Leaf shutter vs high speed sync flash - overpower the sun

Hi,

Just curious about this because in the past with a Nikon dSLR with HSS (at full power) the people were still underexposed with a nice background or vice versa. Given some of the nicer compact cameras are maybe more user friendly on family hoildays etc. Some of them have leaf shutters. Does it allow one overpower the sun without a studio strobe? Like a hotshoe flash?

Cheers.

The sun is a big monster to 'overpower': but I think that I really do understand your question. The answer is: "Leaf Shutters are awesome".

I had two 80mm Leaf Shutter Lenses for my Mamiya 645 Film Kit and I used those with a single Metz "Hammerehead" Flash Unit for Flash as Fill for Outdoor Portraiture in very bright conditions.

I went without any Leaf Shutter Lenses for several years from when we cut over to Digital in 2004 (Canon DSLR) - but a few years ago I bought a Fuji X100s and one of the three main reason for that purchase was to provide a supplement Leaf Shutter to my Wedding and Portrait Kit to allow me to use a single Speedlight for Flash as Fill in very bright conditions.

I am not absolutely sure of all the nuances of the Nikon Flash system, but you 'lose' about 30% of Maximum Flash Working Distance simply by selecting "HSS" (High Speed Sync) on a Canon Flash even if you have not gone faster than the X-Sync Shutter Speed. When you are at 1/800s to 1/1000s shutter, you can lose 50% or a bit more MFWD because the HSS is engaged.

But if you are using a Leaf Shutter at 1/800s or 1/1000s you still have the flash at 'full power;' and thus have all the MFWD at your disposal.

WW

Thank you for that, so you go gain some power back with leaf shutters. :)

Just a side question. If one was to deliberately up the ISO and still use HSS as before. Does this help the speedlight out? This is relating to a non leaf shutter system. Or perhaps not right ... higher ISO, even higher shutter speed = even more loss of flash power.

Thanks.

If one was to deliberately up the ISO and still use HSS as before. Does this help the speedlight out? This is relating to a non leaf shutter system. Or perhaps not right ... higher ISO, even higher shutter speed = even more loss of flash power. .

haha!

You edited and answered your own question just as I got to it!

Yes, you are correct you'll just go round and round in circles.

Let's say for example you are using Flash as Fill for a Portrait Subject who is backlit by bright cloudless sun on a beach and you want a shallow DoF,

You need to pull F/16 @ 1/100s @ ISO100 to get the background landscape/seascape in the correct exposure.

Your camera's X-Flash Sync Shutter Speed is1/200s

So, if you choose to use F/2.8 for a shallow DoF, you'll be pulling F/2.8 @ 1/3200s @ ISO100 - and you'll need to use HSS for the flash and (with a Canon Flash) at 1/3200s using HSS you'll only have an effective range of about 30% of the 'Guide Number calculated' maximum flash working distance.

There would be little use bumping the ISO to ISO200 - because you'd have to use 1/6400s as the Shutter Speed which would in turn place more stress on the HSS and probably cut the MFWD even further.

***

If you want Flash as fill for Outdoor Portraiture in bright situations and only have one Flash Unit, then typically and as a good Rule of Thumb, it is best to use the lowest possible ISO and the Shutter Speed at X-Flash Sync, and not to engage HSS because this will give you the best range of Apertures available and the Flash at its higher 'power'.

If then you need to go to HSS because you need a larger aperture for Shallow DoF, then it is usually best to use the Flash Off Camera and as close to the Subject as possible - the logic being that you will always be using the Flash within its Maximum Flash Working Distance.

WW

Note the term flash 'power' is used loosely. It is not really the power of the flash which is reduced but the effect is so and it is easily described as a loss of power