| Here I'd like to
run down some of the astro imaging techniques I use for various objects. When
I fist started this hobby I bought a Philips SPC900NC web cam and added
the long exposure modification, also known as the
With this camera I proceeded to hunt down some
simple targets like the moon, Sun and some of the prominent planets like
Saturn and Jupiter. You can see some of these on the Gallery page
(link at left). Though these pictures are not perfect, they are a start.
I still need to hone my imaging and post processing
One of the frustrating things that I came
across was trying to get a complete mosaic of the moon. If
you check out my pictures you will see that there are
The process that I used was to start at
the top right of the moon ( west) and take a few shots . Then I would
move the scope over to the left just enough to over
lap the last sequence and take more pictures. I would do this all
across the moon. Each on of these sequences would then
be stacked to for one JPEG image. Finally I would use PhotoShop to
stick each of the JPEG's together to create a complete picture. By
reducing the opacity of each section it is easy to over lay the
matching features with the adjacent picture. Once aligned I set to
opacity to 100%. Inevitably, there will be a piece missing leaving a
hole in the over all picture.
Since then, I was made aware of a technique used by a
number of amateur astronomers which I call the drift method.
Using this method to image the moon :
- Set your scope at the western edge of the
- Turn off the RA tracking motor ( on my setup
with a MEADE 494 AZ/EL Mount I use the terrestrial object
setting which does not track)
- Start capturing images as the moon drifts
by the FOV ( field of View)
- Once you reach the far side stop the image
- Now Move your scope back to the western
side but down just overlapping the previous strip.
- proceed as before capturing the image as the moon
drifts across the FOV.
- Continue until the entire moon has been scanned.
You should have a number of AVI files. One for each
To process the strips into a single image:
- Load a strip into K3CCD select 100 to 150
frames and combine them into a single image.
- Next process the next 100-150 frames. using
the same settings for all the sets.
- Continue un tile tall the strips have been
processed. You should now have a JPEG for each block of
- The final step is to merge these JPEGs in
one mosaic. You can use PhotoShop or other stitching
software to come up with the final product.
IF everything works right you should have a complete
shot of the moon. I haven't yet tried this method but intend to do so at
the next full moon.
(More to come )