Using the Full Dynamic Range of a Webcam CCD.

Once an AVI has been processed in Registax and especially after using the Wavelet sliders, the image can have areas that are washed out or over exposed. One way around this is to limit the raw image to a max brightness of approx. 150 to 180 out of 255. While this works, it doesn't use the full dynamic range of the CCD. It can also cause noise to be more prevalent in the final image.
Here is an alternative method: Image as close as you dare to the 255 upper brightness limit, then after wavelets in Registax, histo' adjust...

After stacking and wavelet adjusting in Registax, bring up the Histogram function.
Make sure you check the Log(Ln), Smooth and Show Peak boxes.
Now adjust the colourweight boxes  for each colour until the highest brightness value on the graph is just below maximum.
There you have it... Your image is no longer washed out.
There is an added advantage that the colour balance will generally be better after this procedure as well.

Hope it works for you!

I also recommend saving in a FITS, TIF or PNG format before importing to another program to final process. I use the png format because my software (Serif PhotoPlus8) doesn't know what to do with FITS files. PNG format is 16 bit colour depth.

The images at the bottom are both stacks of 2850 frames of Mars, taken one after the other.
1.   Used a max level (of the brightest RGB) of 180 out of 255.
2.   Used a max level of 240 out of 255.
Processing wavelets, gausian blur, unsharp mask settings etc. were identical for each image.
Image number 2 shows a little more detail.