Mystery products challenge!!

Today was a bit of fun.
Julian had compiled a collection of random products and hidden them in small groups under some sheets ready to be selected by us to then make use of in whatever way we (Simona, Kiki Peter and myself) saw fit to produce a reasonable create product shot.

We took a while to discuss ideas and then started to test a few of them to see what sort of results we would get. I thank my group members for their input into this task and i enjoyed bringing all of our skills together to create the following:

All shots are un-edited.

Electronic Flash - Guide Number.

GUIDE NUMBER
As you get further away from any light source, the intensity of it reduces (drops off).
As you change the f-stop within a lens, the intensity of the light at the film plane (or digital sensor) also changes.

They change at the same rate, so this statement is always true:
distance x f-stop = a fixed number (Guide Number)

Every combination of FLASH and film speed has one guide number (GN). Faster films and more powerful flashguns have higher guide numbers. Often manufacturers use the GN as a part of the model name labelling - eg Canon 430EX has a GN of 43

You figure out what f-stop to use by dividing the guide number by the distance from the flash to the subject.

When the film plane sensitivity is increased by a factor of 4, the guide number is doubled. So if the GN for ISO 100 is 80, the GN for ISO 400 will be 160.

How film speed changes Guide Number

Film speed:	Guide Number
25	40
50	56
100	80
200	110
400	160

Lighting Ratios in detail..

The following information is simply some of my own online research into lighting ratios, a very important part of all things photography.

Lighting ratio in photography refers to the comparison of key light (the main source of light from which shadows fall) to the fill light (the light that fills in the shadow areas). The higher the lighting ratio, the higher the contrast of the image; the lower the ratio, the lower the contrast.

Light can be measured in footcandles. A key light of 100 footcandles and a fill light of 100 footcandles have a 1:1 ratio (a ratio of one to one). A keylight of 800 footcandles and a fill light of 200 footcandles has a ratio of 4:1.

The ratio can be determined in relation to F stops since each increase in f-stop is equal double the amount of light: 2 to the power of the difference in f stops is equal to the first factor in the ratio. For example, a difference in two f-stops between key and fill is 2 squared, or 4:1 ratio. A difference in 3 stops is 2 cubed, or an 8:1 ratio. No difference is equal to 2 to the power of 0, for a 1:1 ratio.

In situations such as motion picture lighting sometimes the lighting ratio is described as key plus fill to fill alone. A light meter can automatically calculate the ratio of key plus fill to fill alone.

High-key lighting: is a style of lighting for film, television, or photography that aims to reduce the lighting ratio present in the scene. This was originally done partly for technological reasons, since early film and television did not deal well with high contrast ratios, but now is used to suggest an upbeat mood. It is often used in sitcoms and comedies. High-key lighting is usually quite homogeneous and free from dark shadows. The terminology comes from the key light (main light).

In the 1950s and 1960s, high-key lighting was achieved through multiple light sources lighting a scene—usually using three fixtures per person (left, right, and central) —which resulted in a uniform lighting pattern with very little modeling. Nowadays, multiple hot light sources are substituted by much more efficient fluorescent soft lights which provide a similar effect.

The advantage to high-key lighting is that it doesn't require adjustment for each scene which allows the production to complete the shooting in hours instead of days. The primary drawback is that high-key lighting fails to add meaning or drama by lighting certain parts more prominently than others.

Most recently, shows with bigger budgets moved away from high-key lighting by using lighting set-ups different from the standard three-point lighting. Part of the reason for this is the advent of new lighting fixtures which are easier to use and quicker to set up. Another reason is the growing sophistication of the audience for TV programs and the need to differentiate.

The term "high-key" has found its way from cinema into more widespread usage, for example referring to an event that requires much organization or is subject to a great deal of publicity.

An example of HIGH-KEY lighting.

Low-key lighting: is a style of lighting for photography, film or television. It is a necessary element in creating a chiaroscuro effect. Traditional photographic lighting, three-point lighting uses a key light, a fill light, and a back light for illumination. Low-key lighting often uses only one key light, optionally controlled with a fill light or a simple reflector.

Low key light accentuates the contours of an object by throwing areas into shade while a fill light or reflector may illuminate the shadow areas to control contrast. The relative strength of key-to-fill, known as the lighting ratio, can be measured using a light meter. Low key lighting has a higher lighting ratio, e.g. 8:1, than high-key lighting, which can approach 1:1.

