Pixel King Hypersync Results!!!

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Michael
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#1
I just thought I'd share some samples of my Hypersync tests using Pixel King triggers and my battery strobe Jinbei Discovery 1200

After reading a few posts on this forum regarding hypersync, I decided to give it a test...My main driver was being able to use flash with wide F stops outdoors. I was Looking into Vari ND filters and single ND filters to achieive this look, until i stumbled on the posts explaing Hypersync with manual (studio) strobes.

the pixel king transmitter is placed in the Hotshoe as normal, the receiver is connected using the pc port to 3.5mm jack into the power pack.

upto 1/250th Shutter everything is working normal, I am able to get direct flash F11 at about 10ft from subject at 2/3 power about 500w/s :):)

So then you increase the shutter speed past Max sync and at the same time open up your F stop the compensate ( as you would do with an ND filter) as guess what, the same (actually slightly better) flash/ambient ratio and coverage...:) now this is all the way to 1/8000th shutter.:eek::eek:

as long as you compensate for each stop of shutter increase by opening the aperture the same stop, you get exactly the same exposure.

so 1/250th @ F11 is the same output as 1/4000th@ F2.8

example screen grabs below, SOOC.
if you look closely as said, you actually gain about 1/3 stop more efficiency out of your strobe......

I did try this at each power setting on the strobe pack, and got the same results at minimum power and Max power:)

I am blown away by this technique, thumbs up for Pixel Kings..!!!



 
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Ben
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#2
Does this imply that the Discovery has a very short flash duration? Surely if the subject exposure is the same then the strobe emitted the same amount of light in 1/4000s as in 1/250s?

Or am I talking a lot of rubbish?
 
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Garry Edwards
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#3
Does this imply that the Discovery has a very short flash duration? Surely if the subject exposure is the same then the strobe emitted the same amount of light in 1/4000s as in 1/250s?

Or am I talking a lot of rubbish?
No, it implies that we have someone passing off a tin of chopped ham and pork and sticking 'useful information' on the tin
 
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Mike
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#5
Does this imply that the Discovery has a very short flash duration? Surely if the subject exposure is the same then the strobe emitted the same amount of light in 1/4000s as in 1/250s?

Or am I talking a lot of rubbish?
No. The triggers are syncing the shutter-window to the tail of the flash-pulse, which means that most of the peak energy was dissipated before the shutter even opens. The colour balance may be off that way. Depending on your application it might still be useful.

If it was a real sync, the flash exposure would increase when you open up the aperture.
 
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Richard
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#6
Does this imply that the Discovery has a very short flash duration? Surely if the subject exposure is the same then the strobe emitted the same amount of light in 1/4000s as in 1/250s?

Or am I talking a lot of rubbish?
No, it implies the opposite - that the flash duration is long enough to emit light throughout the full cycle of the focal plane shutter. That remains fairly constant at higher speeds, say 3-4ms, 1/250sec-ish.*

There are two kinds of hypersync - peak and tail, and they are totally different. This is tail hypersync and I've never had much success with it. Power is greatly reduced, and the light is very uneven down the frame as the brightness of the flash tails off, and the colour can change a bit too.

This is not a very convincing demonstration. What is needed is shots of a plain wall, at full power on normal max x-sync, with exposure noted. Then a series with the shutter speed progressively raised, to see how the exposure is reduced and unevenness changes.

* slow-mo vid of Canon 5D2 shutter working, showing timings http://www.youtube.com/watch?v=ptfSW4eW25g
 
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#7
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Ben
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#8
:eek: so much to learn!

Thanks Cistron & HoppyUK for the insight, looks like I need to do some proper reading about hyper sync. So what would be the advanytage of a very short shutter speed and a large aperture? Freezing subject + well exposed background?

Regarding colour temperature, I assume this is something to do with the way light is generated in the flash tube itself, and depends on the energy in/out?

I'm really embarrased to admit that I've been shooting SLRs for the last 8 years, and never heard about a focal plane shutter until I saw that youtube video. I always assumed the mirror flipping is the shutter. :banghead:
 
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#9
:eek: so much to learn!

