The Sun and its Spots on 2nd May 2005 Home

These pictures were an experiment to see if different wavelengths of light would produce better pictures.  I have two narrow-band interference filters, one is 631 nm with a bandwidth of 11 nm, and the other is 502 nm with a bandwidth of 8 nm.  I mounted these just in front of the normal IR-rejection filter on my camera and the whole telescope was, of course, protected with a full solar filter.  The pictures were taken on a morning of intermittant cloud and are not of the best but I hope the differences are real and not caused by the seeing.  All the AVIs had to be edited by hand to remove the worst of the frames showing cloud, but apart from that they are processed the same way.  Unfortunately the clouds returned in force before I could get a whole-Sun image with the 505 nm filter.

Sun on 050502 This is the Sun imaged in the normal way using only the solar filter (Baader film) and the IR-rejection filter.  The large sunspot is number 10756.
Sun on 050502 in 631 light This is the Sun imaged in the same way but also using the 631-nm filter.  I found focusing this image difficult, so I can't rule out that the difference is due to focus.  If you see this image rendered as a series of concentric rings, this is an artefact introduced either by your browser or by the html format and is caused by the very subtle changes in shading in this picture;  it does not show that way on the original image. The mouseover is the same image rendered in grayscale, which isn't much better although the smaller sunspots (group 10757) are more clearly seen.
Sunspot 10756 on 050502 These pictures are all of spot number 10756 in the different colours as indicated below each image.  Again I have to admit to difficulty focusing the monochromatic images.  Except for the one indicated, they were all recorded in colour mode largely because the camera is more sentitive in that mode.

I think my conclusion for now is that the filters do not improve the picture, but it may be worth repeating the experiment under better conditions.  I shall continue to image in natural light using the camera's B/W mode.

Date and Time 2nd May 2005 (top to bottom) 12:37, 11:51, and between 10:50 and 11:12 UT
Camera ToUcam 740K
Telescope 270 mm SLR lens and ETX125 at prime focus
Capture K3CCDTools.
Processing Registax. Wavelets 1,2 = 10 (whole Sun), 1-3=10 (spots) 
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