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Fotographing Phlies

Discussion in 'Photography Forum' started by Nicepix, Apr 5, 2008.

  1. Nicepix

    Nicepix New Member

    Here's an article I did for a fly-fishing forum. It might help you understand your camera a little better.

    Macro photography is one of the hardest things for a photographer to get right. The advent of digicams has meant that everyone now has a macro function on their cameras. Previously with film cameras macro photography was the playground of those with specialist equipment. Good news for all, except that the macro function on your digicams comes with severe limitations.

    The first thing to remember is that your camera does not record a scene like you do. Your eyes adjust to light and dark and colour casts without you even realising it in many cases. Cameras cannot do this and this is the main reason why people are often disappointed with their photographs. The nice ladies in Boot's have machines that rescues millions of photographs a year, but even these cannot work miracles.

    A long time ago a scientist worked out that in an average scene if you converted it to black and white and put all the tones in a blender the final result would be a grey tone equivalent to 18% black in 82% white. Every camera's exposure system is based on this average. Obviously, not every scene is average. That is why when you take a snow scene or beach and sea photo the image comes out dark. The camera has tried to adjust your bright scene to fit the 18% grey model. If you want to see an example try photographing a white piece of paper. Your camera will record it like this:-

    [​IMG]

    If you photograph something entirely black like my canvas briefcase, it will come out like this:-

    [​IMG]

    The camera has tried to make your extremes of tone fit the average 18% grey. This ishow it looks putting them together.

    [​IMG]

    The easiest way to ensure a correct exposure is to use a mid - toned background and select the multi zone or centre weighted exposure setting, not the spot meter setting as that is more likely to be affected by small areas of light or dark tones. Once you have got your neutral background in place take a photo and watch the histogram on your viewfinder or display. The hump should be central - too far to the left and the photo will be too dark, too far to the right and it will be too light. Here the hump is slightly to the left (dark) and the exposure adjustment is -1/3.

    [​IMG]


    By altering the exposure adjustment to 0 or +1/3 the hump will be more central and the photo should be correctly exposed.

    As well as light and dark there are colour casts that can throw your camera out. Sunlight is a different colour to shade and tungsten light is not the same as flash or halogen. Each has its own colour cast so you need to take this into account. The colour cast will also depend on your room. The paintwork on walls will reflect in the overall colour cast of the scene. You can't see it, but it will show up in your photos.
    Many cameras have a White Balance selection. For indoor work I use the Custom Setting where I can set the camera to suit the light. It is simple to do, just put a piece of white A4 paper where you vice is and set the custom colour balance by aiming your camera at the paper.

    One of the unyielding rules of photography is that the more you magnify an image the less of the image front to back, is in focus. On a SLR camera you can manually adjust the aperture to give one more appropriate to macro photography. On a digicam you are fixed with a relatively wide aperture which minimises the depth of field, or area of acceptable focus in front of and behind the point where the autofocus has settled. With macro photography the zone of acceptable focus might only be a few millimetres either side of your point of focus. The closer you get, the less the depth of field.

    [​IMG]


    Here the camera has set focus on the area around the hook bend. As you get further away from this point the less in-focus he fly is. A pro photographer can 'stop down' his lens to give more depth of field.

    [​IMG]


    You can't do this with a digicam so you have to employ lateral thinking. These photos as displayed on the screen are 640 x 480 pixels. The original size of these images is 2560 x 1920 pixels. The image on the screen has been re-sized to about 1/4 of the original 5 Mp image to prevent it from spilling off the screen. If you were to back off and take the photo from four times the distance away you would have four times the depth of field and your fly would look sharper.

    Here's what I mean. Moving the camera back, this is the whole shot re-sized to 640 x 480 pixels:-

    [​IMG]


    I then crop the middle bit using an image manipulation program, in this case Adobe Elements, to give a finished image of the same size. Providing that your fly is central in the photo, just go into Image>Resize>Canvas Size and select a manageable size like 600 x 400 pixels. If you get it wrong hit Control + Z to re-instate the image and use the cropping tool to cut out the unnecessary background.

    [​IMG]


    You can see that there is more of the fly in focus than the very first shot of this sequence yet the camera setting have remained unchanged. All I have done is increase the distance between the camera and fly then cropped the final image rather than re-sizing it to fit the screen.

    The Macro setting differs on various cameras. On mine the camera will not focus on a close up object unless I use the Macro setting. These two photos show what happens. Both were taken from the same point with 'Spot Focus' selected and aimed at the hook shank. In the first one when the camera setting was on Normal Picture Mode the focus point has ignored the fly and set focus on the background. On the second photo when Macro Mode was selected the focus has picked up the fly and set focus on it.

    [​IMG]


    [​IMG]


    There are other advantages of backing off too. Along with the decrease in depth of field you also have a greater risk of camera shake when you magnify an image. Backing off reduces this significantly.
    The tripod is only of use when light levels fall to the extent when the shutter speed is too long for hand held photography. Taking the image from further back alleviates the problem a lot, as does flash or artificial lighting.
    The reason I don't advocate using tungsten lighting is that it must be used as the sole light source. You can't mix it with flash or daylight. Also, it has other downsides such as heat generation.