Thanks Cistron & HoppyUK for the insight, looks like I need to do some proper reading about hyper sync. So what would be the advanytage of a very short shutter speed and a large aperture? Freezing subject + well exposed background?
You need high shutter speeds to use flash outdoors, or with low f/numbers for shallow DoF effects. Both situations natually push the shutter speed above the normal x-sync ceiling of focal plane shutters (usually around 1/200sec, all DSLRs have them).

There are a few ways around it, mainly high speed sync which works wonderfully if you can manage the substantial loss of effective power. Or you can push the shutter speed back down with ND filters, but it's not very convenient.

The tail-hack method described above is another trick, but has too many downsides for my liking.

Regarding colour temperature, I assume this is something to do with the way light is generated in the flash tube itself, and depends on the energy in/out?
Yes. The flash pulse starts out quite blue, then gets more neutral, but becomes noticeably yellow as the light tails off. Not usually much of a problem TBH. Then there is the difference between hot-shoe guns (that use IGBT control to cut off the tail) and studio heads. Depends how deep you want to go into this stuff.

I'm really embarrased to admit that I've been shooting SLRs for the last 8 years, and never heard about a focal plane shutter until I saw that youtube video. I always assumed the mirror flipping is the shutter. :banghead:
In normal picture taking, the type of shutter, or how it works, is neither here nor there really. But when it comes to flash, it's vital.
 
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Garry Edwards
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#10
Accuse me of being cynical but...
3 things are clear from the example photos.
1. The flash isn't contributing much in the way of light in either photo, which is a bit surprising given the statement that
upto 1/250th Shutter everything is working normal, I am able to get direct flash F11 at about 10ft from subject at 2/3 power about 500w/s
- well I make that about 800Ws not 500Ws. In my experience at a distance of the claimed 10' the contribution of the flash alone should produce a correct exposure of about f22.5, not f/11 - that's a massive difference.
2. The flash head has clearly been moved between taking the 2 shots - why?
3. I can't see the expected shift in colour temperature between the 2 shots. In the second shot, there should be a marked shift towards yellow/orange that isn't apparent to me, and it should of course be very visible and it should only be visible on the front part of the subject, lit by the flash.
 
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Michael
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#11
Hi all,

Just too address some issues, The 2/3rds power was just from channel A only which gives 800w/s at full this was set at 3.0 so i suppose it was more like 200w/s...sorry for the confusion.

the ambient was about 1 stop below true exsposure ( this is the kind of setting I would use when shooting with flash outside.

the flash head wasn't moved between shots, this would defeat the object of the comparison..?? why do you think it was moved gary.?

As for the colour shift, I not as well up on the tech side as you guys, so I cant comment on that.

HoppyUk, you mentioned a different style of test, against a plain wall.? i can do this if it helps with the conclusions.?

Cheers Guys.
Mike
 
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#12
Hi all,

Just too address some issues, The 2/3rds power was just from channel A only which gives 800w/s at full this was set at 3.0 so i suppose it was more like 200w/s...sorry for the confusion.
Then that's about 530Ws not 200Ws and the aperture should be around f/16 d 8, not f/11 - still a massive difference, unless of course you were way out with your estimation/measurement of distance.

the flash head wasn't moved between shots, this would defeat the object of the comparison..?? why do you think it was moved gary.?
Because the shadow is in a different place



Cheers Guys.
Mike[/QUOTE]
 
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Michael
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#13
Then that's about 530Ws not 200Ws and the aperture should be around f/16 d 8, not f/11 - still a massive difference, unless of course you were way out with your estimation/measurement of distance.

Because the shadow is in a different place



Cheers Guys.
Mike
[/QUOTE]

I think your taking the 2/3rds power too literal, I was thinking 3.0 on the display was 2/3, but seeing as 5.0 = 800w then I'm thinking 3.0 would be 200w, same logic as safari li-on.

The shadow hadn't changed, I was hand held, so the angle has slightly moved.

