100mm L not for portraits?

Nov 17, 2013
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Of course is this lens for portraits. But what am I doing wrong?
I don't know wether I may post this question here but there I go.
I have to make some photos at my work. Today I took a few, but I didn't manage to get both ladies sharp. What am I doing wrong or do I really need another lens for nice (bokeh) photos?

HvMgpxGl.jpg
 
Jack56 said:
Of course is this lens for portraits. But what am I doing wrong?
I don't know wether I may post this question here but there I go.
I have to make some photos at my work. Today I took a few, but I didn't manage to get both ladies sharp. What am I doing wrong or do I really need another lens for nice (bokeh) photos?

HvMgpxGl.jpg
You need to close down the aperture (larger f/stop number). That's all.
 
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To be honest, I took this one in the Auto mode. Not smart of me, but I was a bit lazy. You think that's the way to do it?
I focussed on the eyes of the left girl and those eyes are sharp. When I use the AV mode I still have to focus on the eyes of one child? The aperture was f/2.8 by the way.
 
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Jack56 said:
To be honest, I took this one in the Auto mode. Not smart of me, but I was a bit lazy. You think that's the way to do it?
I focussed on the eyes of the left girl and those eyes are sharp. When I use the AV mode I still have to focus on the eyes of one child? The aperture was f/2.8 by the way.
Yes, f/2.8 is too shallow (in terms of depth of field) at this distance. In this case, I would switch to Av mode and use f/8 or even f/11. It's usually better to focus on the rear most subject if you can't focus on something in between, so that was definitely correct.
 
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At 10' with 100mm f2.8 the depth of field is about 3" front and 3" back. At f5.6 it increases to about 5" front and 6" back. At f11 it is about 9" front and 11 inches back. If you are closer, its even thinner. You can also move to your left a bit to bring them closer to the same plane, pick a point between them. Look for the focus points in the viewfinder for both girls to light up as you change the aperture to be sure they are both in focus.
 
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dcm said:
At 10' with 100mm f2.8 the depth of field is about 3" front and 3" back. At f5.6 it increases to about 5" front and 6" back. At f11 it is about 9" front and 11 inches back. If you are closer, its even thinner. You can also move to your left a bit to bring them closer to the same plane, pick a point between them. Look for the focus points in the viewfinder for both girls to light up as you change the aperture to be sure they are both in focus.

A rough estimate suggests the image in the OP was shot from a distance of a bit less than 5' (if a FF camera; 8' if APS-C). Either way, that means a DoF of about 2-3" for the OP's image which is far too shallow. Given the relative position of the subjects, even f/16 would be barely enough to get both pairs of eyes in focus from that distance at that angle.
 
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Jack56 said:
Of course is this lens for portraits. But what am I doing wrong?
I don't know wether I may post this question here but there I go.
I have to make some photos at my work. Today I took a few, but I didn't manage to get both ladies sharp. What am I doing wrong or do I really need another lens for nice (bokeh) photos?

HvMgpxGl.jpg

Move a bit to the left so that both faces are more or less equidistant from you.
 
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Jack56 said:
Of course is this lens for portraits. But what am I doing wrong?

Grab a "depth of field" calculator and look how deep the dof is for what you've shot (distance, aperture), the result is for a usual export/view size.

Then you'll see why "thin dof posing" is part of a photog's toolkit, if you want to have some background blur or are shooting at close distance, esp. macro, you cannot close the aperture enough to get everything in focus or end up with extremely high iso or very long shutter times.

The problem (if you see it that way) gets worse with a full frame camera, for "everything in focus" snapshots with deep dof a crop, compact camera or a mobile phone might be more adequate... for everything else, you need to put some thought into it before pressing the shutter button :-)
 
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I use the 100 L on a crop 550d all the time for portraits. I think the lens is stunning as its overall colors and IQ are top of the top. As far as your picture a few tips:

1) When shooting 2 kids or more - try and get the kids to be all more or less the same distance from you. Here the right hand child is much closer. I try if possible to pose them a little.

2) I would shoot in AV mode and stop down to f/4 or 5.6.

3) Take a few shots with trial and error - so you can fine tune the focus.

For one subject - you can open up to 2.8.
 
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As others said, your depth of focus (DOF) is not enough. In the old days, manual focus lenses had DOF markings for different apertures, nice and useful.

Have a look at dofmaster.com , gives you tables, online calculations, how it works.
 
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photonius said:
In the old days, manual focus lenses had DOF markings for different apertures, nice and useful.

In the olden days, some Canon bodies even had a helper mode "adepth" for this - af at spot one, af at spot two & it calculates the required f-stop... alas, newer cameras have you-dont-wanna-know how many creative zone programs, but this has been lost along the way.
 
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Marsu42 said:
photonius said:
In the old days, manual focus lenses had DOF markings for different apertures, nice and useful.

In the olden days, some Canon bodies even had a helper mode "adepth" for this - af at spot one, af at spot two & it calculates the required f-stop... alas, newer cameras have you-dont-wanna-know how many creative zone programs, but this has been lost along the way.

Yes ... troublesome but not insurmountable now-a-days. One can simply download a DoF app on their phones.
 
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J.R. said:
One can simply download a DoF app on their phones.

What good is that on its own? If I want to have to required f-stop between a tree 100m away and a hill 130m away, do you carry a long enough stick or an adequate optical tool :-p ... imho your best bet is Magic Lantern, it shows the focal distance in m and you can *then* input into a smartphone. If you have one. Working & with you. Which I haven't. Both not.

With digital, I guess Canon expects people to revert to simply trial & error, that's why they removed a-dep.
 
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you cant have super awesome blurry bokeh and still have a huge area of sharpness in a photo. the only way to achieve this is by dof stacking which is tbh useless for people photography. you "could" get a big blurry background and have the kids in focus (both) if u took e.g. 300mm lens, but that also means u have to move back waaaaay more which is probably not possible indoors.
or, focus one girl first, snap + focus 2nd girl, snap + put the photo of girl 1 and girl 2 in one photo with photoshop or equal.
 
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My key learning here? There are DOF calculators for smart phones!

Just checked, I found 44 on iOS. Awesome! I am not one of those people that can do the math in my head and I sometimes panic or worry when taking group shots as to what to set the aperture to.

Thanks guys!
 
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