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Thread: speed.

  1. #1
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    mark rawlings

    speed.

    ferst i must say sorry for the speling,
    Hi i have a problem whith taking birds in flight ,i have a d7 and use a sigma 135-400mm
    set in m @1/750 f5.6 spot merering. cusom setings(ai servo focus in ai sevo/mf and ai tracking sensitivity +1).
    but it still has problems loking on to flight can eny one help plees.
    yours mark

  2. #2

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    Russell

    Re: speed.


  3. #3
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    Re: speed.

    Maybe I missed it but he didn't address focus?

  4. #4

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    Re: speed.

    Firstly, Mark, 1/750 is a bit slow for many flying birds, particularly anything with fast flapping wings.

    I wouldn't really want to go slower than 1/1000 for gliding birds and preferably twice that, or faster, for anything with medium speed wing beats. Which can cause you problems in poor light. Increasing the ISO can help to achieve better results.

    AI Servo is usually good for obtaining and holding focus but you may still have difficulty focusing where there is a lack of sharp contrast between the bird and background.

    Personally, I would consider using manual settings a bit risky for many conditions. Using shutter priority may give better results. But having said that, if the conditions are stable and you can take a few test exposures beforehand, then manual can avoid some false exposure problems caused by a dark bird against a bright background etc.

    The alternative is to use a bit of exposure compensation.

    Finally, what focus points are you using? I often find that just using a centre point can reduce false focus problems. But it can be difficult to pan the camera while keeping that focus point locked onto the moving bird while waiting for the best moment to press the shutter.

  5. #5
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    Re: speed.

    Our Canon 7d cameras have excellent autofocus capabilities but, I am not familiar with the A/F capability of your Sigma 135-400mm lens. Autofocus is a capability shared jointly between camera and lens.

    Perhaps you might do a google search with "Sigma 134-400mm autofocus" as the search parameters...

    Here is a tutorial which may be of some help...

    BIRDS IN FLIGHT
    A TUTORIAL BY:
    Jim Nieger – Kissimmee Florida
    Photographing Birds in Flight #1 - Exposure
    ________________________________________
    I am a full time professional bird photographer. I specialize in birds in flight. I make most of my living conducting workshops where I teach other photographers how to photograph birds in flight. One of the keys to successfully photographing birds in flight is to be able to make consistently correct exposures. There are usually no second chances, so getting exposure correct is critical.

    Manual Exposure Mode:
    The first thing to learn is to use manual exposure mode. Manual exposure mode is virtually a requirement when photographing birds in flight. The reason for this is the likelihood of changing backgrounds. If you use any of the automatic exposure modes, the camera will decide an exposure for you. When a bird flies across changing backgrounds, the camera may calculate a different exposure for each frame depending on the background. If the bird is in the same light all during the flight, then we want the one correct exposure for the bird, not a bunch of different exposures all but one of which will be wrong. The only way to achieve this is to use manual exposure mode.

    Substitute metering method:
    To arrive at a correct exposure I use a method I developed that I refer to as substitute metering. By substitute metering I mean using something other than the subject to meter on. I don't usually meter on the subject bird because the subject bird is often not present at the time I am determining the exposure. Instead, I use a constant in the environment. Something that is almost always readily available. In Florida I use bright green vegetation that is almost always present. When I was in Alaska in winter, I used snow. The important thing is that it is readily available and something you are familiar with. The first step is to fill the frame with the constant in the same light that you anticipate your subject being in. I usually choose constant that is in direct light. (In the direction my shadow is pointing) Then I adjust my settings so that the meter scale reads zero while filling the frame with the constant. I use full frame EV metering so that my reading is not thrown off too much by small areas of shadow or bright highlight within the constant. It's too easy to hit a dark or bright spot with spot metering, so I don't use it. Step 2 is to compare the constant to the subject. This is a two part process. The first part is common sense. Determine if the subject is darker or lighter than the constant. This tells you if you need to increase or decrease your exposure. If the subject is darker, you need to increase exposure. If the subject is brighter, then you need to decrease exposure. The second part is to determine how much to increase or decrease exposure. This part is based on experience. If you do not have a relevant experience to call on, then you must guess. After you guess and make an exposure you can evaluate how you have done and then adjust if needed. This is how you build experiences to draw on in the future. Try to remember your experiences. This is sort of like keeping a database in your head. After doing this for a while, you will have enough experience to know how much to increase or decrease your exposure in pretty much any situation. One thing to consider is the intensity of the light and its effect on exposure. For example: If you use a middle tone green vegetation as a constant and you want to photograph a white Great Egret, common sense tells us that we need to decrease our exposure to avoid blowing out the white egret. We need to draw on experience to determine how much to decrease exposure. If it’s just after sunrise and the light is very soft, the amount to decrease exposure may be only 1/3 of a stop. If we photograph the same bird at high noon, the amount we need to decrease exposure by will likely be as much as 2 stops. You can see from the example how much the intensity of the light can impact compensation amounts. Once you have built a solid database of experiences in your head and you have become consistent in getting correct exposures, you can easily do things like adjust exposure quickly on the fly when the subject or light changes. This can be done by counting clicks on the adjustment wheels and without repeating the metering process.

