Profoto B1

sk66 said:
The problem with "proper" HSS is you also get very low power from it. The reason it's beeping it f/11 is it can't deliver enough power and keep up w/ the SS. It's probably at it's lowest power already in order to keep up.

The best solution for killing the sun is usually high power and ND's. The best solution for freezing motion is usually low power/short durations from short distances (in a darker environment). The next best option for doing either is really short durations/low power matched to a high SS (HSS).

In your situation you could reasonably expect a T.1 of 1/8000 at min power (possibly higher) as opposed to a 1/8000 SS at min power HSS. The advantage of the first is battery savings. The advantage of the second is that it doesn't require a darker setting.
For all the IGBT heads I've seen actual test measurements for the T.5 is very close to the T.1 at anything but 1:1 and the low power settings (<1/16). At 1:1 it seems to be around 1/3 (3x as long) and at low power it seems to be around 1/2 (2x as long). So you might have almost as fast of a T.1 at ~ 1/16th as you would at minimum.

But I don't think you will need 1/8000 to freeze water being slung off a dog. I think 1/4000 would probably be adequate. The point is, you'll probably have a fast enough flash duration at 1/8-1/16th power with reasonable power and less battery usage. HSS is nice to have, but it's not necessarily your best choice.
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I wouldn't use HSS for my water shots, I merely posted about the new feature :)
 
matty D said:
Just had a quick play in the house, nothing scientific, but I can confirm the firmware update is very simple, takes about 1 minute.

It works faultlessly right up to 1/8000 with full TTL.

I didn't do anything sophisticated, I just put the unit in the corner of my bedroom, 1/8000th f10 I could get a good exposure of the room using TTL, f11 and the unit would beep warning me of underexposure, but it was still ok, f16 not useable
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Matty, be really interested in a simple brightness test if poss.

B1 at full power, normal x-sync, and aperture for correct exposure at ISO100. Then switch to HSS, set shutter speed to 1/500sec, and see how high the ISO has to go to restore correct exposure. Better to do it with ISO as it takes lens vignetting changes out of it, and also potential diaphragm variables.

Thanks :)
 
HoppyUK said:
Matty, be really interested in a simple brightness test if poss.

B1 at full power, normal x-sync, and aperture for correct exposure at ISO100. Then switch to HSS, set shutter speed to 1/500sec, and see how high the ISO has to go to restore correct exposure. Better to do it with ISO as it takes lens vignetting changes out of it, and also potential diaphragm variables.

Thanks :)
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Interesting question.
I think lights that do true HSS do it with a single capacitor charge, so at best 1/2 power for two pops (1/2600 t.5). But I think (???) those same two pops could work for a SS of 1/1000.

Too bad there's not an easy way to automate it (like auto ISO). I suppose the easiest way would be to let it underexpose at the various SS's and determine the stops of adjustment required in post to equalize them (less subjective). I might try this with an SB...
 
sk66 said:
Interesting question.
I think lights that do true HSS do it with a single capacitor charge, so at best 1/2 power for two pops (1/2600 t.5). But I think (???) those same two pops could work for a SS of 1/1000.

Too bad there's not an easy way to automate it (like auto ISO). I suppose the easiest way would be to let it underexpose at the various SS's and determine the stops of adjustment required in post to equalize them (less subjective). I might try this with an SB...
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Assuming it works like a speedlite, and it must be very similar, then it will have to divide one full capacitor dump into dozens of smaller pulses. When the shutter slit is only a mm or so, as it is at 1/8000sec, that's the only way to prevent individual pulses showing - though with my Canon 580 guns, I can see some slight banding at max shutter speed and min flash power with HSS (when the individual pulses are extremely short). Fortunately, I can't imaging a situation when you'd want to use it like that. If the B1 behaves similar to a speedlite, the loss of brightness will be around 2-3 stops at 1/500sec.

There are some other interesting variables that may or may not apply. I don't know if a big flash tube like the B1 'glows' in-between pulses, in which case it might get away with less pulses, though in theory that wouldn't impact much on brightness. And it could be that Profoto is using flash burn times tailored to shutter cycle times, like PW's Peak Hypersync*, and that could boost brightness usefully at higher shutter speeds (up to one stop more with PW, depending on camera and shutter speed). But the B1 would need to know what camera was being used for that to work.

All that is kinda more interesting that relevant though - bottom line is how much light we get.

*Edit, I mean 'enhanced HSS mode' not Peak Hypersync - that's a different PW trick.
 
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HoppyUK said:
Assuming it works like a speedlite, and it must be very similar, then it will have to divide one full capacitor dump into dozens of smaller pulses.
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My current understanding is that a speedlight in HSS mode doesn't care about the SS. As soon as it goes into FP mode it turns into a "constant light" (it works like the "modeling light/buzz function" some flashes have). Because of this there is a drastic hit to power initially (it's running at ~ 1/4 power). And from there, SS controls the flash exposure.

