Focusing technique


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kluke77

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Aug 12, 2008
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#1
newbie here...

just bought my 1st DSLR... basic model Canon 1000D and also another EF 50mm f/1.8 lens.. i have been quited wowed by the blurred effect that can be taken using the 50mm lens.

Here is the problem which i face when using this lens... if i wanna capture just a single person in the photo with a blurred background, i am able to do it, but the problem comes when i wanna capture say 2 person in a protrait, i am not able to capture both person sharp enough. Its either one person looks sharp in the photo while the other is a but blurred with the background...

Not too sure where my focusing point should be for a portrait with 2 or 3 pax while trying to acheive the blurred background..

Any advice on how i should be focusing for such pictures or is this a setting issue???? I have tried so far only using f at 1.8.

Many thanks in advance!
 

spazzer

New Member
May 5, 2007
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BUKIT PANJANG
#2
newbie here...

just bought my 1st DSLR... basic model Canon 1000D and also another EF 50mm f/1.8 lens.. i have been quited wowed by the blurred effect that can be taken using the 50mm lens.

Here is the problem which i face when using this lens... if i wanna capture just a single person in the photo with a blurred background, i am able to do it, but the problem comes when i wanna capture say 2 person in a protrait, i am not able to capture both person sharp enough. Its either one person looks sharp in the photo while the other is a but blurred with the background...

Not too sure where my focusing point should be for a portrait with 2 or 3 pax while trying to acheive the blurred background..

Any advice on how i should be focusing for such pictures or is this a setting issue???? I have tried so far only using f at 1.8.

Many thanks in advance!
focus the eyes and bump it up to f7.1/8(thats what i do when taking group pictures)
 

spazzer

New Member
May 5, 2007
1,997
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0
BUKIT PANJANG
#3
newbie here...

just bought my 1st DSLR... basic model Canon 1000D and also another EF 50mm f/1.8 lens.. i have been quited wowed by the blurred effect that can be taken using the 50mm lens.

Here is the problem which i face when using this lens... if i wanna capture just a single person in the photo with a blurred background, i am able to do it, but the problem comes when i wanna capture say 2 person in a protrait, i am not able to capture both person sharp enough. Its either one person looks sharp in the photo while the other is a but blurred with the background...

Not too sure where my focusing point should be for a portrait with 2 or 3 pax while trying to acheive the blurred background..

Any advice on how i should be focusing for such pictures or is this a setting issue???? I have tried so far only using f at 1.8.

Many thanks in advance!
http://www.clubsnap.com/display.php?file=articles/photography101/photography101.html
hope this would be useful read up more about DEPTH OF FIELD
 

giantcanopy

Senior Member
Feb 11, 2007
6,232
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#5
Hi kluke77

Your depth of field is too thin at 1.8, unless somehow the two subjects have their eyes completely aligned at that same plane. Try using a higher fstop and shoot at a greater depth of field.

Ryan
 

checkers

New Member
Aug 18, 2008
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0
#6
newbie here...

just bought my 1st DSLR... basic model Canon 1000D and also another EF 50mm f/1.8 lens.. i have been quited wowed by the blurred effect that can be taken using the 50mm lens.

Here is the problem which i face when using this lens... if i wanna capture just a single person in the photo with a blurred background, i am able to do it, but the problem comes when i wanna capture say 2 person in a protrait, i am not able to capture both person sharp enough. Its either one person looks sharp in the photo while the other is a but blurred with the background...

Not too sure where my focusing point should be for a portrait with 2 or 3 pax while trying to acheive the blurred background..

Any advice on how i should be focusing for such pictures or is this a setting issue???? I have tried so far only using f at 1.8.

Many thanks in advance!
DOF preview button is useful
 

monktian

New Member
May 1, 2008
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#7
What is the standard f-stop for taking normal picture? E.g. walkabout, people.
 

dision

New Member
Mar 25, 2008
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#9
For bust shots I use f4, group shots I use f8. If u really not sure then you can try using a.depth to shoot but ymmv.
 

vroom1

New Member
Nov 14, 2007
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#10
use F2.8 and F4 when taking portrait.

usually bigger the DOF it is difficult to work out unless u know how to.
 

