Sharpness of a photo

playplay · 15th December 2008

Hi Guys,

Just wondering how do you measure or view the sharpness of a photo?

I tried taking photos of focus chart and other products as well with manual focus, auto focus and all done with a tripod.

Before doing any image re-sizing and post processing, i viewed the image at 100% and realised they were not sharp. I can see a faint 1mm to 2mm blurred line in between background and product. Even for sharpness test using the black squares, i saw a grey line at 100% of 1 to 2mm in between the black n white. At probably 66.7% its still seen quite sharp but not at 100% image size.

Any suggestion or comments?

Kit · 15th December 2008

What were you really expecting viewing your test shots at 100%??? Of course its not going to be sharp.

Go out, take some photos, do the necessary editing(sharpening, toning, etc and print them out in 15 x 10. If you are happy with them, its sharp.

catchlights · 15th December 2008

sharpness is relatively, it depends on your final output, do you need more than necessary? do you always print the photos, display the photos at 100%?

How about you post a photo of your test, let others tell you is sharp or not? or you are pixel peeper

playplay · 15th December 2008

Originally Posted by Kit

What were you really expecting viewing your test shots at 100%??? Of course its not going to be sharp.

Go out, take some photos, do the necessary editing(sharpening, toning, etc and print them out in 15 x 10. If you are happy with them, its sharp.

Okie. I am new to Digital SLR. I thought images would be sharp at 100% since i am using a F2.8 lens. Will L lens be able to achieve that sharpness defined as a clear straight line at 100% image size?
Will post some photos later on..

Kit · 15th December 2008

No, L lenses does not necessarily means sharper photos. L lenses are not about sharpness only and since you are using a fast lense(presumably using the wider aperture), you could be dealing with depth of field issues instead of actual lens sharpenss.

catchlights · 15th December 2008

Originally Posted by playplay

Okie. I am new to Digital SLR. I thought images would be sharp at 100% since i am using a F2.8 lens. Will L lens be able to achieve that sharpness defined as a clear straight line at 100% image size?
Will post some photos later on..

without doubt most f2.8 lenses are very sharp, but not all f2.8 lenses are sharp at f2.8,
and also not all subjects are meant to shoot at f2.8 only,
also don't forget beside f2.8, you can shoot f4 up to f16 or f22.

metalgear · 16th December 2008

are you comparing raw or jpeg ?

from what I know with the anti-alising filter all shots come unsharp in dslrs and need further sharpening to bring the image out. jpeg is in-camera sharpening amongst other things.

how far you want to go is up to you in post-processing - beauty in the eye of the beholder.

babykailan · 16th December 2008

"Microscopic sharpness is of no pictorial value." --Alfred Steiglitz

15th December 2008	#1
playplay Member Join Date: Nov 2008 Location: Choa Chu Kang Posts: 396	Sharpness of a photo Hi Guys, Just wondering how do you measure or view the sharpness of a photo? I tried taking photos of focus chart and other products as well with manual focus, auto focus and all done with a tripod. Before doing any image re-sizing and post processing, i viewed the image at 100% and realised they were not sharp. I can see a faint 1mm to 2mm blurred line in between background and product. Even for sharpness test using the black squares, i saw a grey line at 100% of 1 to 2mm in between the black n white. At probably 66.7% its still seen quite sharp but not at 100% image size. Any suggestion or comments?

15th December 2008	#2
Kit Senior Member Join Date: Jan 2002 Location: Bukit Timah / Melbourne CBD Posts: 6,011	Re: Sharpness of a photo What were you really expecting viewing your test shots at 100%??? Of course its not going to be sharp. Go out, take some photos, do the necessary editing(sharpening, toning, etc and print them out in 15 x 10. If you are happy with them, its sharp. __________________ arkitectural photography http://arkitecturalphoto.1x.com/

15th December 2008	#3
catchlights Senior Member Join Date: Sep 2004 Location: Punggol Posts: 10,775	Re: Sharpness of a photo sharpness is relatively, it depends on your final output, do you need more than necessary? do you always print the photos, display the photos at 100%? How about you post a photo of your test, let others tell you is sharp or not? or you are pixel peeper __________________ Shoot to Live, Live to Shoot www.foto-u.com \| www.benjaminloo.com \| email

15th December 2008	#5
Kit Senior Member Join Date: Jan 2002 Location: Bukit Timah / Melbourne CBD Posts: 6,011	Re: Sharpness of a photo No, L lenses does not necessarily means sharper photos. L lenses are not about sharpness only and since you are using a fast lense(presumably using the wider aperture), you could be dealing with depth of field issues instead of actual lens sharpenss. __________________ arkitectural photography http://arkitecturalphoto.1x.com/

16th December 2008	#7
metalgear Member Join Date: Aug 2003 Posts: 590	Re: Sharpness of a photo are you comparing raw or jpeg ? from what I know with the anti-alising filter all shots come unsharp in dslrs and need further sharpening to bring the image out. jpeg is in-camera sharpening amongst other things. how far you want to go is up to you in post-processing - beauty in the eye of the beholder.

16th December 2008	#8
babykailan Member Join Date: Sep 2006 Location: Singapore Posts: 951	Re: Sharpness of a photo "Microscopic sharpness is of no pictorial value." --Alfred Steiglitz __________________ Canon 5D 17-40L 24-105L 50L Flickr \| Buy Baobao's photobook!