As usual
it depends ...
It depends on what you want to photograph and what you want the results to look like.
Especially it depends on how wide or narrow a
Depth Of Field (DOF) you want, i.e how deep a portion of a scene you want to appear acceptably sharp in the image.
A smaller sensor will give you a wider DOF.
A larger sensor will give you a more narrow DOF with more
blurred Out Of Focus background and foreground (
bokeh).
E.g. if you want to shoot a bug at very close range and still want the entire beast to appear sharp from head to tail you may be better off with a tiny little sensor giving you a wider DOF.
If you want some details of e.g. a flower to appear sharp within a narrow DOF while the
Out Of Focus background is rendered nicely soft and blurred with a
'dreamy bokeh' you are better off with a larger sensor giving you a more narrow DOF (which is what I personally prefer).
Go take a look at the DOFs in the pictures in this macro thread:
http://forum.getdpi.com/forum/showthread.php?t=1812
I have no experience with the Nikon Coolpix P90 and have never read anything about it, so I know absolutely nothing about its Image Quality.
But keep in mind that the area of the APS-C sensor in the D3100 is
nearly 15 times larger than the area of the teeny-weeny sensor in the Coolpix P90.
And in general you get a better image quality with less noise when using a larger sensor
(*)
So I suggest you go with the new
D3100 with the
18-55mm VR kit lens, plus a
dedicated macro lens like the
Sigma 150mm f/2.8 EX APO Macro EX DG HSM.
I believe that would be an extremely strong solution for macro photography.
Common US retail prices:
Nikon D3100 + 18-55mm VR ~ 640 USD
Sigma 150mm f/2.8 EX APO Macro EX DG HSM ~ 730 USD
All together ~ 1370 USD
I assume you meant to say your limit is 2,500, not 25,000, at least if you are talking USD ?
Or what currency are you talking about, where are you in the world ... ?
In any case, welcome aboard, Amandasta
(*) all other things being equal, which admittedly they never really are !
