Canon EOS BODIES CAN ACCEPT PRE-Ai Nikkor OPTICS WITHOUT MODIFICATION
Yes, with the Nikon F mount to Canon EF lens mount adapter, I am able to mount pre-Ai era Nikkor lenses onto my EOS 20D body with absolutely NO problems. AND, I get Aperture-Priority automatic light metering,and Manual,match-diode light metering that's pretty damned good! Yup, a couple weeks ago I mounted the F-to-EF lens adapter onto my old 1975 vintage 55mm f/3.5 Micro-Nikkor lens,and bayoneted the combo onto the 20D's steel lens mount and presto! I was shooting at f/5.6 with the old warhorse,and loving it! I don't have much that's not Ai,Ai-S,or Ai-converted, but I do have a few pre-Ai lenses still,including the 55/3.5, and a very good performing 50mm f/2 also from apprx. 1975 in what was known as the "rubber inset focusing ring" era that came right before the Ai introduction. Now that I know how well pre-Ai lenses work on the 20D,I feel like I can consider buying pre-Ai F-mount optics as being something other than mere paperweights.
The fast-ratio focusing helicoid of the 55mm f/3.5 Micro-Nikkor makes manually focusing a very "quick" and "short" affair. The focusing at close distances like 2,3,4,and 5 feet is very easy; at longer distances,it's more difficult to visually determine the EXACT distance for the EXACT focus placement. The 105mm f/2.5 AiS is very easy to focus. The 85mm 1.4,105 D.C.,and 135 D.C. lenses focus quite easily,as does the 300 f/4 AF-S.
In my somewhat limited experience (a month or so) of focusing by eye at stopped-down or "shooting aperture", shooting and focusing outdoors with the short and medium telephotos set to f/5.6 ALL OF THE TIME is,and I quote, "Not that bad". The reason seems to be the bright,brilliant focusing screen in the 20D; it allows me to see the screen's image pretty well at f/5.6. At smaller apertures, depth of field gets greater and the screen image grows correspondingly darker,and so,as the viewfinder image dims ascertaining precise points of focus at progressively smaller apertures becomes kind of tricky, as is composing and actually SEEING what's going on through the viewfinder.
I own a number of slowish lenses like the 28-200G, 70-300 G, and the 80-400 VR and when those lenses are zoomed out and are admitting only f/5.6 worth of light, the finder image is sub-optimal on Nikon and Fuji d-slr bodies; compared to manually focusing slow AF zoom lenses, establishing accurate focus with manual focus Nikkor prime lenses on the 20D is "Not that difficult",and I can get a reasonably high percentage of in-focus images without too much difficulty,as long as the lens is set to f/5.6 or a wider aperture value,and the lighting is reasonably bright.
It's hard to compose well at f/11 stopped down,let's put it that way, but at f/5.6 or at any wider aperture, the finder image is adequately bright in good lighting conditions for composing,and "not that bad" for focus ascertainment. At wider apertures, shallow DOF tends to make the longer tele lenses "pop in" and "pop out" of focus more noticeably and suddenly than the same lenses do when stopped down more, and that pop in/pop out ease allows for easier pin-point focus placement when using one's hand and eyes to select and set the best focus.
The fact that the 20D body gives me Aperture-priority Automatic light metering and Manual,match-diode metering with a 31-year-old Nikkor on it is sweet. Not even the Nikon N80 can do that! Hell, the N80 cannot even mount that pre-Ai lens! So, as long as the light is decent and I'm outdoors in the summertime, the viewing and focusing issues are really, "Not that bad" at f/5.6; obviously focusing is easier at f/4.5, and f/4 is better still,and when shooting around the f/3.2 to f/2.5 area with short,fast Nikkor telephotos like 85/105/135/200, there's basially NO PROBLEM in focusing the 20D by hand-and-eye. It works pretty damned well. AND, the light metering is pretty reliable too,in actual use. I can even use the exposure compensation system in Aperture-priority Automatic mode, which Canon calls Av mode. For me, the real joy is simply in the discovery that that the pre-Ai Nikkor lenses can mount,and give light metering, on the EOS digital bodies, by means of a machined steel adapter that costs as little as $20 from any one of three dozen e-Bay resellers! That's sweet! The old 55/3.5 cuts a pretty good image on the 20D.
Pre-Ai Nikkor lenses which have not been Ai-converted by removing excess diameter on the lens barrel area can simply NOT be safely mounted on a growing number of Nikon-made bodies. Same for the Fuji d-slr models S1,S2,and S3--attempting to mount almost all pre-Ai lenses will damage the sensing pin located at around the 7 o'clock position on these bodies. Mounting pre-Ai lenses on other Nikon-made bodies will cause the Ai-coupling tab in the body, located around 2 o'clock, to have a problem with the too-large barrel of most (but not 'all') pre-Ai vintage Nikkors PLUS there's the sensing pin danger on the top-tier bodies F5-D1-D2-D200.If you break off that sensing pin located at 7 o'clock on the camera body, you're hosed. The EOS system, since it has no mechanical interface for the lens diaphragm coming from the lens, has basically NOTHING mechancial to interfere with ANY part of a Nikkor lens barrel! There is nothing but pure,open space! So, man, these EOS bodies with these adapters are really great for breathing some new life into pre-Ai lenses. Easy mounting, light metering,and new-found usefulness for pre-Ai cheapie lenses which sell for $5-$25 in pawn shops and at garage sales and on eBay.
In terms of lenses which I think work BEST on the 20D, the prime lenses that are my favorites so far are the 85 1.4 AF-D and 105/2 AF-D DC and the 300 f/4 AF-S and the 55mm/3.5. I have not tried 'everything', but I really am not impressed with the 180 AF-D I have, nor with my 135 DC. The 105/2.5 AiS is the most recent lens I've just trialled, and it is a DAMNED fine performer on the 20D. Just sweet. The focusing is very sure,very certain,but then I've used the same one for many,many years. The 200 f/4 Ai I have shows some promise I think, but is has just entered a trial phase along with the 105 2.5 AiS. Here's a semi low-light,early evening indoor photo done with the 105/2.5 AiS at f/4. http://www.pbase.com/derrel/image/64816592
One thing many of you might not be aware of is that the Ai and pre-Ai lenses typically had a much stiffer, harder-to-move focusing action than the later manufactured Ai-S series lenses,which have a lighter-touch, more-freewheeling mechanical feel and,and this is a big thing, a shorter arc focusing throw than the older lenses had. There are some focusing situations where having a stiffer, harder-to-move focusing action can be good,such as with long-ish tele lenses where you must move the focusing ring only tiny,tiny amounts, or when you do not want to constantly over-run the focusing distance with a hair-trigger focusing ring that tends to run loose in actual shooting conditions,such as when re-orienting the camra from wide to tall, or when moving the camera around minutely, only to see the focusing ring go for a spin. Whenever a telephoto converter is used, focusing EFFECTS as seen through the finder change in relation to the degrees of arc inherent in the lens's focusing throw. On a fast-throw lens,adding a TC can make it damned hard to focus very precisely,since the added magnification renders huge changes in focus EFFECT even with very minute turning of the focusing ring of a fast-throw lens,such as many AF lenses, and in most Ai-S Nikkor teles. Overall, with all the variables added together, I'm pretty happy with the focusing behavior of most Nikkor teles on the 20D body,and the manual focus Nikkor primes I've tried work quite well on the 20D.
I have not even bothered with Nikkor zooms on the EOS,yet. Just the 70-150 (yes,it works,and yes, focusing it is a bugger) for 25-30 frames or so, and about the same number with the 80-400VR. That is IT. Those are the only Nikon-made zooms I've even mounted to the 20D so far. I'm not sure that I'm interested in using a slow-aperture,or a variable aperture zoom on a body that has no autofocus. And since my 24-85 AF-S and 70-200VR and 70-300 are G-series lenses,with no freaking aperture rings, they are useless,minimum-aperture G-series junk when mounted on an EOS. Useless. Removal of _THE FUNDAMENTAL LIGHT CONTROL and FOCUS CONTROL MECHANISM_ is a stupid way to castrate a lens,and that removal is THE main reason the G-series mount really,really tweaks me off.It's like removing the brakes from a car. Or taking the heating element out of an oven. Ya' kinda want some way to control a lens using the LENS as a self-determinant,capable tool in the chain. The camera has the shutter, the lens,since when? since 1884 or so.... has contained...the fucking diaphragm control mechanism! Removing aperture control makes a lens worthless for use with many,many devices. Like an extension tube. Or a bellows, or anything,except a modern, Nikon camera made after the mid-1990's and NOTHING ELSE ever made,before or since. G-series lenses are basically useless when they are reverse-mounted.
I've never really wanted to go with the G-series mount, but Nikon has been pushing it recently,for very little good reason,in my experience. The fact that the 200 VR lens is a G-series lens is a bitter pill for me to swallow. It'd be a GREAT lens on the 20D,of that I am sure. But at f/22, who gives a shit? A seven pound fucking f/22 lens once it's removed from a modern Nikon body? The 200 VR's ultra-sweet bokeh would make it a truly sweet lens for a motion picture camera, or for a Canon body,or a Nikon F2 or F3. But, being a G-series lens, it defaults to minimum aperture except on the latest and greatest Nikon bodies, AND it prevents the lens from being migrated from one body system to another body system,and it prevents the lens from being migrated via an adapter to a 3-CCD Canon camcorder,and so on.The 200 VR is a four thousand dollar,lifetime-grade lens,and the thought that Nikon spared themselves $21 in manufacturing costs by not putting an aperture ring on the 200 VR is truly a travesty.