View Full Version here: : A Slice of Heaven, OK Really Carina
avandonk
09-01-2011, 09:11 AM
Two panels taken with the 300mm lens setup.
Large image FoV 11.8X4.6 degrees 10MB
http://d1355990.i49.quadrahosting.com.au/2010_12/carmos1&2.jpg
The latest modification to the optics has made the production of mosaics much easier. This mosaic is made up of two almost full frames with very little cropping. As you can see the overlap shows no sign of colour gradients or brightness differences due to vignetting.
All we now need is more clear skies.
Bert
DavidU
09-01-2011, 10:35 AM
Great work Bert. I can't believe how many stars you capture in your images.
jjjnettie
09-01-2011, 10:37 AM
Such a pretty slice of heaven too Bert.
dugnsuz
09-01-2011, 10:58 AM
Love the mosaic Bert - what mod have you done to the lens? Is it the external aperture mask and filter?
Doug
avandonk
09-01-2011, 11:28 AM
Yes it is the external aperture in this case now the 82mm Hutech LPR filter. The extended dew shield really helps as well. It was critical to accurately align the 82mm filter to the optic axis. The Hutech 82mm filter is optically quite good as I cannot see any deterioration of image quality.
The most important factoid of all this is that stopping all light that does not contribute to the final image on the sensor from entering the lens is the major factor to increasing signal to noise and reducing gradients.
I also think that the flats correct far better as well. I am using blue sky flats and darks for flats with the camera at -10C.
A camera lens even one as high quality as the Canon 300mm F2.8L does not have the baffling that a quality astro optic such as an FSQ106 has. Since I cannot put baffling into the lens I just try to eliminate all light entering the lens that the baffling would normally minimise.
Bert
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