Photography News Issue 34

Photography News | Issue 34 | absolutephoto.com

27

Review

Buyingused

Thehiringoption

If you want to buy second-hand there are plenty of specialist used photo dealers, and those that sell new will often have a sizeable selection of pre-owned products. There’s always a risk when buying used products, so it’s ideal to get your hands on the kit to physically check it over. If geography precludes this, then a close look at some detailed pictures will have to do. If you do get to see the lens in the flesh, start with a close inspection. If the lens looks well worn, then it has been used hard, but that’s not a problem if it’s optically sound. If the lens has been fitted with a protection filter, then the front element should be fine. If not, a close look under an oblique light will show up any scratches. After the front element, look at the rear element. This is less likely to be scratched, but might need a clean. Taking the lens off the camera and looking at a bright light through it will show up dust on internal elements, and while the odd tiny fleck isn’t a problem, see mould and you should consider moving on. If there’s a layer of dust sitting on inside surfaces it’ll need professional cleaning to avoid soft shots. constant aperture throughout. A lens that’s quoted as f/2.8-4 means it has a variable maximum aperture, ie. f/2.8-f/4. Constant aperture zooms are usually more expensive. Depth-of-field The amount of front to back sharpness in a picture. See the depth-of-field panel. Depth-of-field scale Many older and some current primes have a scale etched on the lens barrel to give you an idea of how much depth-of-field is available at specific apertures. Filter thread Also called accessory thread, a filter thread can be found on most lenses to screw filters and other optical accessories in front of the lens. Some long telephotos have rear-fitting filters because the front element is so big. Fixed focal length lens A lens with a single focal length. Also called a prime lens. Hyperfocal distance Focus the lens to the distance if you want the maximum depth-of-field for the set aperture. You need a lens with a depth-of- field scale or a smartphone app. Lens hood Stray light striking the front of a lens can cause flare. A lens hood can help avoid this problem by stopping any non-image forming light reaching the lens front. Low (or extra low) dispersion glass Special types of more expensive glass used to minimise certain optical aberrations. Macro ratios This indicates the maximum possible magnification with the lens at minimum focus. A 1:1 magnification means the subject will be reproduced life-size on the sensor. Image stabilisation system Camera makers have their own systems to eliminate blurred pictures caused by camera movement or shake. Canon: IS

If you’re happy at this point, fit the lens onto your camera and take a few pictures. The joy of digital is that you can quickly check that the lens autofocuses and delivers sharp, correctly exposed images. A good test is to focus on something close which has plenty of detail. Set the maximum aperture and take some shots. If the lens has focusing issues or a poor wide aperture, these problems will be readily apparent. If open aperture performance is not good, close down two stops and try again. If the result is still soft, move on. At this point, also check that the manual focus, aperture and zoom barrels are working smoothly without any grating or coarseness. If the lens has an image stabilisation feature then make sure this is working too. Look through the viewfinder, partially press down the shutter release and gently jig the camera up and down – the image will seem to float when it is working correctly. So, you’ve checked out your prospective lens’s appearance, mechanical soundness and its optical qualities. If you’re happy thus far and the price appeals then it’s time to get your credit card out and do the deed.

There are many reasons to hire a lens rather than buying it outright. It might be that you’re interested in a specialist lens, like a perspective control optic, but you’re not totally convinced that you will use it enough to justify a purchase. Or it might be that you are thinking of an upgrade, say to a newer version of the lens you already own, and you want to check out the potential benefits before committing. Then there’s the situation where you have a great photo opportunity coming up that you can enjoy more photographically with a particular lens. This can range from a day at an air show to a wedding to a once in a lifetime African safari. Whatever the situation, hiring could be the most cost-effective way to go. We caught up with Stewart Robertson, the director of lensesforhire – one of the UK’s biggest hire businesses – and asked him how things are going. “Lensesforhire is a family business and we focus on three brands, Canon, Nikon and Fujifilm. About 95% of our business is currently Canon and Nikon while Fujifilm is growing. Olympus and Micro Four Thirds is an area we are looking at, and Pentax too. “About 60% of our customers are enthusiasts and with the rest semi-pros and pros. Many of our customers shoot weddings and hire kit for the job in hand rather than make the massive investment in gear. “It’s our busy time right now. It normally starts to pick up after Easter and we stay very busy through to October. Basically, it’s busy when people are out doing things. We have a lot of customers who like to photograph planes or racing cars at the weekend and many customers are wildlife enthusiasts off on safaris, or going to the Farne Islands or Skomer. And there are a lot of people who are just going on holiday and want a high-quality ultra-wide lens to shoot Tuscan street scenes. “We also get a lot of customers who want to try before buying. For example, they may own the original Canon 24-70mm f/2.8 and are considering the Mark II, but it’s a £1500 lens so to make sure it is the right lens for them they hire it first. Our three most popular Canon lenses are the 24-70mm f/2.8, the 70-200mm f/2.8 and the 100-400mm. “We aim to make hiring a lens as easy as possible. Pick the lens and it goes into a basket and the website takes you through the process – it’s between Internet shopping and booking a hotel room. Our prices include VAT, insurance and carriage and, for UK customers, there is no deposit required. “If someone is interested in lens hiring and not sure of their needs, give us a call – that is what we are here for.”

Jargonbuster

Aperture Every lens has an adjustable diaphragm or iris to control how much light reaches the sensor/film. The lower the number (f/2, f/2.8), the wider the aperture. The higher the number (f/11, f/16), the smaller the aperture. APO (apochromatic) An APO lens can focus all colours of visible light at the same point to avoid chromatic aberration where red, blue and green light wavelengths focus at different points. Aspherical element This is a special lens element with a complex surface profile that doesn’t form part of a sphere. It reduces lens size and help to eliminate optical aberrations. Autofocus (AF) Most lenses are autofocus and AF speed, accuracy and effectiveness canvary between brands. Each brand has its own focusing motor, and the latest are almost silent in operation. Canon has USM (ultrasonic motor), Fujifilm LM (linear motor), Sigma HSM (hypersonic motor) and Tamron USD (ultrasonic silent drive).

Image Stabilization; Fujifilm: OIS, Optical Image Stabilization; Nikon: VR Vibration Reduction; Sigma: OIS, Optical Image Stabilization; Tamron: VC Vibration Compensation. Some lenses have a mode for normal shooting and another for panning with a moving subject.

Lens elements A camera lens is comprised of elements.

Optical construction A camera lens is a complex piece of optical design with each lens made up of a number of individual glass elements. These are sometimes grouped together.

Prime lens See Fixed focal length lens.

lensesforhire.co.uk

Tripod mount Telephoto lenses are heavy. Mount a camera fitted with a long lens onto the tripod or monopod using the mount underneath, and you’re likely to strain or even damage the mount. The combination will also be front heavy. A lens collar mount provides a better centre of gravity and reduces risk of damage. Zoom A lens with a variable focal length allowing you to achieve different compositions without moving camera position. Zoom lock A lens feature that locks the zoombarrel so it does not alter when the lens is being carried.

Bokeh The visual quality of the out-of-focus areas in the background. Portrait photographers like ‘attractive’ bokeh. The shape and smoothness varies, and is influenced by the number of diaphragm blades.

Constant aperture A lens that is quoted as a f/2.8 means it has a

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