[BruceBanner]

Stop your lens down more dammit! that will prevent the modeling light from adding to the exposure. But that will also attenuate ambient light which you might also want to capture.





This might seem obvious, did you try just staying in manual and use the green button?





The more convoluted things get for an on location shoot the higher the probability that things will go wrong.

Yes my small test in my house last night is not exactly enough to say whether in real life event the modelling light would contribute to the shot or not, I pretty much just made up some camera settings and tested, but indeed the modelling light of the V1 contributed to the shot (and it has it's own unique warm tone unlike a cool flash, so it kinda looks 'mixed' lighting). I just wanted to see if I could get away with a weak flash shot and have no modelling light recorded in the shot, because if that was the case with a weak amount of flash going off then for a real event it would probably be nothing to worry about... but I'm not so sure now.

I could like you say stop down more and try and prevent the modelling light from adding to the exposure, but I never know what kind of environment I might be shooting in in the future, if I decide a certain mix of ambient and flash is giving me the look I want and to deviate away from that just to get rid of the recorded modelling light then that's less than ideal.

I use up all 5 User Modes currently, my Av mode is a pretty 'strict' Av mode compared to how many other users may have their Av mode set up (specific attention is given to the lower and upper Auto ISO levels as well as the levels used (Fast or Slow etc), and often the ISO is locked, so often it's only the shutter that is varying. I actually use X Mode more for studio work and product shots as the Live View shows a constant 'good for viewing' exposure on the back of the screen (regardless of the camera settings being used), it's just my Manual Mode in this instance is bound for different tasks (manual focus glass that doesn't work in Av mode for example). Green Button is set to Tv shift etc already, it just seems that I think for these kind of shots I may have to bail out of Av and into Manual as it will be the lesser of two evils. Either I create a new User Mode for it, or stay in the Av Mode that I am in (User Mode 1) and just make a mental note of the settings and quickly change it to Manual for the Exposure mode and redo the settings that were working.

As convoluted as this is it's probably the lesser of two evils, what's worse is the getting missed focus shots or having people getting over posing for a shot, they just want in and out of the shot to continue partying!

Another thing that occurred to me. For these posed shots I quite often use Face Detection, just because I'm kinda lazy (I would say not lazy but just exploiting the camera for all of it's benefits ). I believe the AF Assist from the camera and the trigger really only reach out to a small centre point area, it's intended I think for Spot focus. This would also add to the failure rate as Face Detection continued to struggle to find a face even when the Assist was coming on because my framing might have their torso's centre and heads a little higher.

These shots for example were done earlier in the day, example EXIF

Av Mode
-2.7EV
1/60
ISO 200
f2.8
(same set up as ballroom, AD200 in a 80cm octobox next to me)





Face Detection had no problems here as it was plenty bright enough.

I definitely think relying on AF assist in future is a mistake, it's too central for the kinda framing I might have, and at f2.8 it will result in soft shots if locking onto a big beer belly! ahahah

Looks like I need to work out the V1, see how I might be able to exploit its modelling light to help with Face Detection focus whilst perhaps dishing out some fill light (better catchlights maybe?) and trigger the key AD200. @morenjavi I'll let you know how that goes.

I'll follow the thread too, as I plan to buy the V1 in one or two months. My idea is to use V1 on camera, TTL mode, controlling other flashes.



As far as I know, the fresnel head, that is the head with a modelling light inside, doesn't have levels. I only know an accesory for the AD200 with modelling light and levels: the AD-B2. It has a quite bright led inside with power levels (100%-50-25-OFF), but I think this option can be discarded: this thing weighs almost a kilogram, and the leds drain a lot of battery (also levels can't be controlled remotely, just switched ON/OFF).
I think that the AD400 have a setting that disable the modelling light just when you shoot, but I'm afraid the AD200 is less sophisticated.

I have the AD-B2 head, it's usually permanently attached to my BD, so yeah maybe that modelling light might be enough. As I said, I wasn't really planning to cover this event, and was using more light 'running and gunnin' equipment than proper set up. I have yet to buy a proper softbox with a Bowen type rear connection (like what a BD has), all my current softboxes are just the simple umbrella type. I have the 3 westcott 7ft umbrella's which I love, they are light and simple to set up quickly, the shoot through would be the only one I think that the AD-B2 would face the right direction for some direct modelling light so I might try that, or it could be the reflector umbrella's would bounce enough back around the place to help with AF.