Apr 15, 2008
2,291
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Singapore, east-ish
#11
What is the standard f-stop for taking normal picture? E.g. walkabout, people.
well...like calebk said there is no standard :think: But if you want more or less everything in the picture to be tack sharp, f/11 < should do the trick. Of course, if you just stick to that...gonna be a tad boring imho :think:
 

haisoj

New Member
May 23, 2008
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#12
then what is the difference in F8 and perhaps F22?
is it true that till a certain point the higher the aperture is increased the image is blurred again?:confused:
 

#14
newbie here...

just bought my 1st DSLR... basic model Canon 1000D and also another EF 50mm f/1.8 lens.. i have been quited wowed by the blurred effect that can be taken using the 50mm lens.

Here is the problem which i face when using this lens... if i wanna capture just a single person in the photo with a blurred background, i am able to do it, but the problem comes when i wanna capture say 2 person in a protrait, i am not able to capture both person sharp enough. Its either one person looks sharp in the photo while the other is a but blurred with the background...

Not too sure where my focusing point should be for a portrait with 2 or 3 pax while trying to acheive the blurred background..

Any advice on how i should be focusing for such pictures or is this a setting issue???? I have tried so far only using f at 1.8.

Many thanks in advance!
hi, if you want to achieve the 'blur background' effect using f1.8, the distance between you and your subjects is very important. both your subjects might need to be standing on the same distance. so the thin depth of field of f1.8 will not have any effect on them. my explaination may sound abit blur. here r some pics i shoot

heres a shoot using 85mm at f1.8. i place my tripod at a distance away from my wife, focus on her, join her for the self-timed shoot. i did some cropping to this image.


for this image, im using a 50mm shooting at f1.4 . my tripod was about 1.5m away from us.some cropping was done too. details on us are abit soft, but at least still sharp la.


as you can see, the back ground are 'not very blur'. it is because of the distance of the camera, as you go nearer, the background gets blurer,but you will risk your subjects becoming blur too.
but at least, for this case, you get ur subjects sharp.

now my examples might not be the best around, but i think this might be what you want to achieve.

i hope i don't confuse you. and it would be good if someone more pro care to elaborate or correct my points, so as to help us all achieve better photos with such DOF :)
 

monktian

New Member
May 1, 2008
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#15
I am quite puzzled about this though. At times when I use say f/1.8 to focus on a couple standing side by side, it turns out that one person will be sharper than the other. Does anyone got any idea what went wrong here?
 

uranium2k

New Member
Feb 26, 2008
212
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manbehindcamera.blogspot.com
#16
That's because they are standing at different "depths", and f1.8 has a very shallow DOF, hence your focus on one subject may mean the other subject gets out of focus.

I found a simple illustration from another thread:

Image @ f16 (Sharper background) due to deeper DOF.


Image @ f8 (Less sharp background) due to shallower DOF.


Image @ f1.4 (blurred background) due to very shallow DOF.
 

calebk

Senior Member
Jul 25, 2006
10,594
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Clementi
#17
I am quite puzzled about this though. At times when I use say f/1.8 to focus on a couple standing side by side, it turns out that one person will be sharper than the other. Does anyone got any idea what went wrong here?
It probably is because they are not standing exactly in the same plane. One person may be slightly ahead/behind of the other, and with f/1.8, most of the time you're getting really shallow DOF, so it's likely that a slight mis-positioning will render one of the two persons out of focus.

A simple solution is to stop down to something like f/2.8, where you will still get a decently shallow DOF, while having more leeway with DOF than wide open at f/1.8.
 

catchlights

Moderator
Staff member
Sep 27, 2004
21,903
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Punggol, Singapore
www.foto-u.com
#18
I am quite puzzled about this though. At times when I use say f/1.8 to focus on a couple standing side by side, it turns out that one person will be sharper than the other. Does anyone got any idea what went wrong here?
the DOF are too shallow. try close down aperture or shoot from far far away.
 

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