How to achieve such a sharp pic ? - please advice


Ricardo Ong

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Jan 31, 2011
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Hi guys,

i came across this pic

http://www.flickr.com/photos/neilfarrugia/5967226243/in/pool-14295478@N00/

http://www.flickr.com/photos/neilfarrugia/5967226243/meta/in/pool-14295478@N00/


I have noticed that the photographer has used F1.4 but somehow he/she is about keep the 2 ladies in super sharp quality over such a large area of focus (ie you can even see the sweat!) ..the lady on the right blurs out ....

ie, i also owned a Sigma 30mm F1.4 lens with Canon 60D, but i am just unable to produce such a sharp and vibrant colour picture.

please someone explain how can this picture be achieved?

ie settings / equipment used ? (I know a flash used, and some post-processiong was done in Photoshop, are there any other missing links?)


Many thanks!
 

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The flash played a part in freezing motion, giving sufficient light which in turn gave more contrast. Everything added up to result in a sharp picture.

Anyway, by looking at the exif, there should be roughly 8cm of area on the focal plane which should be in focus.
 

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The flash played a part in freezing motion, giving sufficient light which in turn gave more contrast. Everything added up to result in a sharp picture.

Anyway, by looking at the exif, there should be roughly 8cm of area on the focal plane which should be in focus.

hi tecnica,

thanks for your comments, i know the flash player a part, any way you can see from the details what type of flash setting?

also, u commended that looking at the exit, there should be rougly 8cm of area of focal plane - ie where do u see 8 cam of area? - ie 8 cm as in the pic that we are seeing? - sorry if i ask these questions (newbie on tech stuff)

cheers!
 

Hi guys,

i came across this pic

http://www.flickr.com/photos/neilfarrugia/5967226243/in/pool-14295478@N00/

http://www.flickr.com/photos/neilfarrugia/5967226243/meta/in/pool-14295478@N00/


I have noticed that the photographer has used F1.4 but somehow he/she is about keep the 2 ladies in super sharp quality over such a large area of focus (ie you can even see the sweat!) ..the lady on the right blurs out ....

ie, i also owned a Sigma 30mm F1.4 lens with Canon 60D, but i am just unable to produce such a sharp and vibrant colour picture.

please someone explain how can this picture be achieved?

ie settings / equipment used ? (I know a flash used, and some post-processiong was done in Photoshop, are there any other missing links?)


Many thanks!

Have you take a close look at 100% picture, its not all the sharp. One thing for sure is when you downsample your image, you get sharper image. If you do notice, at f/1.4, both subjects are in the sample focal pane, that's why their feature looks sharp.

At f/1.4, it's often a trial and error to get sharp focus because even the camera may miss at times to focus on the right feature on the face. Not unless you have a lot of times doing it. Next for the sample you have provided, it's a low light scene and camera tend to miss in AF at such scenes. You will need the infra red assistance from an external flash to helps in the focusing. Flash is always the buddy to low light condition even when what you are trying to achieve is dim mood. You can always face the flash to the back towards the walls to help lit up the scene mildly and spatially to get a brighter ambient but still keep the mood. Post processing will also help to the scene. If the scene is not too extremely dim, you can use the exposure compensation to have 1 f-stop down to bump up your shutter speed so that you can get the shutter speed you required.

I believe there are a lot of techniques available and to get experience with these scenes is to try out more. I'm sure you will get better over time.
 

30mm focal length does not give you that thin a DoF in the first place. Couple that with a APS-C crop sensor camera, you will be standing further back for the same composition, giving you an even thinner DoF. The 2 ladies are actually in the same plane. With good flashing techniques. Shooter basically went for low ISO, drag shutter, and using flash to freeze the motion of his subjects.

As for calculating the actual DoF, all you need is the camera sensor size, focal length, aperture size, and subject distance. All is found in the EXIF.

Camera Canon EOS 50D
Aperture f/1.4
Focal Length 30 mm
Max Aperture Value 1.4
Subject Distance 1.12 m

plug these numbers in to DoF calculator online http://www.dofmaster.com/dofjs.html

Here are the results:

Subject distance 1.12 m
Depth of field
Near limit 1.08 m
Far limit 1.16 m
Total 0.07 m

In front of subject 0.04 m (48%)
Behind subject 0.04 m (52%)

Hyperfocal distance 33.5 m
Circle of confusion 0.019 mm​
 

Same focal plane, and the "sharpening" benefit of downsizing, then maybe another post-resize sharpen.

If you saw the original file, one of them may not be as sharp as you think.
 

Hi David,

Thanks for your reply ...can i please ask you a few more points ?


