In terms of optical quality, many Canon FD and FL prime lenses are very good even for today's standards, some are excellent. Since the introduction of mirrorless µFT and NEX cameras, old Canon lenses are constantly winning popularity and the prices are ricing- some of them like fast, popular lenses have reached virtually their old prices (inflation not accounted) like when they were still in production:

http://web.archive.org/web/20060228063807/www.canonfd.com/pricelists/pricelist1986.pdf

Unfortunately, there are barely any in-depth reviews regarding FL and FD lenses and none of them covers whole Canon's production line.

On µFT and NEX cameras, the adapters for FD lenses are in most of cases perfectly usable also for FL lenses: if the vertical shift (for full-aperture) is a screw, it can be removed within seconds.

IMO, Canon FD lenses worked simply the best on Canon's SLR cameras they were made for. I still use them on my T-90. They reproduce fine on the µFT sensors, but less good on APS-C sensors (like Sony Nex-7) where wide angle FDs show their flaws. Canon FD zoom lenses in general don't perform on digital bodies as good as the modern zoom lenses do, I void using them.<br> The multi-layer “Super Spectral Coating” (S.S.C.) is superior to “Single Coating” (S.C.) and it was introduced already during first generation of FD lenses (with breech-lock). The glass of the second generation lenses, “new FD” (which are mounted like bayonet-mount, by rotating whole lens) is coated in general with S.S.C but it is not ingraved on the front anymore. There are only few exceptions, like allegedly the nFD 50mm f/1.8 lens.

After all the years, I own a small collection of old Canon FD and FL primes, from wide to tele. I will list now the lenses I know very well. My short comments are regarding usage of those lenses *only* on the µFT cameras (GH1 and GH2) with crop factor x2, both for still photography and for video:

• Canon FD 17mm f/4.0: well built lens, neutral colors performance, not especially sharp, purple fringing is visible in the corners if the stills are magnified, but nearly unvisible in videos. Strangely, if stopped down the fringing gets even worse. But this lens has also one great feature: it is rectilinear, it performs “truly” straight lines without electronical coupling. Directly compared with Panasonic and Olympus lenses who use in-camera correction to produce straight lines, the 17mm FD produces as result less artifacts (like Moiré or aliasing). That fact makes this lens very interesting for the videographers<br>
• Canon FD 20mm f/2.8: prone to flare, colors neutral, quite sharp for vintage lens (but very soft if directly compared to Panny 20mm f/1.7), lots of CA in the corners, similar like 17mm<br>
• Canon FD 24mm f/2.0: excellent lens, CA well under control and unvisible in videos, this is razor sharp lens with good contrasts and performs well even by full aperture<br>
• Canon FD 24mm f/2.8: also very good and very sharp lens, cheaper variant of f/2 version (for half price 95% of value, good deal) excellent lens by all means, it has vibrant color reproduction and great performance already from f/4.0 onwards<br>
• Canon FD 28mm f/2.0: another good wide prime, very sharp, good contrasts tad of lateral CA in the corners barely visible for video, more visible for stills (easily correctable)
• Canon FD 35mm f/2.0: the one with concave front element is the famous lens made by slightly radioactive Thorium containing glass. It is allegedly one of the sharpest Canon FD lenses ever made. I can't confirm any of its excellent reputation- maybe I own a lemon sample but mine is just an average lens by all means, nothing special about it. It doesn't flare but it has bit of lateral CA all over, especially in the corners<br>
• Canon FD 35mm f/2.8: small, cheap lens- stopped down to 4.0 and further gets excellent IQ. I prefer it to expensive f/2 version, but it's pity that it has only 5 aperture blades, bokeh of light spots behind the focus looks bad, so I recommend this lens only for daylight shootings<br>
• Canon FD 35-105 zoom f/3.5: beautiful, very solid built lens, but not so practical for videos (not parfocal) otherwise it is a good lens but the primes beat its performance in its whole focal range<br>
• Canon FD 50mm f/1.2: only the aspherical, “L” version is good (and expensive), other f/1.2 versions are expensive and get good after stopped down to 2.8 or more so why buying them? Big problem of all f/1.2 lenses is focusing them properly, even on µFT sensors it isn't easy (by f/1.2 the DOF is equivalent to f/2.5). The “L” version hasn't got nice bokeh, so I can't mention any good reason to own also this lens<br>
• Canon FD 50mm f/1.4: soft color reproduction, blur and unsharp open stopped down from 2.8 gets better. This is popular lens, but its optical performance isn't stellar. Old Minolta MC Rokkor 50mm f/1.4 PG costs less and beats the peformance of this Canon lens by all means: in contrasts, sharpness, colors reproduction and bokeh quality<br>
• Canon FD 50mm 3.5 Macro: truly superb lens, tremendous sharpness and excellent contrast even widely open. Beautiful vivid colors, no CA at all, no distortion. No field curvature (typical for macro lens), so flaten objects (like walls) will be fully in focus by proper positioning of the lens. This is one of the cheapest and lightest lenses around 50mm<br>
• Canon FD/FL 55mm f/1.2 Aspherical: excellent lens (radioactive), very sharp and with excellent contrasts. Bokeh in background is tad sharp, but didn't bother me. I regret I've lost my sample<br>
• Canon FL 58mm f/1.2: wonderfull piece of glass, superb build quality, stopped down from 2.8 its IQ gets excellent for video, (not as good for stills), this lens has nicest bokeh of all Canon's f/1.2 lenses I know (I only don't know the famous 85mm “L”) and I would call it almost “hidden gem” because it is comparable with much more popular (and expensive) Nikkors and Rokkors 58mm f/1.2<br>
• Canon FD 85mm f/1.8: excellent portrait lens, by open aperture it is indeed sharp, but at same time it makes wrinkles look unvisible so the skin looks younger, stopped down to 4.0 or higher this lens gets razor sharp, impressive change. Beautiful bokeh, great contrasts and colors reproduction. I prefered this lens to f/1.2 version for softer open aperture and much lighter weight and lower price (and for sharpness by open aperture I already owned Nikkor 85mm f/1.4 which outperforms the Canon f/1.2 anyway)<br>
• Canon FD 100mm 2.0: top class lens, crispy sharp & beautifull picture without any distortion, no CA, great even open - what can you wish more? Excellent build quality, very solid and compact, heavy lens<br>
• Canon FD 135mm 2.8: sharp in the centre, nice looking picture, good IQ, if I didn't own the 100mm/2.0 I would use it more often<br>
• Canon FD 200mm 2.8 is excellent mid tele lens and one of the best price/performance lenses one can find for the µ4/3 cameras, it is still quite cheap to find even on ebay (regarding the fact it is a very fast tele lens).