    I hope this helps people get started using manual exposure mode for photographing birds in flight. I use manual mode about 99% of the time. There are many benefits of using manual mode. Manual mode will make you a better photographer in many ways, but it all revolves around increasing your understanding of light and its effect on your photography.

    Photographing Birds in Flight #2 - Settings
    ________________________________________
    The camera settings below are designed specifically for bird photography using long lenses (400mm or more) and hand held technique. The settings were designed to allow all types of bird photography without sacrificing anything and without having to change settings other than exposure while in the field. This means I can always be ready for any situation without having to waste time adjusting camera settings. These settings are for a Canon 1D Mark IV, but there are equivalent settings in most camera bodies.

    Camera Settings:

    1. Manual exposure mode. This is almost a requirement for BIF when you have changing backgrounds. There are many other reasons as well. See Part 1 of the tutorial.

    2. AI Servo AF - To allow AF tracking of moving subjects.

    3. High speed continuous drive. This allows me to shoot in controlled bursts to capture the peak action shots.

    4. Center AF point only for BIF against very busy and or close varied bgs. Center AF point plus surrounding AF point expansion for BIF against distant varied bgs or BIF against smooth sky or water backgrounds. When a variety of backgrounds are possible, I use center AF point only.

    5. Tracking sensitivity set to SLOW. This should be used with bump focus technique. I will discuss this in part 3 of this tutorial.

    6. * button set to AF Lock. I use this when shooting still subjects. It allows me to remain in AI Servo AF and center AF point, but still be able to compose images of still subjects in camera. This way I am always ready for action without compromising my ability to compose images of perched birds. I use the shutter button to focus.

    7. Contrast set to -2 - this only affects the jpeg used in the camera display. It does not affect the RAW file. This allows you to expose to the right a little tighter. It doesn't affect the RAW file, but does affect the decisions we make about exposure that are based on the LCD image, histogram, and flashing highlight alerts.

    Lens Settings:
    1. Lens focus limiter switch set to the longest near focus distance. This helps speed up AF in many situations.

    2. IS ON - Mode 2

    Photographing Birds in Flight #3 - Acquisition Skill
    ________________________________________
    Here is what I teach people in my workshops to do to develop a skill that I call Initial Acquisition Skill. By Initial Acquisition Skill I mean putting the bif in the center of the view finder and then focusing on it for the first time.

    First of all look at the subject. There is a straight line of sight between your eye and the subject. While you are looking at the subject, quickly pop your camera and lens up to your eye in shooting position, and do it so that the imaginary line running from the camera sensor down the middle of the lens barrel lines up with your line of sight to the subject. Make sure you are looking at the subject when you try this. With practice, you can put the bird right in the middle of the view finder every time. Start praticing with static subjects and work your way up to small fast moving subjects. It is possible to get to the point where you can go from a rest position to focused on a bif almost instantly. It takes lots of practice though and the difficulty increases with focal length. If you pre-focus at a similar distance the camera will focus quicker than if you are pre-focused at a very different distance than the subject.

    How to Photograph Birds in Flight #4 - Tracking
    ________________________________________
    After I initially acquire the flying bird (see tutorial #3), I begin tracking and possibly photographing the bird. While tracking the bird I use a technique I call "bumping the focus".

    Bump Focus Technique: To quickly focus or let off and refocus. There are three uses for the bump focus technique:

    2. When I am tracking a BIF against a varied bg and I miss and focus on the bg I will bump the focus to quickly return focus to the bird. Bumping the focus overrides the delay set by the tracking sensitivity custom function. I set tracking sensitivity to slow to get the longest delay possible. This helps when you are focused on the bird and want to avoid focusing on the bg, but it hurts when focused on the bg and you want to return focus to the bird. Bumping the focus overrides the delay allowing you to use the long delay when it helps and override the delay entirely when it would hurt, thus getting the best of both worlds.

