my attempts at SHG images continued
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my attempts at SHG images continued
still fighting with post image processing
but captures are getting better and cleaner
caH
but captures are getting better and cleaner
caH
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Re: my attempts at SHG images continued
caH orig
hey if anyone wants to process for comparisons be my guest
hey if anyone wants to process for comparisons be my guest
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Re: my attempts at SHG images continued
here is my contribution
I would say that youhave to improve focus from the collimation lens : this is why the edge are focus but the surface is not as sharp.
I also would suggest you to try first Ha shot : indeed due to wavelenght, focus is easier
I would say that youhave to improve focus from the collimation lens : this is why the edge are focus but the surface is not as sharp.
I also would suggest you to try first Ha shot : indeed due to wavelenght, focus is easier
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Re: my attempts at SHG images continued
So you say that prime image of sun on slit is a bit off?
MERCI for image!
MERCI for image!
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Re: my attempts at SHG images continued
no, the focus of the lens after the slit. Indeed it is the most sensitive one.highfnum wrote:So you say that prime image of sun on slit is a bit off?
MERCI for image!
How do you currently manage this ?
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Re: my attempts at SHG images continued
The focusing does seem to be off. My technique: Before taking instrument into the field, adjust collimator and camera lens (without telescope in place) to get sharp spectral lines from an emission spectrum source (Ne, Na, Hg lamp, etc.) placed near the slit. Remaining focus, to be done in the field, is largely the telescope, with minor (repeat: minor!) tweaks of camera and collimator lenses. As Vincent mentions, the collimator is often the most sensitive adjustment.
Peter.
Peter.
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Re: my attempts at SHG images continued
thanks all for advice
did some tweak today
this may take several tries
before I get good feel for it
I hope I now qualify for entry into the SHG club
even at low tier
did some tweak today
this may take several tries
before I get good feel for it
I hope I now qualify for entry into the SHG club
even at low tier
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Re: my attempts at SHG images continued
Interesting to read your progress!
http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!
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Re: my attempts at SHG images continued
Here my advice base on friends advice and experience for a good focus :
1- I take my camera (450D) + long lens (400mm) a manage to get infinit focus to a mountain for example.
2- remove from your shg the telescope and the camera lens
3- oriente the SHG to the sun
4- through my 450D+400mm infinit, I manage to get a perfect slit image focusing the collimator (f/8 like this I avoid any specular light from the slit)
5- place again the camera lens on your shg and focus properly the spectra on the wavelenght you want
6- place the telescope and focus it in order to get a sharp spectra edge (in fact sun edge...)
7- adjust/finalise focus with camera lens
The longer the wavelenght the easiest it is to get a good focus....
1- I take my camera (450D) + long lens (400mm) a manage to get infinit focus to a mountain for example.
2- remove from your shg the telescope and the camera lens
3- oriente the SHG to the sun
4- through my 450D+400mm infinit, I manage to get a perfect slit image focusing the collimator (f/8 like this I avoid any specular light from the slit)
5- place again the camera lens on your shg and focus properly the spectra on the wavelenght you want
6- place the telescope and focus it in order to get a sharp spectra edge (in fact sun edge...)
7- adjust/finalise focus with camera lens
The longer the wavelenght the easiest it is to get a good focus....
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Re: my attempts at SHG images continued
Ok
I think I understand
The slit edge should look sharp
As well as edge of sun within slit
space
I think I understand
The slit edge should look sharp
As well as edge of sun within slit
space
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Re: my attempts at SHG images continued
oversampling error
too many frames
then when i fixed clouds rolled in!
got two partials
oversample
too many frames
then when i fixed clouds rolled in!
got two partials
oversample
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Re: my attempts at SHG images continued
That's looking good, mate!
Keep it up.
Keep it up.
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