Hello !
I'm finally testing my own pictures, I bought a Nikon Coolpix 4300, UR-E4 and the FC-E8 lenses.
Here are two pictures:
http://www.panoramas-online.com/fisheye/DSCN0041.JPG
http://www.panoramas-online.com/fisheye/DSCN0042.JPG
I can't make a perfect stitch with them. There are ghost, and the common region (where they overlap) looks darker.
Does somebody know where is the problem?
 
Thanks !!!
Enrique.
 
PS: I'm something disappointed by the quality of the pictures too, although I have seen the camera has an option to save the pictures without compression (I didn't test it yet because I have a CF memory of just 4MB, and it is not enough to take a picture without compression, I need to buy a memory). Can somebody tell me if the quality of those pictures is accordant witht the Coolpix 4300 (and a "Fine" compression), because the cam is not new, maybe is a problem from my cam.

Hi Enrique
 
The problem is you are not using the correct hardware to position the lens. It needs to be done with a panoramic rotator that positions the lens exactly over the "nodal point" and also keeps the two shots exactly level. It looks to me like the camera was pointing up slightly.
 
To get rid of the dark area at the join, render out first to spherical JPEG using Smart Blend, then use LOAD PANORAMA to load the image back in and re-render to QTVR or whatever.
 
THe quality is correct for this camera. The best you can look for with this is to display in a window size of around 320 x 240 pixels.

Thanks Andrew ! I will try to correct the nodal point. From Argentina is really difficult to buy a rotator not only because the price but because the distance too.
With respect to the pictures of the camera, I was asking not for the size but for the quality of the picture, If you look carefully you will see that details are very poor (like blurred), and it looks some noisy.  
I have done another test a few weeks ago, using Kodak Z650 and a fisheye (not FC-E8) that I was supporting in place with my hands:
http://www.panoramas-online.com/fisheye/100_1488.jpg
The picture is smaller but you can see even details like letters.
Here is another from internet:
http://www.panoramas-online.com/fisheye/100_0035.JPG
and another:
http://vcc-dortmund.de/Bilder/Fish [...] nFC-E8.JPG
You can see high contrast and details in the center of the picture, the outer regions are blurred, maybe it's normal, but in my pictures I see everything blurred :-(
Do you think it will become better without Jpeg compression? or that won't make greater differences?
Have you got pictures from a Coolpix 4300 to compare?
Do you think there's something wrong with my camera or lenses?
 
Thanks again !!!
Enrique.

I made more tests and yes, the problem is the camera, the lens are broken :-(