Sunday night will mark the first time in 33 years that a lunar eclipse will coincide with a supermoon. I’m hoping the sky isn’t so cloudy as to block the view of the moon. I enjoy astrophotography, although I don’t shoot enough to warrant buying a telescope and adapter. Getting such gear on short notice is pretty difficult, so I rented a Canon 100-400 f/4.5-5.6L IS and 1.4x II teleconverter.
Screwing up the shots tomorrow means waiting 18 years, so I got some practice tonight! The results are in, and I can confirm that teleconverters do indeed suck (at least this combination). The first shot below was taken f/8@400mm. The second shot was taken f/8@560mm with the 1.4x teleconverter. While the moon is much larger, the sharpness is much lower. It is obvious the costs outweigh the benefits.
I now somewhat understand why f/5.6L 300mm+ lenses cost so much! Maintaining sharpness at those focal lengths requires some high quality glass. I’ll be shooting without the teleconverter Sunday night; but, if anyone has a good lead on a telescope and adapter, let me know.