A wide angle lens is the perfect way to increase the reach of a Pentax camera. As a standard zoom lens has a typical focal length of 18mm (equivalent of 28mm on a full-frame camera), it gives a significantly narrower view than can be seen without the camera. Whether taking pictures of landscapes and architecture or simply trying to squeeze as much as possible into the frame, a wide angle lens can instantly broaden the camera's reach. This guide explains how to buy a wide angle lens for a Pentax camera.
What are Wide Angle Lenses?
As the name suggests, wide angle lenses give the camera a wider angle of view than standard lenses. They do so by altering the perspectives and angles which the camera can pick up. They also have a shorter focal length – less than 35mm for standard wide angle lenses whilst ultra-wide angle lenses can go as short as 8mm.
All wide angle lenses emphasise distant objects appearing further away and smaller, nearby objects appearing closer and larger. Whilst depth of field manipulation on normal lenses can have a similar effect, wide angle lenses not only have a deeper depth of field, but are specially built to take striking pictures. Most wide angle lenses are quite small, relatively portable and lightweight.
Knowing Your Pentax
There are particular things to look out for when choosing a wide-angle lens for a Pentax camera, to make sure the lens is compatible with the camera model:
- The Sensor: most Pentax cameras use APS-C sensors which are smaller than the standard 35mm film or image size. Whilst there are several variants of APS-C, they all crop a few millimetres from each side of the image, which can be apparent when looking through the viewfinder. As such, it is important to figure out what type of sensor is on the Pentax camera and to choose lenses that are designed for the format of the sensor.
- The Crop Factor and Focal Length : Pentax cameras with APS-C-sized sensors typically have a 1.5x crop factor. A 10mm lens on one of these cameras will give a focal length equivalent to 15mm. The bigger the crop factor, the narrower the field of view (as an example, Canon DSLRs typically have a 1.6x crop factor, giving an effective focal length of 16mm with the same lens).
The following points will address the key factors to consider when choosing a wide-angle lens:
The front element of the lens is the curved glass found in the front of the lens. The extreme convex curvature can make it vulnerable to knocks and scratches, particularly when using a wide angle lens as the object can appear further away through the viewfinder than they actually are. Buying a petal-shaped lens hood to use during shooting can be a protective measure.
When buying wide angle lenses it is worthwhile to consider that whilst a lens with a bigger zoom range makes the lens more versatile, photographers rarely use anything more than the shortest focal length when using wide angle lenses. As such, a wide angle lens with a large zoom range may become an unnecessary extra expense. Prime lenses have a fixed focal length and are cheaper and more lightweight, and have a larger aperture – producing higher-quality images but without the flexibility of a zoom range.
It may be worthwhile investing in a low-profile UV filter to protect the front element and lessen the risk of vignetting (brightness or saturation of the image decreasing nearer to the edges, compared to the centre of the image). Once the chosen lens has been purchased, examine the filter thread (notches and grooves on front part of the lens) to ensure the UV filter will fit properly - most wide angle lenses have a 77mm filter thread.
A useful feature on wide angle lenses is a focus distance scale. The distance scale is markings near the back of the camera lens, either by or on the focusing ring, indicating the distance from the lens to where objects will appear in focus.
Lenses will either have a window indicating distance from infinity down to one foot or less, with close distances labelled macro or the distance scale will be printed directly on the focusing ring with markers. It also enables the photographer to set the hyperfocal distance accurately (maximum distance beyond which all objects will remain in focus).
The aperture determines the quantity of light that reaches the camera's sensor. Express in f numbers, the greater the aperture, the greater amount of light that travels to the sensor. It also means faster shutter speed, thus faster picture taking. However, greater apertures also restrict the number of objects that can be focused upon which can be an issue for wide angle pictures. Generally speaking, a large aperture range gives more versatility.
How to Buy Wide Angle Lenses for Pentax Cameras on eBay
Whether having chosen a wide angle lens or wanting to browse and buy on eBay, there are a few simple steps to follow:
· Buyers who have already chosen a wide angle lens can type in details such as the model number and brand into the search bar at the top of the screen.
· To search or browse using the ‘Shop by category' feature, go to the drop-down menu near the eBay logo, then from Electronics to Cameras & Photography. Use the menu on the left hand side to pick Lenses and either choose ‘Wide Angle' from the ‘Type' subcategory or type in the required lens in the search bar.
· Other categories to choose from include: ‘Format, ‘Camera Type', ‘Focus Type', ‘Focal Length', ‘Condition' and ‘Price'.
· Before buying, make sure to read the product description section carefully and prioritise sellers with a good reputation.
· It may also be possible to find suitable Pentax wide angle lenses in eBay's recommended deals section. Click on the link at the top of the screen, mouse-over the Electronics tab, then pick Lenses under the Cameras category.
Buying a wide angle lens can be overwhelming if unfamiliar with what they are and how they can change the way a picture is taken and how the picture will turn out. Buying a wide angle lens for a Pentax camera involves knowing the details of the Pentax camera and of the lens in question. Whether a landscape photographer adding to their collection of wide angle lenses, or an amateur making their first wide angle lens purchase, it is important to make an informed decision when buying on eBay.