Had to go to ISO 200 to get same exposure
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How the B1 only lost one stop I don't know... Unless a 1:1 output isn't actually a complete capacitor discharge, which would reduce recycle times even at 1:1. Maybe this makes sense as a 1:1 pop is rated at under 2sec recycle, which is quite fast for high power output and battery recharge.

It seems like a really nice head... I like the zoom function as well.
 
matty D said:
Had to go to ISO 200 to get same exposure
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Thanks Matt :) Only one stop light loss? That does sounds a bit too good to be true, though if that's what you got it's mighty impressive.
 
sk66 said:
My current understanding is that a speedlight in HSS mode doesn't care about the SS. As soon as it goes into FP mode it turns into a "constant light" (it works like the "modeling light/buzz function" some flashes have). Because of this there is a drastic hit to power initially (it's running at ~ 1/4 power). And from there, SS controls the flash exposure.

<snip>
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Yes, that's pretty much true though PW's optimised HSS trick (not Peak-Hypersync as I said above - now corrected) does take shutter speed into account.

Or rather, total shutter cycle time. In HSS mode, the flash starts to pulse 'continuous' light from fractionally before the first shutter curtain opens, until the second curtain closes. At high shutter speeds, the second curtain closes slightly before it does at slower speeds, ie the shutter cycle time is a bit shorter. What PW does is tailor the flash exactly to the shutter cycle times (it's camera model specific) and at higher speeds the light that would normally be wasted is squeezed into a shorter, brighter HSS burst. It can make quite a big difference, like up to one stop more brightness (Rob Galbraith did some very good tests on this). That's how PWs work with Canon guns, but on Nikon there is no brightness benefit but an improvement in flash recharge time instead.
 
matty D said:
I'll do the test again, and try and be a bit more scientific, might even use a light meter this time rather than comparing histograms :) Will keep you posted
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You can't meter HSS Matt, but it's a very easy test. Best with camera on tripod, and flash in fixed position so the light distribution and camera framing cannot change, in a darkened room. I usually bounce the flash from a wall/ceiling behind as it avoids any hot-spots or reflections etc that might skew things with hard direct flash.

Then take a normal x-sync shot at correct exposure with lowish ISO, switch to HSS and 1/500sec shutter speed, and do the same. Note how high the ISO has to rise before the image looks the same brightness as the normal x-sync shot, histogram to confirm if you like, and that's it (y)

Edit: theoretically, it should be impossible to better two stops or so, likely nearer three at 1/500sec (depending on the camera - makes a slight difference). Then it will go down pro-rata as shutter speed is increased, ie 3-4 stops at 1/1000sec etc. However, ambient exposure goes down exactly pro-rata at the same time so it's that first 1/500sec test that's most revealing.

Edit 2 - Is the HSS exposure perfectly even down the frame? No darker/lighter at top and bottom of the frame than the normal x-sync shot? Cheers!
 
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Just had another go as you described, my original go I had the camera set to ISO 64 to start with, just re tested starting at ISO 100 and its somewhere between ISO 320 and 400, 400 is a touch brighter in my eyes
 
matty D said:
Just had another go as you described, my original go I had the camera set to ISO 64 to start with, just re tested starting at ISO 100 and its somewhere between ISO 320 and 400, 400 is a touch brighter in my eyes
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That's great, thanks Matt :)

Let's say a two stops drop then, at worst - still very good performance. Just thinking about this, I would guess with your Nikons and the B1's basic spec, that a 1.5 stops drop would be the theoretical best possible result at 1/500sec, so clearly Profoto has done a very good job at maximising efficiency (y)
 
HoppyUK said:
That's great, thanks Matt :)

Let's say a two stops drop then, at worst - still very good performance. Just thinking about this, I would guess with your Nikons and the B1's basic spec, that a 1.5 stops drop would be the theoretical best possible result at 1/500sec, so clearly Profoto has done a very good job at maximising efficiency (y)
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I'm looking forward to testing it out in real life situations (y)
 
Ah, makes a bit more sense now. So around 125ws at 1/500 and probably still around 100ws (effective) at 1/1000 (due to the curtain speed penalty at 1/500). That's not bad at all for being in HSS.

It's a really nice option to have, especially if you don't have a darker setting or the idea of killing the sun is spur of the moment. But I still think a ND will be better for killing sun and T.1 durations will be better for freezing motion.

I'm a little jealous... but damn, $2k ea...
 
HoppyUK said:
You can't meter HSS Matt, but it's a very easy test. Best with camera on tripod, and flash in fixed position so the light distribution and camera framing cannot change, in a darkened room. I usually bounce the flash from a wall/ceiling behind as it avoids any hot-spots or reflections etc that might skew things with hard direct flash.