Thanks mike
 
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Richard
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#14
Hi all,

Just too address some issues, The 2/3rds power was just from channel A only which gives 800w/s at full this was set at 3.0 so i suppose it was more like 200w/s...sorry for the confusion.

the ambient was about 1 stop below true exsposure ( this is the kind of setting I would use when shooting with flash outside.

the flash head wasn't moved between shots, this would defeat the object of the comparison..?? why do you think it was moved gary.?

As for the colour shift, I not as well up on the tech side as you guys, so I cant comment on that.

HoppyUk, you mentioned a different style of test, against a plain wall.? i can do this if it helps with the conclusions.?

Cheers Guys.
Mike
Yes, that would be interesting to see. More a different kind of subject than a different test.

It needs to be flat surface, so everything is same distance from the flash, and a plain tone filling the frame to reveal the light fall-off and colour shift down the tail. Basically, a wall. The image will start brighter at the bottom of the frame, and get darker and warmer towards the top.

Then we need to know the exposure settings to compare the light loss against normal x-sync at full power.

Thanks.
 
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Cliff
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#15
Garry, I don't think the shadows in a different place, but you see the edge of it as the OP seems to have moved position slightly.
 
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Garry Edwards
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#16
Garry, I don't think the shadows in a different place, but you see the edge of it as the OP seems to have moved position slightly.
Look again. On the wall to the right, right at the edge of the photo, is something that is in shadow in the first photo and which is lit in the second one.
That has to be a product of a change to the position of the light, not a change to the position of the camera.
 
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Michael
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#17
I assure you, the light Did not change position between frames, I took approx 10 frames with various compositions during the test...it must be a product of light fall off or a difference in flash exposure....:)

I'll do another test tomorrow as suggested by HoppyUk.:):)
 

simon ess

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#18
Garry - first of all, thanks very much for your tutorials on the Lencarta blog. Excellent.

I very much respect your experience and use of light.

In this matter, however, I think you're wrong. Look at the tree behind the area you're talking about. If you were to crop the tree in the second shot to match the first, the shadow would be in the same place relative to the first.
 
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#19
I assure you, the light Did not change position between frames, I took approx 10 frames with various compositions during the test...it must be a product of light fall off or a difference in flash exposure....:)

I'll do another test tomorrow as suggested by HoppyUk.:):)
Cheers Michael, thanks.

Just to keep everybody happy, camera/tripod and flash/stand ;) And low ambient, so it's just the effect of the flash we're seeing (y)
 
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#20
Garry, I've looked again and whilst I fully respect your knowledge in lighting etc. I
think you may be wrong on this, with regards to the shadow, as Simon has said.
 
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Garry Edwards
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#21
Garry, I've looked again and whilst I fully respect your knowledge in lighting etc. I
think you may be wrong on this, with regards to the shadow, as Simon has said.
I don't think so. The flash exposure level in the second shot is substantially higher than in the first but I don't think it explains the amount of light that's visible on that item on the top of the wall.

But let's not argue about it, if the OP carries out a test as suggested by Richard, all will be revealed.

I've seen these tail end flash usage shots before. One of Lencarta's customers very kindly did some detailed tests with the Lencarta Safari and PW AC3 on a Canon ID Mk1V. It worked at all shutter speeds, right up to 1/8000th although the results were a bit strange between 1/4000th and 1/6000th, but the same tests carried out with his 5D Mk11 started to show the shutter curtain at 1/750th.

As Richard has said, the results can be disappointing. Inevitably there is substantial loss of light, but there is also a very uneven exposure. It can 'sort of' work with a busy shot, but not on one that shows up uneven exposure, which can easily be up to 4 stops.

Really, the only way to get decent results is to use a really fast shutter speed on a camera with a between lens shutter, which AFAIK means a Hassie
 
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Michael
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#22
Well I woke up to find it raining today, so I have done an indoor test against a fairly plain wall in the house.

The first set of images are at minimum power so 1.0 on the display of the strobe
camera settings 1/250th @ f4 gave me exsposure without too much blow out.

