Focus on running dogs with D90 using Tamron 18-270 Lens

Discussion in 'Nikon' started by anne_wolff, Jun 29, 2010.

  1. I have been using the techniques suggested to me previously, but am still having trouble getting my focus on the running dog's head. I swear I do, but then it comes out soft and the grass at his feet is sharp! It's been suggested to me that my Tamron 18-270 lens is just too heavy to use hand held and I should try a 55-200 lens. I'm going to try to borrow one and wanted to know what you all think. I do admit that although I manage to get a "fairly" sharp shot sometimes, it's hard to hold steady. Yes, I have been practicing for hours, whenever there are dogs at the park, but I'm still repeating something I'm unaware of. Even shooting at 2000 F6.3 they're not sharp. Even though I'm careful not to press the shutter 1/2 way down until its on the dog's head, somehow its picking the grass or trees to focus on first.
    As alway, I'm very appreciative of any help anyone can give me. Thanks
    00WlZf-255425684.jpg
     
  2. That Tamron lens is probably not going to focus great at the long end since it's slower than the slowest aperture Nikon recommends for it's AF systems. Which focus mode are you using again?
     
  3. Are you doing this in the shade or late afternoons, say after working hours?
     
  4. Sorry , I forgot metadata. This was shot at 10:00 a.m. Shutter priority, 1000, F-10, ISO 640, focal length 270, AF-C, Dynamic, Normal. This was taken before I started setting shutter to 2000. I have gotten a lot of very sharp images with this lens at various lengths, and even some at 270, but I can have a whole morning with very little, and would like to see some improvement. Drives me crazy that sometimes I can do it and sometimes I can't. The most important thing that bothers me is I think I'm centering focal point (rectangle in viewfinder) on head but apparantly somehow focus on grass. Still don't know if I'm not holding camera steady enough or prefocusing on grass before I even get focused on dog! I even cut down to 1/2 cup of coffee! Thanks
     
  5. Anne,
    This image is reminicent of the one you posted previously. The plane of focus is way behind the head here, much more around the right rear leg. I agree with Peter Hamm, min. aperture of f/6.3 might be pushing the limits of the camera's AF capabilities and f/10 is way too tight as it appears the dog has well and truly over shot your intended focal point in this image. This should in theory be an easier shot to nail down as the dog's head is not moving swiftly from one side of the frame to the other but coming on straight down the barrel thus the point of focus should be more or less static ie: no requirement for rapid cross frame tracking.
    I'd have to say it's either a back focus issue with the lens or an auto focus lag issue. Because the plane of focus captured is so far back on the dog here the head is badly out of focus. However, to look at the in focus portions of the dog appear a tad crisper than your previous posted image so I'd say you have the camera steady enough for this shot.
     
  6. Also, that dog is running right at the camera. VERY hard to keep up with that.
     
  7. Matthew, I'm confused. I just looked at it again at 100% and the grass is very blurred behind the head and is Very sharp by his feet. Wouldn't this be sharp if I was able to focus on his eyes and not the grass? And what should my f-stop be? I know it will be much wider when my shutter is 1600 or 2000. Also, the reason for suggesting a lighter lens is that when trying to focus on a thin pole, my rectangle in viewfinder wiggled and the more I tried to hold still with elbows in etc, it still wavered around.
    Thanks
     
