hi ... I both own the D300 and D90 and I can say that regarding continuous auto focusing, D300 is far superior than D90. not only it is faster, but it is accurate and does well even on low light. The D90 hunts when you track a moving subject as big as an athlete even in a well lighted subject. Perhaps with the D90, I get like only 60-70% hits in one burst using AF-C. That is like 3-4 blurred images out of 10. Not good for me. With the D300 and using the same set of lenses, I seldom have missed a single frame even with subjects as small as a flying white egret. With D300, I really dont have problems with AF. Its AF Assist lamp is superb even on the darkest of nights.

The D300 uses the Multi-CAM 3500DX with 51 autofocus points with 15 cross types (mostly on the center) while the D90 has the Multi-CAM 1000 with 11 focus points only with one cross type at the center. The D300 can switch to AF with only 11 AF points and all of them are cross types. This explains why I seldom get a missed shot on an a burst of shots with the D300. My personal setting though is 21 points AF. Seems faster to me than 51.

The D300 does AF well if your subject is moving across you. If your subject is moving towards or opposite your direction, I still get blurred images.

So if you ask me about the D90's AF ... I'd give it a score of 5 out of 10. I guess it focuses well and fast on static objects. With the D300, I dunno how it would compare to Sony's.

I know one of the canon cameras had the detector that knows where your eye is looking at and focuses there, so sony may well have that too. Nikon cameras dont have that. It would annoy me as I look around that frame a lot checking bokeh and backgroud and would hate it if the autofocus followed my eye !!

It is not just the speed but the accuracy as well, what is the purpose of fast and lousy AF as Sony does.
Sony was making a couple of sensors built into Nikon cameras, but today it is not so easy to say who is doing it and, much more important, who designed the Nikon sensors, and it is not just the sensor that makes the picture.

Hmm, I knew that they made a lot of sensors. Not sure cams are as strong. They should have decent glass with minolta legacy. I need to play with the d90 more. Any other thoughts? Would love to hear from the group.

R

BTW, Sony makes the sensors that go in Nikon cameras...

i figured out I was using the A300/350. It is CCD sensor. Can't be near as good as a Nikon! Just impressed by the focusing ability with it's kit (seemed to be 18-55 equiv)

Well for one thing, the A700 is the pro model for Sony and the D90 is for advanced amateurs. Plus the lens you were using on the A700 was probably a better lens than the kit D90 lens anyway.

However, I don't know much about Sony cameras, so I really can't say any more about the original post.

I can see where you might want the ability to turn it on and off, but it was really cool. The range of focus was smaller on the Sony, but didn't seem to be a huge amount. I noticed that the 18-105 took forever to get in focus...are the other nikon lenses better? 16-85?

AF varies from lens to lens on motorized lenses. I'm assuming the lenses on the two bodies are both motorized. Only AF (not AF-S) lenses use on body focusing. That said, I'm also pretty sure whatever kit lens was on the A700 had a smaller range than your 18-105mm, the larger the range the more range for focus. There is an AF-C mode on your nikon but it works with a half press, but I personally would hate continuous AF without a half push of the button.

So, this isn't as much the wrong forum as you think...

I've been looking at cams for a while to jump into the DSLR arena. I tried some Canons and they just didn't seem to feel right to me. Excellent cams, sure, but Nikon really felt good to me. I have some photographer friends that shoot both but I got steered to Nikon.

Settled on the D90.

Then I tried a Sony the other day. Not sure the model, but it wasn't their full frame (A700?). In any case, I know that the Nikon performs great, but the Sony seemed to have blazing fast and intuitive auto focus. The Nikon with 18-105 struggled and was slow as hell. It only focused on half press, which may be their method (vs constant AF), but it still took FOREVER. I have tried other lenses that weren't much better. Still haven't tried the 16-85 that I planned to buy with the Nikon D90 so I'm not sure how that combo works, but...

The Sony constantly focuses! I mean I went from macro to distance and everything that my eye looked at it focused on. It was crazy. No half button push either. I would go back and forth upon close up between two books stacked by each other, one in foreground the other in background and where ever I looked it focused.

Does the Sony have some program that analyzes where your eye is looking?
Am I doing something wrong with the Nikon? Why is it soo damn slow to focus compared to the Sony?
Do the other cam pros and cons make up for this?

Please help, I'm not even close to a pro here. I am probably about a month from purchase and now I'm all sorts of confused!