project has long been writing about photography, but by golly I have advanced in my purpose to start with the basics: http://www.jadbp.org/2011/02/24/fotografia- basic-concepts / . So I refer the reader to the blog of unconscionable to me stepped on the track and when done to continue with this entry, which is also introductory ;-).
A typical problem when taking a picture is blur. The "culprit" can be "portrayed" (A car, a person moving). But when shooting in low light, such as indoors, often what has moved the camera, because when the shutter speed is very low, pulse = picture blurred picture.
What minimum shutter speed needed for a photo no blur? Obviously depends on the pulse of the photographer and even the camera, since a large and heavy camera with a grid is often easier to grab a small (really, for shooting very light and small is bad and is not the same as for video Soon after a tired arm anything heavier the camera.) But above all, as anyone who has used binoculars may deduct affects the focal length: a longer focal length, or whatever it is, more zoom, more noticeable the effect of hand shake and shorter must be the trigger for the photo does not leave moved. In fact, there is an informal rule that says if you do not want the image blur, the minimum shutter speed is the inverse of the focal, ie, if the focal length is 100mm, will have to shoot at least 1/100s , while if it is 300mm should be 1 / 300.
An important detail: the focal length to take into account not just the one printed on the lens of an SLR or a compact lens, except in the case of an SLR analog or digital SLR full-frame (ie, with a sensor the same size as the film in a 35mm film SLR). The focal length to be considered in the rule is effective, ie which should have a digital SLR with a 35mm film from that point to achieve the same level of zoom. The effective focal length increases when the sensor size decreases, because the smaller the sensor, the cut is the image projected on the sensor and thus more expansion (zoom) is if the two sensors have the same pixel Photos are on the same monitor.
effective focal length is calculated as the product focal length multiplication factor (in English crop factor) correspondent to the size of the sensor. This multiplication factor is simply the ratio between the length of the diagonal of a 35mm film sensor and a digital camera. As an example, the DSLR 4 / 3 Olympus and Panasonic have a sensor with a diagonal half of a 35mm film and hence its multiplication factor is 2. For cameras with APS type sensor (Canon, Nikon, Sony Alpha, Pentax, not full-frame) is usually between 1.3 and 1.6. With sizes ranging compact cameras, but in some phones the sensor is so small that the factor can be greater than 20 (for more information see http://es.wikipedia.org/wiki/Crop_factor and http://es.wikipedia.org/wiki/Formato_del_sensor_de_imagen ). The size of a compact sensor is usually on technical specifications, if not find the other option is to compare the focal range that tells the public that written on the camera lens.
An anecdote that shows how the rule of fire to at least the inverse of the actual speed may be informal, but is actually used. Olympus SLR in my mind that I noticed when shooting in automatic flash, the shutter speed is constant as long as you use exactly the same focal coincides with the value obtained by applying the rule. For example, any 50mm lens, the shutter speed is 1 / 100 (because the effective focal length in a digital reflex olympus is 2 times the nominal). Why
shooting with flash always default to the minimum speed to avoid blurring the picture, regardless of for example the maximum extent permitted by the target, ambient light or how far it is the object to be photographed? When shooting without flash, the camera receives an amount of light that does not control and the only discretion is to decide how to let in enough light to take the picture, if the diaphragm opening more or firing more slowly. But when shooting with the camera flash has control over the amount of light entering the camera directly to the flash power setting (this is possible thanks to the TTL system, consisting of just before taking the picture to launch a flash to measure if it sufficient light and adjust the flash power). However, the flash duration is always shorter than the shutter speed the camera, does not affect both the shutter speed to the objects illuminated by the flash, but for those who are out of reach and that the picture is more natural and less shadows, we are concerned that the shutter speed is slow as possible to take without being moved.
Speaking of flash, some people are determined to use the flash even though the object photographed is 50 meters and are using a compact flash that can illuminate an object 3 meters. But reason that there is "something" in their photos and better than if you shoot without flash. Solution: you try to manually set the shutter speed to a minimum so as not to blur (if allowed by the camera, of course) and see the "improvement" that have been allegedly shooting with flash.