Cracking a 7ft umbrella at an event might be a bit ridiculous tho... it would have been ok for where I was that night (large indoor ballroom) but I can imagine other events not so good.

If any of you have good softbox advice I'd love to hear any recommendations for a decent new 80-120cm softbox solution. What I have discovered is that when I do events I either hold the ocf or have it on a stand right next to me (foot on stand leg to keep it stable). This pretty much means I'm using a FA43 for a lot of the shots because it gets me close enough to the portrait shot where the quality of light is not so harsh. I could not for example use the FA77 as easily because I would have to step back with the light stand (or hand holding) and therefore the distance is increased between the subject and light, and its not as pleasing. Of course there are times I leave the stand near the people, but often that cannot be done (drunken people walking around close by, or wind etc). So I guess what I am looking for is a portable large modifier that can stay with me that might get a decent soft light onto the subject when using an FA77. Would a deep octa be the thing to aim for?

PS I also have the EC200, thinking about getting a second one. For the dancing shots later in the evening I tether the AD200 onto my body harness, EC200 then runs from the AD200 up to the camera where it sits on my XT2 trigger. You have a cable about your person, but the set up is pretty comfortable (better than flash bracket imo which I have been there and done that), and you have the power of an AD200 on camera effectively, which is super brill for fast recycle times etc. It might be that I will run two EC200's up to a AD-B2 to the softbox and have the AD200's hang off my harness/person. I would have plenty power for runnin' & gunning', I think it's just about picking the right softbox to get that beautiful FA77 out for more playtime

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Last edited by BruceBanner; 01-22-2020 at 01:44 PM.

[rogerstg]

Maybe you could use a rechargable desk lamp like this, on a table, pointing at the posing area, with just enough light for AF to work. The light is dimmable and the color temp selectable.

[Digitalis]

I definitely think relying on AF assist in future is a mistake

If you were a student of mine, I would caution against reliance on Autofocus and encourage you to develop proficiency with manual focus. I personally use manual focus for just about everything I use AF when I need to work really quickly, or the subject is in constant motion and even in those situations I typically use the center AF point* and I recompose as needed, with occasional focus tweak to compensate for field curvature if it is present.


* That is with Pentax and Leica AF cameras. With my Canon and Nikon DSLRS with considerably more advanced autofocus modules I am confident in using more complicated AF settings.

[BruceBanner]

If you were a student of mine, I would caution against reliance on Autofocus and encourage you to develop proficiency with manual focus. I personally use manual focus for just about everything I use AF when I need to work really quickly, or the subject is in constant motion and even in those situations I typically use the center AF point* and I recompose as needed, with occasional focus tweak to compensate for field curvature if it is present.


* That is with Pentax and Leica AF cameras. With my Canon and Nikon DSLRS with considerably more advanced autofocus modules I am confident in using more complicated AF settings.

I am a student of yours, cyberly

I tried using manual focus for those specific shots, not possible, the people are silhouettes, looking through the OVF was like looking into the void! Live View was no better, I entertained the thought of jumping into X Mode because it's Live View keeps a constant well lit exposed screen for which to see wth is going on... but that would take me from a shutter speed of 1/6th with an ISO of 800 to what... 1/90 minimum with whatever horrid ISO would accompany that (to keep the ambient at the levels I wanted). This was really a difficult scenario from which solve on the night, bit of a damned if you do damned if you don't affair.

I am very comfortable with manual focus and its actually my main 'go to' as well. In fact I'm so serious about manual focus I have a Canon S Type focusing screen en route for the K-1, anything that assists with manual focus at this time trumps AF use. When I do weddings I use manual focus around the ceremony, deliberately to keep the AF noise down so that the FA77 doesn't spoil the mood

Anyway, here's some Manual Focus 'proof';

(spot the lensbaby shots at the wedding )
Eddy Summers - #wilsonyoumarryme2019

All shots with the Takumar 50 (8E)
Eddy Summers - almosthogmanay

And all the dance shots from the recent Lady Luck event were manual focus;
Eddy Summers - lady luck 2020


It was a first for me, to actually find myself snookered for using manual focus. Don't underestimate those shots I opened up this thread with how dark it was, the room wasn't exactly bright itself and I was -2.7EV, that's dark...

[Aaron28]

seems you have had this problem before.....

