The 6" (~153mm) Metrogon is one of those lenses that often comes up for discussion as it has a bit of a "mythos" about it. It was apparently used by the US Military for aerial photography, and is based off of (or identical to) the "Topogon" lens designed by Carl Zeiss (see my Nikkor 2.5cm f/4 review for more information on that design).
I thought a large-format topogon would be interesting, considering my small-format equivalent, so when I found one on eBay with a built-in shutter and on a lensboard made for my Wista 8x10, I splurged and bought it (though it was really pretty cheap).
The lens is quite a big and heavy beast and is quite striking with its extremely curved fishbowl-esque front and back elements:
I had some film to kill so I went out to try it on 8x10. I was quite pleased with how well the lens performed:
That last one was made with a 100mm Linhof slip-on filter made for my 75mm Biogon, which perfectly slips into the front element "hood" built into the lens. It made the tonality of the sky and trees much more as I envisioned it.
Overall I like the lens and it definitely works well as an in-between focal length longer than my 120mm Nikkor and shorter than my 210mm Kowa.
So how good is it? Well, the basic scans I did on these sheets were 180 megapixels or so total - 1500 DPI for the 8x10 sheet. Here is a crop of the first scan at 100% resolution, which would be equivalent to about a 12-foot print at typical monitor resolutions (96 DPI):
Not bad! Of course this isn't really anything special for an 8x10 negative, but still. Oh, just as an aside, all of these were taken at f/32.