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D70 + fast focusing

PostPosted: Tue Aug 30, 2005 10:43 am
by cordy
Hi All,

Something that has got me a little stumped and has for a while now. Can the AF motor in the D70 keep up with extremely fast moving objects? The reason I ask this is I seem to have "issues" :) keeping up with fast moving jets ie F-18 Hornet, F-111. Airliners are not a issue, nor is taking photos of motorsport. I've been shooting with AF-C with motorsport and other types of aviation and consistantly have photos that are in focus.

Is it the nature of the focusing in the D70 to get confused with its focusing point on extremely fast moving objects? Or is it a user issue? :)

Chris

PostPosted: Tue Aug 30, 2005 10:57 am
by Glen
Chris, it is not just the motor, but the AF system itself. The D70 is an entry level camera with Nikon's CAM 900 focussing system, if you really want something to catch things which break the sound barrier, the D2X has their best system, the CAM 2000. I would suggest that.


As an aside, AFS glass has the motor in the lens so will be fractionally quicker (within the constraints of the focussing system). Also using small glass eg a 50 1.8 instead of an 80-200 2.8 will be fractionally quicker due to the mass of the glass being rotated being lower (though you probably want to use a long lens). A D2X has a more powerful focussing motor along with a better AF system.

PostPosted: Tue Aug 30, 2005 10:59 am
by kipper
No, this is normal Cordy, hence why I posted in the PotW thread about how I still think the D70 is slow for AF. I had the issue at the F1GP, not with cars but focussing on fast moving targets such as the F-18 Hornet. It seemed to hunt a lot and this can be an issue if you don't pan correctly so that the center AF sensor (or which ever one you have selected if you're using Single Area). There is a technique that some guys use for bird photography which requires the use of the AE/AF Lock button to actuate focussing. I know of a guy that uses this technique for handholding a 500MM with 1.4x TC. They have the camera setup so that it's in single shot and focussing is on AF-S (not AF-C). They pretty much burst the focussing, and only actuate it when they're 100% sure that the center is over the subject. They have found if you accidently focus with out the center over the target it will try to focus on the background and by then the focussing is too slow to whip back onto the subject.

Of course you could just get a camera with a better AF system, more AF points and a bigger viewfinder eg. D2X or the up and coming D200 :)

PostPosted: Tue Aug 30, 2005 11:16 am
by NikonUser
I think the D70 only has CAM900 not CAM1300

PostPosted: Tue Aug 30, 2005 11:18 am
by cordy
Ahh goodo, im happy with that explanation. I do manage to get some nice shots of the fast jets but the ratio of focus to not focused shots isnt what I would call a good ratio. Bring on the D200 I say :)

Chris

PostPosted: Tue Aug 30, 2005 11:48 am
by Glen
Paul, you are right, the second coffee obviously hasn't kicked in :lol:

PostPosted: Tue Aug 30, 2005 11:53 am
by BBJ
Cordy, i agree with what has been said here and i know that the D70 is not the best for focusing. I would have liked to have tried the canon 20D for this as a test between the 2 just to see how theres works but yeh D200 we hope might be better. I would dearly love the D2x but it is alot of money, i am happy with the D70 other than this problem but like it is no pro camera so you cant have it all. I wish i could though but well we will have to wait and see i guess. Lets hope the D200 is a bit better in this field.