You will need the infra red assistance from an external flash to helps in the focusing. - what is that?

i am using Canon Speedite 320 EX - do they have this function? - i know there is a LED beam light though

Flash is always the buddy to low light condition even when what you are trying to achieve is dim mood. You can always face the flash to the back towards the walls to help lit up the scene mildly and spatially to get a brighter ambient but still keep the mood.

yes, i think the photographer used that, cos if you look carefully at the lady's sunglass, only the top tip of her glass show the flash being tiggered....so i think it possible that he pointed the flash upwards....

is it possible to see if the photographer use a diffuser on the flash?

Thanks again for your comments!
 

Hi daredevil123

thanks for your very detailed explanation....but for a layman like me, do i really need to know the exact numbers / know the maths behind this formula ?

Uncle old liao, brain not used to exotic calculations ....

any simple rule of thumb that i can use / follow instead ?


Here are the results:

Subject distance 1.12 m
Depth of field
Near limit 1.08 m
Far limit 1.16 m
Total 0.07 m

In front of subject 0.04 m (48%)
Behind subject 0.04 m (52%)

Hyperfocal distance 33.5 m
Circle of confusion 0.019 mm​
[/QUOTE]
 

Same focal plane, and the "sharpening" benefit of downsizing, then maybe another post-resize sharpen.

Hi Rashake,

thanks for your reply, when you say same focal plane, what does that mean?

ie do you mean, the gals are standing in a straight line / next to each other (cos their face is touching each other) so i focus on the lady without glasses, the camera will think to focus on the whole area also ?
 

Hi daredevil123

thanks for your very detailed explanation....but for a layman like me, do i really need to know the exact numbers / know the maths behind this formula ?

Uncle old liao, brain not used to exotic calculations ....

any simple rule of thumb that i can use / follow instead ?

Actually.. just know that on a crop cam. a 30mm/1.4 will not give you that thin a DoF. keep your subjects more than 1m away, just focus on any part of the face, the face will turn out sharp. If 2 or more people, make sure their faces is more or less in the same plane.. if they do not stand that way, you can still move around to make it same plane... your tolerance will be 7cm and more... meaning within 1/3 of a head difference, will still be sharp.
 

Actually.. just know that on a crop cam. a 30mm/1.4 will not give you that thin a DoF. keep your subjects more than 1m away, just focus on any part of the face, the face will turn out sharp. If 2 or more people, make sure their faces is more or less in the same plane.. if they do not stand that way, you can still move around to make it same plane... your tolerance will be 7cm and more... meaning within 1/3 of a head difference, will still be sharp.

wow! i like it, very clean cut, simple to understand ... ie last question ...same plane, ie the subjects must be in a same line?

ok!, i will ask the subjects to stand much closer now , ie best if less than 1/3 head apart, so the pics will still turn out sharp...
 

wow! i like it, very clean cut, simple to understand ... ie last question ...same plane, ie the subjects must be in a same line?

ok!, i will ask the subjects to stand much closer now , ie best if less than 1/3 head apart, so the pics will still turn out sharp...

Basically yes... Parallel to your sensor.
 

know DOF and hyperfocal distances helps a lot when trying such pics, esp with large apertures...
 

know DOF and hyperfocal distances helps a lot when trying such pics, esp with large apertures...

...except that the pic had NOTHING to do with hyperfocal distances...
 

elaborate pls?


i not a pro... just chipping in what i read...
 

elaborate pls?


i not a pro... just chipping in what i read...

For the kind of distance between the lens and the subject, the hyper focal distance ought to be behind the subjects. Use the DOFMaster to make it clearer for you. (^.^)
You need to be focusing at that particular distance to achieve relatively sharp pictures for objects further than the hyper focal distance.

Hence it's not relevant to the pictures in this discussion.
 

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elaborate pls?


i not a pro... just chipping in what i read...

First off, do you understand what hyperfocal distance is, and how it's used? Once you have read up on that, you'll understand why it's not relevant to the picture at hand.
 

know DOF and hyperfocal distances helps a lot when trying such pics, esp with large apertures...

...except that the pic had NOTHING to do with hyperfocal distances...

elaborate pls?


i not a pro... just chipping in what i read...

farbird, hyperfocal distance is used when you want everything from a distance to infinity to be all in focus.
 

Roger...

for near subject distances and large apertures, no hyperfocal distances coz the dof is shallow?
farbird, hyperfocal distance is used when you want everything from a distance to infinity to be all in focus.
 

Roger...

for near subject distances and large apertures, no hyperfocal distances coz the dof is shallow?

Yes, large aperture sorta counter-reacts the use of hyper-focusing because on one hand you want to have a diffused background with large aperture, keeping minimal things in focus. while on the other hand, hyper-focusing ensures that everything from bare minimum distance to infinity are in focus, coupled with small aperture.