Sunday, 17 August 2008

Macro Lenses

Digital Macro Photography Lenses
Welcome to macro photography for beginners. This post is all about macro lenses. To achieve good macro photography you will need a decent lens. The highest quality macro lenses (also called micro lenses by some manufacturers) are usually quite expensive to buy. This is because of the way they are designed to gain high magnification without impairing the image with aberrations, ghosting, vignetting and distortion. The end result should be a crystal sharp image throughout the entire focal length of the macro lens. It is not possible to create a perfect lens but the manufactures of camera lenses strive to make them as good as possible. To achieve this manufacturers need to incorporate expensive components into their lens technology.

On several occasion within this blog I have described the Sigma 105mm f/2.8 EX DG Macro and 150mm APO Macro DG HSM lenses as excellent. In fact what I have meant by this, is that they are both extremely good value for money as lenses for beginners (and beyond). This is because they both share a high standard of build quality that produces a sharp image (the 105mm just sneaks it for sharpness but it is very close indeed). These lenses are made in almost every mount imaginable. So they are accessible, affordable and take sharp macro photographs. The Sigma 150mm APO Macro DG uses Sigma 's HSM motor which is very quiet when auto focussing, this can be a real bonus when photographing nervous subjects. It is also a fixed length (not a telephoto) and this is also a benefit for nature photography. A lens that does not rotate is more suitable for use with polarizing filters. These are some of the reasons that Sigma's range of macro lenses have become extremely popular with nature and wildlife photographers. The great aspect about both of these two particular lenses from Sigma is that they can be used for general day to day photography as well. They are both very good prime (fixed focal length) lenses. In fact most fixed focal length macro lenses can be used in this way.

Photographers may question the weight of a particular lens as being too heavy. In my experience, I actually find the heavier lenses easier to use. This is because it can be difficult to hold a very light camera and lens steady. I believe that it is easier to hand hold a heavier lens than a light lens.

Personally aesthetics of a lens are not really important when making a decision. The lens elements, components, and auto focussing motor and price are all important factors. I suppose that if a lens look great on the camera this may create a feeling of confidence that results in a burst of inspiration. If the lens makes you feel good then this is bound to have a positive effect on your photography. It is very difficult to find a poor quality macro lens on the market, the established brands all make very good macro lenses. I can highly recommend The Sigma 150mm APO Macro DG HSM lens for beginners, particularly those interested in wildlife photography. The Sigma 150mm APO Macro DG HSM is a very good macro lens and as stated earlier, it is perfect for beginners to macro photography. It has an aesthetic appeal, admittedly not strictly a criteria for a good lens it is definitely a good looking piece of kit. I have never experienced any problems with this lens and I use it most days and often for long photography sessions. It is a good lens for capturing insects, dragonflies, butterflies, moths etc. Equally it is a good lens for still life and flower photography. If you have the opportunity to try before you buy be sure to take advantage of the opportunity. If you have a Canon camera consider the EF 100mm f2.8 Macro USM. If you have a Nikon camera consider the AF-S 105mm f/2.8G ED-IF VR Micro. (note: VR stands for Vibration Reduction, IS stands for Image Stabilisation)

Some of the best macro lenses available:-

Nikon AF-S Nikkor 105 f2.8G DX ED-IF VR Micro
Nikon AF Nikkor 60mm f2.8 D Micro Lens#

Canon EF-S 60mm f2.8 Macro USM lens
Canon EF 100mm f2.8 Macro USM lens
Canon EF 180mm f3.5 L Macro USM Lens

Sigma 105mm f2.8 EX DG Macro
Sigma 150mm APO Macro DG HSM

Canon also make the ultimate macro lens with their MP-E 65mm 1:2:8 1-5x 65mm. This remarkable lens begins at 1:1 and will take macro images at a magnification of x 5. I would not recommend this lens for beginners as it can be a difficult lens to use.

The Different Types of Lenses Explained
Camera lenses come in a multitude of shapes and sizes and are designed with different styles of photography in mind. Many of these forms of photography overlap so you can buy a lens for one purpose and find that it is also capable of another. However it is best to buy lenses that have been designed for the purpose that you intend to use them. This will provide you with the best results in my opinion. I know that when you step into the world of digital SLR photography for the first time the large array of lenses and their terminology can be a little bit confusing.

Fixed Focal Length (also known as Primes). This type of lens as the name suggest has a fixed length. For example a 50mm Prime lens will always have the same focal length. To frame your subject you have to move the camera and lens closer or further away from the subject. Generally a prime lens will be (slightly) sharper than an equivalent zoom or telephoto lens but this is not guaranteed.

Telephoto lenses. A telephoto lens is a type of zoom lens. This means that it does not have a fixed focal length. Instead it has a focal range that will be displayed on the lens barrel itself, for example 70mm-200mm. Telephoto lens are physically shorter when at the lowest end of their focal range (70mm), when extended to the highest end of the focal range (200mm) they are physically longer. This type of lens can be difficult to use in certain circumstances.

