Here, we would like to answer some of the questions which our team is asked about more frequently or which keep coming up.

Why should I use flashes? Current cameras offer an outstanding image quality even at high ISO and this means I can use LED and FL lamps.
  1. Because of the short flash durations (and fast recycling times) of modern compact flashes and flash generators it is possible to “freeze” motion.
  2. Flashes are very effective. Especially when shooting outdoors i.e. in direct sunlight the light output of typical continuous light sources is way too low.
  3. Short flash durations prevent blurred pictures caused by camera shake/vibrations and allow to gain max. resolution of the best cameras.
  4. In difference to typical continuous light sources it is possible to control the light output of professional flashes over a wide range and to adjust their power to your ideas and the existing light on the set.
  5. In difference to typical continuous light sources professional flashes don’t change color temperature at different power levels.
  6. Flash light provides very good color rendering (CRI 95). Many modern LED and FL lamps cause a mediocre color fidelity (CRI 90 or less).
  7. In combination with high res DSLR’s the short flash durations of professional flashes ensure to achieve the max. resolution of those cameras – factors like camera shake and vibration (mirror/shutter) have no influence on the image quality.
  8. Professional flash systems offer a wide assortment of light shaping tools and therefore more creative possibilities.
  9. When using flashes it is possible to control flash and continuous light independently: Adjusting exposure time mainly changes the intensity of the continuous light (e.g. daylight).


Is it true that Hensel equipment is made in Germany?

Yes! Our flashes and continuous light sources are created & crafted with pride in Germany! If you like, you can even “take a peek across our shoulder” here.

How come that I can connect, and simultaneously use, flash units with 12 V and 120 V respectively 230 V modeling light to the Porty Lithium when using the AC adapter? Doesn’t this damage anything?

You can do so without any problems and the reason is very simple: The Hensel flash units operate with specially encoded plugs. Simply put, the generator recognizes the maximum output of the flash tube and the modeling light’s voltage via the plug ports. The respective output is tied to the corresponding pins of the unit’s socket or connecting cables. This way, you can be sure at all times!

Is there really a compact flash that can manage 40 flashes per second?

Of course! And if needed, flash duration times as short as 1/100,000 s. The completely new mains adapter technology and sophisticated circuit-technology make this possible by combining capacity circuit and electronic flash turn-off. Additionally, there are many setting options, freemask is included, and the unit is fit for 24 hour, non-stop use.

What exactly is freemask? I have heard of it before but can’t quite figure out what is meant by it.

The easiest way to find out about freemask: Our freemask brochure, it will answer any questions you may have regarding freemask: Download (PDF, 220 KB)

I heard that I may need to show a certificate of non-objection for my rechargeable generators when checking in at the airport.

Checks are becoming increasingly thorough and air transport safety has highest priority. Naturally, our lithium rechargeable batteries meet all current requirements.

Certificate for Porty with lithium battery: Download (PDF, 280 KB)

Certificate for Porty with lead gel battery: Download (PDF, 46 KB)

Can there really still be electricity inside the unit even after the mains plug has been disconnected?

Yes! Flash units use capacitors to collect power, store it, and release it “in a flash” as a light pulse via the flash tube! So, if just the mains plug is disconnected or the unit is switched off, there may still be a charge in the capacitors. Depending on the type of unit, the charge is either automatically released via flash when turning off the unit, discharged via resistors, or depletes with time on its own. But even after manual flash release, the condensers still store some remaining charge. So, please make sure that the capacitor charge has been completely discharged before doing repairs.

When is the lowest flash duration time of a flash unit available?

The answer to this is more of a general nature, because there are different technical types of controlling and regulating. In principle, when talking about studio flash, the lowest output does not guarantee the lowest flash duration time. Normally, this only applies to shoe mount flashes.

Example: the new Expert D or also the Porty L units by Hensel. Both series offer the lowest flash duration times even at a medium output level.

