big-guy Loc: Peterborough Ontario Canada

The only way to go. :thumbup: :thumbup: :thumbup:

JohnSwanda Loc: San Francisco

It may be the way to go if you are using multiple flashes or a static situation. The more common use of a flash, such as shooting an event or shooting candid photos of people, where you can't meter each shot, TTL is the way to go.

burkphoto Loc: High Point, NC

Performance MAY vary as a function of specific scene reflectance and the angle of coverage of the flash's onboard sensor vs. the angle of coverage of the camera's TTL or ETTL sensor.

I have a couple of old, cheap, reliable Vivitar 285s I've had since 1980. They still work extremely well, in auto mode. Back throughout the mid-'80s and into the early '90s, I also used a Nikon TTL flash. In the mid-2000s, I used Canon 580 EX and 580 EXII flashes.

The Vivitars are best when photographing a scene of broad, average reflectance, because the sensor reads a broad area and small light or dark objects in the frame don't bias the exposure as much as they might with ETTL/TTL.

The older Nikon TTL scheme wasn't worth jack crap. I was glad when my assistant broke it! From about the SB800 forward, though, Nikon's flashes have been excellent (except for the tendency of the SB900 to melt when used continuously for "graduation handshake" photography!).

Canon's ETTLII scheme is pretty good. But nearly all the TTL flashes I've seen are prone to "subject failure" — a terrible term labs use to describe what happens when any automatic circuit reads the wrong brightness level in a scene.

Manual mode always works well, when you have the time to pre-set the exposure, using the histogram with a target, or a well-calibrated flash meter.

Probably the best automatic flash I've ever seen is the Quantum Q-Flash. It works several different ways, integrating extremely well with Canon and Nikon dSLRs. One of its best features is to read the distance information transmitted from the lens to the camera, and expose for that distance, ignoring reflectance! It's a high-end professional auto flash system for wedding and commercial photographers.

OviedoPhotos

Depends on what your doing.

peterg Loc: Santa Rosa, CA

TTL is my first choice and manual if it causes problems. Example: Some small birds take flight when they see the pre-flash, which sometimes helps create interesting pics.

lamiaceae Loc: San Luis Obispo County, CA

Yes, Auto & TTL only work well with match fully compatible Flash and Cameras. For "studio" work at least, buy a Flash Meter and use manual flash!

lamiaceae Loc: San Luis Obispo County, CA

Auto & TTL only work well with match fully compatible Flash and Cameras. For "studio" work at least, buy a Flash Meter and use Manual Flash!

Bullfrog Bill Loc: CT

It depends on the situation. In the studio or with controlled subject placement I use manual and adjust light output as required. When outside and/or when the subject or model is not stationary, I use TTL. For example, taking portrait with sunset in background I (1) meter the scene in aperture priority, (2) hold the exposure and switch the camera to manual and (3) turn on flash in TTL and bingo a perfectly exposed photo. Yo can play with flash compensation to fine tune the exposure. I usually start with -.7 EV flash compensation.

cjc2 Loc: Hellertown PA

My method of flash varies with the subject and the shoot. For the kids, something quick, the TTL works well, sometimes, but I most often dial-it-down a bit as I do not like the "over illuminated" look. Outdoor, fill-in, is often done TTL with some modifications. When I really want to get it right, and I have the time and equipment with me, there is nothing like a good manual setup where one controls the ratio of flash output from various units. I recently purchased an inexpensive (Genaray from B&H) set of lights/stands/modifiers which are LED, constant on, and I've been having some fun with them as they are very portable, relatively speaking, and will work from a battery pack that I already owned. Have fun testing things out, practicing and learning what works for you. I call that developing style! Best of luck.

chapjohn Loc: Tigard, Oregon

TTL and HDI (Sony) are about the how the flash determines distance to the subject. I understand that another choice is fill (auto) or full flash. Fill being the defualt for flash and full is using the light intensity levels on the flash gun that override the camera default.

It depends on the situation and what result I want that determines if and how I use flash. This requires time with your camera and flash in various lighting situations and using the settings on the flash. One example is using flash on a sunny day on flowers to produce a black background (low ISO helps).

amfoto1 Loc: San Jose, Calif. USA

It's not "Auto or TTL". In fact, TTL is one form of automated flash.

