Sample Video: DOF Control-Nikkor on T1i
 

A short video showing shallow DOF and selective focus achieved with old Nikkor AI-S f1.8 50mm wide open at 1.8 mounted on Canon T1i. Lens is mounted on camera body using an $8 adapter ring off ebay, the lens cost a bit more. I found a near "mint" 50mm f1.8 for $89.

Aperture is strictly manual, turn the aperture ring to the desired f stop just like in the "good old days" as the camera cannot communicate with the lens and therefore is not able to take over and control aperture.

Focus is also strictly manual. The Hoodman USA Hoodloupe 3.0 held on with rubber band makes focusing and viewing in daylight much easier.

Link: Canon T1i with Nikkor lens on Vimeo

Hi Bruce thanks for posting this I enjoyed watching it.

T1i DOF control with Canon lenses
 

Had to add some more tips:

Don't want to go the Nikon lens to EOS adapter ring and hunt for Nikkor lenses? If you have the Canon EF 50mm f1.8 (or the Canon 50mm f1.4) you can get the same effect shown in the video in the first post. Here's the procedure:

1. Turn the dial on top to AV (Aperture Priority) mode.

2. Dial in desired aperture.

3. Press lens mount button to "unlock" lens and watching the LCD gently turn the lens barrel until the f number turns to "00" (the lens contacts are disconnected at this point and the lens and body cannot "communicate" so the camera cannot control the lens). The lens barrel need be turned only very slightly to do this. The lens will now remain at the selected aperture even if the camera is turned off, when turned back on you can resume working at that same aperture.

4. Turn the dial on top all the way to "video" mode. The mirror will go up and a warning message telling you to insure a lens is attached shows. Press the video start button and you have the "live view" for video. With the lens set for manual focus turn the focusing ring until you have focus (autofocus is not available since the lens and body can't "communicate"

5. Press the video start button again to start recording. Again to stop.

6. To return to normal full auto operation turn the lens barrel back until it clicks into the "locked" position.

The 50mm f1.8 Canon EF lens, often priced at about $80 is an amazing lens for achieving shallow DOF. This focal length on the 1.6 factor APS C sensor size camera is an almost perfect portrait length lens and for close up to half length on one or two people will work great with selective focus at f1.8 and you can achieve this in outdoor daylight. I would advise trying for open shade or wait for close to sunset but it will work in sunlight also.

This lens will also do an amazing job in low light even with the lens "locked" allowing auto control to take over.

Even the kit lens can be used in this manner, the maximum aperture will not give as shallow DOF but will still do better than just letting the automatics do it all.

Just thought I'd pass this on.