The most important flash functions to consider are:
Flash units (flash units; in contrast to studio flash units connected to the socket, which are also flash units) are operated with AA batteries. When stroboscopes are used, they are the bottom of the totem pole when it comes to power. Therefore, any replacement piece that you can scrape together is useful. The output of a flash is usually given as its Guide Number, The guide number, divided by the f-number of the aperture setting, indicates the distance that the light will travel with a certain iso and zoom combination. However, many companies cheat by setting the flash to the highest zoom level (see below) to make the number appear higher. To compare apples to apples, make sure that the zoom setting is the same for all flashes, or see an overview in which the power was actually measured with a light meter (e.g. this one on speedlights.net).
Think of the output power as the maximum aperture of a lens. The more you have, the more you can do with it, but the bigger and more expensive it gets.
Tilt / Swivel
By tilting and rotating you can position the flash head in a different orientation than the body. This becomes important for two reasons. When you use a flash on the camera, the method of diffusing the light and giving the flash an attractive appearance bounces off, aiming the flash head at a reflective surface (usually a ceiling or wall). This softens the light. However, to determine the direction of the light, you need to choose your jumping surface. Tilt and pan determine your freedom to do so. Full 360 ° rotation angle gives you full freedom; Rotating 270 ° removes 25% of your selection, and depending on how you rotate in portrait orientation, 50% can be removed.
The second reason why panning is important is when you use an optical trigger system to use the flash-off camera. The sensor for this is usually located in the body and must be pointed at your optical master unit (e.g. the hinged flash of the camera or another light in the setup). When you have swiveled fully, the head can always point where the light should go, while the sensor on the body points to the camera.
If you zoom in on a flash head, the flash tube can move back and forth in the head so that the light distribution corresponds to the field of view of the lens used. You can use this function outside the camera to adjust the focus of the beam. The longer the zoom setting, the further back the light is in the head, the more focused the beam is and the further the light can spread.
TTL, M and Auto modes
TTL stands for "through-the-lens" measurement. This is an automated method of setting the flash output. The camera instructs the flash to send out a "pre-burst" flash with known brightness. measures it and then adjusts the flash output based on the results and the power limits of the flash. Just like using an automatic mode based on exposure metering on the camera body, it is quick and easy to set, but may not be perfect and you may need to choose a correction. Usually you use it for Run & # 39; n & Gun event situations where you move through different lighting situations where you may only have a fleeting chance of a shot and speed is more important than precision or consistency.
Since it is a flash / camera communication, TTL is proprietary and system-specific. If you want to use this function, you have to search for a flash that is compatible with the camera system used.
Also note that film flashes usually don't work with digital SLR cameras. The algorithms for calculating the correct flash exposure based on the film reflectivity had to be modified for digital sensors. OEM flashes for the digital age can normally switch between film and digital TTL, but film flashes obviously only work exactly for films.
MJust like M on the camera, it is a full manual mode in which you can set the flash output directly as a ratio of the total output. The ratios are most often given in point (1, 1/2, 1/4, 1/8, etc., etc.). And just like using M on a camera, this is used to ensure consistency from shot to shot and the precision of the controls. It is most commonly used in studio settings where the lighting is controlled and is unlikely to change quickly without repetition. The wider the setting range, the more control you have over the flash output. For example, a performance of 1/128 can be very useful due to the inverse square law if you work closely together for macro or product work. M also becomes very important as the only way to control flash output if you only use manual radio triggers for flash units outside the camera.
automobile is another method of automating flash light / power output that does not require TTL communication with the camera. It can therefore be found in older film and manual flash units from third-party providers. A sensor on the flash (usually an autothyristor) is used to turn off the flash output at the right time. You may need to enter the aperture and ISO settings used for recording in the flash.
High-speed sync / focal plane flash
Most system cameras today use slit locks. Their shutter speed depends on how big the gap between the first and the second curtain is when they pass over the sensor. At a certain shutter speed, this gap becomes smaller than the sensor itself. And since most flash series are much shorter than the shutter speed, the curtains cover parts of the sensor when the flash fires, and black bars are displayed at the top and bottom / or at the bottom of the frame. This magical shutter speed depends on the body and is called the "maximum synchronization speed" of the camera (usually at 1 / 200s for most dSLRs).
High-speed sync (HSS, also known as "focal plane" sync or FP) overcomes this limitation, but requires proprietary communication between the flash and the camera. Therefore, as with TTL, you need to find a flash that is compatible with the camera system you are using. In addition, entry-level Nikon and Fuji bodies cannot. The camera instructs the flash to pulsate for the duration of the exposure and to act as a continuous light source. However, the cost of rapid pulsation is a loss of power of approximately two stops.
This is most commonly used when filling flashes for portraits with shallow depth of field in bright sunlight. If you want to use a larger aperture in sunshine 16 (ISO 100, 1: 16, 1: 100s), you have to increase the shutter speed. You can also use ND filters instead of HSS. HSS can also be used to freeze motion at high shutter speeds when there is a lot of ambient light.