Force Flash Units to Always use their own LED AF Assist? - Page 2 - PentaxForums.com

[BruceBanner]

seems you have had this problem before.....

Force Flash Units to Always use their own LED AF Assist? - Page 2 - PentaxForums.com

Kinda... in that scenario I was using Cactus and not Godox, but now the issue is that I think in certain scenarios (like I faced in the ball) AF Assist is just to local (centre point of AF frame only), lazy to activate (camera wants to try natively on it's own first, fail and then give in to using it), and basically overall the experience is not ideal.

As someone else pointed out (here or elsewhere) Nightclub shooters experience a similar problem. They are wanting to balance their flash with a very low ambient light to the point that the people being snapped are also silhouettes. AF Beam (from trigger or camera) may or may not come on but could also be ill placed (too central) depending on lens attached.

It seems to really resolve this once and for all I need to get some kind of modelling light going, either LED on its own that has dimmer control or a V1 or something...

Stay tuned...

[Digitalis]

Or you can buy a small dimmable battery powered continuous light and use it instead of flash.

Something like the Aputure LS mini, I know small video production studios and youtube streamers that use these small, powerful and highly controllable lights.

[sbh]

Looking at your sample shots, even at f4 the dof is quite deep due to the wide angle. Prefocus or manual focus + focus confirm might be worth a thought. It could be more accurate and quicker than a hunting af.
On the final image it looks easy because it's well lit, but on location it can be quite a challenge.

[Aaron28]

It seems to really resolve this once and for all I need to get some kind of modelling light going, either LED on its own that has dimmer control or a V1 or something...

maybe but believe modeling is to see how light falls n shadows etc not necessarily for AF as I understand (don't really know).....also modeling is a strobing effect of bright flash maybe not the best thing to have going off during an event effecting whatever dim room but maybe it does not do that.....seems maybe the 'flashlight' might be more isolated

even at f4 the dof is quite deep due to the wide angle. Prefocus or manual focus + focus confirm might be worth a thought

would think this best as an 'X' where to stand is placed and in the effective or set up 'flash area'........24mm @ f4 at a distance of 8 feet has a dof of 10 feet but any wider or further that dof expands immensly.....do not know how close or far you are...not given also it is highly unlikely the camera was on a tripod at a specific distance and it occurred to me that maybe SR do not do 'it's job' at the rather slow speeds you were shooting at affecting what maybe in focus but oof from motion blur......yes flash freezes action but if it's moving the same time reckon blur could occur........it does seem in the particular case of these portraits in set area preset focal distance would be quite effective...…

different story for floating around a room and the distance will vary greatly and of course shooting something wide open f2.8-f1.4 where AF assist would be greatly appreciated......if center point is effective maybe an easy solution is to compose with cropping the composition you want instead of trying to get lock on something far left, right whatever

[Digitalis]

this best as an 'X' where to stand is placed and in the effective or set up 'flash area'........24mm @ f4 at a distance of 8 feet has a dof of 10 feet but any wider or further that dof expands immensly

Not a bad suggestion, in cinematography focus pullers often use this method to instruct actors where to stand and it gives them an approximation of where to hold focus. I have used this method myself in portraiture with my large format cameras, DOF can be extremely shallow with an 8X10 camera I usually have a chair or marker as an indicator of where I want the model sitting/standing.

[BruceBanner]

Looking at your sample shots, even at f4 the dof is quite deep due to the wide angle. Prefocus or manual focus + focus confirm might be worth a thought. It could be more accurate and quicker than a hunting af.
On the final image it looks easy because it's well lit, but on location it can be quite a challenge.

maybe but believe modeling is to see how light falls n shadows etc not necessarily for AF as I understand (don't really know).....also modeling is a strobing effect of bright flash maybe not the best thing to have going off during an event effecting whatever dim room but maybe it does not do that.....seems maybe the 'flashlight' might be more isolated



would think this best as an 'X' where to stand is placed and in the effective or set up 'flash area'........24mm @ f4 at a distance of 8 feet has a dof of 10 feet but any wider or further that dof expands immensly.....do not know how close or far you are...not given also it is highly unlikely the camera was on a tripod at a specific distance and it occurred to me that maybe SR do not do 'it's job' at the rather slow speeds you were shooting at affecting what maybe in focus but oof from motion blur......yes flash freezes action but if it's moving the same time reckon blur could occur........it does seem in the particular case of these portraits in set area preset focal distance would be quite effective...…

different story for floating around a room and the distance will vary greatly and of course shooting something wide open f2.8-f1.4 where AF assist would be greatly appreciated......if center point is effective maybe an easy solution is to compose with cropping the composition you want instead of trying to get lock on something far left, right whatever