Shoot slower, steady shot.
Of course the perfect solution to avoid blur from camera shake is to use a tripod. Learning While holding the camera is generally achieve a higher percentage of photos do not shake at slow shutter speeds (you can search Google and even on YouTube). Sometimes when you move the camera more precisely by pressing the shutter button, even some of us are so clumsy that sometimes move a bit to shoot still camera on a tripod securely. To avoid this, and even small internal vibrations that occur in the chamber by lifting the reflex mirror to shoot, my camera and I guess most offer the option of pressing the shutter the mirror is raised, but wait a second to actually make the picture (open aperture). When the option carrying a tripod is not viable or have the option of supporting the camera somewhere, an alternative to the tripod much lighter is a monopod, but not everyone manages to take advantage of the monopod (this writer is unfortunately in this group and that using a decent one).
many cameras now include stabilization (using a floating system tries to compensate for shake our hands.) It makes a difference, but neither works miracles: in some cases can take more than 3 steps (each step would be to shoot at half speed) but in others much less. Eye, while some are compact stabilizer of this type (often called stabilizer optical) in other cases no such stabilizing, but use of higher ISOs. When talking about dual stabilizer, in a reflex usually refers to optionally can stabilize only the vertical axis (useful for making a sweep) while a more compact nose and throw it usually mean that there are stabilizing "the truth" one side and the tip of the other high ISO.
ISO or ASA value of photographic film dealt with the sensitivity and ISO 200 film is twice as sensitive as an ISO 100, ie in the same light conditions and the same aperture diaphragm, with the ISO 200 as needed half as much light you can shoot twice as fast as ISO 100. The price of using more sensitive films is that the photos show more grain. In a digital camera, there really is no concept of sensitivity of the film, because the sensor is always the same and therefore does not change its sensitivity. In digital photography, raise the ISO is simply to say on camera that they managed with less exposure to the theory that the sensor need to have the same sensitivity as a film ASA100. If we go far the ISO, there comes a time when the threshold of light sensors are too small to make a reliable measure and then produce erroneous readings of random nature, noise, with much less aesthetic results the granules of the cameras. ISO acceptable level for a photo in addition to the photographer's expectations depends on the camera but also the conditions of light the less light there is more high ISO is charged, so the comparisons are misleading attempt to show that a camera has low noise at higher ISOs if the photos are bright. Some
reflex instead of taking the stabilizer in the camera are on target. There is no evidence of any difference in efficacy between the stabilizer moves in the camera or lens, the advantages or disadvantages are cost (where it is cheaper to put the stabilizer). Some people prefer stabilizer on the target, because the goals are good for life while the body of the camera is changed several times, but others (among which I am) argue that multiple objectives are usually purchased as it is cheaper than going stabilization in the chamber and serve well for all objectives, including flights (most expensive SLR sold as a kit with two goals over there and put up for a stabilizer in the body one on each goal.) The Olympus SLR lead stabilizer consumption (less than those of more compact size) and does not carry any of its objectives, even the most expensive hand-polished lenses, while the other makes no stabilizer in the camera because I already have all the high-end goals, yet not usually carry the objectives of cheap kit that came with the camera. Alternatively
: picture darker (burning)
the camera when we press the button halfway down the light reaching analyzes and calculates the exposure value needed for the photo does not burn out or dark (white .) The exposure value is the famous EV: Exposure value. The cameras allow exposure compensation, ie, tell the camera to make as if instead of having obtained that value, you read that passage many steps or more or fewer steps. The EV value is used on around after analyzing a histogram and see if there is dark or burned areas, but can also be useful underexpose slightly (ie, the photo will be a little dark) and normally take an editing program to increase the brightness other details are were a bit dark (in contrast when the photo is burned, no editing software worth). Of course it is usually best not to underexpose, either, but sometimes you have to choose between photo underexposed or moved.
0 comments:
Post a Comment