Please Help - why are pics not in focus and sharp?

[Maria]

I have a 24-70mm f/2.8L lens and am finding that it is not as sharp as i'd expect.  I'm sure it's me and not the lens so hoping someone can help me understand what i'm doing or not doing correctly.

I'm attaching a picture as an example...hand held...here are the settings:

EF24-70mm f/2.8L II USM

59.0mm

1/640 sec;   f/2.8;   ISO 400

Shutter priority;   Spot metering

shot with 70D

when you zoom into the tree it is cleary not in focus/sharp ;(

I've tried at differen shutter speeds but still having the same issue... going to try different apertures next...

[Maria]

redid the test using my T1i... at 1/1000 everything was blown out .... had to set to 1/4000 and ISO 400 to be able to see the test sheet .... it's nice a brigh outside.... when i looked at these shots i can say that they are slightly better than with the 70D but i stress slightly - almost not noticable difference.... on the T1i that center text is not in focus either and the numbers done either side of the chart are about the same result as the previous one (70d pic attached)....  ;( ;( ;(

going to go back out and wait for the sun to be under some clouds then take again using the 70d at f/4 and see what happens.... anything else i should try???

[ebiggs1]

You are using a tripod?

[Maria]

yes using a tripod and a remote so that i don't move it .... there is a little wind but dont' think it's enough to move anything.... tried to take the shots when there was none.... or is should say when i didn't feel any 😉

[Maria]

i believe the test said to not use a flash thus why i had to venture outdoors today 😉

[TCampbell]

You can take these indoors if you'd like.  If the camera is not moving and the subject is not moving, then the shutter speed can be open as long as necessary to get the shot.

For an outdoor shot in full mid-day sun, the sun provides a VERY consistent level of light.   There's an easy to remember rule called the "Sunny 16" rule.  This says that in full mid-day sun, if you set the f-stop to f/16 then the correct shutter speed will be the inverse of the ISO setting.  E.g. at ISO 100 you would use 1/100th.  At ISO 400 you would use 1/400th.  etc.

Doing a focus test you wouldn't want to use f/16... you want to use f/2.8.  BUT... that's an easy conversion.  

f/2.8 is 5 full stops down from f/16  (f/16 -> f/11 -> f/8 -> f/5.6 -> f/4 -> f/2.8).  That means you just need to compensate for those 5 stops using something else.  Assuming you're already at ISO 100 (which is what you should use for a focus test and you should use RAW to ensure the camera does not attempt to apply any in-camera sharpening), you'd count up 5 full stops of shutter speed:  1/100th -> 1/200th -> 1/400th -> 1/800th -> 1/1600th -> 1/3200th.

(BTW... Sunny 16 also estimates how much light is lost for light, medium, or heavy shade or overcast conditions and how to know if your situation calls for "light overcast" vs "medium overcast", etc.)

So:   ISO 100, f/2.8 and 1/3200th sec would give you a correct exposure if shooting outside in full mid-day sun (not in the shade.)

Set the camera to take the image as a RAW shot (vs. JPEG) to prevent the camera from applying any in-camera sharpening.

[Maria]

just retook using 1/3200, f/2.8, ISO 100... image is darker but still not in focus...this is using the t1i...

[Maria]

redid using ISO 100, f/4 and 1/1600th sec and there is no difference... pics look almost identical....  shot in raw and then cropped in PS CS6...

[Maria]

results look worse (i think) on the 70d @ ISO 100, 41mm, 1/1600, f/4  ;( i don't know what is going on ;( 

i can't open the 70d in RAW in PS CS6 - don't have the new plug in for that camera - so using the jpg for this one/camera...

[Maria]

okay so not sure what to do now?????  i feel i should return the camera and crawl under a rock .... sigh.....   everything is closed today but i believe the camera store that i got the lens from is open tomorrow so going to go to them to see if they have any suggestions .... my fear is that since i didn't get the camera from them they may not be as eager to help ;(  but i'm being pesomistic - no need for that right now!

If you have any more suggestions/ideas of things to test/try please let me know!!  🙂

[ebiggs1]

Using the exposure rules that Tim provided and a tripod are you getting a focus confirmation from each camera?

You are focusing right on the printed mark in "one shot"? Not any tracking AF ? Just the center focus point selected in the camera? All camera defaults set to factory?