Focus issues... White horse in Sepia Scene...

[BuS_RiDeR]

I am still having focus issues.... I tried switching to a single focusing point on the camera... aiming the "square" at his/her eye and then recomposing...

I still seem to have a slightly soft focus... In some photos I can get focus... In others it is soft... Seems mostly to be "live" subjects that look soft...

Any advice on better focusing practices would be welcome... I've tried with my 17-85 IS USM and my 75-300 without IS... Same results...

 

[Bitter Jeweler]

What settings?

 

[BuS_RiDeR]

What settings?

I've tried in Tv and Av... this particular one was Av with an Aperature of 5.6 I believe...

 

[Bitter Jeweler]

shutter speed? ISO? The focal length of the image.

 

[sobolik]

If you thoroughly understand and do test shots concerning the following focus lock and aperture exercises and still cannot get it under control then your camera or lens or lens mount are to blame. A shot at f-11 done 10 times should correspond all 10 times to the scientific expectations described below.

Also borrow someone else's camera and see if you get messed up focus. Perhaps your technique/procedure is the cause.

Lets get a little more scientific.

Lets' say you have A 35 mm lens set to f/11. and the subjects eyeball which is about 1.5 meters away is in focus
The depth-of-field scale on the lens (if it has one) indicates that anywhere between 1 and 2 meters in front of the camera will be rendered acceptably sharp.
If the aperture were set to f/22 instead, everything from 0.7 meters to infinity would appear to be in focus.

As you can logically deduce aperture is a big contributer to the in focus zone. Perhaps when you recompose the spot focus is targeting a leaf at many feet to the rear. With a large hole small number aperture this would be bad. What aperture are you using and are you using the focus lock feature when you recompose?

Also as you can logically deduce the larger the hole (aperture) the smaller the zone of sharpness. This can be an advantage to get the out of focus back grounds or a curse if trying to get a group of people in a group all in focus.

Example from the following calculator.

Using a 105mm lens focused at 10 feet and f-4 the in focus zone is 2.01 feet total.

Anything between 9.09 feet and 11.11 feet will be in focus. It is highly doubtful that a human head exceeds 2.01 feet in diameter and therefore means we need not obsess about whether we should focus on the hairline or the eyes.

If using a fast lens at f-2.8 everything between 9.78 and 10.23 feet is in focus. For a total range of .45 feet. Again if the face at 10 feet with a 105mm lens is in focus - the eyes or the hair line - is no difference.

Here is a calculator with charts to aid in grasping this concept fully. Go to this page and then click on the top link for the excel version that you can interact with (you need excel on your computer NOTE: the tabs at the bottom of excel get you to the calculator)

If you thoroughly understand and do test shots concerning the above focus lock and aperture exercises and still cannot get it under control then your camera or lens or lens mount are to blame.

Also borrow someone else's camera and see if you get messed up focus. Perhaps your technique/procedure is the cause.

 

[Bitter Jeweler]

Perhaps it's just camera shake.

 

[BuS_RiDeR]

Perhaps it's just camera shake.

Hmmm... maybe... I am a bit unsteady... I will try the same shot with my tripod and see if there is a difference... When I have the opportunity that is.

If you thoroughly understand and do test shots concerning the following focus lock and aperture exercises and still cannot get it under control then your camera or lens or lens mount are to blame. A shot at f-11 done 10 times should correspond all 10 times to the scientific expectations described below.

...
...
...

Also borrow someone else's camera and see if you get messed up focus. Perhaps your technique/procedure is the cause.

Thanks for the input... I will look into that as well...

 

[Derrel]

It is hard to see what's really going on in the photo...the sepia processing kind of hides some details, like chromatic aberration. But, based on years' worth of experience looking at photos and trying to diagnose faults, to me, the photo looks like it has overall softness caused by perhaps a low-quality UV or clear filter in front of the lens, or perhaps a decentered element...but the processing of the image is hiding a lot of the "real" image quality. It looks, sort of, like the grass is sharper behind the horse than in front of it...so perhaps the focus is just back-focused 2 feet or so...this kind of a focusing error is pretty common with the slower "consumer" type zoom lenses...missing the focus by 1 or even 2 feet at 30-60 feet with a 55-200, 75-300,etc,etc, can mean a photo that's just a leeeeetle bit off...

If we could see the "real photo" perhaps the error or technical flaw(s) would be more readily apparent. It's hard to speak definitively on a shot that's processed this much.

 

[BuS_RiDeR]

It is hard to see what's really going on in the photo...the sepia processing kind of hides some details, like chromatic aberration. But, based on years' worth of experience looking at photos and trying to diagnose faults, to me, the photo looks like it has overall softness caused by perhaps a low-quality UV or clear filter in front of the lens, or perhaps a decentered element...but the processing of the image is hiding a lot of the "real" image quality. It looks, sort of, like the grass is sharper behind the horse than in front of it...so perhaps the focus is just back-focused 2 feet or so...this kind of a focusing error is pretty common with the slower "consumer" type zoom lenses...missing the focus by 1 or even 2 feet at 30-60 feet with a 55-200, 75-300,etc,etc, can mean a photo that's just a leeeeetle bit off...

If we could see the "real photo" perhaps the error or technical flaw(s) would be more readily apparent. It's hard to speak definitively on a shot that's processed this much.

I thought I had removed the filter off the lense but I see it is still attached.. I will re-shoot when I have the chance. Thanks for the input.

Also... this was the original... Unedited... uncropped...

 

[Flash Harry]

I think you might just be enlarging this section too much with the single crop, try cropping in stages and some usm along the way, see if that improves the look. H

 

[DanFinePhotography]

also realize a low resolution image will soften a little when its cropped tightly

 

[BuS_RiDeR]

I think you might just be enlarging this section too much with the single crop, try cropping in stages and some usm along the way, see if that improves the look. H

Thank you for your input... I will play with this as well...

also realize a low resolution image will soften a little when its cropped tightly

Ummm ok... but its a 15 mega pixel RAW to start with... perhaps I am wrong... But I don't consider that to be low res... Should I be?

 

[DanFinePhotography]

i show original was 1024x683 maybe thats just what shows up on this site though. Seems like a rather small image to crop tightly with good results

 

[BuS_RiDeR]

This is what Picassa is showing me for the original...

Photo information
Aug 19, 2010
4752×3168 pixels – 2060KB
Filename: 2010_08_19_IMG_0347.JPG
Camera: Canon
Model: Canon EOS 50D
ISO: 100
Exposure: 1/500 sec
Aperture: 5.6
Focal Length: 110mm
Flash Used: No
Latitude: n/a
Longitude: n/a

For the crop...

Photo information
Aug 19, 2010
2285×1526 pixels – 291KB
Filename: WhiteHorseSepia.jpg
Camera: Canon
Model: Canon EOS 50D
ISO: 100
Exposure: 1/500 sec
Aperture: 5.6
Focal Length: 110mm
Flash Used: No
Latitude: n/a
Longitude: n/a

 

[DanFinePhotography]

it must have reduced in size just for this site then. I kind of like the color version BTW :mrgreen: