Introduction

During almost every workshop the subject of the ideal portrait lens and its use finds its way into the discussion.  We can be sitting in a speedboat humping 60 knots over rough chop and my client seeing an especially pretty woman on water skis will say "what's the best portrait lens.."  We'll be riding elephants in a Cambodian jungle shooting the rare Khmer Dodo bird when a half naked jungle girl in a grass skirt runs across our path and the client asks "what's the best portrait lens.."  Okay, I made that last one up but you get the point.  No matter what subject we normally shoot, we'll always be interested in shooting our favorite people with the highest possible quality.

So what is the best portrait lens?  This might shock you but there isn't one.  Portraits are about creativity as much or more than anything else.  Our subject, the setting, their mood/expression, how we put it together determines the ideal lens of the moment and how we use it.  Certainly the 85mm focal length is one of the most popular portrait lenses if not the most popular.

The manufacturers usually make two 85 mm lenses.  A relatively fast (F1.8) aperture with fast autofocus and very good quality at a moderate price point, and a super fast (F1.2 - 1.4) aperture with much slower autofocus and a price point that sits alone way up there at the top.  The latter is what we're going to discuss today.

 

Application

These super fast lenses are very much specialty lenses.  They take special knowledge and training to use properly otherwise the purchaser is invariably disappointed which most often results in a rant on a photography forum and a return to their favorite camera retailer.

The extreme wide aperture requires a rather large chunk of glass which makes it heavy and in the case of the Canon 85mm F1.2L that heavy glass takes some shoving around by the autofocus system so it's geared low and takes a while to autofocus.  Not because it has trouble finding the AF point, with all that light coming in it finds the AF point very fast.  But because the glass is physically heavy and moving it requires some power.  Also, because the depth of field (DOF) is so narrow, precision is key further reducing the gearing to a crawl.

This isn't the lens to use for sports or even children playing ball.  This is a lens specially built to capture great detail with an extremely shallow DOF, excellent color rendition, and great contrast.  The design will also include more aperture blades designed to produce the much desired holy grail of bokeh.. the perfectly round bokeh character.  Canon's 85mm F1.2L does this better than any other 35mm format lens I know of.

 

Technique

Proper technique is key.  The camera should be set to "one-shot" or static autofocus with only a single AF point activated.  You can select the AF point which is closest to the closest visible eye of the subject.  Center this AF point on the closest visible eye.  This can take some practice.  At this focal length, and because not a single one of these 85's comes with IS/VR, you'll need a very steady hand.  Because portraits involve interacting with the subject you'll also need to move quickly while holding the camera steady as you prompt the desired poses and expressions.  Pre-focus and pre-meter, strike the mood, make the capture.

When shooting at the wider apertures, F1.2 - F2, it wouldn't be unusual to make 20 captures of the same subject / expression, and have only a single frame turn out perfectly focused.  The DOF is so shallow, and this lens requires such perfect technique, that it takes a great amount of practice to use this lens with any sort of competence.  Practice, and practice some more, and then again some more before even considering the lens may be back focusing, front focusing, or whatever the popular excuses are you'll read on the forums. 

I've purchased over 50 high end Nikkor and Canon lenses over the last 8 - 9 years and haven't had to return even one of them.  And as you know from reading this column I'm very keen on sharpness.  You can rest assured, if the lens isn't achieving the desired focus it's faulty technique and not the lens.. in almost all cases.

 

Examples

 

DOF example, focus on far eye

85mm F1.4

 

Above is a standard generic head shot.  Notice the only visible eye is the eye furthest from the camera?  This would be an exception to always shooting the closest eye.  You always choose the closest visible eye and place the AF indicator squarely on the eye.  At F1.4 the DOF will be so shallow on an inch or so in each side of the AF point will be in sharp focus.  From there focus will fall off sharply in both directions, front to back, of the frame.

 

1:1 crop

85mm F1.4

 

Above is a crop of eye.  Notice how perfectly detailed the eyelashes are?  Without sharpening or other processing this is the level of sharpness you should expect from perfect technique and a quality 85mm lens.

 

Kris in Yala, DOF example

Kris sitting on a shaper in Yala approximately head on to the camera

 

During a visit to Yala I had the opportunity to photograph the beautiful craftsmanship of handmade kris' and a search through my camera bag turned up the 85mm F1.2 as the best choice.  The setting was less than desirable so I knew I'd want a shallow DOF for later processing if I wanted to do anything with the resulting images.  For the sake of having the most choice I started with F1.4 on the center of the blade and stopped the lens down to F2, F4, and F8.

Interestingly enough the angle of the kris is about the same as the face of a person would be if you were taking their portrait.  On a human face it's often hard to visualize exactly how much DOF there is because features blend and there's no consistent reference point.  A search through my database turned up these shots of the kris' ideal to visualize DOF.

 

Depth of field example image

Depth of field is indicated by the red markers

 

The red markers show the exact point where the focus goes from sharp to defocused.  These images are still on the small side to easily see DOF, but with the aid of the red markers you should have a good idea.  Notice that at F1.4 we have a mere 2 inches of focus?  At F2 about 5 inches, and by F4 about 8 inches.  By F8 we have close to 12 inches of focus. 

Compare these distances centering on a headshot and the closest eye.  Two inches takes you from the eye inwards to the start of the nose, and outwards to the side of the face.  5 inches includes hair on the far side, and a bit of cheek on the inside.  F4 pretty much covers the entire face, while with F8 we're starting to get most of the hair in focus.

 

Kris in Yala, DOF example

Kris sitting on a shaper in Yala at a 45 degree angle

 

This angle and distance is used often for head shots.  In fact it is the same angle used for the headshot above.

 

Depth of field examples

Depth of Field indicated by red markers

 

Again, another example of DOF which should help you visualize just how much of a human face will be in sharp focus at a 45 degree angle using these apertures at 85mm.  Because the angle increased you'll notice the distances appear to have closed.  They have.  If you can't visualize this try drawing it out on paper and drawing two inch lengths across different angles.

 

Conclusion

Achieving super sharp results at wide open apertures is very possible with the top quality 85mm lenses.  It will take a practiced technique and a great deal of patience, but then you can reliably achieve such results.  What should you expect as a reward?  Let's take a look at a very ordinary headshot:

 

F1,2 exampke, focus on closest eye

85mm F1.2

 

The subject is at a 45 degree angle with his closest eye towards us visible.  At F1.2 his eye will be perfectly sharp and the DOF will extend halfway up the bridge of his nose.  From there everything gently fades into a perfect bokeh.  Notice how due to the depth of bokeh that we can't even tell what the background is?

 

F1.2 sharpness!

crop of eye at f1.2

 

The above crop reveals a tack sharp eye.  Sharp enough to clearly see each eyelash and small veins in the white of the eye.  Sharp enough to see the dirt in the pores of the skin!  This image was shot wide open at F1.2.  I can't imagine wanting any more sharpness in a portrait.  Can you?

A high quality 85mm portrait lens will give you all the practical sharpness you could ever desire at its widest aperture.  The color will be accurate, the contrast appropriate, and the bokeh smooth and creamy.  The lens will become sharper as you stop it down, but not much.  Stopping down such a lens is done purely for creative purposes, not for sharpness.

Again, a high quality 85mm is a specialty lens.  It's an extreme lens which will give you extremely sharp results, extremely great bokeh, and allow you to shoot in extremely low light.  It also takes an extreme amount of practice and perfect technique.  It's an extreme lens.  I love mine.