Not a bad suggestion, in cinematography focus pullers often use this method to instruct actors where to stand and it gives them an approximation of where to hold focus. I have used this method myself in portraiture with my large format cameras, DOF can be extremely shallow with an 8X10 camera I usually have a chair or marker as an indicator of where I want the model sitting/standing.

I only uploaded the focused shots. I gave up on some of the Face Detection and used AF Assist with centre spot but I noticed that the faces were noticeably less sharper (because the chest/breast might be in focus and the face further back), which even for f4 surprised me (due to being quite close to them). Moving further back may or may not be an option but these things all alter the way the photo can look, moving back and increasing subject difference may increase DoF plane but it comes at a price. No.. I really feel I must have the optimum focus placed in the right spot, not an approximation. Manual Focus proves to difficult in low light, the only mode that would succeed for that would be X mode which presents a properly exposed LV screen at all time, but then I am limited to 1/90 as my lowest shutter speed, too high.
I had an X on the carpet and people drift off it, dancing on it, are a little tipsy, an X can only ever serve as a basic guideline etc. Basically if it was studio and controlled manual focus might be ok, but I can see that even f4 focus was an issue when selecting their torso instead of face. And this was with a 12-24/4, if I wanted to use a 28/2.8 then my margin of error is less.

Basically this scenario I found myself in was drifting very close into Nightclub photography where many users have suggested a modelling light or LED light something to help AF is best.

Due to the festivities of this weekend I won't be testing much out, but it seems that to replace the Xpro trigger with a V1 (which I already have) and use it to control the AD200 and also provide modelling light would be the most sensible option to get around it all. It just seems to be a question of whether the ambient modelling light is recorded or not in the final shot, it seems to be something that might occur if the key flash is very weak, but not if powerful enough. Also it's not too hard to toggle it on and off from the hotshoe in the camera if I feel that it does interfere.

Or another option, some kid of small LED light as suggested to assist with AF lock, I have an X2T trigger as well which has a coldshoe so I might be able to fashion a small thingy to hold a light LED on top of the trigger.

Modelling lights are indeed to analyse shadow fall off. I have noticed they can be very generic tho, I have for example used a snoot with one of my V1's and discovered where the actual flash light falls from the shot can be quite a different height to where the modelling light is showing, so I think of it as 'ballpark' lighting help. Modelling light does not strobe, just continuously on.

[Aaron28]

even f4 focus was an issue when selecting their torso instead of face. And this was with a 12-24/4, if I wanted to use a 28/2.8 then my margin of error is less.

if focus is locked on their torso and you are at 24mm f4 and 5 feet away their head would hafta be 2 feet away from their torso to be oof because the focal plane is 3 feet wide......given the slow shutter speed maybe slow sync or rear/2nd curtain sync is needed.....as the flash is more than done it's job at the beginning of a 1/6 sec exposure and light is still being recorded creating motion blur distorting the image.......even if you used a 28mm @ f2.8 at 10 feet away there is 6 feet of what will be in focus

[BruceBanner]

if focus is locked on their torso and you are at 24mm f4 and 5 feet away their head would hafta be 2 feet away from their torso to be oof because the focal plane is 3 feet wide......given the slow shutter speed maybe slow sync or rear/2nd curtain sync is needed.....as the flash is more than done it's job at the beginning of a 1/6 sec exposure and light is still being recorded creating motion blur distorting the image.......even if you used a 28mm @ f2.8 at 10 feet away there is 6 feet of what will be in focus

Yep you'd think so. But I guess there is a peak focus throughout the DoF plane softer on the way in and way out. All I know is I did focus some shots on their torsos and the faces were not as sharp compared to the shots that used Face Detection and worked (21mm also not 24mm, but maybe it's more to do with the circle of confusion vs DoF issue). This is where we can throw all the maths we like at a scenario, but go and do it in practice and compare the difference and you might get different results. Manual focus was not even something easily to achieve because it was dark anyway, and I was not tripodded (tripodding is also kinda limiting for when they do crazy stuff like this ;



