AF for dynamic fashion shots?

Started 3 months ago | Discussions thread
Paul P K
Paul P K Contributing Member • Posts: 645
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Digital Shutterbug wrote:

Paul P K wrote:

Digital Shutterbug wrote:

BBF only with separate shutter release triggering, is IMO and experience based on shooting years of fashion, catwalk and surf photography, not feasible for use with a model moving at full speed, as it means triggering having to switch from the AF with the BBF button with one finger, to another finger to take the picture, causing a however slight delay, allowing the moving model from the spot the AF was at on the moment the decision was made to take the shot, to just a bit closer by in the next split second moment later when the shutter release button was pushed

I've never seen anyone set up BBF and use it that way. The BBF button is generally pushed with your right thumb. Your index finger is still capable of pressing the shutter release at any time, completely independent of the BBF button being held depressed or not.

Duh, of course the BBF button can practically speaking only be pushed with the thumb (which is one of the five fingers on a hand), alongside with the index finger (another one of the 5 fingers on a hand) for pushing the release button

Pushing the BBF button with another finger then a thumb from the same hand when holding a camera is next to impossible, if even possible, anatomically speaking, and apart from the obvious fysical impossibility of course would be extremely time consuming.

But (even) with AF activation by BBF only, and separate release triggering by the release button only, there will be a split second delay between finding the subject in focus, and taking the picture

Basically one would be in the same situation as manually focusing on a moving subject, and after seeing the subject in focus in the viewfinder, taking the picture the next split second before the subject has moved on from the spot it was seen in focus, especially as few have/still have the fast eye/hand reflex to be able to take a picture that way.

I guess there is still something I'm not understanding. If shooting a moving subject, you would surely be using AF-C. While holding the BBF button, the subject, at least walking human, should remain in focus. Obviously, that would be different when shooting a race car coming in your general direction at 200mph. Pressing the shutter release at the appropriate time should result in a properly focused image.

Modern cameras have a shutter release lag time measured in a few milliseconds. If you're splitting hairs, yes the subject moves during that time. If the focus mechanics don't adjust for subject movement during that few milliseconds the focus will be off. But, how much could that possibly be in a walking subject? The DOF should be much greater than the distance a lady moves on the catwalk. Am I just completely missing your point?

What I wrote before about previously, and you clearly did failed to read, is 'BBF only with separate shutter release triggering', i.e. activating the AF with the BBF button only, and decoupling the AF from the shutter release button, which means that button is used only for triggering the shutter, useless for moving subjects

But on the other hand very useful when you are shooting a static subject with very critical AF for a specific area, and you don't want the AF to change whenever you touch the release button.

In the first scenario, using 'BBF only with separate shutter release triggering', you are one moment triggering the AF button with one fingering, and have to switch to another finger to take the shot when you see your subject in focus in the viewfinder (similar to the manual focus film shooting days when you would focus on a subject by turning the focus lens with your left hand till you had it in focus, and having to switch the next moment to your right hand to take the shot)

What you are describing is activating the AF with both the BBF button as well as the shutter release button, (which is doing the same thing simultaneously using the BBF button and the shutter release button, and obviously a bit redundant).

I.e. still having the AF activation linked to the shutter release button ( which means the camera will AF whenever the release button is touched), while doing the same with the BBF button at the same time ( and pretty much a waste of attention and energy).

In the old/early days of DSLR's, there was a small, but for fast shooting significant enough delay between the moment the AF found the subject in focus, and the camera taking the shot the next moment/split second you pushed the release button to take the shot. That delay would come on top of the shutter release that already was came with the the camera when taking a shot, a pretty deadly combination when trying to nail a shot in a very specific moment (eg when shooting catwalk, when catching a specific pose at the very moment it occurs will make or break a shot)

With modern DSLR's and mirrorless the delay caused by shutter release lag has indeed been reduced to negligible fractions of a second, no longer a real shot threatening problem (although of course there are plenty of 'experts' to find it something to still complain about when shooting under laboratory condition during 'tests').

But in my experience with DSLR's (reaching back to the D1/D1H/D2X days) and with the Z6, based on shooting fashion, catwalk, dance and surf, the delay between activating the AF by pushing the release button half way, and taking the shot when deciding to do, is so negligible that using the BBF button while already triggering the AF with the release button is unnecessary overlap.

Only time I use/have used that option is when I want to pick a point for the AF to start focusing from without risking to take an undesired shot (like as described earlier when a model takes a pose at the far end of the catwalk before taking the run down the catwalk towards the camera)

As far as the Dof is concerned, for creative purposes, as well as possible limitations to the fastest shutter speed possible to use in combination with the possible maximum aperture (eg bad/low lighting), especially when using long lenses (like eg in my case at times a 2/200VR wide or nearly wide open ) that DoF may sometime be simply not enough to keep the subject in focus while moving along in that split second, despite of the appealing theory, when using BBF AF with separate shutter release triggering.

In  the case of having the AF linked to the shutter release button, means one will have to trust the AF, and the lack of significant shutter release lag , of the camera used, like I did with my Z6 in this shoot

See in particular shot and, from a series of 14 shots taken within 3 seconds of a model further away to close up. The result of what at that moment my 1st serious shoot with the Z6 late 2018 (with still only FW 1.0) were reason/impressive enough for get a 2nd Z6 within two weeks after that (not widely for sale at that moment yet) despite its at that moment still novelty status

So yes, you are completely missing my point, but that of course may also be due to not  only not fully reading what I wrote, but also apparently never having shot a catwalk show in earnest

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