The term "low key" is used in cinematography to refer to any scene with a high lighting ratio, especially if there is a predominance of shadowy areas. It tends to heighten the sense of alienation felt by the viewer, hence is commonly used in film noir and horror genres.

An example of LOW-KEY lighting.

The above information and photographs were sourced from wikipedia.org

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SUMMARY
The f-stops on your camera lens represent a doubling or halfing of the light that reaches the film or digital sensor.

In other words if your main light that you have metered reads f/8 and then you turn off this light and meter your second (fill) light and get f/5.6 you have a 2:1 lighting ratio because the main light is producing twice as much light as the fill light.

If you have a 2 stop difference in your readings, this means 4 times as much light from your main light so a 4:1 ratio, 2x2=4. If there is a 3 stop difference you have a lighting ratio of 8:1, 2x2x2+8. 

Here is a list of ratio numbers that will make sense once you see how the numbers relate to each other. I will also try to upload a photo example of each ratio as a visual reference.

• 1:1 = 0 stop difference

• 2:1 = 1 stop difference

• 4:1 = 2 stop difference

• 8:1 = 3 stop difference

• 16:1 = 4 stop difference

• 32:1 = 5 stop difference

• 64:1 = 6 stop difference

Electronic Flash.

Electronic Flashguns use the controlled discharge of electricity in a flash tube to make a short burst of lightning. Because the duration of the light is short, it freezes action. It's also cheaper to use and more convenient than disposable flash bulbs. Electronic flashguns use a battery or other power source to charge a capacitor. When the flash is triggered, the power in the capacitor is sent to the flash tube.

Strobe: technically, stroboscopic light is a repeating light, such as an automotive timing light or a disco strobe. In general usage, the phrase is used interchangeably with electronic flash.

PC Cord: A connecting cord for the flash. Named for the Prontor-Compur shutterworks in Germany which developed the shape of the tip.

Hot shoe: a flash mounting slot that has a central terminal so no cord is needed.

Synchronization: the timing of a flashgun and a camera so that the flash is making the most light while the shutter is open.

M Sync: a delay of .026 seconds between the flash starting to fire and the shutter opening. This allows old flash bulbs to reach their peak output.

X Sync: a xero (zero) delay. When the shutter is fully open, the flash is triggered. This is what is needed for electronic flash. Most cameras with focal plane shutters, such as SLRs, have X sync at speeds up to 1/60th of a second. If you take a flash picture with the shutter speed set higher than the X sync speed, you get a picture that is partially blacked out. Some premium cameras offer the feature of a high shutter speed for X sync. This minimizes the chance of a "ghost exposure," one which is made not by the flash but by the existing light.

Automatic Flash: an electronic flash that measures the amount of light which has gone to the subject and bounced back to the flash. It turns the flash off when enough light has been returned for a proper exposure. It can do this in as short a period of time as 1/50,000th of a second.

With an automatic flash, the photographer sets the lens opening once, according to a calulator built into the flash gun. For example, the flash may show that with ISO 200 film, the lens should be set to f8. At all distances up to the maximum range of the flash, the flash will measure light returning from the subject and turn itself off when just enough light has been returned for a proper exposure at f8. The concept is similar to that of a toilet mechanism, which fills itself to a present level and then stops the flow.Early and lower-cost automatic flash guns used a simple switching mechanism. Initially power from the capacitor goes to the flash tube. When the "brain" of the flash decides there's been enough light generated, the remaining power from the capacitor is diverted to a dump tube, which wastes it.

• Fresh batteries (or rechargeables)

• Close distance

• Large lens opening

• Old 35mm rangefinder cameras with cloth shutter curtains (Leica screw mount, Exacta, etc) 1/25th or 1/30th second

• More modern 35mm with cloth or horizontal metal curtains (Leica M-series, Canon VI, Nikon F, Pentax Spotmatic, Minolta SRT-series) 1/50th or 1/60th

• 35mm SLR with metal shutter which moves vertically (Nikkormat, Konica T series, etc) : 1/125th second

• Leaf shutter cameras (the shutter is in the middle of the lens) such as Rolleiflex TLR, Kodak Retina: any speed up to 1/500th

Thyristor: a special type of switching mechanism on an automatic flash which saves the energy not required during a short flash. It simply stops the flow of power from the capacitor to the flash tube, instead of wasting it by "dumping" it. This means that a thyristorized flash gun will recycle more quickly and give more flashes on a set of batteries before they run down.

