Sunday, May 31, 2009

The Pentax AF360FGZ In Detail

I started the Pentax wireless flash sessions but I just realized I have not discussed the flash or flash controls in any detail yet like I have for the camera controls.

So here we start the discussion on the AF 360 FGZ.

The AF360FGZ is a very capable flash as far as configuration goes. It supports all the modes it's bigger brother the AF540FGZ has but lacks the power and the swivel head for bouncing the light off the walls. It does have a tilt head for bouncing off the ceiling which for all purposes is better than front on flash.

For close flash work or for lighting product shots in a light tent environment it works very well but once you step out of it's power range you'll be wishing you had the extra stops of light the AF540FGZ has.

But power aside I love the 360 as much as it's big brother.

The Controls:

Power switch - The power switch does just that, turns the flash power on. If the flash hasn't been used in a while or was turned off right after a flash burst then the flash may take a few seconds for the ready light to come on. The flash will not fire until the ready light is lit. You can however setup the flash while the flash capacitors are charging.

Any MODE settings you have set are lost when the flash is turned off and the flash reverts to P-TTL mode. Settings like camera format and camera type are saved when powered off and even during a battery change. Extended battery removal periods have not been tested by me so I have no idea if they are permanently stored or not. I assume they are.

The power switch is also used to set the flash to wireless operation. For wireless operation set the power switch to the position between the on and off positions.

In normal operation the flash goes into standby after a few minutes of non-use but will come alive again when the shutter button is half pressed when attached to an auto-focus camera. In wireless mode the flash will turn off after about an hour of non-use. The camera shutter button has no affect in wireless mode. The AF360FGZ has no option to change the auto power off settings while the AF540FGZ does.

S Button/Wheel - The S button and wheel are used to adjust the values of the current setting being adjusted. The uses of this button/wheel will be addressed when discussing individual flash settings but in general pressing the S button will engage the value to be adjusted and turning the wheel will adjust the value. There are some settings where the button alone adjusts the value and the wheel has no function. There are other settings where neither the S button or wheel are functional.

The Setting Switch - Located on the right side of the flash (looking at the back) off to the right of the READY/TEST light the setting switch changes the functions of the LIGHT, ZOOM and READY/TEST buttons. In the up position it engages the white text at the top of the button and in the down position it engages the yellow text. We'll discuss this button more when discussing those three switches.

Mode Button - The mode button switches the flash mode between P-TTL, A, Manual and SB (spot beam) modes while in the On position. The SB mode is not available with wireless operation.

P-TTL is a mode where a pre-flash is metered through the camera and depending on camera settings, flash output and/or camera settings are adjusted for proper exposure. P-TTL can be tricked when the scene contains very reflective objects and you may experience under developed images. In P-TTL mode the S button/wheel adjusts flash compensation from -3.0 to +1.0 in half step increments.

With A mode (auto mode) you can set the ISO and aperture to match the camera and the flash will tell you what distance the flash needs to be from the subject for proper exposure. In A mode pressing the S button once allows you to adjust the f-stop value with the wheel. A second press will allow you to adjust the ISO value. Remember the flash ISO/f-stop must match the camera settings for proper exposure. Of course as with any settings you are welcome to experiment for different desired results but start with flash and camera settings matched.

Because the flash itself meters the light reflected off the subject the A mode will not work when shooting flash with umbrellas either reflective or shoot-through. Use P-TTL or even better manual mode when shooting with umbrellas, softboxes or any light modifier that blocks the view of the subject from the flash's sensor.

In manual mode you can set the flash power level from 1/1 to 1/32 power ratios in 1 stop increments. If you have a static studio setting manual mode is the way to go. Set the power so your exposure is in the ball park and then adjust flash to subject distance to fine turn it. In manual mode the S button/wheel adjusts the power ratio value. Press the S button to engage and turn the wheel to adjust.

SB mode is used in low light conditions (infra-red beam) to assist the camera while auto focusing. The flash will not fire in the setting and the flash is mounted on the camera. That said the camera to subject distance is limited for this to work. In SB mode the S button/wheel have no function.

LIGHT/FORMAT Button - The LIGHT/FORMAT button turns on the LCD screen back-light and lets you select what camera type you want to enable. In the FORMAT mode it lets you select the camera format.

The Light button when pressed and released will light the LCD screen back-light for about 10 seconds. Pressing it again while lit it will turn the back-light off. If the flash is mounted to the camera both the camera and flash back-lights will illuminate when either the flash or camera's light button is pressed. Since the camera's light button is easier to press while using the camera this is a very useful function.

When held for a few seconds the light button also allows you to change the slave type of the flash. To fire the flash in wireless mode with K series, *ist series, MZ-S/-L/-6 or ZX-L cameras use the S button to set SLAVE1. For optical slave mode set to SLAVE2. In SLAVE2 mode the flash will fire when it detects a flash strobe and can be used with any camera/flash with X-sync of 180 or below. Only A mode and Manual mode are supported when configured for SLAVE2 type. Use manual mode for the built-in flash when using SLAVE2 optical mode or the pre flashes will trigger the slave flash prematurely and the slave flash may not be recharged in time to fire during the actual exposure time.

When the Setting Switch is in the down position the FORMAT button will select the camera's frame format. You can choose between 35mm, 6x4.5cm, and 6x7cm formats. This changes the flash coverage reading as it is different for each format in each of the zoom positions.

ZOOM/CH. Button - The Zoom/CH. button sets the flash's zoom and what wireless channel the camera and flash communicate over.

