Accessories – The Hood
The title of this article should be the hood – this unknown. The reason is very simple with the passage of time, fewer and fewer photographers make use of the hood, however, making a huge mistake.
Ansel Adams used to say There is no photograph without a hood. Concept absolutely true in his time, when technology was not so advanced to help the photographer also in eliminating reflections sewa lcd proyektor semarang. But we are sure that the current lenses are actually able to eliminate any parasite reflection The answer is no in the photo to follow it is clear how the light rays from the sun start and how in the right part of the image you have created two colored flare.
The reason why you create these artifacts is very simple the light rays coming from outside the field of view (ie not part of the image) go in sideways hitting the front lens causing, due to refractions and reflections inside the lens, flare, stray reflections, light rays, haze effect, ghost reflections, contrast fall.
Eliminate these parasitic elements is possible in two ways with particularly expensive lenses or with very few Euros and a plastic piece to be attached by screwing, before the lens. This piece of plastic is called, precisely, lens hood. As you can imagine then, the function of the lens hood (a truncated pyramid, totally blackened inside) is precisely to prevent the external oblique rays to strike the lens field of view.
When the lens hood should be used Many believe that the hood will serve to cover the direct sun, but it is absolutely wrong these unwanted rays have so much in a day as full sun on a cloudy day. It goes without saying that the lens hood should be used always and especially when front of the camera mount additional filters increasing the number of windows does nothing but amplify the refraction and reflection of the bad rays and then the ‘ increase of artifacts.
The hood, as mentioned, is ultimately a piece of plastic and its economic value is actually negligible. Careful what you buy lens hood it must be consistent with the angle of lens. This means that every goal should have a personal lens hood. Longer the focal length is long, greater will be the length of the lens hood (and thus better fulfill its purpose), most will rather short order, shorter (and open) will be the same hood.