’s a major improvement over Canon’s more humble micro motor. The three-stop stabiliser isn’t the latest and greatest, but it’s pretty efective nonetheless.

The only really limiting factor in this Nikon is its outright telephoto reach, which works out to 300mm when you take the 1.5x crop factor into account. By comparison, the Canon’s 1.6x crop factor puts the EF-S 55-250mm to a much more generous 400mm.

Even so, there are still a couple of extra pluses for the Nikon, as it comes with a hood and soft pouch, which you have to pay extra for when buying most Canon lenses.