Problem syncing my Leica S with my profoto B1 heads

ndwgolf

ndwgolf

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Neil Williams
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Yesterday I had an unsuccessful day shooting with my Leica S and Profoto B1 heads on a beach in bright sunlight. I really think it was operator error so I am reviewing my settings and set up for yesterdays shoot. I have a basic question that I need to get my head around and that is

Which flash synchronisation mode should I have set on the Leica S
Start of exposure
End of Exposure
??????

I say unsuccessful because the images were all looking good on the histogram but the fill light that I was trying to get from the B1 heads just didn't seem to work and look like the flash sync was off. I shot most of the shots with camera on a tripod at 1/125 and whatever f stop was needed to get an in camera balanced exposure.
Also the EXIF information shows that "the flash did not fire" but the flashes did fire but maybe not at the right time?

Anyone have any advice or experience to share on what setting they use with strobes (preferably Profoto B1 heads ?
 
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Okay I have just done some more testing at home that has completely bamboozled me.
I set up a shot looking out of my living room window with a light and dark cushion as my model (as least it docent talk bak :) )
Anyway pointed my Leica S at the pillow and it read ISO 100 and f8 at 1/125 took a picture and the pillow was dark (expected)
1/.
View attachment 41929
I then used my D800 with the same setting and got the same result (expected)
2/.
View attachment 41930

I then took a picture using the D800 and this time uing the profoto set at TTL and took a picture
3/.
View attachment 41931
I then kept the same setting on the profoto head at that time it was 5.6 and took another picture using my Leica S and got this (notice the EXIF shows flash did not fire even though it did..... hu)
4/.
View attachment 41932

Now the the bit that does my frigging head in is that when I metered the flash light using my Sekonic L308 it showed f5.6 (WHY NOT F8) ...........................(funny how the f stop was similar to the profoto head read out) anyway I then got the meter and dialled the profoto head up to the same f8 that I had set in the camera (profoto head now set at 6.7) and took this picture.
5/.
View attachment 41933
I hope all of the above makes sense to someone out there as it is starting to get me pi**ed off how a simple thing like this can be so NOT SIMPLE.
Any feedback will be much appreciated
 
Yes, the flash did fire - you can see that from the otherwise unexplained specular highlight on her sunglasses. The reason that the flash hasn't done anything useful is that the power was set far too low, relative to the level of the ambient light. And the contribution made by the ambient light was far higher than it needed to be because you shot at 1/125th second - couldn't you have used a faster shutter speed to reduce the effect of the ambient light?

Your indoor shots weren't affected in the same way so the results were different.

Your camera can't recognise the presence of an external flash, hence the "flash did not fire" misinfo.
 
If you were using ttl it may have metered off the brighter background and decided you don't need a lot of flash so only put out a little bit.
 
Garry Edwards said:
Yes, the flash did fire - you can see that from the otherwise unexplained specular highlight on her sunglasses. The reason that the flash hasn't done anything useful is that the power was set far too low, relative to the level of the ambient light. And the contribution made by the ambient light was far higher than it needed to be because you shot at 1/125th second - couldn't you have used a faster shutter speed to reduce the effect of the ambient light?

Your indoor shots weren't affected in the same way so the results were different.

Your camera can't recognise the presence of an external flash, hence the "flash did not fire" misinfo.
Click to expand...
Gary the Leica S will only sync with the flash at 1/125 with my current lens. I am getting 2 new CS lenses on Monday or Tuesday next week that can sync at 1/500 so better for outside and hand held shots.
I still believe that the problem came from the flash settings caused by the meter. In the house the meter and flash worked flawlessly but maybe the meter just struggled in the bright outside light.
Can I dod an experiment at home where for example I start off at say f2.5 and see what power setting the b1 head needs for that and work my way up to say f16 and jot those numbers down on a piece of paper and use that as a guide when I am out in the field.
Something like below
B1 head power equivalent f stop

3.0 f2.5
4.0 f 3.2
etc etc
 
Well, you definately do need lenses that go over 1/125th, apart from such a slow speed needing a lot of flash power, it also forces either the use of a ND filter or too small an aperture in bright light.
Frankly, you'd do better to keep this simple and forget about using the meter in this situation - just use your eyes instead, take a test shot, look at the camera LCD and adjust flash power to suit.
 
Garry Edwards said:
Well, you definately do need lenses that go over 1/125th, apart from such a slow speed needing a lot of flash power, it also forces either the use of a ND filter or too small an aperture in bright light.
Frankly, you'd do better to keep this simple and forget about using the meter in this situation - just use your eyes instead, take a test shot, look at the camera LCD and adjust flash power to suit.
Click to expand...
Garry I used the LCD yesterday and they looked okay on the LCD
Heres another chart with 1/500 sec but didn't change anything above power setting 4
View attachment 41942
 
ndwgolf said:
Just did this at home
View attachment 41940
Click to expand...
Those figures worry me a bit. How accurately were you placing / measuring your flash distance?

