#12. "RE: Need help understanding and deciding (Was: image quality comparisons to D300?)" In response to In response to 7
St Petersburg, RU
>The reason, as I understood it, was that is it mainly due to >the AF module of the D300s. It allowed a faster and better >focus even under low light without needing to increase ISO. 51 >focus points vs. 11. The D7000 has 39. > >I have to admit that I do not really understand why we need >all these focus points and how exactly they work together. My >apologies if this is a question that was discussed to death >before, in which case just point me to the reading material... > So: >
What's so great about having many focus points in the AF >module? What's special about the "cross type"? (what >is the other type called?) >
The number is not important, you only need one. But having them in location you really need is more important. For example none of the cameras have FPs near the frame edges that I would like, but for action, having them close together aids in tracking ability. That requirement is lessened by 3D technology that uses color to help identify the locked subject even if it moves outside the array of focus points. A balance between FP density and spread in FX Nikon's favor tracking, but the D300 has, what many think, of a better spread for composing. If there were 500 FPs all would be perfect....if a super computer was tethered to the camera since it takes a lot of processing power to track an object through many FP sensors.
What possible impact could the (supposedly) better AF >module in the D300s, have on real-world images in comparison >with the D7000? In other words, how much of the superior IQ >gap that the D7000 has over the D300 could be bridges by the >51 vs. 39 AF points?
We do not know how well the D7000 compares to the excellent D300s AF system but with 3 years newer technology and faster processing consuming less space and power, the new CAM4800 is probably better in design and capability but is probably also intentionally limited to give a D400 another reason to command $1000 more in price. From subjective reports the new system is very good and possibly equal in speed to the D300s particularly in the most processor intensive operations such as 3D tracking because of more processing power and the very important 2k RGB metering sensor that works tightly with the AF module for identifying subjects. We can expect the full designed in performance of the CAM4800 to be unleashed in the D400. 39 points is a big change from the D90's CAM1000 as is the 9 cross point sensors compared to 1 on the D90. The D90 was no slouch compared to other brands but was not in the same AF league as the D300s,probably the single most important reason for someone to opt for the D300s over the D90 is they were doing action shooting. I suspect that it is reasonable to assume that the 4800 system is scalable and at its base configuration, is more intelligent than CAM3500, but possibly intentionally limited in some way so as to create product differentiation between the D7000 and D400. I expect the 3D mode to be the biggest recipient of the increased processor and sensor power. Most my shots are fairly static, portraits and candids so the D90 is fine for AF using the center cross sensor. But having 9 cross sensors is a big deal since they are more sensitive and handle targets with different polarization better than the single pole sensors. For maximum speed and accuracy in AF, select the fewest number of FP for the scene. A 11 or 9 point setting will out perform the 51 or 39 FP selection but with the increased processing power available the drop off in performance might not be a factor in the D7000, it might have the horsepower to handle all 39 points at once and still maintain fast response. All you guys with D7000's, get out there and take some challenging shots with it and post reactions and impressions....please! > >
Choosing the D7000 over the D300s (almost) seems like a >no-brainer; What am I missing? What reasons are there for >choosing the D300s? > >
Currently the best reason is that it is a known quantity, for some sorts of shooters, that is very important. If you have never had that size body, so there is not a new set of habits to learn the choice can be based on other criteria. One advantage of the D300s few talk about is the fact that 12mpx is a great compromise in all factors from diffraction, RAW file size, resolution etc. Another is weight, if hand holding large telephoto lenses it might feel a lot more comfortable. I will say however that the D90 with a battery grip feels great, better to me than a smaller D700 without a grip, closer to the natural balance points of the wonderful handling of the D3 series. Total weight of a usable system is not much different, lenses, flash, modifiers etc negate differences in body weight. Ruggedness is another factor but I suspect most people equate weight with ruggedness when it really does not in reality. Lower mass items can be lighter in construction for any given impact or impulse accident, a D3, as beautifully built as it is, will likely sustain more performance altering damage from a fall on a hard surface than a 3 ounce point and shoot or plastic phone camera. No one has complained on this forum that I can remember about the D90 or D80 not being able to take a lot of abuse. Mine has been dealing with rough conditions weekly for 2 years with the only affect has been some buttons have their markings worn off. The D7000 shows every sign of being a tough, solid camera that will stand up to abuse as well or better than a more massive camera. Who ever broke a D40 from rough handling?
>Always looking forward to reading your feedback! > >Thanks, >Zevi Tough choice but either way, you know you will have a very competent camera, there are no losers in selecting Nikon. If you really want to convince yourself, go to a store that has both, and compare them to the T2 and 60D, that will convince you in 1 second of solid feel.