    2. This is the most important use of the bump technique. Most photogs will aquire focus on a bif and then try to continously maintain foucs while they are tracking and watching the bif in the viewfinder. They tend to focus continuosly waiting for the moment they wish to make a photograph. Often while watching, tracking, and waiting for the moment, the photographer will miss and focus on the bg. This is extremely easy to do when the bif is flying against a varied bg. This is the reason it is so much more difficult to photograph BIF against a varied bg as opposed to smooth sky bg. When the focus grabs the bg, then the photographer needs to re-aquire focus on the bif. This may take too much time causing the photog to miss the critical moment. I try to avoid this by only focusing on the BIF when I'm sure I'm on target and during the critical moments when I'm actualy making images. So, what I will typicaly do is aquire the bif initialy and focus on it. Then I will let off the focus and just watch it in the viewfinder while tracking it visualy only. As the distance changes, the BIF will start to go out of focus. When that happens I bring it back in focus by quickly making sure the AF point is on the bird and then I bump the focus to get it in focus again. I do this repeatedly as I'm visualy tracking the bird. When the BIF gets to the spot I want to start making pictures, I will focus and shoot all at once. I shoot in short controlled bursts trying to time the critical moments with the best wing positions, etc. Because I have bumped the focus along, the focus is very close to where it needs to be when the moment to make pictures arrives. Then when I focus and trip the shutter it happens very quickly. If I tried to focus constantly while the bif approached I would likely miss, focus on the bg, and miss the critical moment. My goal is to keep the bird close to in focus and in the viewfinder without focusing on the bg and to do this up until the critical moment arrives. Then I try to maintain the focus while making great pictures. Bumping takes lots of practice, but if you develop this skill, it will make your keeper rate go way up.

    3. The third reason to bump the focus is to prefocus. The first task when photographing a BIF is to aquire it in the viewfinder and focus on it. (see tutorial #3) It is beneficial to be able to do this as quickly as possible. When using long focal lengths, the bird may be so out of focus that you can't see it in the viewfinder even if it's there. Then when you do get it in the viewfinder it may take much longer to focus on it if the focus is set to a drastically different distance. To overcome these issues, I will prefocus at the approximate distance that I anticipate for my subject. Then when the subject arrives, I can find it and focus on it quickly. I prefocus the camera by pointing the camera at something at the desired distance and then I focus on it. Now I'm ready for a BIF at a similar distance. If I need to switch the distance I will simply point the camera at something at the new distance and bump the focus. This will prefocus the camera at the new distance. Photogs that use a tripod will often prefocus manualy. Since manual focus is difficult hand held with big glass, I use the bump to prefocus.

  6. #6
    herbert's Avatar
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    Re: speed.

    Here is another good tutorial for you to look at:

    Photographing Birds in Flight

    Alex

  7. #7
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    Re: speed.

    Are you panning your shot?

  8. #8
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    Re: speed.

    I had some time tonight, so I did a google search regarding the 80-400mm Sigma.

    http://www.the-digital-picture.com/R...ns-Review.aspx
    "Focusing with the Sigma 80-400mm f/4.5-5.6 EX DG OS Lens is audible (but not real loud) and very slow. Focus accuracy and my AF hit rate are somewhat lower than I'd like to see, but not bad. This lens will struggle if action sports are its target."

    http://www.photozone.de/Reviews/327-...report--review
    "Unfortunately the conventional AF motor is rather noisy and slow - certainly not comparable to the Canon EF 100-400L USM IS (nor is the Nikkor)."

    Other reviews by owners of this lens seem to echo the above Digitalpicture and Photozone comments regarding focus speed...

  9. #9
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    mark rawlings

    Re: speed.

    thank will do

  10. #10
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    Re: speed.

    Geoff F
    thank for respons i am yousing senter focall pount, i will triy bumping speed up allthowe i triy not to go hiyer then 800 iso, as we hunt in the erly morning of late arternoon thats not ezy but houw sed folkenry or photography was.

  11. #11
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    Re: speed.

    To Richard (rpcrowe)
    Wow, that's an exceptionally useful tutorial on photographing BIF. Clearly written from your own experience and invaluable for people like myself who are struggling with BIF for the very reasons you mention.
    Thank you very much indeed for the time and effort you put into it.

    Best Regards, Mike

  12. #12
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    Re: speed.

    Mike...

    The tutorial was prepared and presented by Jim Nieger of Kissimmee Florida. He is the one that should get the credit for the well done tutorial, not I...

    Jim is an extremely talented nature photographer who is generous in sharing his expertise with us. Jim's website is located at: http://www.naturescapes.net/portfoli....php?cat=10584

    Richard

  13. #13
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    Re: speed.

    Quote Originally Posted by rpcrowe View Post
    Mike...

    The tutorial was prepared and presented by Jim Nieger of Kissimmee Florida. He is the one that should get the credit for the well done tutorial, not I...

    Richard
    Oops, I obviously didn't look carefully. Credit to Jim then for the tutorial, but some reserved for you for posting it, otherwise I'd probably have never come across it. Thanks for the link to Jim's website too.

    Regards, Mike

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