I'll post all the results over 4 posts, so as not to bombard everyone..:)

1st set is just ramping up the Shutter.

Here goes..







 
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Michael
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#23
Minimum power, this time compensating for the shutter increase by increasing ISO to match, as I could open up the aperture low enough for the whole range.







:)
 
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Michael
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#25
And finally the test I originally wanted to try, high power from strobe full from channel A - 800w/s with a base exsposure of 1/250th @ f22
then being able to open up the aperture to acheive a more shallow depth of field, hopefully negating the use of a variND.

Base image and then increase shutter speed to compensate for opening up Fstop.....








Thoughts from everyone..?

Cheers Michael.
 
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Mike
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#26
this time strobe at full power channel A 800w/s, just increasing the shutter speed upto 1/8000th
[snip]
:)
As Richard predicted, here it becomes apparent that the exposure is uneven. The "hotspot" at 1/250 is at the top of the frame, while it moves towards the bottom past the x-sync speed.

Now you've got evidence :)
 
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Ben
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#28
I don't think the op ever claimed that the results at 1/4000 were perfect. Obviously not suitable for a photoshoot for Vogue, but they seem usable enough for certain real world conditions, at least to me!
 
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Richard
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#29
Thanks Michael. Looks like a (qualified) success :)

The shots that are missing are the 'control' images taken at normal x-sync full power, so we can compare the exposure levels, fall-off and colour. From your settings it looks like that might be too bright to shoot, but what does a flash meter say? And what kind of modifier are you using, at what distance? If it's a standard small dish reflector used close, that will inflate the readings a lot.

Even coverage doesn't look too bad for this kind of thing, nor the colour shift. That varies not only between flash units (this one must have a very long flash duration!) but also with cameras and the travel time of their shutters (you using 5D2?) and the exact sync timing that decides which part of the tail you get. Can you adjust the timing with the Pixels, like you can with PWs?

It's hard to see from these shots, but roughly two stops fall-off top to bottom? Maybe a bit more at the extreme edges, but quite a lot less around the middle. Not acceptable for critical work, but with a benign subject in the centre, and ambient light filling in around the edges, it could work.

The big question though is, is there enough power to beat bright daylight? That's the main reason for needing high shutter speeds with flash, and the answer to that would seem to be a qualified yes - though we don't know what modifier was used or the distance, and there would be more light lost shooting outdoors.

Take image 5881 with settings of 1/2000sec at f/8 with iso100, and compare to the Sunny 16 rule (1/100sec at f/16 with iso100) and you'd be two stops above that. There are a few ifs and buts to consider, but that looks like it's workable. I'd say a bit of a result :)

Edit: Still think I'd rather do it with an ND filter ;)
 
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Ben
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#30
What are the advantages of the ND filter approach? An ND filter stops down the light irrispective whether its flash or ambient. Is it just so that you can use larger apertures, or it's again something to do with flash durations?
 
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Michael
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#31
HoppyUK, looks like my sunday morning may have unearthed some questions eh.?? haha.;);)

I was using my Canon 50D for the test, so the native sync speed shots are both of the 1/250th frames at f22 and f4

The Flash was using the standard reflector direct from about 8ft away. so with the shot being exposed 2 stops above middle grey, suppose i would be looking at an exposure of f32ish..? at 800ws, there is the option of combining Channel A+B, this would give 1200ws

I would think that is more than enough to overcome ambient, even through a shoot thru brolly.:):)

Another discovery seems to be more flash efficiency once your into hypersync speeds and compensating by opening the aperture, I do feel you are gaining an increase in flash power by 1/3 or 2/3 stop compared to normal max sync of 1/250th:shrug::shrug:

I did a quick test the other day with the 5d2, and was getting similar results as with the 50D, I do think this is a great way of using an open f stop outside, without the use of ND's, but without the total accuracy of coverage.

Michael(y)
 
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Michael
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#32
What are the advantages of the ND filter approach? An ND filter stops down the light irrispective whether its flash or ambient. Is it just so that you can use larger apertures, or it's again something to do with flash durations?
From my understanding, with strobe/flash use outdoors, it is to allow wider apertures while remaining within your camera's sync speed.

