FZ200 and some teleconverters

I took the FZ200/DMW-LA7 and a couple of lenses out to visit one of the local churches.

Here's a section of wall at 600mm f/2.8 using the camera standalone.

This uses a combination of a shortened TC-E15ED+TC-E17ED at f/5.6

I used the following lens combinations:
..No lens
..shortened TC-E15ED
..TC-E17ED
..TC-E15ED+TC-E17ED
..Tcon17
and for each, uploaded images at f/2.8, f/4.0 and f/5.6 to this Picasa link.

https://plus.google.com/photos/107626094434145385562/albums/5783938787128989953?authkey=COCQkITpqvzi2gE

All images are SOOC, ISO 100, AWB, OIS off, NR=-2, Sharpen=+1. They can be downloaded at full resolution. The filenames include the aperture and lens.

My conclusions from the set:

E17ED was the best extender. Images were clean at all apertures. I could not discern the aperture from any single image at 100%, although I could sequence them properly when examining all three. Would you believe 1000mm at f/2.8?

Tcon17 was next. Images at 5.6 were just a bit softer than E17ED. There was a bit more softening than E17ED as the aperture increased, but the effect was small, and I would consider the 2.8 images quite acceptable. Tcon17 costs about 1/2 stop of light (as I posted a few days ago) so we're talking 1000mm at f/3.5. Considering its weight advantage over E17ED, this is a formidable lens for walkaround.

E15ED was ok at 5.6 - Certainly equal to Tcon17, and perhaps even to E17ED. There was a good deal of softening at 4, and even more at 2.8.

This was a bit of a disappointment. Really no reason to use E15D other than as part of the E15ED+E17ED combination.

The stacked E15ED+E17ED followed the pattern of the E15ED. Images were excellent at 5.6, but softened at 4.0 and again at 2.8. This combination loses about 1 stop, so we have an excellent 1500mm telextender at f/8.0 equivalent, with softening at 5.6 and 4.0. Not bad, but the combination needs 22-24x to avoid vignetting, so I'd consider it a "special purpose" combination, but not something I'd carry around in the hope that I'd come across a suitable subject.

Comments, cropping, reposting, etc are welcome.