HSS - Who is using what

M

mike weeks

Suspended / Banned
Messages
4,881
Name
mike
Edit My Images
No
Not talking on camera flash used in either on or off camera flash but rather battery powered and studio lights.

I have tuned my Pocket Wizards TT1/TT5 to work with my Safari Li-Ion with a D800 and happily get 1/2000 and some subjects suit 1/4000

Be interested to hear what other trigger systems people are using.

Mike
 
treeman said:
Mike sorry I can't help your question, but I'd be interested to know how much flash power you loose when syncing at those speeds.
Click to expand...

Mark, the higher the sync speed the more you lose but that is why this is the 600w power is needed to start with - other issue is that it is by eye adjustments as flash meters can not meter these.

I have the use of one of the new iLux 600 watt units at the weekend and will be testing that out.

Mike
 
DSC_2085.jpg

Well new lights and getting 1/8000 of a second - a test shoot to see if they do what I need and looks like they certainly do :)
 
Last edited:
Very interesting, but can you clarify please?
Are you talking about the mode that fires flashes so close together that, in effect, it produces a continuous light (same principle as developed by Zeiss back in 1953)?
Or are you talking about a tail end sync hack, that utilises a long flash duration?

I've looked on the Photomart website, but don't understand the specifications listed there
• FP flash- FP is suitable for short distance photography, with the camera’s fast speed continuous shooting, you can capture the image of object with different moving speed, and you can select the different flash duration F1-1/11000, F2-1/9000, F3-1/6000, F4/-1/4000, F5-1/2000 according to requirement
Click to expand...

It doesn't say whether these flash durations are t.1 or t.5. If they are t.5 then presumably tail end sync would work at 1/2000th, assuming that 1/2000th is t.5. But it wouldn't work if the time is t.1
 
Garry,

if you read my initial posting it says that I tuned my TT1/TT5 triggers, something you do with long tail sync flash. If you have questions of Photomart it is probably best to send to them direct :) - my tests were using standard settings not any fancy modes.

I do not do electronic testing to calculate flash duration etc. by choice, but could if needed to, much prefer real world tests. This was an opportunity squeezed in at the end of a long day of dog agility and the site owners wanted us out quickly so not much time to finesse, initial tests were of my garden wall and that is not that an interesting image.

My understanding of what you have quoted is that because those lights from Photomart use IBGT technology what they have is a number of settings for short duration flash bursts that are used in the same way as the Lencarta Superfast, i.e. you have to rely on low ambient light and camera flash sync speed - the flash duration is just a matter of switching off the IGBT circuit earlier.

As the Mach-1N triggers are no longer available do you have any other way of getting high speed sync via long tail flash? I have some other triggers coming that I have purchased and seen results from Yongnuo so there are systems other than PocketWizard that can offer this and as we know some lights due to t.1 and t.5 timings are better at this than others.

Mike
 
I'm confused too. It's the terminology, and the lack of clear info on the iLux website.

High Speed Sync or HSS refers to rapid pulsing of IGBT-controlled flash units, creating an even brightness of what is effectively continuous light for the brief period of the shutter cycle, with a big loss of effective power.

Then there is Hyper-sync, and Pocket Wizard defines two flavours of that - Peak Hyper-sync and Tail Hyper-sync. Peak Hyper-sync is PW's unique technology that allows the camera's x-sync speed to be raised slightly (like half a stop-ish) with no loss of brightness. Tail Hyper-sync uses the long flash duration common to most studio-type heads most of the time, and all flash units at full power output. There's a big loss of brightness with Tail Hyper-sync, and exposure also varies significantly down the frame.

Mike appears to be using Tail-Hypersync, but if that's the whole frame of the dog shot we're seeing, uncropped, the evenness of exposure down the frame suggests ortherwise. Then there is this from the iLux site:
• Provides also extremely high-speed multiple flashes from 1Hz, 2Hz, …10Hzl, and MULTI-flash number can be adjustment 5, 10, 15, 20,
I'm not sure what this means. It could refer to a pukka HSS mode.

Back to the OP, Tail-Hypersync is easy to do with most triggers with a workaround hack using an optical slave. I've done it with at least four different types of triggers.
 
People appear to be reading things I have not said, at no point have I said what lights I used and I have explained what I did do.

I will happily link to a full frame image but that does not clearly show any fall off although what there is is minimal.

As an engineer I am more than used to seeing an expression have many different meanings to many people. If this is peak or tail I do not know, but I do know that it works.

As I said I used the PocketWizard to change the flash sync to allow me to shoot with non hotshoe lights at 1/8000 second.

