Refractors for visual white light.

[pluton]

Hello,
I currently have a 80mm refractor ED.y I make solar observations with astrosolar Baader, with mediocre results, ..
And I'm interested to know your views in relation to the solar prism (solar wedge) Lunt 1.25 "and polarizing filter.
This Lunt 1.25 "Solar wedge would give more contrast and sharpness that Astrosolar of baader Planetarium?
Another question if I may: a larger diameter refractor, for example, an achromatic refractor 4.7 "(maybe a 6") would give better resolution in granulation, stains, faculas..etc ..?
Has anyone been able to compare visual observation in a 3 "and 4.7" refractor? Worth? Or what would the jump ...? You maybe a 6 "..?
O really counts in solar observation is not the diameter of the instrument (telescope) but the quality of the lens, the lens here ED.
All this in relation to the solar visual observation in white light.
a greeting
greetings To You
Paul

[ronin]

If you want the granulation then you need the Lunt or Quark bits for the scope, or the full Coronado PST.

You cannot get/see the granualtion with a white light filter such as the Baader Solar Film.

More aperture will not help, actually if you look at the Coronado PST's they are quite small scopes as in around 2" diameter.

In white light the lens quality is relevant, oddly not so important in the narrow band Ha or CaK that is used. Being just a narrow piece of the spectrum there is almost no Chromatic Aberration. However like most things I suspect an ED would deliver sharper images then an achro, just not the significant step seen in normal visual observing.

[Moonshane]

I have used a 6" f11 Newtonian with film and views through even a 80mm f11 achromat with a Lunt wedge were noticeably better. I used a Baader solar continuum filter in both scenarios.

I then got a 120mm f5 cheap skywatcher achromat and detail as well as granulation and other white light features were a big leap. I immediately decided to sell the 80mm. I enjoyed the 120mm and Lunt wedge so much that I have now invested in a 120ed. The solar views are better but not massively so compared with the 120mm achromat but night time views are greatly enhanced in the ed.

I also use a 100mm pst mod using a Talk achromat for Ha observing and this is a completely different experience and cost bracket and a quantum leap from the original 40mm aperture.

Basically, in the politest way I can, I completely disagree with Ronin about almost everything he says :0)

[Stu]

If you want the granulation then you need the Lunt or Quark bits for the scope, or the full Coronado PST.

You cannot get/see the granualtion with a white light filter such as the Baader Solar Film.

More aperture will not help, actually if you look at the Coronado PST's they are quite small scopes as in around 2" diameter.

In white light the lens quality is relevant, oddly not so important in the narrow band Ha or CaK that is used. Being just a narrow piece of the spectrum there is almost no Chromatic Aberration. However like most things I suspect an ED would deliver sharper images then an achro, just not the significant step seen in normal visual observing.

You can see granulation in white light with the right equipment. It can be quite dependent upon seeing conditions but is certainly possible.

A herschel wedge will give improved results over solar film and should allow you to see it in your 80mm. A Continuum filter will also enhance the views. This kit will show you the umbral and penumbral detail plus faculae and granulation. You do not need a lunt or quark for that.

In my opinion 100 to 120mm is about optimum for solar. Aperture certainly does help a lot, but it it also very dependent on seeing conditions. A 120mm gives fairly reliable results, 150mm will ultimately give better results but less frequently due to seeing.

If you want to see prominences, filaments etc then you do need an Ha scope but I don't think that's your question?

Stu

[jetstream]

I use a 90mmAPO and a 120mm ED doublet. In good seeing (now) I see granulation as cell like and the spots, plage etc show depth and structure to them. This is at very high 140x - 240x mag in the SW120ED. The 90mm is good up to about 150x IME and is much less sensitive to seeing and your 80mm with a wedge should give great results too.

In good seeing the SW120ED is gives much more detailed views than my 90mm. The biggest question I would ponder is how seeing limited are you? Your 80mm should be great with a Lunt or Baader wedge.

