Today was a good day for solar photography, and I retried interposing the 2x Barlow lens in the optical path where it provides 1.65x magnification. I did that after reading the most recent digital edition of Sky & Telescope that gave the formula for calculating the ratio of sensor pixel size to focal length with the intent of maximizing the resolution in the final image. My Barlow doesn’t provide maximum resolution, but it balances resolution and visual field so that I can still get the entire solar image in the frame. The last two images in this post are taken with the Barlow in place.
Today’s H-alpha image shows prominences along the north-, south-eastern, and south-western limbs. The sunspot image shows the progression of sunspots moving east to west.
Below is today’s sunspot cameo. Active regions AR3900 and AR3909 are too washed out to see in this image. Region AR3908 close to the eastern limb is barely visible in today’s image – perhaps tomorrow with the Barlow.
Below is the H-alpha image using the Barlow.
The improved detail is apparent in the cropped frame of the solar prominence along the northeastern limb.
