"shadow" at the bottom of frame/shot...

[LewisShermer]

so I was shooting the other day with studio lights at 125th around f8 I think which is pretty standard for studio lights/model set up only the model was moving around a bit so I upped shutter speed to 200th/sec. I didn't notice on the back of the camera (5Diii) at the time but there seems to be a shadow cast from what I can only assume is the shutter or mirror.

I've been shooting for quite a number of years and I've never noticeably come across this. Going out and shooting In daylight at 800th/sec seems no problem with a 50mm 1.4 wide open. Is this just a phenomenon when shooting with flash over 160th/sec at high f-stops and I should just learn not to do it or is there something more sinister at work?

examples attached: 1st at 125th @ f9 2nd at 200th @ f8

 

[LewisShermer]

P.S. nothing changed with regards to lighting set up... umbrella camera left & mid size soft box camera right. very evenly lit so the actual lighting set up hasn't caused the drop off of light

 

[LewisShermer]

P.P.S. only the 200th/sec shutter speed shots are affected

 

[Loswr]

It's normal, unfortunately. The max Xsync speed of the 5DIII is 1/200 s. Any faster, the shutter curtains aren't ever fully open, the two curtains make a 'slit window' that travels across the sensor. With a Speedlite (in the hotshoe or triggered with a Canon optical/RF system), you'd be fine at 1/200 (and the camera wouldn't let you set any faster, unless you enabled high speed sync). But depending on how you're triggering your studio lights, the timing may be very slightly off, meaning you catch a curtain edge and get a shadow - that's what is happening in your 1/200 s shots. Try 1/160 s as a max. Personally, I do use 1/200 s with a PW-triggered monolight/Speedlite combo, but that's with a 1D X and the Xsync is 1/250 s.

 

[That Photog]

What Neuro said. I stay at 1/160 for studio lights and triggers. On camera flash or hardwired you can sometimes get 1/200.

 

[Loswr]

P.S.

If you're using PWs, you can play with the delay in the Utility and tweak the timing so 1/200 s works properly. Takes a little fiddling... Might be possible with other triggers, too, not sure. Did that with the 5DII, haven't tried with the 1D X to get 1/250 s since PW doesn't support the 1D X yet, so I'm just using them as 'dumb' triggers.

 

[LewisShermer]

cheers dudes, thought as much, camera/flash limitations. not had it out yet with a speedlite on but I guess it'll just stop me from going too fast with shutter speeds. It's kinda stupid that even after 13 years I'm still on a learning curve.

at least I don't have to send it for repair. I'm guessing It'll say somewhere in the manual? I should read it sometime...

I still use curly sync leads, by the way, none of that new fangled technology for me.

 

[Loswr]

If you need 1/200 s for some reason, the 7D has a 1/250 s Xsync speed - smaller sensor means less distance for the curtains.

 

[risc32]

what these guys said

If for some reason you need 1/200th in this situation you could just take a step back and then crop the frame a bit to remove the edge. OR you can fiddle with trigger timing, or you could just lower the ambient some and you won't need 1/200th.


I also think a shutter synch speed of 1/200th is a bunch of hoohaa! i want 1/500th.

also, i don't think this is the problem here, but depending on what lighting gear you are using you could possibly be coming up against the flash duration. I think that(flash duration and how it would come into play) and the lack of people asking for it, mostly cause they don't understand it, are the causes for us still having crappy flash synch speeds.

 

[Loswr]

I don't think this is the problem here, but depending on what lighting gear you are using you could possibly be coming up against the flash duration. I think that(flash duration and how it would come into play) and the lack of people asking for it, mostly cause they don't understand it, are the causes for us still having crappy flash synch speeds.

I don't think so. Flash duration, even with a studio light, is much shorter - 1/500 s or faster, and Speedlites are 1/800-1/1250 s at full power, and much faster at lower power.

The problem is the combination of a focal plane shutter and a CMOS sensor. Leaf shutters essentially have no restriction. A focal plane shutter with a CCD sensor is better than CMOS - the original 1D used a CCD sensor (APS-H, not FF, and that helps, too) - it had a 1/500 s Xsync, and some film cameras achieved that, too.

 

[agierke]

i can confirm that a faster flash duration will not improve x-sync as i have AB Einsteins which are capable of very fast flash durations. made no difference in my ability to increase x-sync.

i have also experienced the shadow from the curtain on my 5d mrk2 as well as on others 5D mrk 2's. it is inconsistent though as i can sometimes pull off 1/200th sync while other times i can only max at 1/160th.

now that i think about it....if 1/200th sync speed is absolutely necessary would it be helpful to incorporate the mirror lockup function to at least get a part of the mechanical action out of the way before the shutter is released for exposure? i realize this would introduce a somewhat awkward way of shooting as you would lose the ability to compose through the viewfinder in realtime, but if the camera position is locked in on a tripod and the only concern is for the model to reposition between shots then it should be a minor adjustment to shooting technique.

 

[LewisShermer]

If you need 1/200 s for some reason, the 7D has a 1/250 s Xsync speed - smaller sensor means less distance for the curtains.

Yeah, this was my first model shoot with a 5Diii since using a 7D. meh. It's the little things that kill.

 

[risc32]

mirror lockup? holy cow.

Well, if when i typed " also, i don't think this is the problem here", people thought i was saying this is what i think your problem is, i really don't know how to fix that.
as for the flash duration topic i mentioned, my studio strobes ARE slower than 1/500th under some conditions. that is one head, at higher power settings. many are.

I've posted before about my love of crappy flash synch speeds, and again, i know all about it, and why they suck. Nobody seems to understand how i don't care about all that, i'm 100% certain some clever guys could make it happen. hell, i've got a fairly good idea for a work around, but i haven't the time.

anyone care to argue with my recommendations for the OP?

BTW- with an alienbees trigger/receiver combo i could net 1/400th with a speedlight set on full tilt with my 1dmk2.
yes, i know it's aps-h, just saying.