I took this image 8-21-15
I used bandwidth 2 lines in Wah's program
Is using 2 lines better for caK, caH lines better than 1
since they are wide?
still thrilled I can get filaments in caK pics
caK shg and question about bandwidth option in Wah program
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Re: caK shg and question about bandwidth option in Wah progr
colorized you can see proms at 10 and 9 o clock
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Re: caK shg and question about bandwidth option in Wah progr
With the SHG the final bandwidth comes down to the dispersion of the spectrograph (A/pixel) and the resolution (A) of the instrument.
Using the Nyquist sampling as a guide, you'll need at least two pixel to get resolution.
If you have 0.1A/pixel dispersion then a two pixel strip would give around 0.2 to 0.3A bandwidth resolution.
Always remember resolution is not the same as dispersion.
Using the Nyquist sampling as a guide, you'll need at least two pixel to get resolution.
If you have 0.1A/pixel dispersion then a two pixel strip would give around 0.2 to 0.3A bandwidth resolution.
Always remember resolution is not the same as dispersion.
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Re: caK shg and question about bandwidth option in Wah progr
In most cases this works fine, but it gets more complicated if the collimator and camera have different focal lengths. For the average digital imager these days, with small pixels, binning 2 or 3 in the spectral direction may help. It will cause some astigmatism in the assembled image, though. The ultimate solution is to design the system so that the FWHM of the line profile at the detector is one pixel wide, but that usually involves long focal lengths.Merlin66 wrote:With the SHG the final bandwidth comes down to the dispersion of the spectrograph (A/pixel) and the resolution (A) of the instrument.
Using the Nyquist sampling as a guide, you'll need at least two pixel to get resolution.
If you have 0.1A/pixel dispersion then a two pixel strip would give around 0.2 to 0.3A bandwidth resolution.
Always remember resolution is not the same as dispersion.
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Not blind yet, either!
Light pollution? I only observe the Sun, magnitude -26.74. Pollute that!