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03-18-2011, 12:20 AM   #1
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Focusing questions

Can the seniors suggest what I am doing wrong here. My second day playing with the K-r. If you see this picture, the face is focussed in the centre but on the sides it looks blurred - can you advice what I should do to get the full face in focus.

Second Question: say I have selected the right side focusing points on the side then does this mean the right edge of the picture will get focus?

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03-18-2011, 12:35 AM   #2
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Sorry but none of this is sharp.

Focal Length 35.0mm (35mm equivalent: 52mm)
Exposure Time 1/10s (0.100)
Aperture F/2.4
ISO Equivalent 1600

You are very, very short of light, the shutter speed is far too slow to avoid camera shake, the IS cannot correct the amount of shake you are getting. You need a lot more light to give the camera a chance of getting a sharp picture - the only way to get a sharp one in this amount (!) of light is to use a tripod and delayed shutter release, which obviously is not the way to get pictures of little boys being little boys. Unless they are sound asleep.

Having said that, the photo isn't without charm and a 6"x4" print might be very acceptable to his parents - you are one of them I suspect.
03-18-2011, 12:53 AM   #3
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I agree with cats five. You have to get the shutter speed a bit higher. Try Av mode. Set your ISO to auto 3200 and your f stop a little higher than 2.8, say about f4.5. The K-r should be able to handle the higher ISO easily, and that should give you a higher shutter speed of about 1/50 or 1/60, and better DOF(depth of field)
03-18-2011, 12:57 AM   #4
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Yes, thanks for that input!

Yes it is my daughter! My worry is if I were to go for a higher shutter speed at this aperture how to get more light in since the subject as you rightly mentioned will not be still - what will professionals do in this situation, as I don't want to use inbuilt flash as well but just want to capture the natural light particularly with kids?
If there is no other way then I will feel a bit comfortable knowing that it is not only me but for anyone it is a challenge.

thanks

03-18-2011, 01:06 AM   #5
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What professionals might do doesn't really apply. Some of them might fling up a load of lights, others might pull out a $mega-buck camera, others might have an army of helpers running round with reflectors and some of them might simply tell you to take your child to their studio.

You have missed altopiet's point about setting a higher ISO. You (or your camera) have used 1600, I gather it will go up to 12800 (or 25600 with expansion) which will let you use a faster shutter speed and/or a smaller aperture. Of course you will get more digital noise, but you start standing a chance of getting a reasonably sharp picture.
03-18-2011, 01:50 AM   #6
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QuoteOriginally posted by sany Quote
Yes, thanks for that input!

Yes it is my daughter! My worry is if I were to go for a higher shutter speed at this aperture how to get more light in since the subject as you rightly mentioned will not be still - what will professionals do in this situation, as I don't want to use inbuilt flash as well but just want to capture the natural light particularly with kids?
If there is no other way then I will feel a bit comfortable knowing that it is not only me but for anyone it is a challenge.

thanks
Why not use your flash? You will shoot at up to 1/180th of a second, you can afford to stop down the lens to increase the DOF, and at the distance that you took the picture of your daughter, the built-in flash should suffice. What would a professional do, he or she will do whatever it takes to get the shot. Natural lighting, as in daylight? Your flash is balanced for daylight, as does the Auto White Balance tries to do in all lighting conditions. You try to make the flash shot look natural and you can do that by placing a diffuser over the flash head.

Thanks,
03-18-2011, 03:23 AM   #7
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Sorry but how will a polarizer help in such a low-light situation? I believe it will only hinder.
03-18-2011, 09:13 AM   #8
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QuoteOriginally posted by sany Quote
Second Question: say I have selected the right side focusing points on the side then does this mean the right edge of the picture will get focus?
Seems this one was overlooked. The answer is yes.; that were the focus indicator (the red square) lights up will be the point that the camera is has obtained focus on.

03-22-2011, 11:23 PM   #9
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Focus Points

Thanks for noticing my second question on focussing points, sterretje. However, when I chatted with another friend he was giving me a different idea. So I am again in a confused state.

Therefore I am trying to make my question even clearer with the aid of some diagrams below.

Image A: Say I am selecting the top right focus point (highlighted in red) - does this mean that my picture will get focus in the area exactly seen behind the focus point (red point) as seen in Image B or do we have to interpret the top right focus point to be the top right side of the larger frame of the picture as indicated in Image C?

Hope it will be clearer now. Please explain experts! Note that I am very new to DSLR if my question sounded too childish.

thanks
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03-23-2011, 12:58 AM   #10
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QuoteOriginally posted by sany Quote
Thanks for noticing my second question on focussing points, sterretje. However, when I chatted with another friend he was giving me a different idea. So I am again in a confused state.

Therefore I am trying to make my question even clearer with the aid of some diagrams below.
Image A: Say I am selecting the top right focus point (highlighted in red) - does this mean that my picture will get focus in the area exactly seen behind the focus point (red point) as seen in Image B or do we have to interpret the top right focus point to be the top right side of the larger frame of the picture as indicated in Image C?

Hope it will be clearer now. Please explain experts! Note that I am very new to DSLR if my question sounded too childish.

thanks
answer was bolded.
03-23-2011, 05:18 AM   #11
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Thanks Akanarya, this leads me into more questions:

1. Does this mean that when I select all 9 focus points in the center then the picture will get focus only behind those 9 points and the rest of the surrounding areas will be out of focus?

2. That small space between those nine focus points - will they be out of focus?

3. What should I do to get the complete image in focus? will making the aperture smaller help (am I getting confused with the DOF)

4. Is there any specific reason for populating those focus points in the center as against spreading them to cover the complete size of the picture frame?
03-23-2011, 06:52 AM   #12
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1. It means the system will auto-magically choose which of the 9 points to use as the focus point.

2. no, it depends if they are in the same "focus plane" as the selected focus point's "focus plane".

3. smaller aperture ( higher f. number) will result in larger depth of field. (see this video
)

4. don't know, maybe most images are taken with the focus relatively close to the center.

M.
03-23-2011, 07:43 AM   #13
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You can only have one plane (depth) in the image in 'perfect' focus. If you focus on a subject e.g. at 2 meters distance, only 'stuff' at 2 meter distance (left, right, center) will be in 'perfect' focus; the rest will be out of focus.

If you want the full image in 'perceived' focus, you have to close the aperture for DOF control (as you already mentioned). I suggest you read up on DOF and (related) hyperfocal distance. You can play with Online Depth of Field Calculator as well.

If you select the '9 point' focus option, you allow the camera to choose a point (one of the nine) that it can focus on. I don't know the 'design', but I think the camera will use a trial-and-error method till it has found something to focus on; and that might not be what you want to be in focus.
03-23-2011, 11:18 AM   #14
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QuoteOriginally posted by sterretje Quote
<snip>
I suggest you read up on DOF and (related) hyperfocal distance. You can play with Online Depth of Field Calculator as well.
<snip>
I second that - it's an excellent site and I have found playing with the Online DoF is immensely helpful.
05-23-2011, 07:05 AM   #15
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Focussing Eye & re-composing

Does focussing into the eye of the subject also requires recomposing the frame?
This question comes from the fact, that the focus points in the viewfinder or in the center of the frame and say the subject's eye in my viewfinder is in the top right hand corner - how to focus into the eye in this case.

Is it that, I fix the top right focus point in the center and point this area over the eye of the (super impose over the eye) and get the focus and recompose again so the eye of the subject now is place in the top right corner

or

select the top right focus point while the subject's eye is already in the top right corner of the frame and when the eye gets the focus the the focus point select beeps and blinks?

I wanted to get the focus without recomposing - i am a bit confused here - with center focus point - there is no confusion for me either as such or with recomposing the scene.

Please throw some light on my brain. You can also use the diagrams in the previous posts to explain.

thanks
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