Category Archives: Tips

Tips, tutorials and other educational information

Why you should get a fast zoom lens.

Most manufacturers would have you believe that the reason why you want to get the top of the line fast zoom lens is to shoot in absolute darkness or to get gorgeous bokeh balls. Although there is some inkling of truth in there, the idea is absolutely absurd. The name photography suggests painting with light. Why then would you want to shoot in absolute darkness if the concept is contrary to what photography stands for? Further, are we going to shoot every image so that it has a milky smooth background and gorgeous bokeh balls. Granted, if the idea was to impress your friends and persons who are not knowledgeable enough in photography, you will certainly win some points. But, why by gear often times costing thousands of dollars just to shoot in low light or show how great you can blur the background ? Having set that premise, I will try to describe a practical reason why you should get a fast zoom lens.

To explain, lets have a look at a consumer grade and a professional  lens with similar zoom lengths – the 55-200mm f4-5.6 Nikkor and the 70-200mm f2.8 Nikkor. For the sake of this explanation we will also assume that these lenses are placed on a crop body as the the former is a DX sensor lens and the latter is an FX sensor lens. Certainly, the DX lens is lighter it can certainly allow for zooming within the same range as the 70-200mm. The 70-200mm however allows the user to maintain an aperture of f2.8 throughout the length. The 55-200mm changes its aperture through the process of zooming in and out. This can lead to some difficulty when it comes to maintaining the exposure of your image across different zoom lengths.

If you recall the exposure triangle which is made up of the ISO, aperture and shutter speed, as you adjust one area of the triangle, you are certainly going to have to adjust one or two of the other areas to compensate. So, lets have a look at the specifications of two images

  1. ISO 200, aperture 4, shutter speed 1/200s
  2. ISO 200, aperture 5.6, shutter speed 1/100s

Both images will have the same exposure, or have the same amount of light applied to them. As the aperture changed, the shutter speed was adjusted to compensate for the quantity of light coming through the lens.

Getting back to the comparison of our two lenses. As you zoom the length of the 55-200mm lens the aperture will change resulting in a change in exposure whereas the 70-200mm would not change the aperture at all throughout the length. Thus for a fast moving event like a sports game or animals in a zoo, this is ideal as you never have to adjust any of your other settings. You simply shoot and forget about it.

Now, I know what you are thinking. Why not set the camera in aperture priority and let the camera figure out the shutter speed as you zoom through the lengths. That will certainly allow the lens to behave as if it has a fixed aperture through the changes in its distance from the sensor. Please note that the 55-200mm will still adjust the aperture at its widest position regardless of being placed in aperture priority. But, for the sake of this example we will assume that it does not. If we took our two photograph examples above. This means that the shutter speed will be adjusted accordingly from 1/200 – 1/100 seconds and vice versa. This is great if you don’t zoom past 100mm. But beyond that, you have the possibility of introducing camera shake unless you are on a tripod. As a rule of thumb, it is expected that your shutter speed be the reciprocal of the lenses distance from the sensor. At the extreme of 200mm, the 55-200mm succumbs to the limitations of its design. A limitation which can only be compensated by a fast zoom lens or boosting the ISO of the camera.  Boosting the ISO however leads to other issues in the quality of the resulting photograph.

So, just to recap, you should not be fooled by the marketing gimmick of shooting in low light and bokeh balls. That is not a significant enough reason why you should get a fast zoom lens. A fast zoom lens should be purchased because it helps you overcome the limitations of consumer lenses where the aperture varies and and as a result, the exposure of the photograph. Thus, this allows you to have consistent well exposed photographs throughout your zoom range.

Bhangra – Folk dance of the Punjabi

On a whim, I decided to take an unscheduled trip to Rochester to see the SUNY Geneseo Bhangra Team, aka GB, perform at Rochester’s Fringe Fest. Well the experience turned out to be a lot more than I bargained for as I got an opportunity to shoot the teams performance up front. That, by far, was one of the greater experiences of the evening given that photography was literally forbidden in the the theater room of the except to assignment photographers. But, I will not delay with unnecessary copy of the experience. I will let the photos do the talking and hope you enjoy Bhangra – Folk dance of the Punjabi.

The Need to Continually Practice Photography

While listening to a podcast – The Candid Frame – I heard the host explain the need for continually taking photographs. His explanation was simple. The reason for continually taking photographs is to become an expert in your subject matter, so that you know it inside out, so you can take photographs that accurately express the concept and or emotion you wish to convey. So that is the short explanation, let me see if I can elaborate on this with an analogy.

Imagine for a moment your  back in high school. You have just returned from summer vacation and your teacher asks you to do an essay about how you spent your summer vacation. Certainly your first thoughts will quickly skip to the most prominent experiences in your mind or the most memorable. So lets say you went to a concert and you got to see your favourite band play. Well, if you and any of your classmates went to the same concert then you will probably all recall the same series of events.

But, imagine then that you choose to flesh out those experiences more and explain it from your perspective. You don’t want to explain how classmate A and classmate B saw it. You want to explain what the experience meant to you; what it tasted like; what it sounded like; what it felt like before and after; what was most memorable to you. You want to be able to become an expert in communicating your thoughts and ideas so that someone else reading your essay is transported there, in your shoes and can suddenly experiences everything you experienced but through your words. That is the essence of the need for continually practicing photography.

