Solar Magnifications - white light

[Moonshane]

Hi all

I'd be interested to know what sort of magnifications people use on the sun for white light observing. I find that my lower magnifications of around 50x work best. anyone any different?

[RikM]

Same range for me, 40 - 50x. Sometimes as much as 75x for a more detailed look at an interesting group of spots but overall the view is better at lower magnification.

[iwatkins]

Similar here. Was around 50x-75x on the 80ED using solar film.

With the Baader Wedge, I can get 100x in good seeing with my 6" frac. But very seeing sensitive.

I also find simple EP designs work better, e.g. Orthoscopics over complex ones like Hyperions. I think that is mainly down to reduced internal reflections etc.

Cheers

Ian

[Polar Bear]

50x seemed about optimum with both my 90mm and 120mm refractors. Any more just seemed to magnify the boiling atmosphere to a point where there was no gain in clarity.

Paul

[Moonshane]

cheers guys. confirms my experiences.

[michael.h.f.wilkinson]

I tend to start with the 40mm (50x), using my glass filter (Thousand Oaks) but get best results with the 22mm (93x). I think tube currents are in part to blame for unstable seeing. Just occasionally I can go to 120x (17mm).

[Mark at Beaufort]

Shane the best view that I have ever had viewing the Sun is with my 4" frac (FL 709mm) - binoviewers having 25mm plossls and a 1.6x barlow to gain focus - mag about 45x.

The view is incredible a 3D image. Everything appears more sharp and great contrast.

Although I have a good quality Orion glass filter I would love to try a Herschel wedge to compare.

Mark

[Moonshane]

I suspect that tube currents and seeing are indeed the big issue with solar viewing. A herschel wedge would be great to try but I think I am correct that they can only be used with refractors? binoviewers might be on my long term buying list as so many people really rave about them.

[Macavity]

With a Mak150 - Stopped down to 140mm by my homebrew Baader filter... f=1800 / 31mm Hyperion = ~60x (approx). <G> To be honest, my recent attempts at white light imaging (i.e. "colossal" magnifications!) have been disappointing. Either the seeing is awful or the scope is a bit out of whack (sic), collimation-wise.

Since it's mentioned above, I think I might give my "Thousand Oaks" GLASS filter (on a MAK127) a reprieve though. Not totally convinced that Baader film is entirely the "be all and end all"... or maybe a slightly smaller aperture (3, 4... 5" old-money) is better.

[michael.h.f.wilkinson]

I have heard people bash the Thousand Oaks filters, but I have had good results. I commonly heard people saying that an flat optical surface 8" in diameter would cost the earth. They are wrong. A flat surface is no harder than a spherical. What gives rise to their confusion is that a flat optical surface is not the same as an optical flat. A flat optical surface is flat to within, e.g., 1/8 wave. An optical flat is a surface used to measure the figure of other optical surfaces. In order for this measurement to be accurate the optical flat must be flat to a much higher precision. Edmund optics makes them down to 1/100 wave accuracy:eek:. These optical flats are indeed horrendously expensive.

More info here:

Optical Flats | Edmund Optics

The Thousand Oaks filters are definitely not 1/100 wave optical systems, but they are not "window pane" glass of dubious quality either.

[Merlin66]

Yes, the Herschel wedge is for "simple" achromats or refractors without secondary optics i.e. Genesis....

I have Baader Solar film, JMB glass fiters, 1000 Oak glass and the Herschel wedge (both a DIY - 30 degree prism and a Baader version...)

Using the ED80 the wedge comes head and shoulders above all the rest! I have a "Big Yin" the 150/1200 but haven't had the opportunity to try it on the Sun yet...

Depending on seeing conditions (best in the early morning) I can get up to x120 with the TV plossls....

[johninderby]

I find 60x to 80x works the best most of the time with a Herschel wedge and occasionally just over 100x if seeing is exceptional.

Celestron X-Cel LXs work very well indeed for solar observing, and in fact in several comparison tests between the LXs and some BGOs I couldn't really decide which was better. However I use a zoom normally as it's so convenient and I can get just the right mag.

John

[spaceboy]

x41 for me in my 60mm f12. Really starts to show the orange peel.

[nightfisher]

I will give my opinion when the dam clouds finally part!!

[Merlin]

Nobody seems to want to project the Sun into a dark box these days.

Well-known amateur solar observer in the 1960s, Bill Baxter, would sometimes entertain himself by slipping a 4mm Huygenian into his 4-inch refractor to blow up sunspots to fist-size.

Bill admitted that doing this didn't show any new detail in spots!

[michael.h.f.wilkinson]

I did use eyepiece projection years back, entertaining the other kids at school by showing them sunspots projected on a white screen, with the school's 70mm achromat. Very handy in terms of public outreach, as multiple people can look at the same time. I much prefer using a solar filter, quality, and EP projection is out of the question when using reflectors with fast primaries.

[Moonshane]

confession time. I suspect one reason I asked this is that I have never been completely satisfied with the views I was getting and thought this might be cooling or warming of the scope being inadequate.

it seems that I have been a muppet http://stargazerslounge.com/showthread.php?t=189114

I remade my filter tonight so hopefully will be reporting back with better views. wonder how many other people have done this?

[RikM]

Yep

First couple I made properly and removed the film, then some months after, I made a bigger one and forgot to remove the clear film. I tried to salvage it by cutting the clear film away from the front (fortunately) but I botched up the solar film in the process and binned the whole thing.

[Moonshane]

luckily the design of mine meant I could cut out the two rings on the outside and then take them apart to extract the film. I then redid the rings and have glued it all together successfully. just need to check for leaks etc after the cutting and tugging when the sun is next out.

not the end of the world if I need to buy another sheet - lesson learned though!!