The only way I'd feel comfortable about using manual focus is if it worked and I had some kind of laser pointer to give me the right distance between myself and the target so during the chaos of the night I could backup or move closer. Nothing seems to beat a bit of specific focus in the right place however, that was my take away message. I can even tell in some group shots which face was picked up with Face Detection and if the other people in the group are even a little bit ahead or behind the persons face that was used as focus then they can appear slightly softer. Like this shot;



FD worked for the centre person, and the left and right headshots are softer, but still acceptable. Now factor in that perhaps a similar shot was taken without FD and just AF on torso then all three could become softer (that was at least my impression on reviewing the ones that didn't find good face focus). We're of course getting into lens quality issues here too, sharp centre, soft as we move away from the focus spot outwards. Perhaps f5.6 or higher may have been better for those larger group shots but then we lose the oof aspect of the shot more.

FWIW I DO use Manual Focus a lot, and almost exclusively on a lot of the dance shots;

Sydney Swing Katz | Flickr

Just a different combo of settings however, ambient was enough to see what I was doing to grab focus and shoot.

[Aaron28]

FD worked for the centre person, and the left and right headshots are softer, but still acceptable. Now factor in that perhaps a similar shot was taken without FD and just AF on torso then all three could become softer (that was at least my impression on reviewing the ones that didn't find good face focus). We're of course getting into lens quality issues here too, sharp centre, soft as we move away from the focus spot outwards. Perhaps f5.6 or higher may have been better for those larger group shots but then we lose the oof aspect of the shot more.

maybe 5.6 would be better for that lens as it could be 'soft' wide open....as with most lenses they get sharper as they are closed up some......it's not really about manual focus as it is about working in a preset focal plane......i'm guessing the flash was on a stand and was quite effective in a certain area plus minus and taking shots from the same area plus or minus...and if things are already oof within the group of people the room is surely oof but of course not as much...but the idea is having that working area of moving folks if the lens is set at a distance +/- so AF is not going from inifinity to mfd to adjust....like with my puppers with a 28mm it's generally set @ f4 at 3 feet which gives me about 3/4 of a foot to get 3 feet right guessing the 3 feet and whatever falls in that 3/4 of foot is decently sharp plus the lens is closed 1 stop helping with that versus being wide open...…..this is me following them around the yard etc maybe as fluid as party guests!!

I tend to think more that focus was prolly fine given the dof and may have more to do with motion after the flash.....1/6 is very slow for handheld even at 24mm.....and between any movement after the flash has gone off the shutter is still open able to record the camera moving or the guests creating blur messing with the focus....curious if trailing/rear/2nd curtain sync would work better with such slow speed.....like delay the flash 166 mil seconds the same as the exposure (I think that's how the delay works with cactus as using the exposure time on camera as the delay time) I kinda ferget but did fool around with the delay and got the same flash support in the exposure as without the delay

[BruceBanner]

maybe 5.6 would be better for that lens as it could be 'soft' wide open....as with most lenses they get sharper as they are closed up some......it's not really about manual focus as it is about working in a preset focal plane......i'm guessing the flash was on a stand and was quite effective in a certain area plus minus and taking shots from the same area plus or minus...and if things are already oof within the group of people the room is surely oof but of course not as much...but the idea is having that working area of moving folks if the lens is set at a distance +/- so AF is not going from inifinity to mfd to adjust....like with my puppers with a 28mm it's generally set @ f4 at 3 feet which gives me about 3/4 of a foot to get 3 feet right guessing the 3 feet and whatever falls in that 3/4 of foot is decently sharp plus the lens is closed 1 stop helping with that versus being wide open...…..this is me following them around the yard etc maybe as fluid as party guests!!

