COURSE NAME: PHOTOGRAPHY AND AUDIO VISUAL PRODUCTION (VOCATIONAL) FOR UNDER GRADUATE (FIRST YEAR) PAPER TITLE: BASIC PHOTOGRAPHIC UNIT - 4 : CAMERA CONTROLS - 4 TOPIC: LENS HOOD AND FILTERS OBJECTIVES At the end of the tutorial students will be able to: 1. Understand the importance of lens accessories. 2. Know the various lens filter and hood available in the market. 3. Understand the uses of filters and hood. 4. Differentiate between various lens hoods. 5. Differentiate between various lens filters. Introduction In today s program, we will talk about certain items which are not part of the camera, but without which sometimes it s become very difficult for the cameraman to get the desired result. These are known as accessories. Now, we will see some of the accessories, though there is no end to accessories. Because people manufacture their own accessories, they make their own accessories to get desired the results. However some of them are filter and lens hood. First we will begin with filters. Photography Filters We will take filters now. Filter is an accessory for the photography purposes; it consists of an optical filter which can be inserted in the optical path of a camera. Filters can be round as you can see here, they can be square, they can be oblong also and sometimes we use papers also, which we tie in front of the lens to get the effect we want. Commonly these are the glass filters or plastic filters as I have already shown you, and they are available in the market in huge variety and for different purposes.
We will see the purposes one by one. Let us understand what does the camera do? Basically a filter modifies an image, for example if you are seeing blue color in the sky and we want to shoot into black, we have filters to turn the sky into black. We have a film, which say for example a tungsten based film or type B film but you want the results which are normal to the eye, therefore we use the blue filters to bring up the temperature of the film and get a result which looks normal to the eye. As I have said there are a huge variety of filters available but for ease of understanding we can put them in certain categories, for example clear filters or ultraviolet filters or color conversion filters, color correction filters. We have filters for contrast enhancement. We have filters known as polarizer, neutral density, cross screen, diffusion filters and even close-ups or split diopters lenses, these are the categories into which we generally describe filters. We also have another thing which is known as special effect filters. We will see them as I said one by one. We will see clear filters, this filters is nothing but a piece of glass which is mounted in front of the camera and thereby protecting the lens. On the other hand we have ultraviolet filters. These filters, they cut out the ultraviolet rays or the haze from the environment and give a better picture or a slicker picture. A UV filter passes all or most of the visual spectrum and blocks ultra violet radiation. Sometimes, what we do is we leave this lens of this filter on the lens thereby protecting it at the same time always cutting out the ultraviolet light entering the film. In the case of digital cameras this filters help in cutting out purple fringing which is one of the defects that occurs in the case of shooting with the digital SLR. Let us discuss little more about the ultraviolet or the clear filters. The advantages are if the lens is drop the filter may suffer scratches or damages instead of the front element, the filter can be cleaned at the same time the lens remains intact. Suppose we are shooting in the desert, then the sand which is blowing around us does not reach the lens and thereby protecting it from scratches. Sand is something which causes maximum damage to any electronic or any mechanical equipment. The disadvantages could be that it comes in the way of light, thereby may be reduces a light a bit or at times adding UV filter or a clear filter may sometimes be considered to be causing reduction in the quality of an image or at times it can be possible that the lens hood which we fit on to the lens may not fit properly because the filters extends beyond the lens. Thirdly it is
said that it can cause sometimes a flair because of the reflection and multiple reflections within the filters. The filter here is color balancing. Now if we have as I said earlier on tungsten film the temperature of which is 3200K, we can enhance the color temperature and bring it to 5500K by using a blue filter, similarly on the other hand if we have a film which is balanced for daylight but we want to have the effect of reduce temperature then we have a filter which can be used to bring down the temperature and we can get the color or the results which looks normal to the eye. In monochrome or black & white photography colored filters are more effective. For example if you want to change the color of the sky from light blue to darker blue or to a little darker then we use an orange filter. If we use the red filter then the entire sky will become black, similarly if we have a deep green filters than the sky will become darker but the trees that are there in the surrounding will become almost white giving you beautiful contrast. Therefore in black & white photography color filter plays a very important role, they can give you result as per your desire or at the same time as per your creativity. On the other hand a blue filters will convert the sky into pure white and if there are any clouds so they will be eliminated. One of the most important and most widely used filter, which can be used both for blacks & white and also for color photography is known as polarizer. A polarizer can be round it can be square it can be any shape that I have already mentioned. The point to note is that polarizer cuts out the light from a particular direction say from the right hand side or from the left hand side up to 90 degrees and beyond also but the effects is just the reverse of as it is in the case of less than 90 degree. The point to note is that it cuts out reflection for example you are shooting a surface which contains water and the reflection of water is not coming proper there is shimmering effect than a polarizer will cut out shimmering and will give you a beautiful reflection of the say sky or the mountains or the landscape in a in the water. Polarizer can also darken the sky or lighten the sky because as we move it at an angle the effect keeps on varying and when you get the desired effects you start shooting. Next we have the neutral density filters. These are plain pieces of say filters which are of grey color. Their purpose is to cut out the extra light which is coming on to the film. Suppose for example you want a very shallow depth of field but you have a great amount of light then this filter will come in handy to reduce the light coming in thereby you increase the aperture i.e. the iris and you get a shallow depth of the field. Another thing with the ND filters is that ND
