26th May 2021
Clear skies for the lunar eclipse and here is a selection of progress images, all taken with my DSLR 60D camera on a tripod, using a Tamron 150-600mm lens at 600mm. This was not a bulls eye eclipse, meaning the centre of the Moon did not pass directly across the centre of the Earth’s umbra (shadow).
Hence one edge of the Moon remained extremely bright, almost as though the eclipse wasn’t total, while the opposite edge was extremely dark. It was total but only just, as the image below (adapted from this NAS Eclipse web page) shows:
Lunar eclipses like this can be difficult to image because of the extreme range of luminosity encountered in a single shot. It is difficult to expose the darkness of the region in deepest eclipse (and only reflecting earthshine) while at the same time trying not to over saturate the region which is still reflecting sunlight.
I struggled to cope with the dynamic luminance range at or near totality taken with my DSLR. I haven’t yet processed the images I was taking simultaneously with my telescope but I am not expecting them to cope any better with it. I’ll be checking them tomorrow.
Anyone who has imaged a crescent Moon would know what I mean by this. It’s always a toss up whether to show detail in the bright crescent or the detail of the rest of the Moon which is weakly illuminated by moonshine. You cannot have both.
Note 1 : I shot some of the images off-centre to capture the nearby stars which became visible at or near totality after I had switched to a very high level of ISO.
Note 2: The reddish colour (never “blood red”, don’t believe the hype) of the Moon at a total lunar eclipse is caused by light being reddened as it passes through the Earth’s atmosphere before reaching the Moon.
Note 3: The stars visible in the last three images are all around 4th-6th magnitude.
Note 4: All images are uncropped.
Images © Roger Powell
|Camera: Canon 60D DSLR|
|Lens: Tamron Ultrasonic SP 150-600mm f5-f/6.3|
|Software: Digital Photo Professional & Gimp.|
|Observatory location: 34° South.|
Thanks for reading!
I’m one of the founder members of Macarthur Astronomical Society and current webmaster.