Full sized image http://www.dorsetphotoevent.co.uk/aaa/DSC_2085_full.JPG
 
I'm just interested in learning Mike, which means the terminology, equipment and techniques are important :)

Your dog shot is interesting, thanks for linking to the full image. There is evidence of brightness fading up the frame but it's very slight, and did you have two flash units there? If this is tail hyper-sync, then it's quite possible that both lights are filling in the fading from the other, given that perfect sync of both lights and identical output characteristics are unlikely.

On your original question, I've mentioned the workaround hack for tail hypersync with various different triggers and an optical slave. Off the top of my head, apart from the PWs, only Phottix Odins can adjust the timing off-set to optimise this technique, with a firmware upgrade. They call it ODS - over-drive sync - just to add to the confusion http://flashhavoc.com/phottix-odin-nikon-adds-over-drive-sync-and-light-meter-use/

On the loss of brightness question with tail hypersync, obviously this rises in line with shutter speed, but it's worth noting that since the flash is behaving like continuous light, ambient brightness is also reduced in direct proportion with shutter speed too, so relative flash/ambient ratio remains the same.
 
gary996 said:
Is it not possible to use 2 flashes set at different times to fire. But of course a micro second apart or there abouts.
Just curious
Click to expand...

Normally any group of flashes firing off the same trigger signal should fire perfectly in sync, but with tail-hypersync technique unless both flash units are identical and set to the same power output, then the nature of the fading flash tail will change. That's what I meant.

In the past I've wondered if multiple guns with receivers having batteries of different power levels (new vs old) might fire at fractionally different moments but from tests I've done that's not the case and they all go off together in sync.
 
Richard,

I forgot that I only had one receiver with me so had to use the inbuilt sensor on the second head so was quite amazed to have them trigger together. This is not the first lights that I have attempted this with and I achieved a much better result with these lights. If I can dig out one of the shots of the wall I will as that shows how little loss of light there was and there remains the possibility that with a bit more tuning it could improve further still.

Mike
 
mike weeks said:
Richard,

I forgot that I only had one receiver with me so had to use the inbuilt sensor on the second head so was quite amazed to have them trigger together. This is not the first lights that I have attempted this with and I achieved a much better result with these lights. If I can dig out one of the shots of the wall I will as that shows how little loss of light there was and there remains the possibility that with a bit more tuning it could improve further still.

Mike
Click to expand...

The wall shot would be interesting too. To be clear then, the dog was done with two iLux Summit 600 heads, one triggered by the PW on a D800, and the other optical slaving off that? Both heads at full power? But regardless of the details, that's a pretty good result with tail-hypersync :)

I've done a lot of testing with this technique, and the results vary from very good to useless. I've posted a lot of it on here before, but a quick summary: the key to success is a powerful flash unit with a long flash duration. Something like the Lencarta Safari Li-on is a very good starting point, or most lower-end studio heads. At the other end of the scale, the Elinchrom Quadra with it's short-duration A-heads is hopeless for tail-hypersync, as you might expect, with very severe brightness fall-off up the frame (S-heads will be much better for this). Other things that help are a fast moving shutter, and the x-sync speed is a reasonable guide to that, and also fine-tuning of the exact sync moment as is possible with the PWs.

Also making a big difference is technique, such as keeping the main subject away from the top and bottom of the frame where fall-off is greatest, and another excellent trick is to turn the camera vertical and position the main light on the pentaprism side of the camera, and then use inverse square law fall-off from that light to counter-balance the fading tail of the flash. When everything is working together well, results are excellent.

BTW, as far as the varying exposure up the frame is concerned, shutter speed is irrelevant - if it works at 1/500sec, it will work at 1/8000sec. In fact, at the fastest shutter speeds, evenness up the frame is marginally improved.
 
HoppyUK said:
The wall shot would be interesting too. To be clear then, the dog was done with two iLux Summit 600 heads, one triggered by the PW on a D800, and the other optical slaving off that? Both heads at full power? But regardless of the details, that's a pretty good result with tail-hypersync :).
Click to expand...

Yes that is exactly the set up used, TT1 on D800 and TT5 cabled to first iLux Summit camera right and second on camera left triggered by inbuilt slave. Both heads on full power. Just used the clip on diffusers.

Mike
 
Thanks Mike :thumbs:
 
Just out of interest Mike, why did you want 8000th sec, is that needed for jumping dogs? (I've no idea BTW)

Interesting to note that you've lost at least, by my reckoning, 5 stops of light output from two 600W/s lights on full power with no mods.

I was really excited about high speed triggers when I first heard about them, only to soon realise, it was a bit of a con, certainly for my needs anyway.
 
treeman said:
Just out of interest Mike, why did you want 8000th sec, is that needed for jumping dogs?
Click to expand...