filters also come in a graduated form that is to say the light is very strong on the upper half that can be cut down while at the lower end the light is less, and thus you can balance the pictures. These are known as graduate neutral density filters. Another categories of filters is known as the star filters or cross screen filters you must have seen some night shot where every light that is there looks like a star it can single cross it can be double cross it can three times cross it can have eight ends but they all are created using a star filters it s very creative and anyone who knows how to use this filters can add drama to the picture. Then we have diffusion filter. It is also called softening filter. With this you can create a dreamy effect and is particularly used for models where you want the models to be almost looking like dreaming and this kind of pictures are mostly taken in the case of females. What really happens is that the two lines which may otherwise look very distinct, they merge into in each other thereby creating a flow in the pictures. You can create diffusion filters at home also by taking a clear filter and by smudging it with the Vaseline or with a cream which does not show very clearly on to the filter. This will give the same effect as you get in the case of a diffusion filter the amount of diffusion that you want depends upon you. You can accordingly smudge the filter with the cream. Next we have is the close ups filters this filters enables you go closer to the subject and thereby take a close shot of the subject this come in various sizes and various diaopters for example here is one which I have loaded on to this camera and there is another one which can take me even closer to the subject thereby giving me a larger magnification however my personal experience is that they are not very useful and they do not come out with the results which one requires when it comes to taking close-ups. I prefer to use other material for example macro lenses for example even extension tubes to go closer to the subject. One of the major disadvantages in my opinion is that it offers very-very shallow depth of field. As you can see filters come in various sizes and they can be fitted on to the various cameras by virtue of the arrangement that are made with that here for example I will show you how a square or cocking filter can be loaded on or can be mounted on to a the 52mm Nikon lens, for which I have already have a filter which fits in here but suppose I want another filter to be used on this then I have a arrangements here I can first mount this then now we have this arrangement on this I can fit any of these lenses or the filters and take the pictures according to my choice, this filter is available to me I can use this filter and take the picture the second
is that I can remove this filter and put a blue filter it s much easier than every time removing the circular filter and putting another circular filter and another thing which I find is very we can put a circular polarizer for which special window is made here this polarizer fits in here and it can be moved to get the right kind of reflection or the colors or the sky and the angle at which we want this is one of the best arrangement I have found as per the use of these filters is concerned. Filter size is one of the important factors when it comes to manufacturing equipment or for that matter buying equipment. For example, Nikon have tried a lot to bring you the filter size of 52mm, therefore all the lenses or the filters that I have are of 52mm size and it and I don t have to run around for a new filter every time. For example, I have a filter here. This filter is much bigger than 52mm. It s a soft filter but I use it for another camera I don t use it for Nikon. Though mind you I can arrange this even on another filter by having some kind of arrangements or some kind of system which gives me extra diameter but it has its own disadvantages. In all cameras at some stage or the others you have to have more than filter for this I think Cokin filters are the best. Whereby you just need another adjustment and that s all you can put them on to any camera and use the filters. The same set of filters can be used for different cameras by changing only one arrangement. Filters add extra effects or abilities to the working of a camera system. Understanding how filters work is very important in order to get the kind of results that you want. In the case of ultra violet filters one should not go and for the cheaper variety of filters, because they play very important role besides protecting the lens one should buy a good quality ultra violet filters so that they may be used both creativity at the same time protect your lens from scratches or other disabilities which can occur. Lens hood Lens hood is very important accessory as far taking a picture is concerned. It cuts out the flare but when you over do a lens hood then it can cause a defect which is known as vignetting. Therefore, for different kinds of lenses we have different kinds of lens hoods. For example this is a lens hood which I used for a 28mm lens but if I use it on a 20mm lens it will cause vignetting. It will in fact come in the way of my picture and cut my picture. and I will show you a picture of this kind, similarly if I take a 28mm lens and use this hood than it is serving no purpose because it is covering much wider than what is expected, therefore it is
serving no purpose. Because it is it is covering much wider than what is expected, therefore it has no purpose. Similarly we have lens hoods which are built in, like this one, this is a telephoto lens and it has a built in lens hood. Now this lens hood doesn t require anything extra and it is perfect and it is made for this. It will never cause any problem. Similarly for this lens that I have got the lens hood is built in. It has given to me as a separate item I can fix it here and use it. So it will protect my camera, my film, my photograph from flare effect. This is yet another kind of lens hood which is used with 80 to 100mm lens which I have got. Therefore lens hoods are very important, they come in various sizes they give different results. The basic purpose of lens hood is to cut out flare. If we have a narrow lens hood or and a wide lens hood it is preferable that we use the wider one because it might give you the desired result but the one which is narrower view, it is definitely going to affect your picture. Conclusion To conclude today we saw some of the important accessories which are available for making your picture more creative. Make it more useful; make it as per your choice. The advantages and disadvantages have been discussed. Just to sum it up for example we have the filters which can particularly in the case of monochrome or black & white pictures can give dramatic effects. You also have polarizer which can be used for both color and black & white photography. Then we have other filters like ND filters and so on. We also have the lens hoods as accessories which helps us to cut out the flair. That s all is we have for you today thank you.