It's "TTL" versus "thyristor" flash... which are two different forms of auto flash control. (There have been some other forms... such as Olympus "OTF" and "OTS" some other brands of cameras that used... these measured both flash and ambient illumination "off the film" and "off the shutter".

TTL measures the flash through the lens itself (TTL means "T"hrough "T"he "L"ens, after all), using the camera's built in metering system, and is what most modern systems use. This is possible now because the camera's internal metering systems are faster and more precise than they were in the past.

Thyristor flash uses a separate light sensor on the body of the flash itself, that essentially turns off the flash as soon as it senses enough light has been emitted to adequately illuminate the subject/scene. This is an older method and generally not as accurate as TTL. Modern camera's TTL flash can be very carefully controlled and does things that were never possible with older thyristor flashes.

However, there were some interesting variations on thyristor flash control. For example, for a while I use a couple Vivitar flashes with fiber optic sensors that clipped to a macro lens' hood, "feeding" light back to each flash's thyristor sensor and did a really good job controlling the flashes with small, close-up subjects.

Today with TTL it might be even easier, since the metering is being done directly off the subject through the lens, so the angle of view of each lens or zoom setting is always being taken into consideration. Plus, in many cases you also can choose among the camera's different metering methods: Matrix/Evaluative, center-weighted, partial or spot.

And, yes, the modern iTTL and ETTL systems of Nikon and Canon cameras use a pre-flash (1/64 power, if I recall correctly) to determine a "correct" exposure, then fire the flash as needed to render the exposure that was determined. However, any "delay" is almost imperceptible. I don't think I even notice that it's two separate flashes most of the time, it happens so rapidly. It's really only a concern if you or someone else is using additionally flashes with optical triggering. The pre-flash can cause those to trigger too early.

The latest Canon ETTL II also uses distance data it acquires from the lens and AF system, to better set a "correct" exposure.

In general, so long as you know how to use it and are aware of some of its limitations, modern TTL is faster and easier, plus gives better results than thyristor flash. But, when used right the old style flash... or even fully manual flash (which is also possible with most modern flash units)... also can give good results. It's really more a matter or learning how to use it well, whichever type you happen to use.

"Fill" versus "Full" flash with ETTL on Canon cameras is simply a matter of which exposure mode you set. If you use any of the auto exposure modes (Av, Tv, or P), the camera will continue to set the exposure according to ambient light (as if the flash weren't there), and will reduce the flash output by about 1.66 stops to act as "Fill". But, if you switch the camera to Manual exposure mode instead and set all the exposure variables yourself, the flash will be treated as the only light source... i.e. "Full" flash. In M mode and with Full flash you can more fully control the balance of ambient vs flash light recorded... which can be a useful device. For example, you can make a background go fully black behind the subject... or make it darker relative to the main flash-lit subject... or carefully balance them so both appear equally lit.

In either case - Fill or Full - with many Canon flashes you can increase or decrease the flash output as you see fit (in 1/3 or 1/2 stop increments), with Flash Exposure Compensation. This can be dialed in on the flash or, with many camera models, directly on the camera itself. In many cases there also is FEL or Flash Exposure Lock, which does essentially the same thing as AEL or Auto Exposure Lock when not using flash. There also is means of doing Flash Exposure Bracketing, if needed.

I imagine Nikon and other brands have similar features, but may call them something different.

GoofyNewfie Loc: Kansas City

There was Auto before the Auto thyristor models came onto the scene.
Honeywell developed the automatic flash in the mid 60's.
My first automatic "thyristor" model was the Vivitar 292 in the early '70's.

Adding a thyristor unit to an automatic flash was a way to save the unused current, allowing for faster recycle times.
It was not a light measuring device, it was an energy saving device.


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.
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.

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.

Ernie Misner Loc: Lakewood, WA

For TTL, we are talking fast paced action in changing light such as events and receptions.

Ernie Misner Loc: Lakewood, WA

A quick look at the histogram and adjusting settings works well too.

stan0301 Loc: Colorado

Generally I will use it set to -2
Stan