[Dave In Vermont]

I'll 2nd. the Baader Solar Continuum Filter suggestion. It will turn the Sun green, but I got used to it and the assist it gave was worth it to me. Currently I use a tricked-out ST80 F/5 for my solar viewing. Up front I am using an Orion filter like this:

http://www.telescope.com/Orion-400-ID-E-Series-Safety-Film-Solar-Filter/p/102779.uts?keyword=Solar%20filters

These are different from the Baader-foil ones. This being from Thousand Oaks:

http://www.thousandoaksoptical.com/solar.html

They yield a yellow-orange solar-image rather than white. Between this and the Baader Solar Continuum filter, I'm quite happy.

Bright Skies by Day,

Dave

[LukeSkywatcher]

My solar observing set-up is: 

70mm Celestron Travelscope

1.25"  Hershel Wedge

1.25" ND3.0 filter

1.25" Solar Continuum filter

1.25" Variable Polarising filter

Its all new gear (apart from the scope) and only been used a handful of times so far. The views are far more spectacular then just using the solar film type filter. Granulation is visible and can be stunning. Sun spots are also visible and are so much more defined and sharper. The solar continuum filter turns everything green but thats not a problem really. As well as the ND3.0 filter, the polarising filter i feel is essential. It gives you total control over the brightness of the Sun (and boy is it bright). 

I was a bit reluctant at first to invest in the wedge and filters but it has been worth it. I could have probably got myself a PST for the same price as all my bits cost me, but it didnt cross my mind to go down that route and well.................it just really didnt cross my mind. Hind sight is a great thing. Maybe in the future, because i'd love to do some H-Alpha observing. 

The great thing about solar observing is that you set up during the day and you dont need a torch etc and its good for your health to get some vitamins into your body. The views are a bonus.

[bomberbaz]

question on this, if you used a lunt wedge in a 100mm frac and then added a HA filter to the eyepiece at the business end, would this show you prominences?

ps, if not, why not

Steve

[Stu]

question on this, if you used a lunt wedge in a 100mm frac and then added a HA filter to the eyepiece at the business end, would this show you prominences?

ps, if not, why not

Steve

Simple answer is no unfortunately Steve. It's because the bandwidth on an Ha filter is not narrow enough to block out the rest of the light so the proms still get swamped. You need a dedicated Ha scope or Quark (basically with a tuned etalon to get the tight bandwidth), and that costs significantly more

[bomberbaz]

I see, thanks buddy. I thought not but had to ask.

[Peter Drew]

Probably answered a lot of other people's first thoughts.  

[Moonshane]

Plus the lunt wedge would remove 95% of the ha (along with other spectra) which would be too faint even if the filter were adequate.

[michael.h.f.wilkinson]

If you want the granulation then you need the Lunt or Quark bits for the scope, or the full Coronado PST.

You cannot get/see the granualtion with a white light filter such as the Baader Solar Film.

More aperture will not help, actually if you look at the Coronado PST's they are quite small scopes as in around 2" diameter.

In white light the lens quality is relevant, oddly not so important in the narrow band Ha or CaK that is used. Being just a narrow piece of the spectrum there is almost no Chromatic Aberration. However like most things I suspect an ED would deliver sharper images then an achro, just not the significant step seen in normal visual observing.

Wrong on several counts:

1: Granulation can certainly be seen in white light. A Herschel wedge is definitely better than Solar film. Adding a solar continuum filter makes granulation even more prominent. Bigger scopes always help, but I can already see granulation with my 80 mm triplet and Herschel wedge. As shown below

2: In white light aperture does a lot. Check out SolarChat, where you can find dozens of extreme high-res shots with 8"refractors, and even the odd C14

3: Even in H-alpha, aperture certainly helps. The following shows a comparison going from 35mm on the LS35THa, via the SolarMax-II 60mm, to the 75mm system with Solar Spectrum filter

(click for full resolution)

4: Finally, even though colour correction is of little importance in H-alpha or CaK, optical quality is. A lens with good optical figure is needed to avoid other aberration or just generally poor performance.

[Peter Drew]

In fairness to Ronin, I think the term "granulation" tends to be use rather loosely. The granulation seen in white light  is at a different level than that in Ha leading to the fact that granulation texture can be seen in either but of different origin. I suspect the granulation referred to by Ronin was that seen in Ha which would require a Ha filter.    

[michaelmorris]

Whilst not as effective as a Baader Solar Continuum filter, any decent green filter will tend to enhance granulation contrast when imaging the Sun in white light.