Then take a normal x-sync shot at correct exposure with lowish ISO, switch to HSS and 1/500sec shutter speed, and do the same. Note how high the ISO has to rise before the image looks the same brightness as the normal x-sync shot, histogram to confirm if you like, and that's it (y)

Edit: theoretically, it should be impossible to better two stops or so, likely nearer three at 1/500sec (depending on the camera - makes a slight difference). Then it will go down pro-rata as shutter speed is increased, ie 3-4 stops at 1/1000sec etc. However, ambient exposure goes down exactly pro-rata at the same time so it's that first 1/500sec test that's most revealing.

Edit 2 - Is the HSS exposure perfectly even down the frame? No darker/lighter at top and bottom of the frame than the normal x-sync shot? Cheers!
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Only just seen edit 2, and yes perfectly even :)
 
I have no idea what you are all talking about but I am away to buy the Profoto B1 kit so I thought I would jump on the thread to try and understand all this HSS and x-sync jargon :)
 
ndwgolf said:
I have no idea what you are all talking about but I am away to buy the Profoto B1 kit so I thought I would jump on the thread to try and understand all this HSS and x-sync jargon :)
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A full understanding of how flash works can get very technical, but you don't need to know all that yet - or possibly even at all. But what you certainly do need to know is how a focal-plane shutter works (as used by all DSLRs, and most other cameras), how it varies the exposure while the shutter curtains run at a constant speed (about 20mph!) and the critical change that causes difficulties above the max x-sync speed, usually 1/200-250sec.

This is a good link explaining that (first 4 mins) and how high speed sync (HSS, or FP/sync in Nikon speak) gets around problems at highest shutter speeds

 
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HoppyUK said:
A full understanding of how flash works can get very technical, but you don't need to know all that yet - or possibly even at all. But what you certainly do need to know is how a focal-plane shutter works (as used by all DSLRs, and most other cameras), how it varies the exposure while the shutter curtains run at a constant speed (about 20mph!) and the critical change that causes difficulties above the max x-sync speed, usually 1/200-250sec.

This is a good link explaining that (first 4 mins) and how high speed sync (HSS, or FP/sync in Nikon speak) gets around problems at highest shutter speeds

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Hay Richard
On my works computer the link you sent me is just a square with a exclamation mark in it can you just post the link??
 
^^^^ Fantastic Richard Thanks for sending me that link and taking the time to help me understand this stuff......................cheers mate
 
ndwgolf said:
^^^^ Fantastic Richard Thanks for sending me that link and taking the time to help me understand this stuff......................cheers mate
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You're welcome Neil :)

Even though you'll have a big pile of shiny new kit, take it easy and start with just one light, one step at a time. You can do a huge amount with just one and it's often all you need (maybe with a reflector board) and learn a lot. Any more than that and there's a good chance you'll end up with a mess of conflicting shadows and not know how to fix it.

A few things to bear in mind:
- Even in multi-light set-ups, one light - the key light - will be doing the lion's share of the work. All the others compliment that and add different aspects, but are almost always subordinate. Treat each separately, eg background light, hair light etc - all doing different jobs on different areas. You'll find a flash meter helpful when it comes to setting-up multiple lights.
- The larger the light source, the softer the shadows. And size is relative to distance - move a softbox close for an almost shadowless effect, or pull it back to progressively harden the shadows.
- With studio lights, brightness falls off rapidly with distance - much more quickly than you might imagine. It broadly follows the inverse square law that says double the distance equals one quarter the brightness - a drop of two stops.
- Light bounces off a surface at the same angle it strikes, like a snooker ball off the cushion. Ditto reflections. Use this when positioning reflector boards, avoiding reflections off glasses etc, or when bouncing off walls/ceiling.
 
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Than
HoppyUK said:
You're welcome Neil :)

Even though you'll have a big pile of shiny new kit, take it easy and start with just one light, one step at a time. You can do a huge amount with just one and it's often all you need (maybe with a reflector board) and learn a lot. Any more than that and there's a good chance you'll end up with a mess of conflicting shadows and not know how to fix it.

A few things to bear in mind:
- Even in multi-light set-ups, one light - the key light - will be doing the lion's share of the work. All the others compliment that and add different aspects, but are almost always subordinate. Treat each separately, eg background light, hair light etc - all doing different jobs on different areas. You'll find a flash meter helpful when it comes to setting-up multiple lights.
- The larger the light source, the softer the shadows. And size is relative to distance - move a softbox close for an almost shadowless effect, or pull it back to progressively harden the shadows.
- With studio lights, brightness falls off rapidly with distance - much more quickly than you might imagine. It broadly follows the inverse square law that says double the distance equals one quarter the brightness - a drop of two stops.
- Light bounces off a surface at the same angle it strikes, like a snooker ball off the cushion. Ditto reflections. Use this when positioning reflector boards, avoiding reflections off glasses etc, or when bouncing off walls/ceiling.
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Thanks again Richard.
I am currently on an Oil Rig in Nigeria right now and wont be home until the 16th Jan but will have the B1 kit waiting for me when I get home. I will look forward to posting up some pictures once I get home.......................Happy Christmas and a fantastic New Year to you and your family.
 
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