Sunday 25 May 2008

D3 Picture Control and TTL/BL Flash observations

What's your experience with D3 Picture Control and TTL/BL Flash?



Here's an interesting thing... if you set the D3 Picture Controls to something nearer to 'Vivid' when using balanced fill flash (TTL/BL) with the SB-800 you can expect to get some strange skin tones.

Checking back over some recent outdoor portrait work I noticed just how ghastly some shots are when using Standard Picture Controls setting. I hadn't noticed quite how bad some are until I got hold of a new NEC LCD2090UXi colour monitor last week.

Now that I can see colour the way it's supposed to look I've discovered what I need to do get these fill-flash colours looking more realistic - tone down the saturation.

bfn
Greg

Thursday 8 May 2008

Nikon D3 in the field - focus options

Over recent weeks (May 2008) there have surfaced some observations from real shooters describing how they use the spectacular Nikon D3 for action photography.

'At last!' I say, since if you're doing up-close action you really need to know what your options are and when to use them when using an instrument like the D3. So I thought, as much for my benefit as anyone else who stumbles on to this, I should offer up my recent experiences and observations on getting the most from D3 focusing system.

And since most of my photography is bicycle racing, here's my take.

Shooting styles.


Single subject moving at speed across the frame.

This style usually applies to 'time trials' or downhill competition when a rider is on their own in the frame. I don't need to be concerned about quickly shifting focus like I would when a bunch of riders are blasting past. If the rider is a reasonable distance away I can use the D3's Auto-area AF mode - the solid filled icon on the AF mode switch.

A reasonable distance is, say, 5 metres or so when the depth-of-field is enough that it matters little if Auto-area AF mode selects the rider's helmet or handlebars - the difference in focal distance is tiny and won't affect the final result enough to notice.


Bryn Atkinson - Nikon D3 70-200mm, f/4.8 1/1600s ISO200 -0.7EV

This shot from the Australian MTB Downhill competition is a case in point. I don't know (but could check the EXIF data to find out) where the D3 chose to set focal points exactly, but they were obviously on the rider somewhere. But since the subject was about 5 metres away then there's no need to be super-precise with focal point selection - the D3 figures it out every time.

Even though this was shot at f/4.8 the DoF is enough at this distance to catch the subject and his immediate surrounds. The flying dirt may have been more defined with a narrower aperture but it looks okay to me. (Why -0.7EV? - better to be bit under than over-exposed to retain colour saturation - we can always crank the exposure later.)

I apply the same style to road cyclists in time trials - one rider, no clutter and the D3 has no problem grabbing the subject.

Bunch of riders at speed up close

Single subject shots are less common than a swag of riders moving at speed. Here the shooting gets a bit trickier and I find I need to take over from the D3's focusing decisions. This means either making quick decisions as the riders fly past, or deciding on a composition and focus settings before they enter the 'shooting' zone.

The most critical decision for me is 'composition'. Other than out-of-focus subjects there's nothing much worse than having any number of nice compositions presenting themselves only to end up with the one where the main subject is nicely focused but banging their against the picture frame...it doesn't need to happen, and that's why I use Dynamic-area AF mode - I want to take control of the shot.


ACTVCC - Nikon D3 70-200VR f/9 1/500s ISO400 -0.3EV

In this shot the bunch is approaching at around 40km/hour, passing from right to left, so I want the riders on the left of frame to be in focus right up until they leave the frame.

As they approach, I'll quickly move the focal point across to the left of frame and then track those lead riders using the AF-on button (not half-press shutter release) until they're where I want them and then pop 'em.

With the D3's 'predictive' focusing working for me, I can be confident that the closest subject will stay in focus if I pan with him or her as they pass.

Operating an aperture of f/9 I can be reasonably confident the depth of field will just be enough at this distance to have everyone in reasonable focus, even though by focusing primarily on the closest riders ie. those passing from centre to left of frame, the DoF is going to be more foreground than mid-scene.

Of course I'm panning with the bunch so I can follow the lead riders out of the frame, but once they're past me I'll pan back to the approaching riders to capture them too. Sometimes as riders pass out of left of frame there's a short gap to the next bunch of riders. Now, instead of waiting for this next bunch to arrive where my focus point is I can make a quick, blind stab at the centre of the focus point selector to centre the focal point and we're away with a new composition.

Of course none of this is possible if I was using Auto-area AF since focus selection is not up to me and since the riders are going to be fairly close by the time I shoot both depth of field and focal point become critical so I need to take over.

