The sun- blank disc what to focus on?

[Patw#73]

Look ing at the sun on Saturday afternoon, (in white light) I could not see any activity at all. Then I was wondering how I could be sure that I had got the best focus and thta I wasn't missing any smaller details etc.

The seeing wasn't too good either with a lot of boiling going on.

Does anyone have a tricks/tips etc?

[Merlin66]

If there's nothing else, you have to use the edge of the Sun's disk.

Check with Raben to see if there are any listed sunspots and double check your focus on that area.

Maps of Active Solar Regions | raben.com

Ken

[Patw#73]

Ken,

Thanks - just had a look at Raben, brilliant.

Pat

[Mark at Beaufort]

Hello. I have not checked today but there were two small spots close together yesterday. I will check it out later and update the thread.

I agree with Ken and I focus on the edge of the sun's disc.

Mark

[russ]

Hello. I have not checked today but there were two small spots close together yesterday. I will check it out later and update the thread.

I agree with Ken and I focus on the edge of the sun's disc.

Mark

There was also a third fainter spot just along from the other two spots. Although it was quite hard to see and the seeing was quite poor.

I always focus on the edge first and then look for spots.

[Mark at Beaufort]

Thanks for that Russ. I used my little William Optics yesterday so perhaps I will switch to the 4" today.

Mark

[Mark at Beaufort]

Just been outside with the 4" frac, Ethos 8mm and an Orion glass filter. The two spots are very clear but can't see the faint 3rd.

Mark

[russ]

I missed it too for almost the whole session, then caught it just as i was about to pack up. They were in a line, bright one, another one and then the faint jobby. All equally spaced but the faint one was incredibly faint.

[Mark at Beaufort]

Thanks for that Russ. I have had another look and used a green filter to reduce the brightness a bit. I am not sure that there appears to be a 'spot' in the middle of the two others. I can't see another otherwise.

Mark

[russ]

I wonder if it was disappearing yesterday? I'll take another look this evening, see what i can see. Hopefully i can spot the one in between.

[brianb]

I always focus on the edge first and then look for spots.

Yeah, unless there are large spots that's the only way. If you can see spots, focus on those. Otherwise focus on the limb & search for spots - if you come out negative, try focusing very slightly "in" or "out" & try again.

With 4" or more and goodish seeing (allowing a magnification of around x100, at least) you may be able to see the granulation well enough to use that as a focusing target - try rough focusing on the limb then rolling slowly through the focus point whilst concentrating on the centre of the disk.

The wee spots aren't that hard to see today ... though they probably will escape you if your focus isn't accurate.

[russ]

Had another look yesterday evening (seeing much better) and its 3 very small groups at the moment with two or three spots per group. With a 10mm eyepiece and #56 Green filter, the sun was beautiful. granulation all over and some lovely detail around the sun spots groups.

[Mark at Beaufort]

Agree Russ. Checked the sun this morning with the 4" frac, green filter and 8mm Ethos. The 3 spots are well defined now with the surface having nice granulation.

Mark

[russ]

Agree Russ. Checked the sun this morning with the 4" frac, green filter and 8mm Ethos. The 3 spots are well defined now with the surface having nice granulation.

Mark

Mark, sounds just like i saw it. Could only see the one spot this morning. Hopefully some new ones soon.