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Baader AstroSolar PhotoFilter

Yesterday I constructed a new solar filter for photographing the Sun with my Coolpix 4500 and the webcam. I constructed the filter from cardboard and Baader AstroSolar PhotoFilm with a neutral density of 3.8. This filter is only for photographic use! Do not use Astro

Solar PhotoFilm for visual observation without an additional neutral density eyepiece filter! That’s what the big yellow sticker on the filter says. You should use a neutral density filter ND=2, preferably one from Baader. Follow this link to find more information on the Baader AstroSolar PhotoFilm. It should be used with great care, and only by people who know the danger of observing the sun!

This filter should provide me with sharp images of the sun using much shorter exposure times (about 1/1000s). The trick is to use the Baader AstroSolar Film for visual use (ND=5) for locating the sun and focussing the image. Then mount the camera on the telescope and exchange the visual filter (ND=5) for the photographic (ND=3.8) and shoot the images. Again I must say don’t use this filter for visual use without a ND=2 greyfilter. Even if you look through the viewfinder of a normal camera, do this by holding a ND=2 filter between your eye and the camera.

I still have to test it, so I will keep you update.

For detailed instructions on how to construct a solar filter using Baader AstroSolar Filter or Baader AstroSolar Photographic filter, please follow this link!

Here are a few images that should give you an idea how I constructed the filter:

First construct a cylinder that will fit around the dewcap or the telescope
tube real tight. I used some white paper/ cardboard to do this.

Then cut two rings out of cardboard that will fit on the cardboard cylinder.

Glue the filter material between the two rings. Cut of the redundant filter material.
Your “filterholder” is ready.

Glue the filterholder onto one end of the cardboard cylinder
you made, and secure it with some extra tape.

Put the sticker with the warnings on the cylinder. This should prevent you and others
from using it visually.(I got stickers in german language, but I presume that Baader will
also have stickers in English.

Posted by Math on 07/16 at 05:03 AM
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