I know the ISL gets unreliable close up but there should be a straight 2 stops difference from 3 feet to 6 feet. :confused:

With a little practice you should be able to get a feel for 6 feet, then just use your known power out in the field. Like Garry says though, when mixing flash with ambient, the screen image is the best 'measure' of what's happening.As long as you're confident and don't arse about too much a model expects a certain amount of 'test shots'.
 
ndwgolf said:
Phil
I just paced out One step and two steps and took the meter readings
Click to expand...
Good - not scientific then which explains the results being not entirely what I'd expect.
 
Garry Edwards said:
Well, you definately do need lenses that go over 1/125th, apart from such a slow speed needing a lot of flash power, it also forces either the use of a ND filter or too small an aperture in bright light.
Frankly, you'd do better to keep this simple and forget about using the meter in this situation - just use your eyes instead, take a test shot, look at the camera LCD and adjust flash power to suit.
Click to expand...
Yea I forgot about that I used an ND filter yesterday just for that. After my first attempt of a beach shoot a few months ago I was being very conservative with the lights as I didn't want the old lady looking like she was photoshopped into the picture
 
Well, if I was photographing her I would certainly consider using a beauty dish, but it wouldn't work for the example shot you posted.
Beauty dishes are specific tools that emphasise good bone structure and high cheekbones - which is why it is ideal for producing a shot that shows the qualities of her face - but it wouldn't work in this situation for three reasons.
1. It needs to be directly in front of where the face is pointing, to create the right shadows in the right places
2. It needs to be high, for the same reason, and that hat with its large brim could not be used.
3. It needs to light the eyes, not the sunglasses.

But, we're overcomplicating things. Forget about metering for the flash, forget about those fancy numbers, forget about placing the flash at a specific distance. Place the light where it flatters your subject, set the power to where it looks right on the LCD.
 
I think Garry has nailed it, in his last paragraph. Flash and daylight balance can be tricky to measure accurately, but more to the point it's very subjective. If you want a subtle splash of fill-in that's one thing, and might not need that much power, but if you want to over-power the sunlight and darken the background, that's entirely another. The difference between the two can be very substantial, like three or four stops, and in the latter case you need a massive amount of flash power on a bright day. The best way to assess that is really by learning to judge the LCD image accurately - that's what really matters and the numbers will only get you ball-park at best. Put a black cloth over your head if needs be (some do!) and know what the histogram and blinkies are telling you.

Have you established that the flash is synching properly? I think so. To know what your flash is capable of power-wise, take it outside* at night, at full power, at typical shooting distance (accurately measured!), and meter it. Then you'll know where you are, and what is possible in bright daylight. If you need more power, move the light closer** (will also make the shadows softer), or use a more efficient (smaller, more directional, harder) modifier. *The same test indoors will be unrealistic, inflating the flash output by half maybe a whole stop, depending on the room/position/ceiling etc. **Halving the flash-to-subject distance will roughly quadruple flash brightness, two stops, big difference. Doubling it reduces brightness to one quarter - inverse square law. The combination of a smaller modifier, used a bit closer, can give you a lot more effective flash power without changing the result too much.

On the other hand, that situation is just perfect for using a reflector IMHO, without flash. Bypass all these problems. Maybe a white one, or silver. You can get a heck of a lot of light with silver, used closer. Remember that light bounces off a surface at the same angle it strikes, like a snooker ball off the cushion.
 
Phil V said:
I know the ISL gets unreliable close up but there should be a straight 2 stops difference from 3 feet to 6 feet
Click to expand...
The ISL works in direct light situations, ISL is compromised in the OP's test because of the large amount of large amount of light that is bouncing around the room the OP has selected for his tests.
 
redsnappa said:
The ISL works in direct light situations, ISL is compromised in the OP's test because of the large amount of large amount of light that is bouncing around the room the OP has selected for his tests.
Click to expand...

For the Inverse Square Law to work absolutely, it requires very strict conditions like a point light source suspended in a vacuum or something. To take an extreme example, if you're using a softbox and meter it at 2ins, it's not going to drop two stops at 4ins. But for the kind of distances and lights we use, it's a pretty good guide.

I just took some measurements, using an 80cm softbox. Typical domestic room with the light close to a white ceiling for say full-length portraits, then with the light at about chest height for some sitting portraits, then outdoors.

At 1.0m, indoors high f/8-d8, indoors low f/8-d6, outdoors f/8-d5.
At 2.0m, indoors high f/5.6-d1, indoors low f/4-d9, outdoors f/4-d5.

So the ISL is working well, within a couple of tenths and certainly good enough as a working rule of thumb when setting up, with the caveat of the working environment sometimes having a significant influence, as you'd expect.
 
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