  8. Peter - I have found when I'm shooting birds in flight that I can capture them easier when they fly right down the barrel of my lens ie: head on but I'm using different body and lenses so my obs. might be irrelevant on this point. I struggle more with subject matter that swoop rapidly across the frame but again that may be me and my ability to pan horizontally....
    Anne - you must understand that the camera is not specifically focusing on the grass per se. It's focusing on a given plane of focus - and dependant upon aperture and focal length a certain amount of space in front of the focal plane and a certain amount of space behind the focal plane will appear to be in acceptable focus. I think the problem your camera/lens combo is having is that the camera is focusing upon a given point but by the time the shutter has tripped, the dog has moved forwards so much that the original desired focal point is now way down along it's body hence the rear right leg (and the grass alongside that leg) is in focus.
    If I were repeating your exercise I'd be trying to get the shutter to trip as fast as possible. At the distance you are working from and the shutter speeds you require to freeze the dogs in action you need to use a larger aperture (f/6.3 is as wide as your lens opens at full zoom) and boost your ISO to 800, 1250 or higher to try to snap the action nice and crisp and still. As Peter points out, your current lens only opens as wide as f/6.3 at the long end of it's zoom which is beyond the minimum f/5.6 Nikon recommends for it's camera's auto focusing systems to perform best at.. In an ideal world you would want to shoot with a 200mm lens which has a much larger aperture like f/2.8, that lets much more light into the camera's auto focusing system and assists it greatly to track fast moving subject matter like your dogs.
    As for your thin pole anecdote, I'm quite sure what you mean here, I'm guessing you have your camera set to AF-C and the focus points are jumping around? AF-C is best for moving subjects, for stationary subjects use AF-S or M.
     
  9. Hi Anne,
    Just some more tips that could help :
    - Kneel down, lower your 'Eyepoint " to the dogs "Eyepoint"so that you get the dog straight in the face. This makes it easier to focus on the dogs face instead of the area around the animal.
    - And if possible use only "Center Focus" ( one focuspoint) for animals running towards you, or away from you, and multiple focus points for "Focus Tracking" for animals running past you ( is there a good english word for that ? ) .
    - If shooting from a lower angle you can ( depending on camera-type) set up for trip focuss, where you allow your camera only take the shot the moment something is in focus ... ( there are several techniques to be found on the internet for that..).
     
  10. I would suggest you use a monopod and perhaps shooting at f12 for f14 to gain a little more DOF to compensate for focus error. All cameras have trouble focusing and keeping up with the correct focus when an object is moving quickly towards or away from a camera (although some obviously do it better than others). You will get better results if you position yourself on an angle to the dogs although their movement is obviously hard to predict.
    You are probably best off using the center focus point as your primary one and keep that point on the subject's face as best as possible as it moves.
     
  11. I will second CPM's advice to consider changing your angle of view. As I mentioned in an earlier thread, Anne, I spend a fair amount of time photographing running dogs (usually coming right at me, or at a diagnoal across the frame). I do almost all of that shooting while sitting or lying on the ground. This is also why I have clothing/gear just for that use! Even so, it's why my particular choice of subject matter also means I get a lot of ticks, poison ivy, and spider bites. Art = suffering, and whatnot!

    But in practical terms, a lower point of view will sometimes help a great deal by greatly increasing the difference between the subject (the dog) and the background. As you look down on the dog, the surrounding grass and other cover is very prominent, and easy for the AF system to latch onto. When the things behind the dogs head are actually trees that are fifty yards away, it's easier for the AF system to make the distinction.

    The downside to that, of course, is that you'll often end up with distracting elements in the background (houses, fences, power lines, and other annoying things). This is where you have to find the aperture sweet spot - where you open up enough to throw the background pleasingly out of focus, while staying stopped down enough to keep Fido's head in reasonable focus as he moves towards you. I've found that if I have to do a little cloning in post production - to remove those power lines, for example - it's easier if that background is nicely out of focus.

    As pointed out above: try to keep your focal length short enough, with that lens, to allow f/5.6 (don't zoom so far that f/6.3 is your max aperture). Even if you'll be exposing at f/8, the AF system is working with the lens wide open before you shoot. If that's as slow as f/6.3 because of the lens's physics, you're definitely cutting down on your AF system's agility.
     
  12. some very good suggestions/tips.
    i would just add that not only is the min. 6.3 aperture working against you here, but also the lens' focusing motor. micromotors such as the 18-270 has are just not that fast, especially at longer focal lengths. an AF-S nikon or HSM sigma would be much faster. perhaps you can rent or borrow a 55-200, 18-200 or 70-300 nikkor and see if you get better results with that. undoubtedly, it is possible to get acceptable results with your current lens, but as you have already found out, it can be an exercise in frustration. one other thing you might want to try is focusing with the AF-on button instead of the shutter. this might make following action a bit easier. i would also use CW metering, not matrix, along with the center focus point.
     
