An option is to perform these steps:


generate a synthetic blue channel
balance the colors by outlier removal through analysing the channel historgrams. For a GPL'ed approach, see here
then create the RGB composite


Concerning the generating of a synthetic blue channel:

Since I don't have SPOT5 data here, I cannot make a test. But I found this formula (Knudsen):

Blue_synth = 0.70 × Green + 0.24 × Red - 0.14 × NIR


Transform SPOT5 images to natural color images
Being a beginner, I can't see why I must choose an 80-200 over an 18-200. Are there scenarios where an 80-200 would be preferable over an 18-200?

I will be buying a D7000 soon and am looking at these:


AF Zoom-NIKKOR 80-200mm f/2.8D ED
AF-S DX NIKKOR 18-200mm f/3.5-5.6G ED VR II


but similar considerations would apply to other brands as well.
