The D90 is an old machine, either D7000 or 60D. The technology of three years ago can't be compared with that of today. If the landlord knows Moore's Law and the cost remains unchanged, then the number of transistors that can be accommodated in the finished circuit will double and the performance will double every 18 months. That is to say, 18 months later, you can buy anything with twice its performance at the same price, so D90 is not recommended, and the price of 60D is almost the same now, and it will be stable for a long time, unless a new machine comes out or the price changes greatly, because 60D has been out for more than half a year, and the role of SLR is to manually. If it is automatic, it is best to use a high-end card machine. For example, Canon G 1 1 G 12, if it is automatic, will definitely be better than the ordinary card machine, but it will only achieve the effect of a high-end card machine without manual debugging. Let's practice with the lens first, Nikon/KOOC-0/8-/KOOC-0/35 Canon/KOOC-0/8-200.