Im fairly sure is doesn't have anything to do with the flash durations.
 
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Mike
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#33
An ND filter stops down the light irrispective whether its flash or ambient. Is it just so that you can use larger apertures
Correct. For the exposure it doesn't matter whether the light is "eaten" by the aperture or the ND filter. So if your flash/ambient level is fine at f/16 1/250, it will be equally fine at f/5.6 1/250 with 3-stop filtration.

edit: ahhya, should have flipped to page 2...
 
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Richard
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#34
What are the advantages of the ND filter approach? An ND filter stops down the light irrispective whether its flash or ambient. Is it just so that you can use larger apertures, or it's again something to do with flash durations?
The three ways of managing high ambient light or low f/numbers, and therefore high shutter speeds, with flash, are:

- High speed sync. Works perfectly, fully integrated with auto-TTL metering, but big loss of power so only works at close range and you can forget overpowering the sun.
- Use an ND filter to push the shutter speed back down below x-sync ceiling, restoring full power of the flash. If you don't need more than two or three stops of ND, this works well.
- Tail-hack hypersyc. Problems of light loss and uneven exposure are reduced by a) having a very powerful flash studio type flash head, b) with a long duration, and c) camera with a higher x-sync speed and therefore fast travel time to minimise fall-off. Unusually, the OP has all of these.

If you want both high shutter speeds and big power in a mobile package, you need to throw money at it. Like this guy with an eight-gun rig firing in HSS mode http://www.youtube.com/watch?v=xNDAINwhTWU
 
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Michael
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#36
dont want to beat this one to death, but just for comparison i did a quick test using my Canon 5D2.....just for information for full frame users.:)

base shot with no flash, then 1 version at normal Max sync 1/200th using the flash as fill light.
and second using tail hypersync to allow shallow D.O.F
again, im happy with the real world results of this.:)







Michael
 
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Richard
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#37
Thanks Michael.

Flash distance, modifier, power setting?
 
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Michael
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#38
No probs, distance 8ft, direct flash with normal small reflector and power.... whatever I needed to fill the ambient shadow to F10, I think around 150 -200ws. thats about 2.5 - 3.0 on the power scale.

and I promise, No more shots of my garden bushes...;);)

Michael
 
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Garry Edwards
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#39
No probs, distance 8ft, direct flash with normal small reflector and power.... whatever I needed to fill the ambient shadow to F10, I think around 150 -200ws. thats about 2.5 - 3.0 on the power scale.

and I promise, No more shots of my garden bushes...;);)

Michael
I think you may be a bit confused about the power settings on your flash...
With the head connected to socket A and without all of the power directed to socket A, it will produce 800Ws at power setting 5 - so 2.5 on the power scale will equate to 400Ws, not 150 - 200.

There are no real rights or wrongs with photography, but a more normal arrangement might be to expose the foreground (lit with the flash) correctly and to have the background underexposed, rather than the other way round as you have done.

Generally, we use natural light to light the background and flash to control the lighting on the foreground.
 
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Richard
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#40
No probs, distance 8ft, direct flash with normal small reflector and power.... whatever I needed to fill the ambient shadow to F10, I think around 150 -200ws. thats about 2.5 - 3.0 on the power scale.

and I promise, No more shots of my garden bushes...;);)

Michael
Thanks for that.

Just doing a bit of rough mental arithmetic, it looks like your ambient exposure is close to Sunny 16, so with the flash at full power you have a good chance of beating it there.

But only just. Although the flash contribution is very evident, it's still fallen short of wiping out the shadow cast by the sun to the left of the planter. The difference in flash power needed for a good dose of fill-in (which is only really lifting the shadows) is a lot less than the power needed for the flash to also provide bright highlights.

But it looks like you have a good chance there. All I can say is, that flash must have a very long duration, like 1/200-1/300-ish. Not a t.5 time, but in terms of an equivalent shutter speed (confident guess ;)).
 
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