New sunspot near eastern limb - 20210404

[Boso36]

Hi all,
I am making a better sunscreen for my computing station, and was testing this, and just imaged this by accident, not expecting any sunspots.
I hope to make a better solar telescope setup with a 90mm F10 achromat refractor and a better camera, in a straight through imaging configuration, with motor focuser as well.
Is it important to rotate the sun to a certain axis ? I say this because the image in spaceweather.com is slightly rotated compared to mine.
How do you know how much rotation to make ?

Thanks,
Magnus
London

Sun-White-light-20210404-124600.jpg (252.52 KiB) Viewed 136 times

[Boso36]

Sun now add some colour and unsharp masking done.

Sun-WL-colour-20210404.jpg (520.34 KiB) Viewed 129 times

[dhkaiser]

North up is best, I compare to this link... http://jsoc.stanford.edu/data/hmi/image ... 6x4096.gif

[Montana]

There is a lot of discussion about orientation in this topic in the reference library
viewtopic.php?f=7&t=28249

Beautiful images

Alexandra

[Boso36]

There is a lot of discussion about orientation in this topic in the reference library
viewtopic.php?f=7&t=28249

Beautiful images

Alexandra

Thanks Alexandra for sending me the link.
I see that is a lengthy thread so I will read it properly tomorrow when I have had a time to rest.

Magnus

[rsfoto]

HI Magnus,

Well done but the spot is nearing the Western limb ...

[rsfoto]

Hi Magnus,

Forgot to mention. Images in SDO and other professional pages are rotated in that way that the North/South pole axis is perfectly vertical and East is always on the left side.

If you want to orient like that, you first need to orient your camera in that way that your North/South pole axis is exactly as depicted in the program Tilting Sun and then you need to rotate e.g. now CCW the angle Tilting Sun is giving you in the value of P.

You can find Tilting Sun here https://www.atoptics.co.uk/tiltsun.htm

[marktownley]

Good whitelight Magnus!

[EGRAY_OBSERVATORY]

Hello Magnus, Rainer's method is correct, but there is a but...!!!

EQ-mounts will often flip-over around mid-day, so attached scopes and cameras will flip the image/viewing accordingly.

For imaging purposes, comparing with the SOLAR DYNAMICS OBSERVATORY satellite-imagery to what you intend to process, will certainly get the North-up, South-down, East to the Left and West - in the only-other quarter...

https://sdo.gsfc.nasa.gov/ shows all the very-up-to-date/time imagery - 24/7/365...

If there is not much action on the surface or prominences/flares, then it can be very difficult to know which way to process the picture the right way round.

Also as EQ-mounts will likely/may flip-over around mid-days, then equally the view/image will also need to be adjusted for accuracy, although that is not mandatory and does require an extra-part of the processing - such as "Mirror" / "Flip" / "Rotate" (depending on which processing program is being used.

Also the use of Hershel-Wedges and other prism-types will also cause some extra work for the same reasons and no doubt that could apply to some telescope types too...

Confucius Say...

Terry

[rsfoto]

.. but there is a but...!!!

EQ-mounts will often flip-over around mid-day, ...

Hi Terry,

That is correct, but ... another but ... Many equatorial mounts allow to start before the meridian and so you avoid the meridian flip ...

... and I guess imaging the Sun does never take as long as imaging DSO objects and so one can plan accordingly ...

When starting e.g. on the East, you put the camera in the correct position and when you need to flip meridian then you just turn the camera 180° and voilá it is done ...

[DeepSolar64]

I would like to get an Amici prism diagonal which orients east-west and N-S correctly in the eyepiece or camera.

[rsfoto]

I would like to get an Amici prism diagonal which orients east-west and N-S correctly in the eyepiece or camera.

Hi James,

I agree for visual observing but it is cheaper for imaging orienting the camera correctly