The shutterspeed mystery/nonsense

You don’t want to know how often people ask me about this topic, and how many cameras are “destroyed” online due to a so called limitation of shutterspeed when working with strobes, but also strobes are destroyed online because they don’t work as people think. So I thought it would be helpful to write a very short blogpost explaining how it works.

X-sync
When you take a picture a lot happens in the camera but in short you can see it like this.
The shutter opens, the first shutter curtain starts to open and after an X amount of time the second curtain follows covering the sensor and the mirror flips back up.
Now this X amount of time is of course variable and will change with the shutterspeed.
As you can image there is a point where the second curtain actually is following the first curtain pretty quickly and this is where the problem lies for people to understand strobes. When the two curtains are closing so close to each other this means that there is NO point in time where the WHOLE sensor is lit by the light, it’s always just a small part (bigger part by slower speeds, smaller parts by higher speeds).

Now when we start using strobes you can imagine that it’s important to choose a moment where the whole sensor is available to catch the light.
And this is what we call the X-Sync speed, X-Sync speed is always the maximum speed in which a sensor is 100% free of a curtain or any other thing blocking the light so it can catch the whole light emitted by the strobe. In most FULL FRAME DSLRs this is around 1/125 to 1/250 although most cameras will be between 1/125 and 1/160. All my Canons for example topped out at 1/125 when using radio triggers and barely 1/160 when using the cable.

Yes indeed with a cable it’s possible that you get a little bit extra.
Now why do people think that you can get much higher sync speeds with strobes?

Small flash
Small flash or system flashes are cool and a lot of people start out with these strobes.
Often these systems sync up to 1/200 or 1/250, however when used in a mode called HSS (HighSpeedSync) you can achieve shutterspeeds up to 1/8000. This is however not 100% true, the strobe will actually not flash in it’s normal mode anymore, it will literally “strobe”, due to this “strobe” effect it will actually light all the “gaps” that the two shuttercurtains create. A BIG disadvantage of this system is that it actually eats through your batteries and the poweroutput of your strobe is limited a lot compared to the one “blast” of light.

However people see that it can sync up to 1/1000 so they “think” that’s “real”.

Studio strobes
Now studio strobes are different.
There is no communication with the camera, in other words there is a signal coming from the camera that simply says “FIRE” and the strobe fires… well and that’s it. This means that there is no HSS option for studio strobes. (at the moment of writing) This means that because there is ONE blast of light it’s important that the whole sensor can be exposed, meaning you will have to stay at or below the X-Sync of your camera. If you don’t… well you will see a small (or larger) black bar in your image, which actually is the shuttercurtain you see.

Pocket wizard
Some solutions are claiming to break this X-sync and some do work indeed, like the Pocket wizard. On some cameras you can get spectacular results with their system however there are some serious drawbacks, you will need “slow” strobes, the slower the better. If you try for example the Hypersync option op Pocket wizard on a D-Lite from Elinchrom you can get around 1/800 with a Canon 5DMKII but if you use it on Ranger Quadras with A heads on the fastest flash duration I never was able to break the 1/250 speed. For some images however this is a very nice option.

Why it really doesn’t matter
Unless you use Pocket Wizard with the right strobes it all boils down to very small differences.
Let’s say camera 1 syncs up to 1/160 and camera 2 syncs up to 1/250, for some people this is HUGE and when you read the forums sometimes it would be the difference between shooting with sunlight or going day to night…. yeah…… well in reality the difference is only 6/10 of an Fstop or in other words you are 2/3rd stop faster. If you really want to see a big difference in cutting ambient light you will have to be able to do a LOT more, think about at least 2-3 stops. For this kind of speeds you will need a MF camera with Leaf shutter lenses (1/1000 often without loss of lightoutput and 1/1600 with some loss depending on the strobes used) Meaning if you want to really hit the ambient with let’s say 3 stops you will have to go from 1/125 to 1/250 (1 stop) and after that to 1/500 (2 stops) and after that to (1/1000) which makes it three stops, as you can see that the difference from 1/125 to 1/160 or 1/250 actually hardly makes any difference, although it’s of course always the small things that help but in no way a reason to NOT buy a certain camera or to bash it online.

With most cameras a good solution to kill ambient light is using strong strobes like the Ranger RX from Elinchrom with for example the Maxilight. With this combination on full power you will probably end up with values that are much higher than you can set your lens to (sometimes we meter 1/32 but often much higher with this combination) to get this all in “sync” and shoot on a nice aperture to create the look you want you can use ND filters to cut the light and actually shoot on a much wider aperture than the light would be without.

So if 1/125 is enough according to you, then how do you freeze action?
After people get this the following question is often “how do you freeze action?”
Well that’s easy.
Let’s look at this diagram.

Let’s imagine that the flat line between 1 and 125 is the ambient light, as you can see it’s a flatline, meaning it’s doesn’t register, maybe it will climb up after 1/30 or 1/15 but at 1/125 there is no ambient light, meaning if you would shoot at 1/125 there is a black frame without any information.

Now the big bump is when the strobe fires this is actually where the action is frozen.
Now the top of the bump is not a point as you can see but it’s actually flat, this is because EVERY strobe has a certain flash duration, some are very short, some are very slow but mostly you will find strobes sitting between 1/800 and 1/5000 with some exceptions, one could say that this number is actually the freezing moment so if you use a strobe that has a flash duration of 1/800 it means that it will freeze the action on 1/800 of a second, but the shutter will stay open for 1/125 for the simple reason that this is the ONLY time where the whole sensor is lit, if you choose a faster shutter speed there will be a black bar in the frame.

I hope this blogpost helps a bit in understanding the way a strobe and camera work together and why some things are important and others aren’t 🙂

If you like this blog post but want to read something that is MUCH more in-depth, more intense and covers many more aspects make sure to check out my new book “Mastering the modelshoot” it’s available from all stores and of course Amazon, you can order it here.