White light v Ha for sunspots

[Highburymark]

It was nice to get an hour or two this afternoon - and some semi-clear skies at last -to have a gawp at the Sun, and catch up on the lovely sunspot groups which I notice others of the forum have  been enjoying recently while I’ve been buried in work. I had my 70mm Ha scope set up, but also my 4” frac/Baader wedge to see how things were looking in white light. It was another reminder that - if the seeing’s steady - nothing beats white light for revealing detail in and around sunspots. Now that we are starting to see bigger and more complex spots developing, pairing a decently figured refractor with a Herschel wedge or solar film is still one of the best investments in amateur astronomy. After all, sunspots are largely photospheric features, and even sophisticated Ha filters, revealing the chromosphere, can’t show the intricate detail in umbra and penumbra that white light can. It’s much easier to draw out that detail with a binoviewer, a hood to block out light, and a decent pair of eyepieces, so borrowing a technique from Stu (orthos/Delites and binoviewer/GPC and barlow/add T2 spacers for extra power) I managed around 250x today while still retaining sharpness - at least part of the time. Absolutely exquisite views. 

[Stu]

Quite agree Mark, you can’t beat white light solar on a nice big AR when the seeing is good.

I was doing exactly the same thing today, although no Ha. Pretty much the same setup, glad it works for you as well as it does for me! 👍👍

[AdeKing]

Thanks for posting this, I'm glad that I'm not alone in this respect @Highburymark.

Whilst I'm not intending to get rid of my Lunt LS60DS anytime soon I have to confess that when there are complex sunspots visible in WL I much prefer viewing in WL rather than H-a.

As you say, the intricate detail visible in the penumbra and umbra is exquisite and truly is a sight to behold.

I think that my 1.25" Lunt Herschel Wedge is probably my best value and most used astronomy related purchase to date.

[Roy Challen]

I noticed this too. I recall that WL through my f/10 100mm achro gave fantastic sunspot detail. 

This morning I stopped my Daystar down to 30mm f/30, and the improvement was immediately obvious. Much improved contrast and exquisite detail on the two ARs.

Must get another Herschel wedge soon, as a complement to Ha, not an alternative.

[NiCo10]

Agreed, much prefer sunspots in white light. I really ned to try a binoviewer now, that set-up looks fantastic!

[Knighty2112]

Got a new f11 ‘frac today, so with blue skies and plenty of sunshine I got my first light with it with solar with some nice AR’s in view in WL. Managed a snap of it too with my iphone that didn’t turn out too bad. Not viewed in HA before, but on my list to do. However, nothing beats a good sunspot to glare at through a scope, even with a home made filter.

 

Edited May 27, 2021 by Knighty2112

[Stu]

4 minutes ago, Knighty2112 said:

Got a new f11 ‘frac today, so with blue skies and plenty of sunshine I got my first light with it with solar with some nice AR’s in view in WL. Managed a snap of it too with my iphone that didn’t turn out too bad. Not viewed in HA before, but on my list to do. However, nothing beats a good sunspot to glare at through a scope, even with a home made filter.

 

Great looking setup. The f11 achro scopes are nice enough, so I imagine the ED is cracking 👍

[Victor Boesen]

I've never really taken the step into white light solar despite 3D printing a solar filter with Baader white light film more than a year ago for my Evostar 72. This is mostly due to the fact that sunspots were rarely visible back then and I the Evostar is just on the limit for observing granulation comfortably(I believe at least). However, since acquiring my quark chromosphere(which I already like a lot!) I have gathered new motivation to give white light another go, perhaps with a TS solar wedge at some point.

My 102mm F7 APO and Evostar 72ED could make a killer solar observing setup on a dual alt/az mount like the giro ercole or even the mini (for extra grab and go). But nothing comes without a cost unfortunately.... Please keep going though, I don't mind reading about some great experiences with white light observing

[Stu]

1 hour ago, Victor Boesen said:

I've never really taken the step into white light solar despite 3D printing a solar filter with Baader white light film more than a year ago for my Evostar 72. This is mostly due to the fact that sunspots were rarely visible back then and I the Evostar is just on the limit for observing granulation comfortably(I believe at least). However, since acquiring my quark chromosphere(which I already like a lot!) I have gathered new motivation to give white light another go, perhaps with a TS solar wedge at some point.

My 102mm F7 APO and Evostar 72ED could make a killer solar observing setup on a dual alt/az mount like the giro ercole or even the mini (for extra grab and go). But nothing comes without a cost unfortunately.... Please keep going though, I don't mind reading about some great experiences with white light observing

I think a Wedge would make a great addition to your setup Victor (am I helping? 🤣🤣). You could switch around obviously, but full disk Quark in the 72mm and white light in the 102 would be great. I think 100mm really helps with white light, to get the resolution to show granulation clearly.

[Victor Boesen]

8 hours ago, Stu said:

am I helping? 🤣🤣

I'm not sure at this point Stu However, you're definitely not wrong so I don't blame you;)

[Steve Clay]

Some interesting points in this thread. Especially full disc with a 72mm and quark. @Stu so a SW ed 72 and quark chromosphere will show full disc? 

Steve

[Stu]

26 minutes ago, Steve Clay said:

Some interesting points in this thread. Especially full disc with a 72mm and quark. @Stu so a SW ed 72 and quark chromosphere will show full disc? 

