Well preparations for this years chase expedition continue – the lens change-outs are almost complete (will discuss in further detail when everything is done/resolved), but here are some test shots to share…
In preparation for the possible opportunity to document the near/at sunset Annular Solar Eclipse in W Texas/E NM on 20 May, 2012 (and the even-more-rare 5 June, 2012 Transit of Venus!), I picked up a couple of 2x MC4 Kenko Teleconverters (at half price!) to test with the Canon EF 70-200 IS F4.
I was willing to even try these with the Kenko Pro 300 1.4x teleconverter I picked up three years ago (that produce no appreciable image quality degradation with the 70-200)!
So yes I was expecting loss of image quality, but will that matter when dealing the a sun so close to the horizon that atmospheric effects are already maximized…
This attempt (hand-held!!!) with 200 x 2 x 2 x1.4 – 1120 mm of reach allowed me to capture these geese passing in front of the sun!! Also note that this is pretty much right at the first contact with the local horizon (note the distant tree-tops) and includes a contrail.
It also looks like there may be a couple of sunspots visible (I know sunspot #1429 was big around this time, but I am not experienced enough at sun observing to say for sure) – click on image for larger version:
So I tried – so far I am happy! I will continue with various combinations of the TC’s to find a sweet spot of image quality and magnification – that again may be dependent on the given state of the troposphere!
This combination (also hand-held!) also seems to hold some hope for some interesting compressed ‘skyscapes’, like this example from the same series: a mix of cirrus, old contrails that have evolved into cirrus, big middle-aged contrails, and one new contrail being created:
It seems that, at least with high and distant clouds, the image quality loss from all that extra glass, is at least, not unpleasant.
Will look forward to exploring more (and with the tripod)!!