Using Classic Manual Focus Lenses on the Canon Digital Rebel

The Canon EOS lens system began in 1987, which is a pretty short historical period, and none of the earlier Canon lenses can be used on Canon EOS cameras. Based on that, one might think that Canon owners who appreciate the finely crafted manual-focussing metal bodied lenses of yesteryear are out of luck.

In fact, it is just the opposite. It is possible with adapters to use Leica reflex, Contax (Carl Zeiss), Pentax screwmount, Olympus OM and Nikon Nikkor lenses on EOS bodies, and these focus to infinity. This is possible because the Canon EOS mount has a larger opening than these other brands, and the lens-to-sensor distance is shallower. Recently, adapters have appeared that allow Pentax K lenses to be used on EF-S body EOS cameras (on full frame EOS, there is not enough mirror clearance, so the Pentax aperture lever would have to be removed).

The most useful of these options is the Nikon mount, since it has the largest quantity and variety of good quality lenses available at reasonable prices. Nikon sometimes likes to boast that it has used the same "F mount" system ever since 1959, but in fact it is only Canon owners who can use the whole line without modification. Prior to about 1978, Nikon lenses did not have AI notches cut into the back of the aperture ring, and these earlier lenses cannot be mounted on some modern Nikons such as the D80 or D70 all. The later AI lenses can be mounted on a newer Nikon, but without metering capacity. (The more expensive Nikon D300 and D3x do allow metering with AI lenses.) The newer Nikon D40 and D60 allow you to mount pre-AI lenses, though they offer no metering.

As Ken Rockwell writes, "Oddly, Nikon manual focus lenses on most Nikon AF cameras are almost useless and provide no metering. These same manual lenses used with these adaptors on Canon EOS cameras provide metering, more function than on most Nikon AF cameras. Strange but true!"

The fact that they offer no metering on most newer Nikon cameras, together with the fact that there are so many of them around, has driven down the price of these older Nikon lenses. Excellent quality lenses that originally sold for hundreds of dollars can be had for a fraction of their original price on eBay. The Nikonian's loss is the Canonite's gain.

With an inexpensive adapter (about $25 from various vendors on eBay), any Nikon lens, including pre-AI ones, can be used on a Canon EOS camera. Not only can they be mounted, but metering works. Put your Digital Rebel in aperture priority mode, and the shutter speed will automatically adjust to get the right exposure. To stop down to a smaller aperture, you turn the aperture ring on the lens. (For this reason, the newer G series Nikon lenses, which don't have an aperture ring, are not a viable option.) In theory there is no reason why Nikon cameras shouldn't offer this option, and I suspect that if Nikon wanted to, they could implement it on the D70 with a firmware change, as Pentax did with the *istD. However, as a business decision, they probably prefer not to, since it lets them sell more new lenses.

The fact that most Nikon lenses up to about 1999 had aperture rings is the key to their usability on EOS cameras. In another irony, there are some older third party lenses made for EOS (especially by Sigma) whose CPU is incompatible with Canon DSLRs. For example, the Sigma 24mm f/2.8 is a pretty good lens. (In MTF tests at www.photodo.com, it scored slightly better than either the Canon or Nikon equivalent, but is less than half the price.) However, the EOS version is useless on a DSLR, because it can't be rechipped, and it doesn't have an aperture ring. So if you want one of these for your Canon DSLR, buy one with a Nikon mount!

There are a few different Nikon to Canon EOS adapters on the market, with one made by Novoflex costing about $200. The precision of the Chinese-made $25 copy is no doubt a bit lower, but it is quite adequate. It has a little tab you push that makes it easy to unlock the adapter from the lens. There is another version (Ukrainian made?) which requires you to use a small tool for this job.

The best reason for getting one of these adapters is to take advantage of the many 50mm f/1.4 Nikkor lenses that are on the market that can be picked up cheaply, often for as little as $50 on eBay. The oldest ones, designated just "Nikkor S," do not have multi-coating, and are reputed to have lower contrast and more flare. However, starting in the early 1970s, with the Nikkor S.C version, they have all been multicoated. They all have seven-bladed diaphragms, which helps to render a nice smooth appearance to the out-of-focus backgrounds, which is referred to in Japanese as good "bokeh."

With the 1.6 multiplication factor for a digital camera, the 50mm lens becomes the equivalent of an 80mm lens. That's an excellent focal length for portraits.

