Hello all, here are some notes to check out, you can print them out and bring them on Thursday if you wish, and also ask lots of questions!
Intro, Technically speaking a long exposure can be anything from half a second to several hours.
Generally, a tripod will be an essential part of your kit with exception of some panning type shots which with practice can give very nice results.
Your exposure time will vary according to the available light and upon what you want to achieve.
If you want to convey a sense of motion or drama in your image then anything from 1/15th of a second up to about 1.5 seconds should cover most scenarios. This will depend of course on how active or fast the waves and or clouds are coming in and how much light is available.
For an exposure of up to 30 seconds most cameras will do this provided the light is sufficient. But to capture a 30 second exposure with nice golden light from a rising sun may require the use of filters.
Another aspect of “extended’ exposures is to go for an exposure of maybe half a second to up to several seconds. This will blur the fluid part of the scene and will inject a sense of movement and drama that can produce very pleasing results. Sometimes, a circular polariser and a smaller aperture will be enough for this type of shot.
If you want to produce an image that conveys a sense of peace or quietude then you may wish to push the exposure time to two minutes or even longer. To do this you must have the camera set to “Bulb” mode. This means that the shutter will stay open as long as you wish, but you have to manually switch it on and off using a remote battery operated device or a simple cable release, this is my choice due to its simplicity. To make one of these two minute (or longer) exposures and still have enough light to light the scene (hence avoiding excessive noise) will require a light reducing filter system to help achieve this. There are several different brands of filters. “Lee”, which for many years has been the go too brand for serious ‘togs and more recently, “Nisi” which many consider to be superior to Lee due to their lower “colour cast” attributes. I sue the Lee 100 mm system and find it excellent, and besides, any colour cast can be easily fixed in post processing.
The Lee system includes a square filter holder that fits on to the front of your lens. In this filter holder are three slots. There are dozens of different coloured filters available. However, for my style of shooting I have a set of three GND’s or Graduated Neutral Density they are .3, .6, and .9 of a stop each. I usually use only a .9 in the middle slot (and sometimes the .6 in the outer slot) for the purpose of lessening the difference in brightness and contrast between the sky and the area below the horizon and in the slot closest to the lens I use either the Little Stopper (6 stops) or the Big Stopper which is 10 stops. There is also a Super Stopper of 15 stops which, for example can turn a half second normal exposure into a marathon 4 hours and 16 minutes!!
It is best to try and keep the sun out of the frame during an extended exposure because you will more than likely end up with a big blob of overblown white out. This can be troublesome to fix and sometimes impossible. Of course, there are exceptions to everything and a nicely placed “Sun Star” just peeking out from the horizon or from behind a tree or building can give a very pleasing result.