The Zoom button cycles the flash zoom values from auto to manual 24mm through manual 85mm. In auto zoom the flash adjusts it's zoom value according to the focal length of the lens attached to the camera to provide the optimal flash coverage. Use auto zoom when the flash is being used on camera and manual zoom when off-camera. Set the flash zoom level where it provides the most even coverage of the exposed frame or for desired artistic results like isolating or highlighting a portion of the frame. When using an umbrella, bounce or shoot-through, set the flash zoom to spread the most light across the umbrella with out any light spilling over the edges of the umbrella. This is called the fill pattern.

The CH. button sets the wireless channel that the camera and flash communicate over. There are 4 channels (1-4) available. This will allow you to shoot independently with wireless flash with up to 3 other Pentax operators.

Unfortunately you can not manually set the wireless channel in camera. You have to attach a flash to the camera and tell the camera to read the channel from the flash. This IMHO is a severe limitation to this function as it does not allow the use of simultaneous flash setups to provide different lighting conditions by selecting the flash channel in camera without completely tearing down and re-building your lighting setup. However if you are into using multiple simultaneous lighting setups you're most likely going to use some other system with more elaborate controls.

READY-TEST/MODELING button - The Ready-Test/modeling button has 3 functions; to let the photographer know when the flash is charged enough to fire, to provide a way for the flash to be manually discharged and to provide a 1 second strobed burst of modeling light.

The Ready light is just that, the flash's way of letting the photographer know the flash is ready to fire when told. Be mindful to check the ready light on each flash in a multiple flash setup so the frame will be lit as intended.

The Test button will fire the flash. When in A mode (auto) the A indicator on the camera's LCD will be flashing to
indicate the flash provided enough light. The test button can also be used to manually fire the flash to expose a long or bulb exposure. You can walk around in complete darkness (relative to the camera exposure settings) and pop the flash to light the scene. You can add different colored gels in between flash pops to provide colored lighting. Multiple pops in the same area will brighten that area. Be careful of overlapping flash coverage areas.

The Modeling light feature while somewhat useful as a modeling light is better suited to special effects photography. 1 second of strobe bursts provides a single frame stop motion image of moving objects. We're not talking high speed finely tuned sync flash for capturing images of moving bullets, but imagine capturing a bee or butterfly in motion as it moves past your frame. The power output of the flash in modeling mode is very reduced so the flash to subject distance will have to be very close. Think static wide-ish angle camera and hand-held flash following the subject at close ranges.

WIRELESS Switch - The Wireless switch set what role the flash is to play when in wireless mode. The choices are
Commander, Master, or Slave. In Master or Commander role the flash needs to be attached to the camera, directly or via cable.

In Commander role the flash only controls the other flashes (which should be in Slave role) and does not contribute any light to the image.

In Master role the flash is the control flash just like the Commander role, but it also contributes light to the image. This role is great when some fill flash is needed in the image.

In Slave role the flash takes it's commands from the Master/Commander flash or the built-in flash of the K-10D which incidentally also can be in Master or Commander mode though the setting is named something different in the camera settings.

SYNC. - The SYNC. switch selects how the flash is to sync with the camera. The four sync methods are (from switch position left to right) front curtain or normal sync, Rear or Trailing curtain, Contrast Control, and High Speed sync. We're not going to cover each sync method in great detail in this session as each sync method will be covered in detail in later sessions but we will discuss each in enough detail so you have an idea how and when each method should be used.

In Front curtain or normal sync the flash fires when the front or first camera curtain is pulled back or in other words in the digital camera world when the exposure is first started. For 99% of your static images this is the mode you want to use. However if the subject is moving during a longish exposure there is a tendency to capture a ghostly trail which can ruin an image as the trail appears after the flash has fired and seems to be leading out to the front.

The Rear or Trailing curtain sync fires the flash right before the second or rear camera curtain closes or in the digital camera world right before the exposure is complete. This illuminates the subject last and leaves the moving ghost trail behind the subject. This mode is most excellent when photographing moving images and you want the effect of the ghost trail behind the moving object enhancing the illusion of motion.

Contrast control sync is used when a lighting ratio (1:2) is warranted when using two flashes. One of the flashes will fire at proper exposure and the other will fire at 1/2 exposure. One of the two flashes can be the built-in flash or another Pentax flash supporting Contrast Control can be mounted to the camera. The flash that you want to be the 1/2 ratio will be the flash set to Contrast Control sync. The other flash will be set to normal sync and provide full exposure. If only one flash is used the flash functions in normal mode even when in the Contrast Control position. P-TTL mode will be selected when using Contrast Control sync. If you're unfamiliar with off camera flash ratios and want a simple 1:2 lighting ratio with your K-10D and the AF 360 FGZ then this is a mode you will want to try out at first. As you gain confidence in flash photography you will graduate to using manual mode and setting your own lighting ratios when using multiple flashes.

High Speed sync is used whith shutter speeds above 1/250 second (X-sync) are used. High speed sync has its limitations however and one of these is as the shutter speed increases the power of the flash decreases. In order to maintain proper exposure levels the flash must be brought closer to the subject. For each stop of shutter speed increase the flash must be brought approximately half the distance closer to the subject in order to provide the same amount of light.

That about covers the AF360FGZ. Stay tuned for the details on it's bigger brother the AF540FGZ.


Justin said...

Thanks for covering Pentax gear, seems like few in the Strobist or photog community in general bother to mention it ever.

One question regarding the AF360FGZ flash, can it be used in slave mode without another flash mounted to the camera body? Can you or have you explained somewhere how to set this up? (E.g. what are the in-camera settings that would allow the K10D or other body to trigger the AF360FGZ remotely without an external flash attached to the body?). Thanks!!

justsmartdesign on Flickr

PhotographyRulez said...

The K10D built-in flash will act as a master flash.

Follow setup steps in this series.