11 replies to this topic

[BYoesle]

Test driving a HelioStar 76, once acclimatized an centered in the small Jacquinot spot the image is pretty uniform and has very good "double Stacked" contrast for a single etalon system.

 

 

FLIR Grasshopper 3, best 110 of 630 frames. Click for larger.

[rigel123]

Looks great Bob!

[Savage Henry]

Bob, after our conversations a few weeks ago, I did some math, I decided on APERATURE , and pulled the trigger on the Heliostar bundle when I saw it under $3k, with the Skywatcher 30 day “try out”.
The scope arrived 3 days ago, the mount has yet to arrive.
But I put it on my CG4 tripod/ alt/az mount , and have viewed with it, and my 50 mm Lunt Single stack, side by side 3 times now.
In no way am I saying anything bad about the Lunt, but the very first views, to today have not been anything but amazing to me.
Surface detail, prominences, looking at the huge sunspot and the penumbra at what seemed like varying depths, almost like when you can “see” into levels of the steel you torch as it rises in temp and changes the predictable colors, INSIDE…
I am not technically knowledgeable enough to give proper review thus far, but I am loving that tuner for its “live” like action through the transitions.

[Savage Henry]

Also, I saw the sun has DEFINED  “punk hair spikes” on the surface I clearly saw, not in profile at the edge, but “on the surface”…

I cannot even believe a year ago I had never really heard of this stuff.

[Durkinphd]

Test driving a HelioStar 76, once acclimatized an centered in the small Jacquinot spot the image is pretty uniform and has very good "double Stacked" contrast for a single etalon system.

Thank you for sharing. When was this image taken? 

[BYoesle]

Hi Dan,

 

Yesterday at 23:20 UT.

 

Here's another from earlier today:

 

Click for larger.

Edited by BYoesle, 17 June 2025 - 10:25 PM.

[Durkinphd]

 

Here's another from earlier today:

 

Thank you, Bob! Today's image is especially fantastic - I was observing at the same time and enjoyed the bright region at 8 o'clock with the small spire.

[fiston]

Great shot! nice uniformity across the entire image.

[Foc]

The camera seems to be a great match for the scope

[BYoesle]

Hello Foc,

 

The camera is a good full-disc imager with my 900 mm FL OTA's, but is a bit under-sampled with the HelioStar. Ideally with Grasshopper 3 and the HelioStar 76 a 1.5x Barlow would provide a better sampling level.

 

For a 630 mm FL instrument like the HelioStar 76 and no Barlow, a camera with pixels under 3.0 um would be better. 

[hopskipson]

Nice images, Bob!  

 

If I didn't have a double-stacked Lunt 80, I would be tempted to purchase the Heliostar.  I wonder how it would perform with the elusive 75mm external Lunt etalon.

 

Is this your personal scope or a loaner for review?

[BYoesle]

Hi James,

 

A dialed-in Lunt 80 is a better telescope overall - images very similar to my DS SM90 system, has a larger Jacquinot spot, and better suited for imaging and binoviewing with the straight-through BF and Feathertouch focuser options.

 

Using the HS76 with another front etalon would give you a little better contrast, but an even smaller Jacquinot spot and dimmer image. Because of those two results, my preference is that once the double limb is no longer visible (and it is just about that with the HS76) then I'm done with more stacking attempts - especially when using three front SM90 etalons!

 

The HelioScope 76 was on loan, but I've decided to keep it. It's especially convenient for outreach where I mostly show full-disc views. It's easy to set up and  track with the SolarQuest mount, and doesn't risk untoward events with my no longer available Tucson-era SM90 DS system, and is easier on my low-back than the much heavier Losmandy G-11 mount system I've been using for over twenty years...