Trigger outside the camera
The strobe type of studio lighting with flash units outside the camera is common and you may be bitten by the beetle. So think about how many ways you can fire a flash when it's there Not on the hot shoe. The following features should be noted:
- PC sync port (Protor-Compur) (usually only for high-end flashes)
- 1/8 "(or 3.5 mm) mini jack sync connector – like headphone jacks (third party only)
- proprietary wireless (TTL) slave mode (Canon: Wireless eTTL; Nikon: CLS)
- "stupid" optical slave mode (Nikon: SU-4 mode; "optical slave" mode from third-party suppliers)
- built-in radio receiver (normally only works within a specific (brand-identical) radio trigger system)
The main distinction is how many signals are transmitted from the camera to the flash (full hotshoe protocol or only the synchronization signal) and via which mechanism they are transmitted (radio, optical, cable).
For example, PC and 1/8 "sockets with cables can be used for manual triggering or as a way to connect a manual radio trigger without using the hot shoe. The camera hot shoe and the flash base of the flash can be connected with a TTL cable for Full communication, and of course you can either connect to some optical / radio triggers or sync connector adapters (ie a way to add a sync port if your flash or camera doesn't have one).
When a trigger system is labeled "TTL", it not only means that you can run TTL from the system, but that most of the hotshoe signaling protocol can be used. With these systems, you can control the flash remotely as if it were on the flash shoe (possibly with a few exceptions). However, trigger systems that are "only manual" can only trigger the flash in sync with the exposure.
optical triggering systems communicate with light. Proprietary TTL / HSS-capable optical systems translate the hotshoe protocol into light signals. Generic "stupid" manual systems use a sensor on the flash to detect when another flash has fired. Optical systems are limited by "line of sight" (the sensor must "see" the master signal) and ambient light conditions (the more light there is, the more the signal can be overwhelmed).
radio Triggering is not hindered by lines of sight or ambient light conditions and has a better range and reliability. Most triggers – especially the built-in ones – only work within a specific system. It's incredibly rare for triggers to work across brands or systems. Additional triggers may give you more flexibility in choosing. However, built-in triggers often offer more features (e.g. power / zoom control for manual flash units) and are more practical because you don't have to remember to bring along triggers and extra batteries for them.
As with all other trigger systems, the scope of communication can vary: some are synchronous signals (only manual), others enable synchronization and remote control of the power supply, HSS or tail synchronization, and some imitate proprietary optical or RF systems. Think about how much communication you want or might want in the future. Also consider what upgrade paths are available when you get an integrated RF trigger.
Radio triggers are usually part of a specific system. As a rule, you cannot combine mix & # 39; n & # 39; match triggers from different manufacturers, even if they all work on the 2.4 GHz bandwidth. And it is worth considering what a system can offer in terms of future extensions.
Yongnuo, for example, has three separate, mostly incompatible, release systems that you cannot use to mix the super-affordable, purely manual transmission with the TTL / HSS transmission. And they only offer flash units. And they only support TTL for Canon and Nikon, and you can't mix the two. You are trying to fix this problem with the YN-560-TX Pro. Currently, however, firmware upgrades that are required for use with existing YN devices are not readily available or cannot be easily applied.
If you ever plan to add or switch to mirrorless cameras, or if you need to share your lights with a shooter from another system or need more power than a flash can provide, this can be problematic. In addition, it can be frustrating if you are used to remote control TTL and HSS from your flash units when you are not using the same thing with a combination of flash units and studio flash units.
You may want to see if a lighting / triggering system supports you with options larger than the flash, whether you can mix TTL and manual equipment, and whether or not it provides cross-system support. There are many systems that offer one or the other or both (e.g. Cactus V6, Jinbei / Orlit RT, Phottix Odin II, Nissin Air, Profoto Air). The Godox X system is a current favorite as it offers both cross-system and larger headlights with flash units at Yongnuo-like prices as well as flash units operated with lithium-ion.
Battery connection / Li-ion battery
Flash units usually use four AAs. When under heavy use, these AA batteries may need to be replaced several times, so an external battery pack can be useful. A larger power source can also reduce reuse time (however, there is a higher risk of overheating).
There are some flash units on the market that use a Li-ion battery instead of AA batteries. This reduces battery management for multiple flash units and works like an external battery (increases capacity; shortens recycling time) without the need for cables and an additional device.
You have your eye on this super cheap Yongnuo, right? Even if it makes sense, just understand what you're giving up by using the lower price. The quality of the creation, the consistency of the copies and the quality of the components are probably more variable than with OEMs. Support, warranty and resale value are likely to be of much lower quality. And future / downward compatibility is likely to be lower.
Most third-party manufacturers are revising the hotshoe communication protocol. As a result, the flash may work very well with a current camera model, but may not work as well with a future or older model or, for example, a film body with what is supposed to be the same flash protocol. To fix this problem, some third party flashes can update their firmware, but most super cheap manuals (YN-660, Godox TT600, etc.) cannot.