Using the same laser pointer as in my previous post AF Assist tool v3.0 – laser pointer trials, I decided to stick a cap from a dollar store laser. You know the caps. The ones that draw hearts, or arrow, etc.

I tried a few, and one really stood out as sharp pattern, and coverage across the largest area of the frame.

Frame coverage at 50mm, on a crop body (x1.6). Not a very large coverage, but the contrast it produces is very defined. Even at 40ft the image is crisp. All focus points have no problem locking on even on f2.8 lens (not just the center cross type AF point)

I will have to investigate other laser pointer caps to see if I can find something that has a larger area coverage and provide lots of contrasty details for the AF sensors on the entire frame to use to acquire focus.

There is this diffraction lens I can get  but I don’t think it will project much larger then the bow and arrow I already tried.

Ideally something like this
Frankfurt Laser Company – Grid
or this
Frankfurt Laser Company – Ring/Concentric
would be perfect, but again, it all depends on the size of the image it projects.

On the other hand the pattern can’t be TOO large because at distance it looses it’s contract effectiveness as the pattern gets to spread out.

This pattern will get too thinly spread out. It’s great if you’re only a few feet from the subject but much more then that and the space between dots/patterns gets too large and the AF sensors/points can too easily fall between the patterns.