Answer is Mark that I would rarely use that speed however as it is potentially possible I wanted to test to see what is possible. What I might use is 1/1000 at something like Moto-X and if you can do 1/8000 then 1/1000 is easy enough. As the speed increases you do start to lose power but that is something that holds true for any light trying to sync at high speed - personally I reckon I was at full power at 1/1000 and it the halved with each increase in speed i.e. 1/2000 gave about half the power and 1/4000 about a quarter power.

Mike
 
Thanks for the wall pics Mike, but they're puzzling, eg it is unlikely to get increased fading up the frame just by using a faster shutter speed, though that is what's showing. As I mentioned above, if anything, higher speeds reduce fading very slightly. What may be happening is that you've adjusted the flash output in line with shutter speed, ie at 1/8000sec the flash is at full power, or close to it; and at reduced power with 1/2000sec.

Flash power setting makes a big difference to the evenness of exposure, and that's what PW's off-set adjustment is about. You can either have more brightness and increased fading, or lower brightness but more even exposure. You can't have both, and the relationship is not linear but varies quite a bit with power setting. Whatever off-set adjustment is chosen, it will only be optimum at one power output.

Are you also adjusting the aperture? If so, vignetting can skew the result too. For these kinds of tests, suggest using a higher f/number to minimise vignetting and adjust exposure with ISO rather than aperture if necessary.
 
treeman said:
Just out of interest Mike, why did you want 8000th sec, is that needed for jumping dogs? (I've no idea BTW)

Interesting to note that you've lost at least, by my reckoning, 5 stops of light output from two 600W/s lights on full power with no mods.

I was really excited about high speed triggers when I first heard about them, only to soon realise, it was a bit of a con, certainly for my needs anyway.
Click to expand...

Advocates of this technique do tend to rather over-egg it ;) But it's not new, and has never really gained popular favour because of the inherent limitations - big loss of power and uneven exposure. It can work well though, if you get a good grip on the technicalities and can work within those limitations, use the most suitable flash and camera, and do some tests to find optimum settings and employ appropriate techniques.

But beating bright sun, with decent sized softboxes, at realistic working distances - that needs a nuclear powered flash unit. IMHO, the best way of doing that is with studio-type flash and ND filters for static subjects; or for action, by ganging multiple speedlites (like eight!) in proper HSS mode. That delivers a good punch, with auto-TTL control too, and is actually not that unrealistic these days at Yongnuo prices.
 
mike weeks said:
I kept power the same and my thoughts are that when changing from 1/2000 to 1/8000 it might be identifying that a little more tuning could help. As I will most likely be working at 1/2000 then I am more than happy.

Mike
Click to expand...

Yes. The 1/2000sec example is an impressive result :thumbs:
 
mike weeks said:
personally I reckon I was at full power at 1/1000 and it the halved with each increase in speed i.e. 1/2000 gave about half the power and 1/4000 about a quarter power.

Mike
Click to expand...

I'd be interested to know if it was at full power, that's a potential game changer if it was. When you get a spare 5 mins Mike, maybe you could test it please. (y)

I suggest lighting a subject with your lights on full power, get the correct aperture/ISO at 250th and see if the exposure drops off as you increase shutter speed.

HoppyUK said:
But beating bright sun, with decent sized softboxes, at realistic working distances - that needs a nuclear powered flash unit. IMHO, the best way of doing that is with studio-type flash and ND filters for static subjects.......
Click to expand...

That's exactly where I'm at now, but even with 1200w/s packs I struggle at times!
 
treeman said:
I'd be interested to know if it was at full power, that's a potential game changer if it was. When you get a spare 5 mins Mike, maybe you could test it please. (y)

I suggest lighting a subject with your lights on full power, get the correct aperture/ISO at 250th and see if the exposure drops off as you increase shutter speed.



That's exactly where I'm at now, but even with 1200w/s packs I struggle at times!
Click to expand...
It must have been at full power, the flash duration at full power seems to be pretty long (going from the published specs, which aren't at all clear) and as this an IGBT it is obvious that at anything less than full power the flash duration would have been too short for the shutter to cycle.
 
I may have misunderstood, and I realise he was on full power setting, but I thought he meant he was also getting the full 600w/s of light, the same as he would if he'd been on normal sync speed.
 
Garry Edwards said:
It must have been at full power, the flash duration at full power seems to be pretty long (going from the published specs, which aren't at all clear) and as this an IGBT it is obvious that at anything less than full power the flash duration would have been too short for the shutter to cycle.
Click to expand...

Oops! I forgot that small fact in my previous reply LOL
 
Pocketwizards and SB900/910s are just a killer combination up close in bright sun.
 
You must log in or register to reply here.
Back
Top