The Expert D units, for example, have a flash duration time of ca. 1/5.600 s (t 0.5) at an output setting of 8.4. In practice, this can often be the deciding factor for achieving a well-done exposure. Units which only have low flash duration times when set to a low output setting are usually insufficient for many applications! However, this information is seldom listed in catalogues and can usually only be found in user manuals or on data sheets. Generally, this also applies to generators, but here other factors play an important role, especially the number and type of flash units attached.

Here’s a list showing the flash durations of all current Hensel monolights.

My old flash units do not have ventilators and are, of course, much quieter than current units. Why can't we do without ventilators today?

One of our bestsellers in the 90’s was the Contra E 500, with a recycling time of 2.1s at max. power and shortest flash duration of 1/1200s. Nice back then, when most photographers used relatively slow analogue cameras. This unit didn’t need a fan. Today our Expert D 500 fires a full power flash every 0.5s and reaches 1/5600s flash duration. The fastest flash sequence time is a maximum of 9 flashes – continuously. If you relate this to cars, it is like comparing a VW Beatle with a Porsche Carrera.

Generally, the airflow has to be matched to the output performance of the flash. Units offering top performance also need proper cooling to match it. When necessary, the ventilator dependably blows all hot air out of the unit. In this case (at high performance levels) it may become a little bit louder.
The ventilator is temperature controlled which means you will hardly hear it at normal level of operation. However, when ‘push comes to shove’ one can absolutely rely on the equipment’s durability and the ventilator increases the airflow inside the unit. On top, this active cooling extends the lifespan of the electronics.

Which light output can be expected at even longer distances ?

An overview of possible f-stops at a distance of 15 meters (49 ft).

Measured distance 15 m – outdoor (no room reflection etc.)
ISO 100, 1/250 s (no measurable interference caused by ambient light)
Porty L 1200, EH Pro Mini 1200 Head, full power

Click here to see the table of light formers (PDF, 41 KB)

We just measured some common reflectors to give you a rough guideline. The values approximately relate to other construction forms. Data of all reflectors and a nice table comparing the different lighting characteristics can be found at our light former comparison.

Light intensity decreases with the square of the distance, so the best solution is always: Place the light sources as close to the subject as possible! This increases the light output and limits straylight. Instead of using a large softbox over a huge distance, it’s better to go for a smaller one from a short distance.

Why do most modeling light defects occur when switching the lamp on?

This can be explained by the significant power increase that briefly occurs when switching the unit on. The resistance of the halogen lamp is lower at initial operation than after warm-up. The lowered resistance leads to a brief power surge when turning-on which, in turn, may cause older lamps to burn out.

How can I extend the life of my modeling light?

By working with Hensel equipment, for example!
During maximum performance, most compact flash unit’s modeling lamps are not supplied with full mains voltage. Depending on the type of lamp, 10-20 V less extend the life of the lamp ten to twentyfold. Another option is the modeling light’s automatic stand-by function.
This function automatically dims the halogen light when not in use (pre-select the time). This substantially increases the life of the lamp and saves energy. Of course, gentle handling is also important! Lamps which are turned on are much more sensitive to shock and vibration. A hot glow filament breaks much easier than a cold one. If you keep this in mind, you will have less trouble and save money!

Do I need to worry when my Expert D unit starts making noises?

To enable the performance of Expert D inside a compact flash, so-called switch-mode power supplies have to be used. Otherwise, the units would become too large and heavy.

Switch-mode power supplies work with high switch frequencies. This may cause noise development which is completely normal and ok. Even small switch-mode power supplies as used in computers or televisions are rarely completely silent. Even more powerful power supply units are used in professional flash units than in computers or consumer electronics. More powerful switch-mode power supplies are, however, more noise intensive.

People who are used to working with conventional units may think that the humming and cracking noises of flash units in use are unusual. But this is completely normal for such units and absolutely no technical problem. The noise intensity also depends on the quality of the power supply and the operating temperature.