Recycle Time: how long you must wait after one flash before the flash is ready again. With a thyristorized flash the following choices make the flash recycle faster:
A TTL flash system uses a sensor in the camera to measure the flash Thru The Lens, which is more accurate when taking extreme closeups or using a long lens.

Dedicated flashguns are designed to work with a specific late model camera or family of cameras. They have additional connectors to carry information back and forth between the camera's brain (CPU or Central Processing Unit) and the flash. All dedicated flashguns set the camera to the one and only proper shutter speed for flash sync. Some also set the lens opening, on cameras which have automatic lens opening exposure systems. Most activate a flash readilight in the camera's viewfinder. Older cameras with mechanically timed shutters don't need, and can't take advantage of a dedicated flash.

Multi-dedicated flashguns by companies such asVivitar, Sunpak, Rokunar, Achiever, etc, can be adjusted to provide minimal dedication with several different brand cameras. In general, they will set the proper shutter speed, activate the readilight in the viewfinder, but will not set the lens opening.
Some flashguns, such as the Minolta 280PX, do not have a built-in exposure sensor. They can only be used on specific cameras that have a built-in sensor for TTL flash. For example, the Minolta 280PX can only be used on the X-570 and X-700 cameras.
Autofocus cameras usually have full dedication and also a built-in near-infrared light source that makes it easier for the camera to focus in low light levels. Failure to use a fully-dedicated flash wipes out many of the benefits of buying such a good camera.


What shutter speed can I use?
If the light from a flash picture is to get to all of the film, then all the negative area must be uncovered when the flash goes off. With a focal plane shutter, at high shutter speeds only a portion of the negative is uncovered at any instant - a slit exposes each segment sequentially. That's the reason you'll sometimes see a photo properly exposed at one end and very dark at the other.
Some top-end cameras can be used with special flashguns at really high shutter speeds such as 1/4000th of a second. The special flash actually lasts long enough for the shutter curtain to complete its passage across the full length of the film.
Most cameras require that you use a slower shutter speed. On some, the highest shutter speed that is usuable with electronic flash will be painted a different color on the shutter speed dial, or marked with an "X."
Here's a rough guide to camera types and the highest shutter speed for flash sync (a slower speed is always safer)

Product Photography.

Today was good.

We had the opportunity to bring in a product or two, nothing big and photograph it in a studio environment to hopefully produce something usable.

Julian had set up a number of light and scene settings in both of the studios. We split into groups and got stuck into it.

Here are a few behind the scenes snap-shots.

And here are a few of the photographs my group and i managed to produce. I felt it was a solid start to our semester of product photography.

80mm - ISO 100 - f/11 - 1/125s
Products not at an ideal angle.

80mm - ISO 100 - f/11 - 1/125s
Product angle improved.

80mm - ISO 100 - f/11 - 1/125s
Adding colour to the background.

80mm - ISO 100 - f/11 - 3.2s.
Forgot my shutter speed was wrong.
Everything now looks odd.

80mm - ISO 100 - f/13 - 1/125s
Change of aperture. Everything now
looks dull.

80mm - ISO 100 - f/13 - 1/125s
Change of aperture. Everything still
looks dull, but reflector to the right
has added to the side of box and
the inside of the coffee cup.

80mm - ISO 100 - f/13 - 1/125s
Bringing the soft box more in front
of the box helped add punch to more
of the box. Reflector was not in use
for this shot.

80mm - ISO 100 - f/13 - 1/125s
Bringing the soft box more in front
of the box helped add punch to
more of the box. Reflector was
brought back in to the right of the
box to add punch.

80mm - ISO 100 - f/13 - 1/125s
Bringing the soft box more in front
of the box helped add punch to
more of the box. Reflector off to the
right remained in use.

80mm - ISO 100 - f/13 - 1/125s
Much the same lighting set up as
the previous product. Reflector was
used off to the right to take away
the unflattering shadow.
PRODUCT IS CROOKED :[

80mm - ISO 100 - f/13 - 1/125s
Much the same lighting set up as
the previous product. Reflector was
used off to the right to take away
the unflattering shadow.
PRODUCT IS CROOKED :[