Sol'Ex ; How to use IntI for when focal is too big?

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ChrisHalpha2017
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Sol'Ex ; How to use IntI for when focal is too big?

Post by ChrisHalpha2017 »

Hello ,

I've been playing with my spectro-coronagraph for 24 years now !! and i'd like to try it on SHG but the big problem for me was to use INTI (usually used with Sol'Ex by Rondi). The problem is that may focal is 1200 or 1350 mm and I cant image the sun in one go.

How can I proceed? Apparently InTi needs SER where there is the start of the sun's limb...

How can you do it in my case? I've seen many people who imaged the sun in making a mosaic but noone explained how they scanned the different part of the sun and use InTi..

Thanks if you can help...

Chris


spectro-coronographe ,Bresser 127/1200 ; Bresser 102/1350 , ASI 178MM
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Re: Sol'Ex ; How to use IntI for when focal is too big?

Post by thesmiths »

The person to ask about this is Jean-Francois, who sometimes makes an appearance on Solarchat. See his post on Astrosurf: http://www.astrosurf.com/topic/159976-s ... de-127-mm/.

Yes, you need to capture both limbs (east and west, if scanning in RA; north and south if scanning in DEC), as the reconstruction software needs to be able to do edge detection. Doing the image in thirds will work -- so top of the sun, middle of the sun, bottom of the sun. That will work with 1200mm focal length. With the 4.5mm long slit of the Solex you will not have much room to spare so you will need to be quite precise about displacing the subsequent scans. In principle, 3 scans will cover the equivalent of around 1400mm.


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Re: Sol'Ex ; How to use IntI for when focal is too big?

Post by Jean-Francois »

Hello Chris,

As Douglas mentioned it ... you need 3 scans with a telescope with 1000 to 1200 mm focal length (and with the standard Sol'Ex ... 80/125 objectives and a "178" camera).

First have a look at the position of the slit on the camera. Depending on the alignment and the temperature (my Sol'Ex drifts a little with the temperature), the image of the slit can move on the camera. So have a look how much you have on the left and the right side of the detector.

Then I move to see the "left" side of the sun on the camera image and I move it near the beginning of the slit. I move the telescope back and I start the sequence of several + and - movement (10 or 20 individual scan). After that I move to the center of the sun. I center the "upper" part in the middle of the detector (correctly at the middle of the slit). After the sequence of the center, I move to the "right" side of the sun and I move the sun near the end of the slit.
You need to have a good alignment of the slit rotation relative to the telescope movement direction and the camera clocking has to be good.
Below some examples with 3 telescopes: Bresser 102/1000 mm, Bresser 127/1200 mm and HaT8" (Celestron) 203/2032 mm.

Concerning other points ...
I think that it is not necessary to see both limb of the sun ... as long as you know the correction angle and Sy/Sx ratio.
The INTI (note all large characters) software of Valérie and Douglas can process any film with a manual value of the angle and the ratio.
I have for that an opposite-example ... you can process a film that does not move.
SHG_Bresser102_1000mm.jpg
SHG_Bresser102_1000mm.jpg (337.26 KiB) Viewed 989 times
SHG_Bresser127_1200mm.jpg
SHG_Bresser127_1200mm.jpg (355.57 KiB) Viewed 989 times
SHG_HaT8_2000mm.jpg
SHG_HaT8_2000mm.jpg (429.98 KiB) Viewed 989 times
10_36_26_TSAPO72F6_Ha_1x1_shift=0_clahe.jpg
10_36_26_TSAPO72F6_Ha_1x1_shift=0_clahe.jpg (562.28 KiB) Viewed 989 times

Regards,
Jean-Francois


ChrisHalpha2017
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Re: Sol'Ex ; How to use IntI for when focal is too big?

Post by ChrisHalpha2017 »

oooh thank you very very much!!!
I have both bresser 102/1350 and bresser 127/1200 but i dont have Sol'Ex ; i have a much powerfull spectro as the focal of both collimator and chamber objective are identical and of 205mm focal length :)
I'll try as soon as tomorrow with all the advice you gave me :)

Thanks very much .

Chris


spectro-coronographe ,Bresser 127/1200 ; Bresser 102/1350 , ASI 178MM
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Re: Sol'Ex ; How to use IntI for when focal is too big?

Post by Montana »

Wow!! these are terrific images :bow :hamster: you could easily zip these together to make a full disc :)

Alexandra


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