Full disk solar mosaic

[Paul Haese]

Pretty average conditions today but luckily the proms were good.

Still waiting on my new 80 Lunt so for now it is working with the solarmax 60

Click here for image.

[Larryp (Laurie)]

Great image, Paul!

[Peter Ward]

Not bad Paul.....but what I'm going to say I fear is the eqivalent of, "yes your bum looks big in that"...

Toss the camera in the bottom drawer for a bit, and look at the sun with a warm eye and well corrected eyepiece (and solar filter! )
Your hopefully will see....

• Very smooth solar hemisphere flux, there are no seams, it's basically a glowing sphere with "frilly bits" on top
• there is no chaotic (blurred/double image) structure
• proms don't have "glowing auras" and are well defined against black space.

How you choose to represent a monochromatic image (h-alpha) of the sun is of course up to you....but processing artifacts, to me, should be avoided at all costs, as, like black rings around over-sharpened stars, they simply don't exist.


Hope that helps

[nandopg]

Paul, great image. I love your full disc and the way you process them, bringing out details while keeping the smoothness.

I think I got Peter's comment about the soft halo around the solar disc and I think that is a good discussion.
For my personal test hoewever, I prefer not to clip the black totally letting the smooth gradient around the disc.
In fact I think that by black clipping this image, one would be introducing more distortions to it than not to clipping, as it is on Paul's image.
Also the fact that our eyes are not capable to grasp this subtle gradient from the solar disc to the darkness of the space doesn't means too much given the reduced dynamic range proper of the human eyes.

Fernando

[Paul Haese]

Thanks guys.

However to be fair, all my images have soft bits and you can see the joins. This is caused by the sweet spot effect with this scope. Something I hope to get rid of as soon as I get the Lunt 80. It annoys the crap out of me, I have been doing larger mosaics with more panels to eliminate most of the issue but getting the etalon setting just right is problematic. The older solarmax 60 which I have suffered from sweet spots so this is what you have to deal with. Viewing the sun the sweet spot is just barely visible but when imaging it becomes obvious. When imaging at higher res this problem disappears but means lots of panels to do a full disk. So Pete I am familiar with what the sun actually looks like and trying to emulate that but at present I am hamstrung.

The glowing aurora around the proms is a product of this sweet spot problem too. One hemisphere ends up being very bright once the blend occurs and this needs to be even up to make it look "right". I personally don't mind this look myself because in the eyepiece the sky looks like a faint red around the sun, when in fact it ought to be near black when looking away from the sun (ie if you were in close orbit and looking at the limb). Personal taste I suppose but not to everyones liking.

You have to use what you can, at present I am in the waiting game.

[Peter Ward]

No worries Paul, I figured you would take it as a positive criticism...there are way to many ways to process an present data, none of which are really faithfull... unless you make it a 665nm red ball

(...which is outside of Gamut of any monitor in any event! )

[Paul Haese]

Originally Posted by Peter Ward

No worries Paul, I figured you would take it as a positive criticism...there are way to many ways to process an present data, none of which are really faithfull... unless you make it a 665nm red ball

(...which is outside of Gamut of any monitor in any event! )

Certainly understand what you are driving at, hence why you have gone to a single frame and I am seriously considering it. Either with the 2.8 or the 6. I often get good seeing here so 6mp might be what I want rather than the 2.8 which would force me to do a mosaic of 4 panels with the Lunt at 1120mm. The 6 would require only two panels. Tossing up yet what to get and I know of the issues you have had but I don't have any of this problem with the flea 3 running at 50-60 frames per second. Albeit quite small but over 50 seconds I get rather large files sizes. External drives are what you need.

I like the colour I get but hate looking at the soft spots and inconsistent views. I can truthfully say I have wrenched all that I can from this little 60mm and am now looking forward to moving onward.

[Matt Wastell (Matt)]

Good one! Congrats on the Venus transit disc in A S & T too!

[RickS (Rick)]

That's a wonderfully active sun, sweet spots or not!