I was taking an outdoor photo during the day with a deeply overcast day. A coloured wall will give the light a colour tint.Daylight shines 100% of the time the shutter is open and a flashgun can shine for 1% of the time. Quality street sweets are famous for providing different colour wrappers that can be used for different effects.Fast and Slow:?What I am really referring to is the duration of the light, ie how long the light is shining while the photograph is being taken. This is achieved by under or over exposing the subject. This can produce a surreal effect.

 

An unabridged version of this article?and others can be found at:?John's Blog on 'One Light'All this with just one light; just think of the variations with two or more lights.The distance from the source to the reflecting surface and then to the subject, compared to the distance from the source light to the subject, will greatly affect the strength of the reflected light. A textured surface will give a soft weak light. In most cases though, you will get a combination of two lights; China led grow light full spectrum Manufacturers one shining 100% and the other a fraction of the time. A shiny surface will give a hard strong light. I place two flashguns with orange gels and the photograph turned from a dull picture to one that looked as though it had been taken late in the evening with a lovely warm glow.Front, Side and Rear: Choose the position of the main light.?Explore,?discover and understand. Each position will create a very different effect, from fully lit to silhouette. Often the form comes from the outline of the subject.Explore my website to see some of these effects in practice in the Galleries.

The details of the subject are either blown out or in deepest shadow.Invisible: Infra Red is not visible to the naked eye, but filters can be attached to a camera which allows that light to be picked up on the sensor or film.So there we have it, a lightening, fast pass over variations with just one light. Different surfaces reflect different amounts of infra-red.Direct and Reflected: Direct light comes from your source light and usually has an obvious effect. Reflected light will come from any other surface that is not totally black. Explore making your own photographs with just one light. Reflected light can be used to fill in shadows.Placing coloured gels over?a flashgun colours the?light and will produce different effects.Low and High Key: This is were the tones of the photograph are primarily dark or bright.

Megosztás a facebookon

Tolerances in today's high-pressure hydraulic systems require strict control of system contamination. Prior to startup, contaminants built into the system must be removed during manufacturing and assembly to ensure that the system has proper and predictable performance throughout its useful life. New or rebuilt hydraulic systems should be flushed before operation.

Typical instructions state that flushing must be performed at a normal system fluid speed for a certain period of time and a certain degree of filtration. More stringent specifications may require specific levels of fluid contamination and need to be documented through fluid contamination analysis. Flushing instructions typically specify the level of system cleanliness that must be achieved, and sometimes the fluid speed that must be maintained during the flushing process. The concept of flushing is to loosen and remove contaminant particles inside the system by forcing the flushing fluid through at high speed. Theoretically, this keeps the inner wall of the fluid conductor as clean as the new fluid to be installed.

One disadvantage of all these flushing methods is that they are based on a cleaning fluid procedure, but ignore the internal cleanliness of the system. Even with the greatest degree of visual care during pipe and conduit installation, the human eye can only see particles larger than 40 µm. Even the roughest and most basic hydraulic systems require far less than this level .

Experience has shown that dimensionless Reynolds numbers (and other factors) are used to classify fluid flows as laminar, turbulent, or transitional flows (between the two). The Reynolds number depends on the viscosity and speed of the fluid and the ID of the pipe. These flushing speeds are not sufficient to ensure the cleanliness of the inner diameter (ID) of the system conductor. A brief review of basic fluid dynamics can explain why.

The speed must be high enough to reach a Reynolds number (NR) of 3,000 or more. Reynolds numbers flow during the transition between 2,000 and 3,000. The speed must reach or exceed the normal design speed of the system fluid. When the Reynolds number is greater than 3,000, the flow becomes disordered, which is defined as the situation where the fluid flow line is no longer orderly.

Megosztás a facebookon