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Sol in H⍺ - 12th May 2022


Hughsie
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A short observing session today which was interrupted by haze and the clouds coming in.

 

Full solar disc as at 08:24:51 UT. There are four active regions on the disc today. Starting in the northern hemisphere we have AR13008 and AR13009. The latter is classified CAO, comprised of 6 sun spots and located at N16W27. In the southern hemisphere we have two much larger regions of activity, AR13007 and AR13006. Some prominences are also visible mainly on the western limb.

Solar_Disc_20220512_082451UT_JWH.png.aabfc30bf0080b8633847d7529807804.png

 

AR13006 is now approaching the western limb and is pictured here close to a filament and the largest prominence on the limb today. This area of activity is comprised of 27 sun spots and is classified EAO. So far today it has been producing C class flares but it has produced an X1.5 class flare on 10th May 2022, peaking at 13.55 UT.

AR13006_20220512_084917_x4_Bin2_JWH.png.5d91189d1cb2510493bb89710fc76d7c.png

 

AR13007. Now off the eastern limb this area contains 34 sun spots having increased by 14 in the last 24 hours. Classified EKC it has produced a single C class flare so far today and managed an M2.2 class flare yesterday peaking at 19:31 UT.

AR13007_20220512_083556UT_x4_Bin2_JWH.png.474e0aafabccd2d065969c5284e424b5.png

 

AR13008 is smaller in comparison having only 5 sun spots at this time, however, it is growing in size having added a further two sun spots in the last 24 hours. Classified CRO it has yet to produce any flares.

AR13008_20220512_084245_x4_Bin2_JWH.png.f660d8e1831d74a535dfaf12b9798c14.png

 

All the best,

 

John

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3 hours ago, PhotoGav said:

Great results John, impressive! I'm interested to know the optical chain you employ for the close-up work, please?

Hi Gav.
 

Other than the solar disc image which did not have any Barlow/powermate attached, I use a double stacked 60mm Lunt with stock Lunt B1200 diagonal. On this occasion I added a 4x TeleVue Powermate then a ZWO ASI174mm with tilt adapter. I apply unity gain for this camera of 189 and today I binned the camera 2x2. This enables me to work at low exposure settings and achieve high fps. 2,000 frames are captured and 10% stacked.

I also posted earlier this week images captured with the same equipment, swapping out the 4x powermate for a 5x powermate, again with the camera binned 2x2 to reduce over-sampling and achieve low exposure/high fps.

Flats are also acquired at the same gain using a crumpled old sandwich bag and lacky band!

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1 hour ago, Hughsie said:

Hi Gav.
 

Other than the solar disc image which did not have any Barlow/powermate attached, I use a double stacked 60mm Lunt with stock Lunt B1200 diagonal. On this occasion I added a 4x TeleVue Powermate then a ZWO ASI174mm with tilt adapter. I apply unity gain for this camera of 189 and today I binned the camera 2x2. This enables me to work at low exposure settings and achieve high fps. 2,000 frames are captured and 10% stacked.

I also posted earlier this week images captured with the same equipment, swapping out the 4x powermate for a 5x powermate, again with the camera binned 2x2 to reduce over-sampling and achieve low exposure/high fps.

Flats are also acquired at the same gain using a crumpled old sandwich bag and lacky band!

Thank you John. So you just put the Powermate in the diagonal and the camera in the Powermate? You manage to achieve focus with no problem? I’ve struggled to find a good setup with my Lunt 50 and a 2.5x Powermate. 

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7 hours ago, PhotoGav said:

Thank you John. So you just put the Powermate in the diagonal and the camera in the Powermate? You manage to achieve focus with no problem? I’ve struggled to find a good setup with my Lunt 50 and a 2.5x Powermate. 

Hi Gav.

Correct. I put the Powermate in the diagonal and the camera in the powermate.

Btw, I never have the diagonal fully inside the focus tube. The tube from the B1200 diagonal is quite long so I can introduce some back focus without extension tubes. For my set up and 2.5x powermate, the diagonal is about 15-20mm pulled out. When I swap out to a 3x Barlow I pull the diagonal out more and further still with the 4x powermate. If I don’t do this then I will never achieve focus.

I use SharpCap Pro for image acquisition. The Pro version allows you to stretch the image live on screen by selecting the ‘lightening bolt’ button on the histogram. I then move the mid tone line to introduce greater contrast making the image on the screen easier to see (at this point I also have a black sheet over my head to assist viewing). With the image on the screen clearer and pointing at a feature on the Sun I then use the fine control on the focuser to dial in focus.

Hope this helps.

John

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Superb, thank you John. I will see if I can tease my setup into Powermate cooperation! I love the mental image of you with Victorian photographer style black sheet over your head. And it works, makes it all easier to see! Look forward to more of your images. Gav.

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10 hours ago, Hughsie said:

Hi Gav.
 

Other than the solar disc image which did not have any Barlow/powermate attached, I use a double stacked 60mm Lunt with stock Lunt B1200 diagonal. On this occasion I added a 4x TeleVue Powermate then a ZWO ASI174mm with tilt adapter. I apply unity gain for this camera of 189 and today I binned the camera 2x2. This enables me to work at low exposure settings and achieve high fps. 2,000 frames are captured and 10% stacked.

I also posted earlier this week images captured with the same equipment, swapping out the 4x powermate for a 5x powermate, again with the camera binned 2x2 to reduce over-sampling and achieve low exposure/high fps.

Flats are also acquired at the same gain using a crumpled old sandwich bag and lacky band!

Why unity gain? What is the reasoning for that?

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2 hours ago, Freddie said:

Why unity gain? What is the reasoning for that?

In my case I get much lower exposure times, higher fps, I can collect more frames over a short time frame with not much noise.

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1 hour ago, Hughsie said:

In my case I get much lower exposure times, higher fps, I can collect more frames over a short time frame with not much noise.

Thanks but why specifically unity gain? Go a bit higher than unity and your exposure will be even shorter. So why unity rather than a gain setting that gives a good compromise between exposure and noise? Thanks

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Posted (edited)
1 hour ago, Freddie said:

Thanks but why specifically unity gain? Go a bit higher than unity and your exposure will be even shorter. So why unity rather than a gain setting that gives a good compromise between exposure and noise? Thanks

You are correct, I could go higher but above unity gain read noise does reduce but not at the same rate. But you have to start somewhere so unity gain seems like a good place to and so far I am happy with it, though always open to suggestions.

Edited by Hughsie
Usual typos
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My experience with the 174 is that lower gain gives better results so I operate at around 100. If I remember correctly, unity is just under 200 so you may want to experiment at lower gain to see what you get. As you say, unity is somewhere to start but there is nothing special about unity so it is just a starting point.

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20 minutes ago, Freddie said:

My experience with the 174 is that lower gain gives better results so I operate at around 100. If I remember correctly, unity is just under 200 so you may want to experiment at lower gain to see what you get. As you say, unity is somewhere to start but there is nothing special about unity so it is just a starting point.

Thanks Freddie. Next clear session I have I will give 100 a go. 

All the best,

John

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