Focus-Recompose SHARPNESS for weddings! GAH!

[William Michael]

<p><strong><em>“Let me know what you guys think about this test”</em></strong></p>

<p>Well I don’t think I can add much more to what I have written, but I can apply it specifically to your shot of the man, step by step:</p>

<p>> “[i was using] f/3.5 . . . I know that at that range, DOF should be pretty adequate to keep everything sharp within a foot or two”</p>

<p>Nope. For the shot of the man (assuming it is a full frame crop) that is a <strong><em>Full ½ Shot in Vertical Format</em></strong> – you need to pull about F/8 to get 2ft DoF . . . at F/2.8 you have less than 12inches and F/5.6 will give you just over 12 inches</p>

<p>> As I already mentioned using F3.5 buys you zip all more DoF from F/2.8.</p>

<p>> The man looks tall - so from the centre of the frame to his face (i.e. the distance traversed when recomposing) is about 2ft to 2’6” – so there goes about 3” DoF.</p>

<p>> When recomposing, if you moved the camera position (backwards) maybe an inch – there goes another inch DoF making <em>your effective Plane of Sharp Focus a whole 4 inches in front of the Man’s face </em>. . . and you had less than 12inches DoF to play with, to begin.</p>

<p>For the shooting scenario of the Man, I would have chosen F/8 to be within my safe limits using F&R Technique, as F/8 would give me about 18” to 2ft DoF to begin.<br>

<br />WW</p>

[William Michael]

<blockquote>

<p>"Basically I spin or twist, when I recompose: attempting to keep the camera over a point on the ground (as if there were a <strong><em>plum-bob</em></strong> attached to the camera's bottom)."</p>

</blockquote>

<p> <br>

Crikey! The auto spell check thing–a-ma-gig is worse than the Auto Focus on my 20D . . . it is not a fruit thingy . . . its a <strong ><em >plumb bob</em></strong> . . . I shall go back to manual proof reading . . .<br>

<br>

WW</p>

<p > </p>

 

[ilkka_nissila]

<p>I think the head in that shot is quite close to the top of the frame and is outside of the area which is imaged best with this lens. To solve the problem I would recommend using the outermost or the second row center focus point (the outermost one seems to be less sensitive) and recompose as necessary. I would also fine tune the focus manually and maybe bracket the focus. To do this effectively I have removed AF activation from the shutter button so I don't have to worry about AF kicking in if I momentarily let go of the shutter button and press half way back in. The newer 70-200 II which is released in a month is supposed to be optimized for current AF systems (according to Nikon), so it may work better in this respect.</p>

[William Michael]

<p>The head of the Female is in approx using same portion of the lens as is the man. . . </p>

<p>i.e. it too is: <em>"is quite close to the top of the frame and is outside of the area which is imaged best with this lens."</em></p>

<p>Would you expect the lens to behave in this fashion - one shot being better imaged than another, when using the same edge area of glass?</p>

<p>I am not sugesting that the solution proposed is not a good technique or will not reasolve the problem - what I am asking about is the reason being proposed AS the problem. </p>

<p>WW</p>

[alec_myers]

<p>William W (and Alen)<br>

There's another way to get that shot in focus. For William's example, put one eye in the centre of the frame and focus on it. Then step to the left (or right) half the distance between the heads (18 inches or so).<br>

<br />For the 1/2 portrait, stoop or bend to chest level and focus there. Then stand up straight.</p>

<p>In other words, slide the camera instead of turning it.</p>

[William Michael]

<p>Hi Alec - That's the "Dolly Recompose" method I referred to above:</p>

<blockquote>

<p>"Another technique to use is the Dolly Recompose – that is linear movement and keeps the Focal Plane parallel to the Plane of Sharp Focus. (“Dolly” as in a Cinematography Camera Dolly).<br>

This technique is not always suitable and it does take practice to step sideways, correctly. For those who are adept at the Dolly Technique, one large step is usually the limit if working with very tight DoF – I move more accurately to camera right, than to camera left."</p>

</blockquote>

<blockquote>

<p>"I only use Dolly Recompose when shooting at tight quarters – maybe 6ft to 15ft."</p>

</blockquote>

<p>I find it easier (and more suitable) for landscape orientation (i.e. stepping to the side) - because as I mentioned I usually on Dolly Recompose at close quarters and bobb ing up and down changes the Camera Viewpoint and thus the forshortening.</p>

<p>WW</p>

[alec_myers]

<blockquote>

<p>Hi Alec - That's the "Dolly Recompose" method I referred to above:</p>

</blockquote>

<p>Ah yes... you're way ahead of me, as ever!</p>

<p> </p>

[William Michael]

<p>FYI. . . it wasn't meant nastily, just embellishing on what you wrote and putting both our ideas in one block - easier to for others to read <br>

cheers, WW</p>

<p > </p>

 

[mark liddell]

<p>Use continuous AF mode (AFC) and dynamic 21 or 51 points. Focus and when you recompose the camera will track where you locked focus meaning there is no recompose error.</p>

<p>Either that, or get very quick at moving the focus point around with the selector eliminating any need to recompose.</p>

<p>I use a combination of both to good effect but shooting at at 1.4 and 1.8 I won't have a 100% success rate but not all pictures work with 2 eyelashes in focus anyway!</p>

[alen_z]

<p>Err...Mark, isn't that gonna be even worse? If I focus on the face and shift to the midsection, it's gonna lock focus on the midsection if I'm using AFC. I think the solution to this problem is using the different focus points...sucks, but oh well, it is what it is...</p>

[William Michael]

<p> . . . or for the shot of the bloke - use F/8 . . . maybe F/7<br>

<br>

*** <br>

<br>

Ilkka, what do your reckon about the both the male's and female's head being located in about the same position within the frame?<br>

<br>

WW</p>

 

[mark liddell]

<blockquote>

<p>Err...Mark, isn't that gonna be even worse? If I focus on the face and shift to the midsection, it's gonna lock focus on the midsection if I'm using AFC. I think the solution to this problem is using the different focus points...sucks, but oh well, it is what it is...</p>

</blockquote>

<p>No it won't if you have dynamic af set and keep the button half down (or af-on button if you have the camera set up that way) it will focus track when you recompose. Do some reading on the cameras af system.</p>