This is Duncan's piece which in his effusive style he asks, "sharp tree roots and softer everything else with nice reflection" which I think is short hand for saying the tree roots are nice and sharp, and the reflection is "nice" - and sharp too, I guess, but why is everything else soft?
What follows is the sort of image assessment that we teach. It is something that we have the luxury of doing in the digital age without the PIA of having to take notes for the camera settings for every shot we took.
Reading the EXIF Data to learn what camera settings you used
What we will use is the EXIF data. This is information that the camera stores in the electronic file with the image. It tells us the camera settings that were selected. From Duncan's shot, we know that it was taken at ISO 160, using focal length 5.7mm (this is the widest setting) aperture f/4.5 and shutter speed of 1/450s. We also know that it is a shot taken with a Fujifilm S5000 camera. The camera was on Auto and Normal Exposure was used. We used the Adobe Bridge Software to show us this information, but most photo library or photo editing softwar will show you this data. It is called "Metadata" because it is not the data itself, but additional explanatory data.
So now we know how he shot it we can begin to assess the cause of the issues he perceives. He is bobbing down to take this shot - we can tell because he has the horizon in the middle of the shot, yet has quite a bit of foreground. Looking at the image, I would say he has focused quite close to him - perhaps 1.25m or four feet or so - this appears to be the sharpest part of the shot.
Using the Depth of Field Calculator
With this information we can use the wonderful DOF Master Online Depth of Field Calculator to calculate his depth of field. So, putting this information into the form:
- Fujifilm S5000 Camera
- 5.7mm Focal Length
- f/4.5 Aperture
- 1.25 metres Subject distance
and pressing the "Calculate Button", the little tool calculates for us:
- Near limit of acceptable sharpness: 0.67m
- Far limit of acceptable sharpness: 8.91m
- Total Depth of Field: 8.24m
- Depth of field in front of subject: 0.58m (7%)
- Depth of field behing subject: 7.66m (93%)
- Hyperfocal Distance: 1.45m
So, the issue is one of acceptable sharpness, and using the rather arbitrary view of what constitutes acceptable used by photographers for a long time, this tool has made these calculations.
I can hear Duncan saying, "So what"
Understanding the things that affect Depth of Field
Well Duncan, all these things - focal length, aperture and distance from subject (and the type of camera you have too, but that might be hard to change) affect what we call the depth of field - the area in front of the subject and behind the subject that is acceptably sharp - after all, it is only the subject itself or more precisely, light reflecting from a plane that is the subject distance from the camera that is perfectly sharply focused on the film or the sensor - everything else is soft or softer.
In this case, about 9 metres away from the sensor the subject matter - the trees in the background, for instance, become soft enough to be not acceptably sharp, and the trees which I guess would be 50 or 100 metres away become even softer again.
What did Duncan need to do?
What went wrong? Well, in a sense nothing. the 1/450s should be adequate to stop camera shake, even though Duncan might have had a beer or three. The camera focused where Duncan pointed it, and half-pressed the shutter. His selection of what to focus on was the issue, however, if he wanted the whole image to be sharp. From the calculations, we can see the hyperfocal distance of 1.45m - if he had focused (for instance on a different root) just 20cm further away than the 1.25m he did focus on, everything would have been in acceptably sharp out to Infinity. Unfortunately I can't just go and take the picture to prove it to you, but perhaps Duncan is looking for an excuse for another 4WD trip with his mates anyway.
On the other hand, we might want even more of the background soft - what then?
Now, Duncan may actually wanted to shoot the roots and have them nice and sharp and have even more of the background out of focus. If he used "Aperture Priority" Mode and selected aperture f/2.8 (I think this is his largest aperture), and then used the shutter button/reframing feature to focus as close to the camera as possible, the DOF Calculator says that his DOF will be reduced to 82.6cm. Of course this might be rediculously narrow for his interests, but the things he needs to do is either increase the aperture (smaller f-stop) or decrease the subject distance (and if he is happy to have a different composition, he could also increase the focal length - zoom in a bit, but this will change what features in the frame because it will have a narrower field of view).
Focusing and reframing - an important skill to learn
The steps required are firstly, to reframe the shot so that a point 90cm from the camera (or thereabouts) is in the centre, then by holding the shutter button down half-way, allow the camera to focus on that point - generally it will need to have the AF sensor rectangle directly over it, and the AR rectangle will generally flash, or the camera will beep to indicate focus has been achieved. Next step is while keeping the camera the same distance from the subject, AND whilst holding the shutter button down half-way, reframe the shot, by rotating the camera up/left/right as appropriate so that the elements of the scene you want in the frame are in the right position, then caress the button down (no need to lift your finger until the shot is taken), and there you have it
This is a skill that you should learn to do without thinking about it - make it second nature. It is particularly important for portraits, where you really want to focus on the eyes. Get out and practice it. Take a lot of photos using it. Do it lots of times today, and then get your camera out again tomorrow and practice it again, and you will make it a second-nature skill that you do without needing to think.
Sharpening in Photoshop and Tonal Treatment to simulate Velvia Film
We did do some photoshop sharpening on the image for Duncan, just to show him that all is not lost, and we also thought that Duncan's shot would look nice with a slightly different tonal treatment, which we did using the Velvia Vision plug-in for Photoshop.
If you have any questions about this, just ask ... And watch this space for some other articles on related aspects of this question ... there are other reasons besides the one afflicting this shot of Duncan's that can make you think the camera is not focusing properly when it is just doing what you tell it ;-) after all, it is the people not the machines that are stupid ;-)