Are my photos or lens sharp?


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Mar 19, 2005
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#1
Hi,

I am wondering how to tell whether my lens are sharp. I know That everyone says that you can zoom in your camera LCD or view it on computer to check.

My qn is when i zoom in on my camera LCD, am i suppose to zoom all the way? If thats the case, then I dun think ANY of the photos i have taken are sharp at all.

Then I have heard that you should zoom in 100% to check for shapness, I am guessing for this one i should choose 100% view when I open in my viewing software? Again when i try this method, i cant say that its absoultely sharp.

So i am very worried because i dun know if I have gotten some bad copies of lenses or is it i cant even take a proper sharp picture :(

anyway.. i put in a photo below and hope to get some advice.. am i doing something wrong or is it ok?



The above was taken with Canon 400D with 50mm f1.8 lens.

Thank you.
 

night86mare

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#2
1) your focus looks off to me

2) no lens is going to be as sharp wide open as it is at f/8, take note of that
 

Mar 19, 2005
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#3
Yes aware of the aperture as well.

But can you advise, how i can check whether my photos are sharp?

Thanks.
 

Kit

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#4
Sharpness is subjective. First, you need to recognise your expectations of sharpness and of course the various factors that will affect sharpness (or your perception of it). You need to have a basis to judge against. Using your camera's LCD is not the correct way to go about judging it.

No one can ever judge sharpness on a jpeg over the monitor. In this instance, the ambient lighting is pretty flat and doesn't render much contrast. That might have just affected your perception of sharpness. Besides shutter speed, aperture, shooting parameters, etc, having a good post editing workflow is also essential for getting the best out of your photos. You might want to read up on digital workflow.

As for judging, there's nothing more satisfying than printing your images out to a least 8x10 or 8x12 and see the prints for yourself. Taking into consideration that you have done all the right thing leading to the final product.
 

Rashkae

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Nov 28, 2005
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#5
on that pic, it looks like you focused on the yellow metal bar.
 

chalib

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#7
Shoot a test chart or newspaper to see your lens sharpness.... do it on tripod then post it here for others to comment accurately...
 

Mar 19, 2005
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#8
Sharpness is subjective. First, you need to recognise your expectations of sharpness and of course the various factors that will affect sharpness (or your perception of it). You need to have a basis to judge against. Using your camera's LCD is not the correct way to go about judging it.

No one can ever judge sharpness on a jpeg over the monitor. In this instance, the ambient lighting is pretty flat and doesn't render much contrast. That might have just affected your perception of sharpness. Besides shutter speed, aperture, shooting parameters, etc, having a good post editing workflow is also essential for getting the best out of your photos. You might want to read up on digital workflow.

As for judging, there's nothing more satisfying than printing your images out to a least 8x10 or 8x12 and see the prints for yourself. Taking into consideration that you have done all the right thing leading to the final product.
Thanks for sharing.

Yes no post processing was done on my photos.. I do understand the need for the digital workflow.. just have not gotten there yet...still very new and learning..

Thank you will note that :)
 

Mar 19, 2005
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#9
on that pic, it looks like you focused on the yellow metal bar.
yes I was trying to apply the one third rule.. but i think i dun really know how to do it...

I half press the shutter to focus on her then moved my cam for the composition... its prob wrong right.. i should have manually selected the left focus point on my cam?
 

Kit

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#10
Your camera will focus again just before releasing the shutter so the focus obtained the 1st time before you re-compose will be over-ride. You can either remain the shutter position in half pressed position after you focus to the point of re-compose to release the shutter or use the focus lock function, in which the focus will lock on to the subject for a period of time enough for you to re-compose and take the shot.
 

Mar 19, 2005
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#11
Shoot a test chart or newspaper to see your lens sharpness.... do it on tripod then post it here for others to comment accurately...
I have no tripod.. so i rested it on something and used the 10 sec timer... I just took a shot of a newspaper... hope its what you meant...



The above was taken with a Sigma 18-200mm at F4.5.



The above was taken with a 50mm at F2.8


Thanks for comments and help.
 

calebk

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#12
yes I was trying to apply the one third rule.. but i think i dun really know how to do it...

I half press the shutter to focus on her then moved my cam for the composition... its prob wrong right.. i should have manually selected the left focus point on my cam?
Yes, you should have, or you could have done what Kit said.

Referring to your newspaper test, there is no point doing something like this when your newspaper is not even perpendicular to your image plane.

Really, there is no point in newspaper tests, test charts, or anything of that sort; just go out and shoot, and if you find that you are happy with the detail rendered in your final product, that's what matters.
 

sunboi80

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#13
Yes, you should have, or you could have done what Kit said.

Referring to your newspaper test, there is no point doing something like this when your newspaper is not even perpendicular to your image plane.

Really, there is no point in newspaper tests, test charts, or anything of that sort; just go out and shoot, and if you find that you are happy with the detail rendered in your final product, that's what matters.

i think he is trying to find out whether he has a bad copy of the lens... :)
 

Rashkae

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#14
From the newspaper shot, it looks sharp at the center, with the expected OOF blurriness in the bottom and top sections.
 

Mar 19, 2005
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#15
Your camera will focus again just before releasing the shutter so the focus obtained the 1st time before you re-compose will be over-ride. You can either remain the shutter position in half pressed position after you focus to the point of re-compose to release the shutter or use the focus lock function, in which the focus will lock on to the subject for a period of time enough for you to re-compose and take the shot.
What i did was half press the shutter when subject was in the centre, then while still holding the half press shutter, i recompose and then depress the shutter completely to take the shot. Is that the same as what you meant by "remain the shutter position in half pressed position after you focus to the point of re-compose to release the shutter" ?

As for the focus lock function, i still have to discover that function on my cam :)
 

viewwing

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Nov 6, 2006
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#16
A few things for u to check...

1. Make sure your Auto Focus is set to SINGLE and not Continous focus.
2. Your aperture for your first picture is F2. Which means your DOF is VERY THIN. If you're looking for a shot thats overall sharp... try going F5.6 up to F11. You should have some good shots.
3. Shutter Speed. at 1/80 you should not have camera shake problem. But try the shot on a brighter day. Also some of the setting of the camera might make the picture look smudgy due to the camera post process. I'm not a C user, so u might want to check with fellow CSer on their camera setting for the 400D.

When all else fail bring the lens and see whether it can be calibrated... for all u know it really could be faulty.

Good luck!
 

user1

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#17
There is a "one shot" option in the AF selection button for the 450, maybe 400 also have....
 

Kit

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#19
What i did was half press the shutter when subject was in the centre, then while still holding the half press shutter, i recompose and then depress the shutter completely to take the shot. Is that the same as what you meant by "remain the shutter position in half pressed position after you focus to the point of re-compose to release the shutter" ?
Yes..
 

Mar 19, 2005
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#20
Great! At least i know i got the method correct :)

Hmmm.. so that means that my subject was probably not as sharp cos of other factors like the fact that i was using the aperture wide open?
 

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