Avid reader but first time posting. I have to say that I love my G5. I have had some excellent results in my opinion, the color and sharpness have been great...of course maybe I am just easily impressed??? 
Either way I have been reading a lot of posts about the different teleconverter lenses (canon, tiffen, olympus, raynox all seem to lead the pack) but am still unsure which is optimal for say an airshow (and of course general use but then the LCD comments below wouldn't apply).
I went to an airshow recently and shot a lot of photos all stock setup at highest res. and was maybe lucky enough to fill 25% of the screen with an airplane. At 100% on a monitor though they look great!!!, just a whole lota blue around them when viewing the whole frame.
I tend to use the viewfinder more in this situation... (1. it's so darn bright out to use the LCD and 2. it's easier to follow the action as they pass...at least for me but don't get me started about the LCD being closed with MF) ...but am worried that the lens will block even more of the view. I have read a few posts that mention 80% - 90% blockage!! Also I want to be able to zoom out at least a little bit from full zoom to capture the ground in some of the low pass shots but avoid the dreaded vignetting.
Suggestions, comments, experiences with these lenses and the viewfinder would be greatly appreciated!
Thank you all!
Stephen