I tend to think more that focus was prolly fine given the dof and may have more to do with motion after the flash.....1/6 is very slow for handheld even at 24mm.....and between any movement after the flash has gone off the shutter is still open able to record the camera moving or the guests creating blur messing with the focus....curious if trailing/rear/2nd curtain sync would work better with such slow speed.....like delay the flash 166 mil seconds the same as the exposure (I think that's how the delay works with cactus as using the exposure time on camera as the delay time) I kinda ferget but did fool around with the delay and got the same flash support in the exposure as without the delay

I think you're underestimating the power of freezing subjects with flash. It can have ridiculous freezing properties with the right power and distance, something more akin to 1/1000 of a second, which for people standing still is just coolio. As I think you know I do the 'drag shutter' thing for dance shots and you can see where it works and doesn't work and a lot of that can be hit or miss and much is to do with distance to subject and strength of the flash and how much cakes the victim... sorry... subject... hehe You can see shots where not enough flash reaches the subject and ambient light blur is adding to the mix... vs what looks like straight up 'soft focus' shot. I have done enough weddings and events now to sus out when I am taking the ambient shutter speed down dangerously low that if I have an inadequate flash power reaching the subjects then that might result in what looks like soft shots, but there is still a difference to be seen in the images. It becomes something that you can see, motion blur vs soft focus, you can see traits when you've gained experience.

All in all this has been a very interesting discussion and I appreciate everyone's opinion (otherwise I would not have posted in the first place). I know that the DA 12-24 at f4 can be sharp in the centre in the same way that the HD DA 20-40 @ f2.8 is sharp also, in the same way that the FA43 is also sharp at f1.9, but there is a diminishing return when moving away from centre or... the place of focus. There is a lot of opinions that the FA77 for example is soft at the edges, but that can stem from the idea that if you focus centre then the edges suffer, but if you actually focus edge then it's not as bad as you might think, and I think that has a lot to do with this scenario. If Live View nails focus at it's widest aperture at somewhere slightly off centre it can still be rich in sharpness, if you nail focus dead centre and are then judging how sharp something is even a small amount away from that focus point... even if the physics suggest that it should technically be in the DoF plane and in focus bla bla bla... then why the heck is it still soft? My experience has taught me to get focus right, period. (hence even people saying focus>recompose>and then refocus as opposed to just simply focus>recompose = vastly differently results).

Throw away the math and what should be feasible is actually what translates from my experience and the images I have taken, theory only takes you so far. If Face Detection works a treat in certain scenarios and other AF mode workarounds (or manual focus) is not yielding the same quality of images then troubleshoot what is the lesser of two evils, in this instance for me it's about giving the camera more light to work with so it can use the most effective AF mode for that specific shooting circumstance.

This might be a bad example (as I have edited and tried to compensate) but here's what I mean;



This shot was taken earlier in the afternoon in a similar set up, the only difference is I had plenty of ambient light to help with the AF mode gaining focus (which was Face Detection). This time it's a different lens, an HD DA 20-40 in FF mode (23mm) on the K-1 and I think a small crop as well. f3.2, 1/60 and ISO 200.
What fascinated me with this shot was during the editing process I could see clearly the mans face was the face chosen for FD, it was sharper and cleaner than his partners face, yet look at the shot, their heads are practically on the same focal plane and placement, their heads couldn't be closer lol, yet I recall having to do quite a lot of additional sharpness work on her face (especially below her yes and at the jaw line) to make her seem 'on par' with her partners clarity (and so she didn't seem mis focused etc).

Do the math, f3.2, 23mm, x distance from flash and camera bla bla and there should be no difference in focus, they should both be the same.... but they were not when it came to editing time. It seems to feel where focus is focused is focus! To use a generic DoF plane as a recipe for a shoot seems for me to be a last straw attempt at resolving a problem (and you still need to see what you're doing in the first place to even set yourself up for some decent manual focus success, which this really wasn't applicable scenario to do easily).

Shutter speed it all depends. You can have 1/6th and everything (that matters) frozen if the subject is caked properly in flash. Herein comes also other factors such as modifiers, zoom on flash head etc. Here we have 1/10th ambient but everything is pretty much frozen very well because the flash was direct;



vs 1/10h here and the flash bounced off roof and the same intensity of freeze power is not the same so some ambient motion is coming into play;



1/6th is absolutely fine shutter speed for a stationary shot of some guest if the flash is sufficient and placed close enough. Here's a 1/13th and you can get that motion blur of a person who wasn't getting enough flash on them to freeze them (which I think works really well for the shot/style) but those that were caked enough in flash are perfectly fine;



You just need to forget about the whole '1/6th handheld = tricky' thing because that's only affecting some of the shot and not all of it, another part of the frame where the flash reaches you're in really safe territory.

1/4th, where the flash touches is frozen fine, and i'm deliberately twisting the camera throughout the shot for this one which is how you get the trails. The freezing power of the flash is truly remarkable;