Focus is technically optimal focus at a point, in a distance to the camera sensor, which makes the sharpest image from the foreground to the background near distance. This distance is called Hyperfocal Distance.
When using optimization techniques focus?
When the scene has foreground close, you want to make it clear that from the foreground to the background at infinity, you should apply this technique.
When you do not need to make clear in the foreground, as the foreground is the black ball (silhouette), or no foreground (space) then you do not need to apply this technique. In that case you should focus on the subject or the most important highlights in the frame if any, otherwise focus on detailing the latest in a picture frame (near the lower edge of the frame) and combined with export optimized for focal point you are taking (details below post)
What is clear?
Clarity is only a relative, except the viewers eye health, clarity depends on 2 factors:
* Image size:
At the same distance, the smaller will see sharp images as clear, sharp images will see more and more to blur. For example, you see a general picture on the screen everything looked very well, but when the press releases 100%, those details are not clear as when viewed at small sizes before this to.Dieu showed reporters images 12 mp will see sharper images when viewed at 36 mp integer pixel mode 100% with all other factors are equal.
* Distance view photos:
the same principle as above, will see sharp images as far as clear, sharp images as close’ll see more and more blurred. For example, you see the ad to the highway very clearly from a distance, but up close it close to find those details are very rough and fuzzy print. So when you see the image at a distance of 3 meters and you will find a better definition is that you come to a close at a distance of 25 cm.
Why tables optimal focus may be wrong?
As a second factor that the board focus on availability (Hyperfocal distance table) and computer software definition (Hyperfocal distance calculator) are more out there may not be accurate if it does not tell you is that it is based on the size image size and image viewing distance is.
Most of the above table and the software is copied over from the 35mm, with printed image size is almost constant (equivalent to the 24mp digital camera). Nowadays digital cameras with different generations have different resolutions, for a variety of different image sizes. That size affects the definition as stated above, so if you use other machines 24mp, the parameters in the feature table available credit or computer software mentioned above will give you sharp focus distance is not optimal and there can result in blurred images in the foreground or background.
Clarity of the picture
Unlike human eyes always feel everything clearly from close up to infinity (because the human eye “focus” continuous), lens-field (DOF), is a clear space in the gallery, outside of field space that is part blurred. Depth of field / long or shallow / short depending on two factors:
* Focal distance:
The shorter the focal length (eg 14mm wide tube) as far-field / focal length and back again as long (200mm telephoto lens), the image field as shallow / short. This is why it is often used in landscapes ranging from 14mm to 24mm tube, because it gives us depth of field, allowing High Definition pictures from near to far. From 35mm onwards, the depth of field is not enough, or not enough quality for resorting to f22, the smallest gate, the image will be blurred more strokes due to diffraction (diffraction).
The smaller aperture (large f number, eg, f11, f16, …), the depth of field as long / and vice versa greater aperture (smaller f number, eg F2.0, F1.8 ….), The pictures are running field /short. So it is often used in landscaping small aperture f8-f16 usually to deep-field / long.
Optimal aperture in aperture scenery is just exploit possible sharpness of the lens and at the same time provide enough clarity image-field from near to far.
If you’ve read through the review (review) of the lens, you see that almost all of the lens for 35mm DSLR camera types are sharpest aperture f5.6 and f8 in. Depending on user focus, aperture f5.6 and f8 whether or not the school can supply photos that we should be in the landscape, so you need to choose one that has an optimum aperture at the sharpest of the tube glass which has just had enough of field that we need for the scenery for each focal length range. You can use the following optimal aperture, and check the actual image when shooting, by launching a 100% enlarge and view foreground and background are not enough definition, then up and down from there.
* These machines are diffracted 36mp started strong (diffraction) after f / 13-f / 14 reduces the image quality such as contrast and sharpness significantly, so unless in situations where you are required to border closed to f / 16 or f / 22 (eg, to make solar rays flashed) then you should not use the aperture to f / 13 or f / 14 this.
** On the 35mm focal length 24mm full frame or cropped, the optimum focus point too far to the foreground application to, because in the long focal length, the foreground which derive clear focus to infinity, then it too far, too small, lost the purpose for which you need to take it on, get it to make interesting attraction for photos. If approached and clearly focus the background will be blurred.