The following table shows some lens resolution test results that I found in back issues of Modern Photography Magazine (which is no longer published, having been absorbed by Popular Photography). These should only be viewed as illustrative, as there is a considerable amount of variation among individual lenses of the same model, due to variations in manufacturing quality. Arguably, the Carl Zeiss Planars were the best 50mm lenses made, and the 50mm f/1.7 is available at relatively modest prices.

50mm lens resolution tests from Modern Photography Magazine
	Lines of resolution at different apertures, central area
	1.4	1.8	2	2.8	4	5.6	8
Canon 50mm f/1.8 EF Mark I (1988)	na	45	na	50	56	56	63
Nikkor 50mm f/1.4 S.C (1974)	60	na	67	67	67	76	85
Nikkor 50mm f/1.4 AI (1980)	49	na	55	62	69	78	78
Leitz Summilux-R 50mm f/1.4	49	na	49	62	62	69	69
Carl Zeiss Planar 50mm f/1.7 T*	na	62	na	62	70	70	70
Carl Zeiss Planar 50mm f/1.4 T* (1976)	62	na	78	78	78	78	78

The 1.4 lens is fairly sharp in the center even wide open. By f/2.8, it is sharp even in the corners as far as the Digital Rebel's frame is concerned. The following examples compare a 50mm Nikkor to a 50mm f/1.8 Canon EF lens, both at f/2.8. There is a large difference in sharpness, especially in the corners.

Of course, at large apertures there is very little depth of field, so you are going to get sharp pictures only if you focus carefully and accurately.The viewfinder in the Digital Rebel is not bad for manual focussing, although of course it can't compare to the great viewfinders of old. Straight lines and sharp edges snap into focus pretty well, with a good demarcation between in and out of focus positions.

In good light, or on subjects with sharp lines, I find that I can manually focus even a 24mm f/2.8 lens pretty easily. My Sigma 24mm, at f/4, is considerably sharper than my Canon 18-55m zoom lens, so in a dim environment where flash isn't permitted, it becomes a good option. In dim light where there is not much detail, it is not easy to manually focus even a 50mm f/1.4 lens. In such circumstances, autofocussing isn't perfect either, but it is faster. However, with digital, there is the advantage (at least with still subjects) that the photo can be taken over again until the focus is perfected. With practice, manual focussing becomes easier.

In addition to the 50mm lens, there are good values in manual focus Nikkor macro (which go by the name of "Micro-Nikkor" and telephoto lenses. The 55mm f/3.5 Micro-Nikkors can usually be purchased for under $50 in excellent condition, which is a screaming value for such a sharp lens.

While used Nikkors are by far the most common, there are also some very nice SMC Takumar M42 screwmount lenses by Asahi Optical (Pentax) that can be used. One of my favorites is the very sharp 35mm f/3.5, a tiny lens weighing just 150 grams.

Recently, I acquired a 135mm f/3.5 Nikkor-Q lens (made around 1966) in very nice condition for $18. It is one of the sharpest lenses I've ever owned. Manual focussing is particularly easy with a long focal length lens.

Here is a crop from a photo taken with it, wide open at f/3.5:

Using Manual Focus Lenses for Video on the Canon Digital Rebel T1i 500D

Some of the newer DSLRs now enable you to make videos as well as stills. While the early implementation of video on DSLRs is somewhat primitive, there are significant potential benefits to this feature. A DSLR has a much larger sensor than the typical camcorder, allowing better videos in dark surroundings with less noise. In addition, use of fast lenses on a larger sensor camera allows professional effects such as blurring the background to isolate the main subject. However, in order to do this, the camera has to offer manual control over aperture. This is something that has been implemented on the expensive 5D Mark II, but is so far lacking on the T1i. (There is some hope that a future firmware upgrade will make this possible.)

However, there is a way to force the T1i to give you manual control -- namely, by using one of the manual lenses discussed on this page. I just put a Nikkor 50mm f/1.4 on my T1i, and set the camera to video. With a Canon auto lens, the camera automatically lifts the mirror and goes into live view when you turn to video, but with this lens there is first a black screen with the message "make sure a lens is attached, and then press the video record button." Once you press that, the camera goes into video mode with the live screen.

I found exposure to be accurate, and manual focussing with the f/1.4 lens wide open is a breeze on the high resolution LCD of the T1i. It's much faster to focus manually than using the slow auto focus available in video mode. So there you have it, the more technology progresses, the more these old lenses have become useful.

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(c) 2009 by Peter Spiro