SDO, (Solar Dynamics Observatory) Options

[Guest_PhilCo126_*]

So it's fingers crossed for the Solar Dynamics Observatory, destined to help the predictions of "space weather".
SDO promises to become an exciting mission as an orbiting solar observatory with multiple high-definition telescopes has never been attempted before…

The prelaunch readiness press conference will be held at 1 p.m. EST, on Monday, 8th February 2010 from the Kennedy Space Center News Center. It will be immediately followed by the SDO science briefing, both briefings will be
broadcast live on NASA Television. Launch is set for 9th February 2010 (10:30 – 11:30 a.m. EST).

[S_Walker]

I agree- there's nothing like the experience of seeing/imaging the Sun, Moon, or planets yourself compared to images produced by spacecraft. SDO is great, but the beauty of owning your own solar scope is you can watch changes occur on the Sun in real time. A good, small solar hydrogen-alpha scope is very affordable nowadays.
I use an old Coronado PST and a webcam to record prominences, filaments, and active regions on the Sun every day it's clear (and something interesting is visible). Here's a mosaic I took last week using this combination. BTW, the scope, camera, and tracking mount I use cost a total of just under $1000 US.

[jgoldader]

I agree- there's nothing like the experience of seeing/imaging the Sun, Moon, or planets yourself compared to images produced by spacecraft. SDO is great, but the beauty of owning your own solar scope is you can watch changes occur on the Sun in real time. A good, small solar hydrogen-alpha scope is very affordable nowadays.
I use an old Coronado PST and a webcam to record prominences, filaments, and active regions on the Sun every day it's clear (and something interesting is visible). Here's a mosaic I took last week using this combination. BTW, the scope, camera, and tracking mount I use cost a total of just under $1000 US.

Could you share more on how you made this mosaic? Other than an adapter for the webcam, did you need anything very special? What software did you use, and were there any non-transparent steps (e.g., removal of aberrations due to vignetting, etc.)?

We have a PST, and I would love to be able to use it for this kind of thing.

Many thanks!
Jeff

[S_Walker]

Sure Jeff-

first, I used a very short 2x barlow to increase the image scale. Had to be very short because the PST doesn't have much back focus.
I shot 9 short videos with the DMK; each were about 600 frames long. These had generous overlap between each because the PST has very uneven illumination across the field; it's not vignetting, the problem is the narrowest region of bandpass is pretty small on the PST, so I tune the "sweet spot" to be at about the middle of the image, and simply use large overlap and crop out the areas that I don't use. Also, choose an exposure that doesn't overexpose bright regions on the solar sisk and use the same setting for all your videos; this avoids problems with overlap between frames.

After taking the videos, I bring them into the freeware RegiStax and stack the best 150-200 frames per video, and sharpen them gently using wavelets.
Next, I bring the stacked images into Photoshop (or Gimp, if you prefer) and align each frame, then cut off the areas of each I don't want to keep.

Finally, because I use a monochrome camera, I colorize the sun for aesthetics. I like a yellow sun with orange/red prominences and filaments. This last step is completely arbitrary; remember the PST looks at a narrow slice of the red spectrum (656.4 nm, less than 1 angstrom). Visually, the sun appears dark red, but the eye doesn't see contrasts well in red, so thus I colorize the image to improve visual contrast.