This blog post has been on its way for quite some times, it has been written and rewritten more than once. I wanted the post to by my personal experiences with area of flash photography. Let me start out with saying that there is not one size fits all here, and I am sure regardless of which position I take, Manual or Automatic, there will be someone thinking differently. My aspiration with this post is to convey my considerations.
Natural light is beautiful and amazing, whenever I can go with naturel light that is what I am going to do. Unfortunately, there are situations where we simply do not have enough light, or situations where we need to soften a shadow. The ability to expose with flash in any light condition is necessary, and a skill every photographer ought to learn. There is no article, blog or video that will be able to teach you flash photography. Small changes to the angle will mean world of difference. Like with studio lighting, speed lighting has to do with understanding of shadows and light… but hey! Which part of photography is not revolving around just that? Therefore, there is really no substitute for practice, practice, practice.
With modern cameras, came automatic photography as with modern flashes TTL in play. There is similarities, between using your camera and using your flash… there is situations where your cameras built-in logic allows you to run full auto, and achieve stunning photographs, but I betchya, there is a heck of a lot where you just can’t trust the magic of your Sony Camera. TTL and flashes are no different. My camera dial seems to be stuck at M, and my flash loves me best when I operate it in full Manual. I guess TTL for the most part is too inconsistent to me, yet there is situations where I also use TTL. Dynamic distance to my subject is one of these situations that can drive me into using TTL. Otherwise that that… I guess I said it before… Full Manual.
Shooting in controlled/static situations, full Manual allows me great control of precision and more importantly, it gives me repeatability. Manual is consistent; the power level does not vary from shot to shot.
Why TTL works and often fails
The way that the TTL is doing its magic, is by letting the TTL metering calculate the exposure based on what the light does bouncing off the subject. The light from the flash fires and shuts off when the camera has seen sufficient amount of light, magic. Can you assume that TTL is fool proof, by no means; the camera’s meters are still looking for 18% gray even in flash exposure. White or black subjects can throw the metering off and cause bad exposures. Size of the subject and placement in the frame can likewise cause exposure problems.
On a budget
Another neat thing, using your flash in manual, opens up for buying a range of high-end flashes, which no longer is compatible with modern cameras. I would always prefer an outdated high-end flash to a cheap compatible flash. The reason for this is power, high-end flashes is often able to emit far more light, and yes, that quickly becomes important. Distance between the subject and the Speedlight matters because the Inverse Square Law is always lurking out there somewhere. I am sure you noticed that the closer your light is to the subject, the brighter it appears. If your flash is 1 meter from subject, it appears brighter than if it is 3.5 meters from your subject. So the longer the distance the more power your flash needs to emit, and it quickly means cheaper flashes becomes insufficient for lighting your scene.
Two exposures in one
I look at flash photography as combining two different exposures into one photo. One having the flash to light the subject, and secondly setting the camera for the ambient light in your scene. Manual flash photography essentially comes down to metering and setting your camera up for two exposures all at the same time. The steps is fairly easy, set up your camera so you get the right exposure for the ambient light and set up your flash for the right exposure of your subject, and you will rock the world of flash photography J.
Controlling power is a cornerstone, the power range goes from 1/1 (full power) to around 1/128 (lowest power). Obviously emitting full power has impact on the energy and time taken to charge the capacitors. Emitting full light might be counterproductive to what the situation require, while it also means enduring longer recycle times. Ok got it… lowering the emitted light, quicker recycling, that will be handy when you just want to pop the colors of the bride and groom as they appear, without having to wait between recharging.
When balancing for ambient vs Flash then it is important to understand what influence the two. Ambient light, exposures are influenced by shutter speed and aperture, where Flash exposure are influenced by flash-to-subject distance and aperture. Do notice that the aperture is common for the two sources, and it is here we can balance the two. The shutter speed must be changed to match up with the constant aperture (for proper flash exposure) to properly expose the ambient light. At the same time, the flash-to-subject distance must remain constant to provide the correct exposure for that aperture.
Ps. Do read Heaps of light, the much-criticised HVL-F60M