F80 - Dynamic Area Focus, need HELP
I actively use F80 for birding since 3 months ago. Still in learning curve. After more than 30 frames on flying bird(small) I noticed that almost all of it is a little bit out of focus.
I was using a combination of Continous Servo mode with Dynamic Area focus. Which according to manual it should be tracking the subject when I locked it using customs function no.11 set to 3.
With the foto results I decided to test it yesterday. The findings is more frustrating, when I locked on the stationery subject and I move the lense with the subject is moving around the 5 auto focus censor, the F80 focus will shift to another backround subject even with the button halfly pressed(which suppose to lock the auto focus). According to manual it will continue to focus and track the moving subject and shifting the focus to another focus sensor to ensure the subject is on the focus all the time. In my case it did not happen.
Can anybody help. Is the technique is wrong or my F80 is not fast enough to track the fying bird. For the info I always use my SIGMA 170-500mm at 500mm end with F8 focal length. According to manual also it is compatible as nikkor D series lense.
#1. "RE: F80 - Dynamic Area Focus, need HELP" | In response to Reply # 0frankie Basic MemberMon 18-Dec-00 10:42 AM
First of all, the system requires good camera technique. Camera movement is not the same as object movement to the camera. You still must track the object you're following. If you shift to "make sure its working" you'll confuse the sensor array.
Also, it wouldn't surprise me one bit if the firmware in the Sigma lense was not properly reporting distance information and that the camera was compensating...
#2. "RE: F80 - Dynamic Area Focus, need HELP" | In response to Reply # 1jnscbl Basic MemberMon 18-Dec-00 11:16 AM
This doesn't sound like a lens problem. If you are tracking a distant flying bird across the sky or background of trees or whatever, and the image of the bird is quite small in the frame, then the autofocus isn't able to lock on. Also at a 500mm focal length, the aperture is at f6.3, which is below the minimum for autofocus to work properly on the Nikon F80, especially at such a long focal length. Try setting the camera to manual focus and pre-focusing on a tree at about the distance the bird will be at. Also, you will need fast film and a 1/500 sec. minimum shutterspeed if you are not using a tripod. All these things apply to any brand of lens, with or without "firmware".---scott
"I am always doing that which I cannot do, in order that I may learn how to do it."
#3. "RE: F80 - Dynamic Area Focus, need HELP" | In response to Reply # 2N80 Charter MemberMon 18-Dec-00 07:31 PM
LAST EDITED ON Dec-18-00 AT 10:32 PM (GMT)
Attempts that I have made on shooting small or distant flying birds have been frustrating too and I sense the biggest problem in my case is that the subject is too small for the autofocus to track. But ALL of the above come into play. I don't think I can fault my auto focus for this. I suspect what one needs is a whole lot of light (for a small aperture for depth of field), proximity, and a fast shutter speed. All can be hard to come by
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#4. "RE: F80 - Dynamic Area Focus, need HELP" | In response to Reply # 3
Thanks alot and I think scott is right. I do take to a consideration about the SIGMA compatibility. In this case I think the size of the subject play a major role in Dynamic area focus. Why? caused I only shoot small bird in particular for the past 3 months, on one type of bird in order to learn anything about it. I got it spot on at around 90%(monopod used) of the time with SIGMA with the exception of flying bird. I can conclude that my F80 is not need to be serviced yet but I will take it for the test on bigger bird such as Kite to check on the technique.
I will post the finding perhaps by early Jan 2001 as the holiday is coming and I will be out of reach for a week or two.
Happy New Year Nikonians.
#5. "RE: F80 - Dynamic Area Focus, need HELP" | In response to Reply # 4timmy Basic MemberSat 06-Jan-01 09:06 AM
I haven't had an opportunity to "test" the N80, but intend to. I can relate to the difficulty of focus, especially of birds in flight. I've used my 8008s with the data back "set" for "focus trap" and auto-focus set to "off" on the camera body. Then, as I "pan" the subject (bird), and I'm holding the shutter release, when the bird is in focus the camera "trips". Of course, the only "area" is the center (on the 8008s), so I have to crop a significant amount from either side to achieve a pleasing composition. With the ability to "change focus area detection" on the N80 (and F5, but I don't have one), I'm looking forward to capturing images.
As an aside so you can appreciate "what focal length do I need", a simple formula of "reduction times focal length equals distance". A subject that is 2 feet (pretty good sized bird's wing span) and I want it to be 1 inch on film means 25 focal lengths. That works out to around 25 feet with a 300mm lens.
#6. "RE: F80 - Dynamic Area Focus, need HELP" | In response to Reply # 5
As promised, I post here my findings from the two weeks of shooting birds in flight. But I could not have it without this forum and guide from fellow nikonians. Thanks in advance.
I would conclude that at first attempt to shoot small bird in flight the problem is that, the size is small where with my 500mm view the bird is just enough to cover the center censor marker. And when it move and twisting around in the air sometime the position would change from wide to thine like you view a peace of paper form above as compared to the side view, where the F80 would not track it. In this instance I could not blame the matrix metering.
End of the second week, I had a change to shoot a kite and the metering is spot on when tracking where I tracked the bird from 3 positions, bottom, 45 degree side and 90 degree side from an elevated position. From 5 frames I got it as sharp and in focus using Continous focus mode. The result which support my conclusion above.
Other birding finding, Always have your camera ready even when you are eating. I missed the change to have a grey eagle while waiting for the mechanic to rescue me on the inter state highway when it flew acrosed on top of my head 100 meters away. I could have filled it with my 170-500mm sigma set to 200mm for the closed encounter. Anyhow I was lucky to have a hornbill 1/2 an hour later when all drivers passing by looking at me thinking that I'm the traffic police set to trap them speeding. A good lesson...