D90 features over D40/D60.
1) Now AF and AF-D lenses will autofocus. A lot more lens choices.
2) Bigger viewfinder with illuminated grid.
3) 11 AF points for faster focusing and more AF points to chose from.
4) 12mp for more cropping when needed.
5) NO MORE MENU Digging! Dedicated controls and buttons for Focus mode AF-S AF-C,Also button for Single-Continuous-wireless remote selection. ISO,WB,DoF buttons Metering Pattern.
6) Top LCD for seeing all settings at a glance.
7) Two thumbwheels controls for quick changing aperture and shutter.
8) dedicated button to see ISO setting in viewfinder.
9) CLS Flash commander mode for wireless controlling your flashes.
10) Auto Bracketing
11) True Battery grip with controls for vertical shots with extended battery use.
12) High ISO on the D90 is a great improvement that allows me another stop for those lower-light handheld situations. Every little bit helps.
13) Dynamic Range - The D90 gives about 1EV of additional range.
14) 3" lcd display - For these old eyes I need all the help I can get. And blurry out of focus shots I can see without zooming to delete.
15) ISO displayed in viewfinder also can change ISO on the fly with the sub-command wheel.
16) Shutter Life - D90 is rated 2x the D40/D60 at 100,000 clicks.
17) D-Lighting - Improvements there also.
18) 3D tracking - Lock on subject and during recomposing the AF Point will change to keep subject focused. Great for motion tracking?
19) Self-Cleaning - Still skeptical how well this feature works.And appears to actually clean dust off. So far looks helpful. And on my D80 required a wet clean every 4-6 weeks. Once in 9 months so far on the D90.
20) Info Button - Now can get quick Top Lcd readings on back LCD with built-in changing of D-lighting,High noise NR,Picture adjustment,Function button assignment,etc.
21) Picture preview - When reviewing picture tap up once and all picture settings and exposure info displayed with small histogram all laid out in nice easy format to read.
22) Frame rate - D90 gives 50% more at 4.5fps the D60 3fps.
Many that become serious. Became frustrated with the entry level camera like the D40/D60 within 3-9 months. I got frustrated with lack of controls and features. And those make for a more enjoyable and less frustrating experience.
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