Monday, May 8, 2017

Astro Imaging and Processing the Sun

This tutorial is taken from SkyatNight Magazine and written by Pete Lawrence.
I think this tutorial can be very helpful for our members that enjoy the Sun as much as the stars. 

STEP-BY-STEP GUIDE:

STEP ONE
Before pointing your setup at the Sun, check and fit your white light filter and remove or cap any finderscopes. Locate the Sun using your camera and focus on a sunspot or the limb (I recommend getting and using a dedicated solar finder or you can use scope's shadow... much easier ~ km). Center on the middle of the solar disk and check for overexposure – there should be no white visible. The levels meter should read just less than maximum.

STEP TWO    

Move the telescope (slightly) in RA. Orientate the camera so that features on the Sun move parallel to the bottom of the image frame. Push the front of the scope up, note the direction – the leading edge of the sun is the northern limb. Apply pressure to the front of the scope to push it to the West; the leading edge of the sun is the western limb.

STEP THREE   

if your software allows, reduce the gamma on the image to make the Sun's surface easier to see. A green or solar continuum filter over a monochrome camera can enhance solar granulation. Record 500 – 800 frames or each section of the Sun: make sure that captures overlap. Process each using a registration and stacking program.

STEP FOUR   

Load the first processed frame into a layer–based graphics editor and cropped off any white borders. Increase the canvas size with a black background to accommodate the final image size. Open and adjoining frame and draw a selection box around the image that cuts off the border. Paste this into the base frame as a new layer.

STEP FIVE     

Align the upper layer using surface detail. If there are no sunspots, try using solar granulation –  it's tricky, but possible! Move the upper layer roughly into position then toggle its visibility on and off to align. Once done, use the Curves tool to match tones approximately. Remove any share overlaps using an Eraser tool set to 10%.

STEP SIX   
Repeat for all mosaic frames then flatten the image. Taking a sequence of white light mosaics over several days allows you to reveal the Sun's motion: load each mosaic into your graphics editor, in order, as separate layers. Align them and set the blend mode of all upper layers to darken to show the spots on the layers below.

This all sounds good to me and should be easy to do in Photoshop, however I have not tried to use this tutorial. Above all be very careful imaging the Sun.
Keith

Monday, April 10, 2017

The Full Moon rising out of the clouds and mist

I noticed the full moon and Jupiter rising up through the trees and just out of the haze and clouds.
I managed to run to the camera without hurting myself or anyone else and propped myself against the garage door to get this shot. I took multiple shots to expose for the moon and Jupiter as well as for the clouds and then layered them together in the same location as the originals.
I decided to post the color and b/w because I haven't chosen which I like best.


Tuesday, March 21, 2017

Tuesday, March 14, 2017

I haven't heard from anyone in a while so I decided to send this out.

Most of you know of the image of rising Earth over the Lunar horizon taken by the Apollo 8 crew member William Anders on December24,  1968. 
A lot of you may have experienced the event live or remember the news articles. I, unfortunately, was out of the country at the time but even then I heard about it after a short time later. 
It's an amazing picture.
Here is a recording taken from the LRO (Lunar Reconnaissance Orbiter) during that moment when the historic shot was almost not taken.
Here is the link to see and hear it all:    https://www.youtube.com/watch?v=dE-vOscpiNc

Thursday, February 9, 2017

This video visualizes the real effects of light pollution:

This article and video show us that there is absolutely no substitute for dark skies. Notice how you can barely make out the basic shape of Orion in the city light pollution, however at the darkest location you can see clearly the Rosette nebula and Barnard's Loop

Sunday, February 5, 2017

Recently Judson Graham set out to image M81 & M82. 
Not an easy thing to do for many people but with a teenager's persistence he showed everyone that came to the Research & Astroimaging meeting Friday night, that good things happen when they listen to sage advice from experienced members.
The image he first displayed looked nice but he insisted it wasn't good enough and wanted to know how to better use his processing software.
This image is the result of his makeover. An outstanding job by any account.... but he wants to keep learning how to squeeze the best out of  each shot.

DSS did not want to stack this, I was getting all sorts of weird halos. so I resorted to my backup program "Sequator" which does a great job with stacking but left both sets of diffraction spikes!

His new camera and 8" telescope seems up to the challenge:

Here's the technical off his AstroBin page:
Resolution: 4522x2869
DatesFeb. 3, 2017
Frames:
 47x120" ISO1600
 14x300" ISO1600
Integration: 2.7 hours
Avg. Moon age: 6.13 days
Avg. Moon phase: 36.86%
Astrometry.net job1435394
RA center: 148.956 degrees
DEC center: 69.339 degrees
Pixel scale: 0.970 arcsec/pixel
Orientation: -83.729 degrees
Field radius: 0.721 degrees