The idea is to become proficient in the art of visual storytelling – technical as well as emotional – such that a viewer can experience what you felt, what you thought, what inspired you and captured your attention through the images you take.

In summary, the need to continually practice photography is to become proficient in using the camera and knowledgeable in the subject so that you can express your ideas more effectively.

The Importance of White Blance

If you are like most photographers, your white balance is set to auto – job well done! For most cameras, if your white balance is set on auto white balance, then your camera will be correct 95% of the time. What happens for the extra 5%? Well your camera can be fooled! The best solution for this of course is to understand white balance and what role it plays in adjusting the colors in you final image. Below, I will attempt to explain the importance of white balance and how an uncalibrated white balance setting can throw your image off.

A camera measures white balance in Kelvin. The Kelvin temperature scale is correlated to the colour intensity of a an object. Interestingly, in Kelvin, the warmer the temperature gets the more it approaches blue. Direct sunlight in camera terms is around 5200 Kelvin and cloudy is considered around  6000 Kelvin. So, I know your first question – why is a cloudy scene considered warmer than a sunny day? Well, if you have a look at the image below you will notice where cloudy, daylight  and other white balances fall.

Kelving Scale White Balance
Kelvin Scale White Balance

Because cloudy days appear bluer than warmer direct sunlit days it is considered warmer.  To understand why this happens, you have to know that Kelvin was developed to determine the temperature of hot objects which radiate light like metal being forged or stars twinkling. These are objects which are physically hot and thus radiate different colours of the spectrum. And, based on our scale,  because cloudy days appear bluer compared to sunny days to a camera then it  is considered warmer.

To correct the effects of either too much blue or too much red, the camera applies a colour to counteract the dominant temperature colour. So, for a too blue setting, the camera applies more yellow and orange.  Similarly for a too orange scene, the camera applies a blue setting to counteract. That is pretty much what happens in the camera.

Now, as I said before, if you have your camera set on auto white balance, you are pretty much set. However, if you have a scene which may include different light sources like an incandescent light with light coming in from a window then the simple whitet balance  pre-sets provided by our cameras will not suffice. Further, if you have light which is being transformed as it passes through a translucent layer like a coloured curtain, or painted glass you will have different types of colour casts being formed. That is the time to take a grey card or white card to properly set your white balance. I would explain how that is done  but I would not be able to keep the instructions completely camera agnostic. This is best explained through your camera’s manual. However, when it comes to capturing accurate skin tones when different light temperatures are introduced into a scene, it is important to properly calibrate your white balance for your camera to get the right  look to your images.

Below I have provided two images – one before white balance adjustments shot with the incandescent setting on the camera and the other after white balance adjustments. The light source provided is a lamp which is covered by a beige shade which is off to the left.

Before white balance adjustments
Before White Balance Adjustments
After white balance adjustments
After White Balance Adjustments

The colours are much more representational of their actual colours in the second image. Notice the shirt is blue and not a purplish colour. Also notice the skin colour is a lot more natural rather than a slight cast to orange. In short, colours are much more realistic when they white balance is properly adjusted. Neither of the images were altered in any way and represent the image taken straight from the camera.

Now, can these be corrected in PhotoShop and other popular editing programs? Sure they can. Do you want to spend the time it takes to do so? Well it all depends on how much time you have on your hands. And, if you work for a client whom you have to send proofs to before sending the actual raw file or if you work for a newspaper whom you have to email the jpeg so that it can be printed because time is of the essence, you probably don’t have the time to edit in PhotoShop. In such a case(s) it is better to get it right the first time in camera.

The Lens as a Shaper of Image

The question I hear most often from various friends and persons whom I instruct in photography goes a little like this – “I am thinking of getting lens – xyz; What do you think?” To be honest, I think the question should really be rephrased to – “I am thinking of doing this type of photography or taking these type of pictures; Do you think this lens is adequate?” It is true that you can take a photograph of the same scene with just about any lens but the qualities of different lenses allow you to interpret the scene differently. In the following text, I will attempt to explain how the lens is a shaper of image.

Telephoto Lenses

Telephoto lenses do two things particularly well – they isolate sections of a scene and they compress an image. By isolating a part of a scene, it is possible to make the subject of the image a lot more prominent and eliminate distractions. This is especially true if you are making use of a telephoto lens with zoom capability. With such a lens, it is possible to isolate your subject out of the environment and give you a more intimate photograph of your subject.

Further, by the very construction of the lens, telephoto lenses are more likely to create bokeh –  a natural blurring of the background and or foreground due to the shallow depth of field.  This allows the photographer to eliminate distractions by using the natural optical properties of the lens.

Wide Angle Lenses

Wide angle lenses allow for the spreading out of items in a scene giving the impression of more space between items. Lenses like these are frequently used by landscape photographers to show the grand scale of things. They have also been used in portraiture in unique ways. Arnold Newman used telephoto lenses to get as much into his photographs to explain more about the person whom he photographed.

The lens does not only change how much one can put within his/her frame but how he/she tells the story. And, dependant on the lens, chosen for the scene, a photographer may tell the story more effectively. I have posted a small video below to give a more visual explanation of how a lens can shape an image. Although, the photographer discusses more about telephoto lenses, I think he touches on some key points which explain the differences between using a wide angle V.S. a telephoto lens.