Steve

Yes, that should be the case. In the past I’ve used a Tak FS60C with a focal length of 360mm and that easily gave full disk. The statements I’ve seen say that full disk is achievable with up to 450mm focal length, so the 72ED with 420mm should be fine. I would suggest a 32mm Plossl would be the best choice for viewing full disk and keeping the magnification reasonable.

https://www.firstlightoptics.com/daystar-quark-solar-eyepieces/daystar-quark-h-alpha-eyepiece-chromosphere-prominence.html

[Steve Clay]

5 minutes ago, Stu said:

Yes, that should be the case. In the past I’ve used a Tak FS60C with a focal length of 360mm and that easily gave full disk. The statements I’ve seen say that full disk is achievable with up to 450mm focal length, so the 72ED with 420mm should be fine. I would suggest a 32mm Plossl would be the best choice for viewing full disk and keeping the magnification reasonable.

https://www.firstlightoptics.com/daystar-quark-solar-eyepieces/daystar-quark-h-alpha-eyepiece-chromosphere-prominence.html

Thanks Stu. As soon as I asked the question I thought stop being so lazy and find the info yourself. Looked at exactly the same as you. Think I'll get the 72 for my solar quest and quark and move the ed 80 onto other duties.

Steve

 

[Victor Boesen]

45 minutes ago, Steve Clay said:

so a SW ed 72 and quark chromosphere will show full disc?

Indeed. My Evostar 72 shows the entire disk in a low magnification Plössl eyepiece. Even with some room to spare to prominences.

This is a photo taken with my phone a couple days ago

[John]

Good thread this

A timely reminder for me to dust off (metaphorically speaking) my Lunt HW and get some WL solar observation in with one of my fracs, now that there is something interesting to observe.

I am not a regular solar observer and mostly used the HW for the outreach sessions that Bristol AS used to do and an local annual school visit. Those were really enjoyable but obviously have not been possible for the past 15 months so I've become a somewhat lapsed solar observer lately.

Time to correct that I think

Reading other threads on WL solar observing I see that O-III filters are being used to enhance the experience. Would that be in addition to the polarising filter that I use on the bottom of the eyepiece barrel or instead of it ?

Cheers

[Stu]

32 minutes ago, John said:

Reading other threads on WL solar observing I see that O-III filters are being used to enhance the experience. Would that be in addition to the polarising filter that I use on the bottom of the eyepiece barrel or instead of it ?

Cheers

I use a Continuum filter John, but have, along with others, used an OIII in the past to try to achieve a similar result. It is certainly worth trying. I use my Continuum without a polarising filter, just the ND3.0 in the wedge. A lot is down to personal preference around what brightness level you are comfortable with. The polarising filter does allow you to tune the brightness obviously, so I would try either way.

[Highburymark]

I tried an OIII filter for WL last year I think and didn’t see any improvement on the Continuum, but then my filter is virtually an antique, sold back in the era when Telescope House was on the Farringdon Road, the London phone code was 0171, and we all thought the Earth was flat.

Also read of people trying double stacked continuum filters. Of course more effective than any of those options is - if possible - to get observing as early in the morning as possible.
 

[Stu]

11 minutes ago, Highburymark said:

I tried an OIII filter for WL last year I think and didn’t see any improvement on the Continuum, but then my filter is virtually an antique, sold back in the era when Telescope House was on the Farringdon Road, the London phone code was 0171, and we all thought the Earth was flat.

Also read of people trying double stacked continuum filters. Of course more effective than any of those options is - if possible - to get observing as early in the morning as possible.
 

To be clear, I’m not suggesting the OIII would be better than a Continuum. It’s just if people don’t want to invest in a Continuum but have an OIII already, then it can show a benefit over just a polarising filter.

Is there a benefit to stacking Continuum filters do you know?

[Stu]

13 minutes ago, Highburymark said:

I tried an OIII filter for WL last year I think and didn’t see any improvement on the Continuum, but then my filter is virtually an antique, sold back in the era when Telescope House was on the Farringdon Road, the London phone code was 0171, and we all thought the Earth was flat.

Also read of people trying double stacked continuum filters. Of course more effective than any of those options is - if possible - to get observing as early in the morning as possible.
 

Looking again, that’s probably an excellent filter, original Lumicon. Mine is similar but has the percentage throughput for each frequency bandpass, all are very high.

[Highburymark]

Understood Stu. 
Think the benefits of two continuums are marginal at best, but I haven’t tried it

[Highburymark]

5 minutes ago, Stu said:

Looking again, that’s probably an excellent filter, original Lumicon. Mine is similar but has the percentage throughput for each frequency bandpass, all are very high.

Think I bought it from fellow forum member Mark at Beaufort (?).... 5-6 years ago

[Highburymark]

52 minutes ago, Stu said:

Looking again, that’s probably an excellent filter, original Lumicon. Mine is similar but has the percentage throughput for each frequency bandpass, all are very high.

Here’s the other side of the case Stu...... 

[John]

1 hour ago, Stu said:

... It’s just if people don’t want to invest in a Continuum but have an OIII already, then it can show a benefit over just a polarising filter.....

 

Unless the solar bug really bites, that is my situation. I do have a nice Astronomik O-III filter that I could try with / without the polarising filter.

 

[Highburymark]

34 minutes ago, John said:

Unless the solar bug really bites, that is my situation. I do have a nice Astronomik O-III filter that I could try with / without the polarising filter.

 

Do report back on that John. I’d be interested to hear your impressions

[Solar B]

Christ I thought I'd tried every filter there was possible for WL viewing , double stacked , triple stacked , giant hay stacks and you guys are saying "there's more" 🌞