A typical zoom lens also has a focal range but it operates differently. The lens elements move inside the lens housing which means that the physical length of the lens remains the same when the lens is fully extended. Some zoom lenses are known to create a vacuum effect that draws dust and debris into the camera. This can be a problem when taking photographs in places where there is a lot air born dust. This could be a motor-sports event like an off-road rally stage or where there are dirt bikes, mountain bikes or motorbikes etc. This is not so much of a problem for macro photography but if you use your camera for this type of event you can expect more sensor dust and that can be a real problem for macro photography because it shows up most when smaller apertures are used.

Most compound lenses are made from a number of optical lens elements. Each element is carefully engineered to reduce unwanted aberrations, reflections, ghosting or distortion in the image. However there are also some lenses that are designed to actually cause distortion of the image. Fisheye lenses are an example of this type of lens. A fisheye lens purposely produces a very distorted image. (for example:- Nikon AF Nikkor 105 f2.8 DX Fisheye Lens)

Weight – Sometimes Heavier is Best.
In basic terms the lens elements are either plastic or glass (sometimes other materials and coatings are used such as fluorite in expensive lenses). Cheap and cheerful lenses often use plastic internal elements to reduce weight and overall cost. However in a lot of cases they are adequate for the casual or amateur photographer. High quality lenses have a better build quality for professional use, which means the lens is made to higher standards. A professional quality lens has to withstand the vigour of being used (and abused) on a daily basis. This is often what you are paying for when buying a very expensive lens. It is not just the optical quality but also the built quality, which means having better seals etc. Higher quality lens elements mean better image quality and usually more weight.

Summary of Macro Lenses and their uses based on their focal length and working distances.
50mm [Short working distance] This lens would be ideal for small objects, still life photography. A good example would be product photography for auction or retail websites.

100mm [Medium working distance] This lens would be suitable for small objects, flowers and insects. Although the working distance may cause some problems for some subjects. An ideal lens for coins, stamps and flowers)

150-180mm (Long Working Distance) This lens would be the best choice for insect and small animal photography.

Working Distances
The working distance of a camera lens is the shortest focussing distance between the lens and the subject. This means that if you move the lens closer to the subject you will be unable to sharply focus on the subject. To retain full magnification (typically 1:1 on most macro lenses) you must maintain the working distance. Simply keep the camera and lens at the same distance from the subject. This can be difficult when hand holding for insect photography. This is why it is important to buy the lens that most suits your subject matter. Insect macro photography requires greater working distance so look at lenses that at least 100mm. If your photography interests extend to dragonflies, moths and butterflies and small animals then you should consider 150mm – 180mm macro lenses.

Still life macro photography is much easier to accomplish than wildlife and nature photography. It can still have it's challenges though! Working distances are less important and a shorter lens (typically 50mm Prime) is an adequate lens for studio macro photography. A studio does not have to be fancy for macro photography either, a soft box (or a light box) can be obtained or created quite easily and without a lot of expense. To get consistent results it is better to provide evenly diffused lighting for the subject against a plain background (usually white). This works better than using flash photography as this usually casts hard shadows when the light hits the subject and can be reflected back towards the camera if the subject has a reflective surface.

A serious word of warning: If you attempt to build a still life studio, softbox or lightbox yourself, please ensure that any electrical wiring and the situation of bulbs is safe. By this, I mean ensure that light bulbs will not come into contact with any flammable materials. Still life macro photography is a lot of fun, burning down your house is not! If you are not certain that your creation is entirely safe you can ask a qualified electrician to check it for you.

If your lens requires a lens collar make sure it come with one.
A light weight camera lens with a short focal range (for example 18mm-55mm kit lens) will not require a lens collar for attachment to a tripod. They are designed to be used for hand held photography primarily. When used with a tripod the camera is connected directly to the tripod head or via a quick release plate.

A heavier lens with a longer focal range will require a lens collar to attach it to a tripod. Lens collars are simply a detachable ring with flat connection plate that contains a female threaded connection. Lens collars are surprisingly expensive so make sure that your lens comes with one as standard. The lens collar can be connected directly to a tripod or tripod head. I recommend that you use a good quality tripod head with a quick release mechanism to reduce the chances of damaging the collar's thread. A top tip here, is that you can actually make your own reduction rings (from household materials such as cardboard and duck tape) to use a larger collar on a lens with a smaller diameter. This is relatively easy to do and can save you a lot of money. Make sure that the reduction ring holds the lens as tightly as an original component before using it because camera lenses do not tend to bounce too well.

I hope that you have found this article interesting, useful or entertaining in some way! ...and a quick thanks to everyone who has sent feedback recently.

Marvin Africa