    Flash is ideal because the brief burst fixes the image onto the sensor. The flip side is that the camera may calculate the flash exposure on the background and over expose the fly.

    If you brace your elbows on a firm surface like a table and gently squeeze the shutter button you will reduce the chances of camera shake.
    My own camera has an image stabilisation system to prevent camera shake in low light. That was the main reason I bought it.

    [​IMG]


    [​IMG]


    [​IMG]


    You can also safely employ flash from the greater distance. If you do use flash you might have to re-adjust your exposure compensation as the fly being nearer than the background may result in it being overexposed. Experiment with different compensation settings.

    This is what can happen if you use flash when you are too close. It is overexposed and detail is lost:-

    [​IMG]


    By backing off and then cropping the image you get a much better result:-

    [​IMG]


    [​IMG]


    The problem with over exposure on flash photos is down to the system on cheaper cameras pumping out the same amount of flash light for every shot irrespective of whether it needs it or not. More expensive models, and here we are talking about £200 plus may measure the amount of light needed and only supply the correct amount of flash. Even then, on a fly shot it might read the exposure from the greater area of background leaving the small fly over exposed. Very expensive SLRs overcome this problem with programmed flash exposure linked to the focus sensors but I don't know of a digicam that does this.

    There are several ways to overcome the digicam's shortfalls in this department.
    You can put some semi-opaque material over the flash to dilute it. This may result in unwelcome colour casts.

    You can reduce your camera's sensitivity - the iso figure. A lower figure will be less sensitive to light and less prone to over exposure. 100 is half as sensitive as 200.

    You can increase the distance between the camera and fly and then use your zoom to reinstate the magnification.

    Here is an over exposed flash shot at iso 200 from about 25cm from the fly.

    [​IMG]


    Here I have reduced the sensitivity setting to iso 80 otherwise it is the same shot.

    [​IMG]


    And here I have moved back to around 70cm, zoomed in and taken the shot using the original iso 200 setting.

    [​IMG]


    If you double the distance between flash and fly the amount of illumination reaching the fly from the flash is reduced to a quarter.

    So, putting it all together:-

    Make sure the appropriate White Balance is selected, Custom for ambient or artificial light, but if you use flash switch the White Balance to Daylight.

    Put a suitable background behind your vice, at least 20cm away, a bit further if you use flash to avoid shadows.

    Take an photo of the background and adjust your exposure compensation to ensure the histogram is central. Be prepared to experiment with the exposure compensation.
    Take your photo from 4 times further away than you would normally do and crop the image to suit.

    Use Spot Focus and aim the focus area at a central point. The hook bend is good.
    These are two identical shots taken with a 5Mp Panasonic digicam. One was taken with flash and the other without flash, but with the exposure compensated, and with the White Balance set using the custom function and a piece of white paper. The background is a 99p fleece hand towel draped over a book around 25cm behind the vice.

    [​IMG]

    The flash photo shows the fly to be slightly lighter in comparison to the background.



    Regards,

    Clive[/quote]
     
  2. Baramundi Bob

    Baramundi Bob Super Leeds United !!!

    Hey nice one Clive. I will have to reread a few times for a lot to sink in but its good stuff. Ive never thought about the background being behind before like that and also the tip of taking the pic from further away and cropping down will be really useful too. Thanks for posting this.
     
  3. mattylamb

    mattylamb Rockling

    that's a brilliant article. thanks very much
     
  4. Nicepix

    Nicepix New Member

    Yes. It's amazing how many times the background is behind something :whistle:

    :laugh:
     
  5. carpyken

    carpyken New Member

    Great article Clive, I messed with marco photography a few years ago to photograph small archaeological finds like coins etc. I still got most the kit, an old 35mm SLR camera, extension tubes (is that what they are called?) and a home made copy stand etc :happy: So much easier these days with digital cameras :happy:
     
  6. Baramundi Bob

    Baramundi Bob Super Leeds United !!!

    How would you do something like this Clive. Is this aperture ?

    [​IMG]
     
  7. Nicepix

    Nicepix New Member

    That sort of shot uses selective focus. Basically, the photographer uses a combination of focal length, camera to subject distance and aperture to make the subjects stand out from the background. The photographer has also selected a subject and viewpoint where there are no distractions behind. If there had been bluebells in the background it would not have worked so well.

    On some SLR cameras you have a depth of field preview button. This allows you to view the scenes as it will appear on film. Nowdays with digital cameras it is as easy to take a shot and view the results on screen.

    If you wanted to replicate that shot with your camera you would need to select spot focus and set focus on the centre of the scene. If you were using aperture priority 'A' then I would got for something like f8 or f11. On digicams I would try Landscape Mode and Portait Mode and see which gives the best result.

    As Ken says, with film cameras it was much harder. You had to squint down the viewfinder with the d of f button depressed and hope it turned out OK after developing. Digital makes it so much easier, not just because you can see results immediately, but the digital cameras can do macro better due to their smaller sensors compared to film formats.

    These two shots show selective focus. In the first I wanted the sporidia to stand out from the background. In the second I wanted my old dog Jet to be recognisable in the background behind his replacement Jaf.

    [​IMG] [​IMG]
     

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