@xenogears, @HillTop1 Unfortunately the calibration process is not as easy as setting back focus on ENG lenses (which usually just entails turning a screw) - you'll probably need rails and a lens support bracket, or at least SOME way to keep your lens supported horizontally when you do this.

Rather than write up the process myself (I'm super busy today) I'm going to copy and paste a post by @Balazer made on the mflenses forum that describes the process pretty well (thanks Balazer!), and is where I learned to do it:

"To make the Canon FD 35-105 mm f/3.5 lens be parfocal, more than likely you need to adjust the back focus (lens-to-flange distance), and nothing else.

Just in front of the aperture ring is a black plastic ring with "35-105mm" in green letters, an orange line, and a serial number in white. It has three Phillips head screws with the heads painted black. Remove the three screws. The black plastic ring can now slide forward, revealing four more Phillips head screws. With the lens pointed downwards, loosen those four screws. They'll be tight, so push in with a lot of force so that you don't strip the heads while removing them. With those four screws loosened, the lens's mount and aperture ring are free to slide up and down. If you didn't have the lens pointed downward, the mount could slide off completely, leaving you to figure out how to slide it back on. So don't remove it. You just want to be able to slide it up and down a bit, and then re-tighten the screws when you have it in the right position.

Mount the lens to your camera. Set the aperture to the widest setting and the zoom to the maximum. Focus on a distant object. Set the zoom to the minimum, and adjust the lens-to-flange distance until the picture has sharp focus. Note that with the four screws loosened, the mount can tilt, so be careful to keep the mount's axis aligned with the lens's axis while you're making your adjustments. If in doubt, check for equal focus at the four corners of the image. Repeat these steps until no further adjustment of the lens-to-flange distance is required to have sharp focus across the zoom range with the focus ring in the same position. Re-tighten the four screws that hold the mount in place. You'll want them to be quite tight, as they are supporting the lens's entire weight."

@Quadri check out Metabones Speedbooster (google it), saving you the technical details, basically it's voodoo magic for your lenses - it makes them wider and brighter. It's not cheap, though there are some cheaper variations coming out of China (Mitakon is one), but it's an investment worth considering if you're serious about using older manual lenses on a M4/3 camera.

@Qadri I use a metabones speedbooster, so the 35-105mm becomes a 24-75mm f2.5, so that extra stop of light and that extra width in FOV really helps for indoors.

The Panny 35-100mm would be longer focal length and slightly darker (when compared to the FD with Speedbooster), plus the focus ring on the Panny is focus-by-wire, which you may or may not want.

Personally, I like the character of older glass, and I like using my Speedbooster on all my FD lenses, but that's entirely a personal decision. To each their own!

@all

Check LPowell notes.

This topic is for making good list of video friendly lenses and with very tight discussion restrictions. Do not turn it in all-in-one.

Ok fine. I asked about brightness as in many respects it determines whether a lens is friendly or not for video.

Anyway, here is another lens that along with the Canon FD 35-105mm, has also been referred to as a "stack of primes": SMC Pentax-A 35-105mm f/3.5 constant aperture"stack of primes" lens.

On the downside though, it physically extends when zooming. (info provided to me by someone else):

First ring, closest to camera is aperture ring. The next ring allows zooming from 35-105mm. The final ring controls the focus from 1.5m to infinity and also in macro mode. Apart from lens extending issue, great for video as suffers from minimal focus breathing

Length of lens at 35mm and infinity = 98mm (from mount flange) Length of lens at 105mm and infinity = 107mm Length of lens at 105mm and closest macro = 120mm

Did anyone rank the AFC quality on the 14mm 2.5 and 20mm 1.7? I would think that qualifies as a fast lens for low light shooting.