Дата: 30-12-20 18:24
Гена, кое точно от цифрите не разбра, точно за динамичния обхват и шума?
Виждаш ли при какви стойности на исо сензорите произвеждат толкова шум, че стават неизползваеми за прилични резултати.
Този олимпус произвежда толкова много шум, че хората са решили, че над исо 800 е за боклука. Някаква смешка за фотографията. Образно и кратко описание за шестаци Иначе е малко по-сложно, и безнадеждно за теб
Заключението им като резултати от целия сензор, не са ли точно отговора на спора ни?
Бай Генча, измий си опиканите ръце и прочети обяснението за стойностите които съм дал по-готе, и които са точно за шума и динамиката на сензора.
Landscape score: Maximum Dynamic Range
Landscape photographers carefully compose their images and choose the time of the day for shooting in the best light. This type of photography commonly involves mounting the camera on a tripod and using the lowest possible ISO setting to minimize noise. Unless there is motion in a scene, relatively long shutter speeds are not an issue with a tripod. On the other hand, dynamic range is paramount. Photographers will often aim for detail in high-contrast settings, juxtaposing a bright sky with shadowy foliage or mountain ranges. Ideally, the dynamic range of the camera should be greater than the dynamic range of the scene, otherwise details in shadows are lost or highlights are burned.
Dynamic range falls rapidly with higher ISO settings, as any analog or digital amplification performed will increase the noise in the darker areas, making it harder to distinguish among fine levels of contrast. Maximum dynamic range is the greatest possible amplitude between light and dark details a given sensor can record, and is expressed in EVs (exposure values) or f-stops, with each increase of 1 EV (or one stop) corresponding to twice the amount of light.
Dynamic range corresponds to the ratio between the highest brightness a camera can capture (saturation) and the lowest brightness it can capture (which is typically when noise becomes more important than the signal — that is, a signal-to-noise ratio below 0 dB). A value of 12 EV is excellent, with differences below 0.5 EV usually not noticeable. Dynamic range is an open scale.
Sports & action score: Low-Light ISO
Unlike the two previous scenarios in which light is either generous (studio) or the camera can be mounted on a tripod (landscape), photojournalists and action photographers often struggle with low available light and fast motion in the scene. When shooting sports or action events, the photographer’s primary objective is to freeze motion, giving priority to short exposure times. To compensate for the lack of exposure, photographers have to increase the ISO setting, which results in a decreased signal-to-noise ratio (SNR). How far can ISO be increased while maintaining decent image quality? The DxOMark low-light ISO metric will give you this information.
The SNR indicates how much noise is present in an image compared to the actual image information (signal). The higher the SNR value, the better the image quality, as detail is not drowned out by noise. The SNR is given in dB, which is a logarithmic scale: an increase of 6 dB corresponds to doubling the SNR, which in turn equates to half the noise for the same signal. A SNR value of 30dB means excellent image quality. We have therefore defined low-light ISO as the highest ISO setting for a camera that allows it to achieve a SNR of 30dB while keeping a good dynamic range of 9 EVs and a color depth of 18bits. A difference in low-light ISO of 25% equals 1/3 EV and is only slightly noticeable. Low-light ISO is an open scale.
Не плачи Генчо, не си ти виновен, най-верочрно не зависи от теб
Публикацията е редактирана (30-12-20 18:54)