D600 Auto Focus Points - Who Thought That Would Be A Good Idea?

Started Mar 29, 2013 | Discussions thread
Sdaniella Contributing Member • Posts: 500
AF points are IDEAL if put narrower/closer to center, just outside key pts, than wider

Steve D Yue wrote:

RATHER: any photographer who is beyond "entry level" is also beyond "one-thirds-rule"

AF points are IDEAL if put narrower/closer to center, just outside key pts, than wider

if you ever adhered to the beginner's 'one-thirds' rule exactly, one will discover due to every OVF usage (which varies from one person to the next) means one's 'eyepoint' is never exactly on-center 100% (face and nose shape ensures this is impossible) when looking through the OVF. it doesn't matter whether the OVF offers 100% view or 98/96/94%, because the AF points spread, are IDEALLY distributed NARROWER than you presume to want. in PRACTISE, if you used an AF too far off center, which you presumed 'matched' your 'one-third rule' points, you'd end up RISKING OVERCROPPING your COMPOSITION, and thereby have NO MEANS of recovery in terms of Proportions AESTHETICS.

If your shots are intentionally 'for the record' and NON-ARTISTIC in purpose, then of course overcropping won't matter at all.

By intentionally DESIGNING AF points that are just a touch NARROWER in distribution positions, the ENSURE that there is a margin of ENSURED UNDERCROP (which is desireable; given no one 'sees' through an OVF ever the same, but differently, even if one had 100% view or less). Actually having less than 100% view is completely acceptable in top line model dSLRs.

The KEY in 'aesthetic compositions' where AF must be positioned, they are best rigged for undercrop LEEWAY. Additionally, the ideal aesthetic proportions are closer to 'natural golden ratio' than 'one thirds'.

IF you ever wonder WHY. Now you know.

IF you ever wonder why some dcams/dSLRs off 4x4 grids instead of 3x3 grid???

for the 'amateur beginner' who is still learning composition, the 3x3 grid (one-thirds rule) is simply a starting point for CONSISTENT composition aesthetically. the 'cross +' of such a 3x3 grid coincides with the 'one third' proportions.

however, that is only suitable for beginners. not for more experienced shooters who have already started to learn 'aesthetic compositional proportions' AWAY from amateurish 'one-third' rule.  This means amateurs use the 0.333 and 0.667 positions for composition.

WITNESS the fact that dSLRs also offer the 4x4 'one-quarter' grid... WHY IS THIS?

SIMPLE. Nobody REALLY wants a silly 'grid +' to OBSCURE the FOCUS of the SUBJECT itself, so the 4x4 grid actually allows the SHOOTER to compose the subject within the 'box'.

IF you look at any 4x4 grid, if divided horizontally or vertically by EIGHT, you then have 'centered' boxes, where the '3/8th' box and the '5/8th' box center around TWO KEY POSITIONS: the 0.375 and 0.625. BOTH of which are slightly 'overcrop' positions beyond the 'ideal' golden ratio positions of 0.382 and 0.618, both of which, if has AF points on the INNER side of those two points, ensures 'undercropping' LEEWAY desired, to ensure no shot is 'un-golden'.

THUS, ideally, AF should be positioned INSIDE the golden boundaries of 0.382 and 0.618 (closer/narrow towards the CENTER AF focus point)

in this respects, more experienced 'aesthetic compositors' will use ONLY the INNER NINE AF points [8 for the 'box' and 4 for just the inner 'corners'], if not the next closer 'four corner' ones.

IF you use AF points OUTSIDE the inner most 9+6=15, the other outer ones, serve other purposes, such as AF of fast moving subjects that move laterally across the FoV. But this is intended for better focus, at the EXPENSE of composition entirely. (who can 'track' off center of a moving object 'all the time'??? very few, to NONE). If you ONLY use the OUTTER most AF points closer to the 'one-third rule' proportions, you will surely experience OVERCROPPED compositions in a severe 'hit-n-miss'. It may seem a 'purist-perfectionist' attitude of getting 'perfect one third' compositions without ever resorting to post-cropping later offline, but this is impractical, and the camera makers know better than to cater to this, when more experienced shooters would NEVER want to shoot 'one-thirds', they have LONG weaned off that, and progressed to a more 'free format' composition that naturally settle towards the center, towards the natural golden ratio proportions, and AWAY from the too simplistic 'one-third' proportions intended only to teach beginners in how to 'see' aesthetics of proportions in a common rectangular fov.

hope that helps. lots of folks still new to AF pts, composition, grid usage or not, will assume incorrectly why AF are not where they expect them to be.

extremely experienced shooters using, say a 5DMkII (with only 9 AF pts), know that on the INNER 4 points making the 'inner rectangle' are rigged for 'undercrop leeway' just within the golden ratio positions. whereas the OUTER 4 'diamond' are outside. having other uses that actually are 'overcropped' horizontally and 'nearly overcropped' vertically for 'one-thirds'. i'd never use them except for NON-aesthetic compositions (subject is 'whole wider scene' rather than narrower, or a subject where it is very non-symmetrical and very off centered).

AF points are IDEAL if put narrower/closer to center, just outside key pts, than wider:

0.333/0.667 [one thirds positions]: risk overcropping compositions, this is why 3x3 grids exist for beginners to composition (the cross '+' pts matter for 'targeting') [too wide; hit and miss; proportions are amateurish; hardly aesthetic at all; unrecoverable 'bad' compositions.]

0.375/0.625 [3/8ths and 5/8ths positions]: closest to golden ratio (best to use AF points INSIDE these points), this is why 4x4 grids exist at all [the unobscured center of the 'box' of the grid matters more than the '+' cross points (ignored)], who no longer use 'one-thirds' at all, but are progressing to 'golden ratio' without really realizing it. [almost there; inner AF pts have proper undercrop leeway for flexible post-cropping]

0.382/0.618 [phi (golden) proportional divisions]: AF points ideally INSIDE these two key points [most mfrs have key AF points 'just' within these positions] those who use these 'inner' AF points know, they're rigged for 'golden ratio undercropping leeway'. [just right, max flexibility, minimal lost compositions]

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(not 'Steve D Yue' (my husband (RIP)))

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