  13. Thanks for all your suggestions. I think I was kneeling down for this shot, since I do for almost all. I abhor shots looking down on dogs, and am thinking of getting knee pads since my knees have been ground into little stones on beach, etc.
    Anyway, I hate to be dense here, but CPM - when you said to use Center Focus (one focus point) did you mean Dynamic? Then when you said use Multiple focus points of "Focus Tracking" for dogs running past me, did you mean 3-D Tracking? I have tried that but the rectangle dissapears in my viewfinder when the dog is running and I don't know if I'm focusing on the head the whole time. Usually everything is very out of focus!
    Eric, I just changed to Center Weight Metering, so I'll see how that goes. What did you mean by "try focusing with the AF-on button instead of the shutter"? Did you mean in AF Area Mode, change from Dynamic to Auto Area?
    Thanks
     
  14. look on the back of your camera; at the top there is a button for AE-L/AF-L. this is the Auto Focus-lock button, which can be configured for AF Lock or Auto Exposure lock. i think this is custom setting F4 in your in-camera menu. what you want to do is set the button for AF-ON.
    basically, this button locks focus when pressed. and unlocks when you take your finger off it. what this means is that you no longer have to half-press the shutter button to fire; just use AF-ON to focus--look for the green focus confirmation dot--recompose in the viewfinder, and fire away when you want to shoot.
    in theory this does the same thing as the shutter button. in practice, this works great with moving subjects, especially in AF-C mode. it's a little bit faster than using the shutter button to focus and shoot, allows for easy focus/recompose while tracking subject movement, and means that once you've acquired a target, you can keep shooting all the way through the action sequence without refocusing every time, as long as you have buffer space. basically, this is how you want to shoot action; try it and see if you dont come up with more keepers. it takes a while to get used to using the button to focus and not the shutter, but it's a nice little feature to have once you figure out how to do it. you can also use the custom setting to reconfigure the button for AE hold or AE lock, as well as AF-lock (which stays on, even when you take your finger off the button, until you hit the button again).
    also, you dont want to use Auto-Area AF for this type of shooting; Dynamic should produce the best results for moving subjects.
    and just to give you some background on CW vs. matrix, matrix evaluates the entire scene and meters accordingly. this can lead to AF confusion if there's not enough contrast between subject and background. with CW, you're putting metering emphasis on the center of the focus area, which tends to highlight your main subject better. basically, you want to use Matrix when you have both light and dark areas in the same shot and/or are shooting still subjects or things that dont move. it's a good general setting. but for action shooting, tweaking the metering to favor the subject a bit can result in more AF accuracy, because you're not telling the camera to meter for the whole scene, just your intended point of focus.
     
  15. Thanks Eric, I will try everything you suggested. I very much appreciate the time and effort you and everyone else have given me. I am still very serious about doing pet photography professionally and intend to do everything I can to learn and practice.
    So, I thought I would just show you two pictures that I am actually very pleased with. They have been sharpened but not by much. Also, I checked all of my best images and almost all were taken at less than 110mm. The odd thing about these images was I took them a month ago and had the camera set to AF-S instead of AF-C and forgot to turn on the VR the entire morning!
    00WlpW-255623884.jpg
     
  16. Don't know what happened to the white dog. I'll try again!
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  17. Anne,
    Love the shot of the border collie :D You don't happen to shoot in the UK, do you? I'm on a quest to get reference shots for my sketching for huskies, BCs and samoyeds. Anyways, back to the topic.
    Have you tried Trap Focus? I've read about it but never reallly tried it. Google "nikon trap focus" - a fair few hits!
    For me I use AF-On technique, and try to release the shutter when the subject is seemingly in focus in the viewfinder. I also try to stop down to get dof to minimize focusing errors, compensating with a bump to the iso. I recently shot at a flyball demonstration, managed to get a few keepers this way but I had something to focus on first...
    HTHs!
    Alvin
     
  18. I have a D90 and a Tamron 18-270 VC. I like them both very much but the Tamron is not a very fast focusing lens. Try not zooming all the way to 270mm. At shorter focal lengths you'll be focusing at a faster lens opening and the lens should focus faster. That could be why your best shots are at 110mm.
     

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