Sunday, January 8, 2012

Hyperfocal Distance and How to Use It on the Lumix DMC-GF1

Okay, "hyperfocal distance" is a really technical-sounding term, but it turns out it's really useful for street photography and other instances where you want your camera set up to respond in the fastest way possible, should something you want to capture appear unexpectedly.  So, what does it mean?  In the interest of sticking to my goal of providing my own insight, rather than rehashing other perfectly-good explanations of basic photographic principles, I will refer you here for an excellent explanation and the graphic below:

So, for me, this means that I can make a manual focus setting before starting off down the street, which will maximize my chances of getting an unexpected subject, at a distance that I only know roughly, in focus in the resulting image.  If I choose the hyperfocal point, everything from half that distance away from my lens to inifinity will be "acceptably" in focus.  I put acceptable in quotes, because there is only one correct focus distance, and the rest of the range is just subjectively pretty sharp.  The hyperfocal mark is indicated on most rangefinder lenses, but not many zooms, and not on ANY of the Micro 4/3 format of Lumix lenses that I know.

So, how do I use hyperfocal distance on my Lumix cameras?  Well, this took some digging, and help from my friends to figure out.  Since I normally use hyperfocal distance for street photography, I have learned how to set it on my favorite street shooters, the GF1 and the LX5.  I will describe the method for the GF1 here, and the LX5 in a later post.

First off, keep in mind that the depth of focus (size of the hyperfocal range) increases as you close down your f-stop, going to higher numbers.  It also decreases with lens focal length, so I avoid using zooms, and choose a moderate wide angle prime lens.  The Lumix 20mm f1.7 is my go-to lens for street photography on the GF1.  I find that setting the GF1 to A (aperture priority) or M (manual) exposure, with an f-stop of 5.6 or greater gives a very large hyperfocal range.  It is important to use an exposure mode that does not change the f-stop automatically, as that also changes the hyperfocal distance.  

Now, here's the trick with the GF1, which was provided to me by my very good friend and shooting buddy, James McKearney, who found it on the dpreview forum:

Essentially, all you have to do is set the camera to manual focus, and cycle the camera power off and back on.  The lens automatically resets to the hyperfocal distance for the current f-stop.  I believe this works on all of the Lumix Micro 4/3 cameras, but have only confirmed it on the GF1.  I would welcome feedback from others who have tried this technique on other models.

I hope you find this useful in turning your whiz-bang, auto-everything capable GF1 into an instant response, street shooting machine!