By setting Dynamic-area auto-focus I can then select an initial focal point for the composition that I 'think' the approaching rider/s are going to create, or that I'd like to capture, and then tweak the point selection as the scene resolves itself.

The essential choices

The choice between Auto-area and Dynamic-area AF is usually the last 'buttons and switches' decision to make before hitting the shutter release. But there's much to be decided in the menus before getting to the AF-area button.

Since I use Dynamic-area most I'll discuss menu options relevant to it and maybe come back with some info. about Auto-area focus menu options in another post.

AF-Area mode

Even when we ignore 51 points 3D tracking, the choice amongst 9 points, 21 points or 51 points for the active focus group can be confusing.

I don't know the 'right' answer here, but I do know that when shooting a moving bunch of cyclists I'll pick the focal point that best suits the evolving scene and then attempt to maintain a tight visual lock of that point on the eyes of the rider that I want to be at maximum focus.

And since the dynamics of bicycle racing is reasonably predictable I don't need to worry about not being able to maintain that visual lock. So 9 active focus points is usually enough.

I haven't tested it, nor read anything about it, but I imagine 9 point focusing is probably computationally faster than 21 or 51 points - maybe a bit of a test in future is warranted - since faster is better.

AF-on and Shutter release

I have the D3 (and D300) set to initiate focus using the AF-on button only and not via the shutter release.

Apart from the advantage of fewer premature shots (and with the D3's 9-frames per second it takes only a hint of pressure to blast off 3 or 4 dud shots accidentally in all the excitement) the biggest and best advantage of the AF-on button is that I can focus on a spot where I want to shoot a scene long before the riders arrive at that point, release the AF-on button, recompose the shot for the scenery and fire the shutter release just as they arrive, all the while holding the pre-focus.

You might think it strange that I'd want to shoot scenery, but that's where most sport shooters go wrong in my view. The point is it's 'all about' the scenery - it's the environment, the distant hills and autumn leaves, it's 'where' the action is happening that matters to me. Scenery can turn an otherwise interesting sports shot into an exciting photo. Just check Graham Watson's stuff to see what I mean. Even check some of my stuff for a newby's attempt - http//greglong.photostockplus.com

VR or not to VR

VR (Vibration Reduction within the Lens) is a no no for most fast-paced sport photography. And here's my three reasons -

1). in most cases the initial stabilization is way too slow,

2). unless your doing slow-pan blurs at say 1/20s, its just not necessary for typical shutter speeds of say 1/500s and faster, and

3). it can ruin a shot by actuating during shutter release - the few times I let this to happen to me was very annoying.

Unfortunately, the new pro lens that I prefer for bicycle action have VR - the 24-70mm f/2.8, 70-200 f/2.8 and 18-200VR DX - but at least I can turn VR off... or on since there are plenty of occasions when VR is very useful, but not during a bike race.

Focus tracking with lock on

Now, here's the darndest thing to understand about D3 focusing - trying to interpret the D3/D300 User's Manual when it discusses Focus Tracking (menu Custom-a4). The discussion about Long, Normal and Short lock-on tracking makes no sense... until you read the 'Off' option. Here's what the Off option says - "the camera immediately adjusts focus when the distance to subject changes". In other words, it immediately refocuses on what ever is under the active focus point.

So, the "Long" option must mean that the camera will NOT adjust focus immediately.... and "Short" just means it won't take quite as long to adjust as does the "Long" option.

Well, two things to say about that:

1. whether Short, Normal or Long I think that it's only relevant when I'm the one doing the erratic movement and the subject is stationary. If I'm in a canoe shooting waterbirds and boat keeps bobbing about then I'd use tracking - but not when I'm crouched on the side of the road shooting cyclists,

2. as I described earlier, I want to re-focus quickly after a rider blasts, so I always have tracking "Off" --- focusing only with the AF-on button makes this a bit quicker too - at least it feels quicker.

The idea that my chosen subject may be 'briefly obscured' by an even more interesting subject is enough that I want tracking to be inactive so that re-focus is done instantly, and the D3 refocusing is as good as 'instant' - something that continues to amaze.

Summary

Here's a summary of menu and switch configurations I use for my style of bike photography:

1. Set AF-On button (Custom a9) to AF-On only so I can elect to pre-focus and recompose a shot

2. Set Dynamic-area (switch) on, pick a preferred focus point and keep it right on their eyes.

3. Set 9-point focus area (Custom a8) and be precise with focus point positioning

4. Set Focus Tracking (Custom a4) with Lock-On to "Off" and use AF-On to do the auto focusing

After much trial and error - and hunting in the 'dark' to figure this stuff out - that's what seems to work best for me.

bfn

Greg