If you're shopping for a strobe....

[Dee]

There's a new feature on Strobe Finder feature on Digital Diver. Bob has done an excellent job compiling and writing this new information.

 

[2 Bar]

Dee thanks for all the info you have been posting on this subject. I have been reading through them, trying not to ask a question covered on 50 threads.

Here's the 1 millionth strobe question (do I win a prize?): Many places giving info don't explain basic terms. They just use the terms in explanations, and I can figure some of it out but not enough. Is there a place where I can first learn strobe terminology and then refer to the links such as this? Terms such as but no limited to - Pre-flash Compatibility
TTL
TTL setting
Optically fired
Cable fired
Target light
Diffuser
etc.

Thanks!

 

[Dee]

Here's the 1 millionth strobe question (do I win a prize?): Many places giving info don't explain basic terms. They just use the terms in explanations, and I can figure some of it out but not enough. Is there a place where I can first learn strobe terminology and then refer to the links such as this? Terms such as but no limited to - Pre-flash Compatibility
TTL
TTL setting
Optically fired
Cable fired
Target light
Diffuser
etc.

Thanks!

It IS confusing, isn't it? I'll take a stab at it but I'm not very good at descriptions so maybe some of the more techinical minded folks can give you a more thorough explanation.

TTL - Through The Lens - Your camera will 'read' the shot you have framed and will set the proper exposure for you.
TTL setting - The setting on your strobe that allows it to work with your camera to get the proper lighting according to what the camera says the settings should be.
Optically fired - strobe is triggered by your cameras internal flash, via a fiber optic cable.
Cable fired - Strobe is triggered by electronic connection via a sync cable.
Target light - small light built into the strobe that lights the scene, usually in dim or dark situations, so your camera can see the subject to focus. Can also refer to any small auxillary light you mount on your rig to do the same thing.
Diffuser - an opaque cap or panel attached to your strobe that softens and widens the flash.

As I said, there are more techinical definitions but that should cover the basics. (I've never been a fan of TTL so I could be a bit confusing in my explanations!)

 

[ReyeR]

First I'd like to say that when you run the strobe comparator you will see that some of the feature descriptions are clickable links - when you click on them it'll pop-up an explanation on what that feature means, e.g. click on Pre-flash Compatibility:

Pre-flash compatibility refers to how, or if, a strobe is able to handle the 'pre-flash' generated by a digital camera. Most digital cameras fire one or more very brief flashes of the onboard flash, which aid the camera in determining exposure and white balance for a given scene. It is important to remember that these preflashes and the resulting calculations take place in just a fraction of a second, immediately prior to capturing the image.
Strobes built prior to the advent of digital cameras, whether they are triggered optically or electrically fire on the first trigger event that they detect. With digital cameras, that is the pre-flash. Once these older strobes have fired, many cannot recycle quickly enough to fire again for the main exposure (remember, we're talking about milliseconds), making them un-suitable for use with digital cameras.

The good news for owners of these 'legacy' strobes is that many digital cameras include the option of turning off the pre-flash, also known as 'slave mode'. Legacy strobes can, in most cases, function with digital cameras that have a 'hot shoe' or 'PC' connector which supply an electrical signal to external strobes. Another option for users of some legacy strobes is the digital adapter manufactured by Matthias Heinrichs (See the Specialized Compatibility section below).

Manufacturers of modern digital strobes have addressed the issue of preflash compatibility in one of two ways, either by mimicking the pre-flash, or ignoring it. Some models even offer the option to do either. Models that mimic the preflash are capable of ultra-quick recycle times needed to fire the pre-flash, and then fire again for the image capture.

To supplement Dee's explanations:

TTL:
As Dee said it stands for 'Through The Lens. It is a method of measuring exposure, whether it's the amount of ambient light or the amount of light from a flash or strobe (TTL flash). Simply put it is a method of measuring the amount of light coming from a scene by placing sensors behind the lens.
For TTL flash photography the camera uses this measure to control the flash/strobe itself and quenches the flash/strobe when it thinks the scene has been lit properly by the flash or strobe - so in a way the camera is 'talking' or 'communicating' with the flash/strobe. For this to work the flash/strobe must understand the TTL protocol or language that the camera uses. Unfortunately different manufacturers use different protocols, making it difficult to swap strobes between manufacturers.

TTL setting:
The strobe comparator refers to this as whether the strobe has a position on the switch or dial which, when selected, will allow the camera to communicate in TTL with the strobe.

Optically fired:
Sometimes also known as a 'slave strobe'. Refers to whether the strobe has an optical sensor (or facility to connect an external optical sensor) that can detect the light coming from another flash or strobe (called master). The sensor can then fire the slave strobe 'in sync' with the master unit. In some cases it can even 'mimick' the master unit and quench when the master unit quenches.
Some strobes use a fibre-optic cable to 'channel' the light from the master strobe so the slave fires more accurately and realiably. This is done by attaching one end of the fibre-optic cable to the front of the master strobe and the other to the optical sensor of the slave. For digital cameras with clear housings that do not allow you to connect a sync cord (see below: Cable fired) and electrically control the strobe this is the only way to get an external strobe to work in sync with the camera's shutter. In this case the 'master' is the camera's built-in flash.

Cable fired:
Refers to whether the strobe has a connector to which an electrical cable (known as sync cord) can be connected. In this case the strobe is controlled or fired in sync with the camera's shutter by an electrical signal (as opposed to an optical or light signal) sent from the camera's hot shoe. For this to work the camera must have a hot shoe (or provision for connecting an external flash), the housing must have a bulkhead connector, the correct sync cord must be used and the strobe must have a connector to which the sync cord is attached.

Target light:
Also called an aiming light. A light built into the strobe itself that helps you to aim the strobe correctly. Due to the refraction caused when light passes from water to air (in your mask) subjects (fish) appear closer than they are and it is easy to aim the strobe too much in front of the subject. The target light helps you to overcome this. However, depending on the amount of particles present in the water (also called backscatter) and how close the camera is to the subject, it is often not advisable to aim the strobe directly at the subject but away and behind it so the subject is lit by the edge of the cone rather than the centre of the cone of light. Aiming the strobe directly at the subject can also cause 'hot spots' or 'blow-outs'. Some strobes have a laser and some use a normal torch bulb to provide the target or aiming light. With the latter some photographers use the aiming light to provide additional illumination to help the camera focus. In this case it is functioning both as an aiming light and focus-assist light.

Diffuser:
A diffuser is any device placed in front of the strobe that affects the light coming out of it. Its primary function is to 'soften' the light so shadows appear less harsh and highlights don't 'blow out'. It can also increase the angle of coverage of the strobe. It'll also, invariably, reduce the amount of light coming out from the strobe. This is usually expressed in f-stops. For example you will come across terms like 'reduce the amount of light by 1 f-stop' or a '0.3 diffuser'. Simply put, when using the diffuser, the former means it is like closing the camera's aperture by 1 full f-stop, and by 1/3 f-stop for the latter.

HTH.

 

[2 Bar]

Wow!
Thanks for all that information. I was just looking for the source to retrieve it myself so not to keep hounding you all. Thanks for that effort. Many people are benefiting from your sharing.
I didn't notice the terms had links. That's what I really needed. That now helps me in my research and understanding of strobes.