The capture process is a bit for bit identical copy of the original on tape. So, this issue can be explained by one of two things. Either the problem is in the footage, or observer error.
the image on my camera look excellent,
full of ligths and color....
when I do play you can see nice quality image on....
but who is observer error mean.?
Limited knowledge here but maybe I can help...
Use Premiere's in-built capture functionality via Firewire cable - at least that's what I do and the footage looks perfect.
If the footage is grainy, it might be because you are filming with low light on auto (for example), where grain will often occur. Try looking at some footage which is shot in good light, outdoors, for example - and it should look of good quality even if you are using auto settings.
In terms of improving your low light footage, try shooting with one of the common XHA1s presets which are widely available, as a starting point.
Hope that helps