6d flash speed

[glider64]

Can anyone explain why the 6d flash shutter speed is only 180th ? surely it could be upped with a software change?

[@imagesBV]

Re: 6d flash speed

I believe the limits are determined by the mirror flip up speed....I think you could probably go upto 1/200 or 1/250 though.

[AndyMulhearn]

Re: 6d flash speed

If I recall correctly it's the shutter that drives it not the mirror. In the old days of film, the shutter moved across the film as slit for high shutter speeds but for slower speeds it opened fully. When using flash, the shutter needed to be completely open at the time the flash fires to expose the shot uniformly so the fastest sync speed was the fastest shutter speed the camera could manage with the shutter completely open.

If it's the same on digital then the same logic applies and it's a mechanical thing, not software, so won't be fixable by a firmware upgrade.

[AndyMulhearn]

Re: 6d flash speed

Out of interest, while not about flash specifically this shows how shutters work on a DSLR for the higher speeds - http://petapixel.com/2015/01/29/expl...es-per-second/ - but you can inteprepet it to see the problem with flash...

[AndyMulhearn]

Re: 6d flash speed

Even better, though longer - https://www.youtube.com/watch?v=0j5AHzAGaFk

[collywobbles]

Re: 6d flash speed

I believe the sync speed for the 6D is 1/180th sec. However, you can set your flash for high speed sync which is what I have done with my 580 EX Mk II

[collywobbles]

Re: 6d flash speed

Out of interest, while not about flash specifically this shows how shutters work on a DSLR for the higher speeds - http://petapixel.com/2015/01/29/expl...es-per-second/ - but you can inteprepet it to see the problem with flash...

I was going to comment on the state of his camera till he explained at the end. Good advert for the durability of Canon cameras!

[AndyMulhearn]

Re: 6d flash speed

I was going to comment on the state of his camera till he explained at the end. Good advert for the durability of Canon cameras!

Definitely. I spotted that it was covered in paint early on and wondered how it got like that...

[AndyMulhearn]

Re: 6d flash speed

I believe the sync speed for the 6D is 1/180th sec. However, you can set your flash for high speed sync which is what I have done with my 580 EX Mk II

With an attendant loss in power output as the flash has to provide continuous output?

[DrJon]

Re: 6d flash speed

With an attendant loss in power output as the flash has to provide continuous output?

Yes, although it is a series of flashes not a very long flash.

[LarryPlane]

Re: 6d flash speed

It does seem odd to me, as a fossil from the film age, how slowly flash sync speed has advanced as a technology. I can remember when a camera came out in 79, can't remember which one, a Pentax I believe, that rose the sync speed from bogs standard 60th to a dizzying 125th, and the press predicted then, as it is want tp do, that by the end pf the century, cameras would be able to sync at a 1000th and beyond....

Here we are, 16 years into the new century and the advancement in flash sync speed has been less than stellar.

[El Sid]

Re: 6d flash speed

Not only is it less than stellar, in some ways it's gone backwards. I have a (whisper it) Nikon D50 which has a top sync speed of 1/500 - admittedly that's via an electronic shutter mechanism rather than the mechanical curtains but even so if a modest consumer camera of the mid noughties can do why can't today's? Maybe it's something connected with the fact that the D50 has a CCD sensor not CMOS but even so...

[Robert Scott]

Re: 6d flash speed

The EOS 1D, introduced in 2001, has a flash sync speed of 1/500 second - and is also the only EOS digital camera with a CCD sensor. The fast sync speed is obtained by turning the sensor on and off as the flash fires (often known as an electronic shutter).

CMOS sensors, used by all other EOS digital cameras are excellent in many respects, but cannot be turned on and off as quickly as a CCD sensor, so do not offer the faster flash sync speed.

[briansquibb]

Re: 6d flash speed

I dont understand what the fus is about as the flash provides light at all speeds

[El Sid]

Re: 6d flash speed

I dont understand what the fus is about as the flash provides light at all speeds

It may do but not necessarily at the same time the shutter is open... With electronic flash the burst itself is generally very short, often in the order of 1/10,000 of a second and in order to guarantee that all the sensor/film receives the same amount of light the shutter must be fully open - the sync speed is the fastest speed at which both shutter curtains are guaranteed to be clear of the imaging area.

At speeds faster than the sync speed the second shutter curtain is already closing across the imaging area to end the exposure and as a result a darker to black area may appear in the image where part of the sensor/film has received less or even no light at all as the second curtain got in the way. At very fast shutter speeds, assuming the flash fires at all, you may see either a narrow strip representing the gap between the first and second curtains as they cross the imaging area or in extreme cases a totally black frame because the shutter had either already closed or not yet opened when the flash fired.