Jump to content
SimonPierce

Sony A7rIII Flash Sync Speed – Limited to 1/200 sec?

Recommended Posts

Hi all,

 

I just wanted to check whether anyone has been able to successfully achieve 1/250 sec flash sync with a Sony A7rIII. I'm getting a black bar on the top of the picture at 1/250 sec using both fibre optic and electrical sync cords (both work fine at 1/200 sec) with YS-D2 strobes.

 

It looks like it was possible with the A7rII?

 

http://www.uwphotographyguide.com/best-settings-for-sony-a7rii-underwater

 

Any suggestions greatly appreciated!

Share this post


Link to post
Share on other sites

Hi all,

 

I just wanted to check whether anyone has been able to successfully achieve 1/250 sec flash sync with a Sony A7rIII. I'm getting a black bar on the top of the picture at 1/250 sec using both fibre optic and electrical sync cords (both work fine at 1/200 sec) with YS-D2 strobes.

 

It looks like it was possible with the A7rII?

 

http://www.uwphotographyguide.com/best-settings-for-sony-a7rii-underwater

 

Any suggestions greatly appreciated!

 

 

If you would like to use TTL function the max shutter speed is 1/250 in a7 series. The A 6000 series max is 1/160.

The High speed sync in TTL mode is not preferred.

If you want use it over 1/250 You have to set the strobe max power and reduce the light with aperture and iso.

Thats the only right way. :(

I think there is not high speed flash in the underwater market.

Share this post


Link to post
Share on other sites
Posted (edited)
Sony A7rIII has sync speed 1/250 only with Sony compatible strobes. Using other strobes, the real sync speed is 1/160. This is not written in camera Specifications. At 1/160 the shutter window is fully open at the moment of flash. At speed 1/200 the shutter curtains begin work as HSS, begins appear a small gradient on the top of picture, sometimes almost invisible. Yes, the 1/200 is a threshold value. At 1/250 there is a dark strip on the top of picture.

In common case of underwater photography, user must have Sony TTL Converter inside the housing, to have 1/250 sync speed.

Edited by Pavel Kolpakov

Share this post


Link to post
Share on other sites
In common case of underwater photography, user must have Sony TTL-converter inside the housing, to reach 1/250 sync speed in TTL mode.

 

Case in point, any word on your Sony TTL converter release date? ;)

Share this post


Link to post
Share on other sites

Sony A7rIII has sync speed 1/250 only with Sony compatible strobes. Using other strobes, the real sync speed is 1/160. This is not written in camera Specifications. At 1/160 the shutter window is fully open at the moment of flash. At speed 1/200 the shutter curtains begin work as HSS, begins appear a small gradient on the top of picture, sometimes almost invisible. Yes, the 1/200 is a threshold value. At 1/250 there is a dark strip on the top of picture.

In common case of underwater photography, user must have Sony TTL Converter inside the housing, to have 1/250 sync speed.

Hi Pavel. Did you check the A6000 series? I think there is only 1/160.

Share this post


Link to post
Share on other sites
Posted (edited)

Hi Pavel. Did you check the A6000 series? I think there is only 1/160.

Hi Balazs,

I did not check A6000 yet. Maybe it has only 1/160. I don't know.

Edited by Pavel Kolpakov

Share this post


Link to post
Share on other sites

 

Case in point, any word on your Sony TTL converter release date? ;)

Hope it will be on the market next month.

Share this post


Link to post
Share on other sites
Posted (edited)

A6300 (and, I presume, other A6xxx/A5xxx series cameras) are limited to 1/160 when the pop-up flash is up, or the shutter is set to silent mode (electronic-only). I'm pretty sure they support HSS with compatible strobes, but I don't know how they behave in normal sync mode with external flashes as I don't own one.

Edit: By 'limited', I mean that you cannot select any shutter speed faster than 1/160s when you twist the knob that you've set for shutter speed selection.

 

 

Hope it will be on the market next month.

 

Next month being May? Bummer :(

Edited by Barmaglot

Share this post


Link to post
Share on other sites

With my Sony a9 and YS-D2J's my max sync speed is 1/200th. When I use my YS-250's, I can use 1/250th. This is with a Nauticam housing, their Sony Mini Flash Trigger and shooting all manual.

Share this post


Link to post
Share on other sites
Posted (edited)

With my Sony a9 and YS-D2J's my max sync speed is 1/200th. When I use my YS-250's, I can use 1/250th. This is with a Nauticam housing, their Sony Mini Flash Trigger and shooting all manual.

Yes, everything should be so. YS-250 round tube has burning time 5 times longer than YS-D2 linear tube, because of tube shape. Such long flash lights picture all the time while open strip goes through the shutter window (HSS type shutter work at 1/250). This case picture is lighted by YS-250 uniformely.

This is "pseudo-HSS" lighting, such trick of course works only with manual long flash, but this is not for TTL.

Edited by Pavel Kolpakov

Share this post


Link to post
Share on other sites

Thank you Pavel for that additional information. I figured there was a reason.

Share this post


Link to post
Share on other sites

My Sony a7riii + Sea & Sean YS-D2 Strobe max sync speed is 1/200; I only shoot in manual mode, do not have a converter to TTL on my Ikelite housing. If I move up to 1/250 the dark strip appears in the top of the frame. This makes it difficult to get the dark background but can be done in post.

Share this post


Link to post
Share on other sites

I'm unable to go past 1/200 on my a7RIII using YS-D2J's, but I'd certainly be interest in any flash trigger that would would expand that...

Share this post


Link to post
Share on other sites

My Sony a7riii + Sea & Sean YS-D2 Strobe max sync speed is 1/200; I only shoot in manual mode, do not have a converter to TTL on my Ikelite housing. If I move up to 1/250 the dark strip appears in the top of the frame. This makes it difficult to get the dark background but can be done in post.

Hello ,,

 

The curtain what was you could see there. The flashsync is not real sync. You can read here how works the high speed:

https://www.exposureguide.com/high-speed-sync-flash/

Maybe you can set the strobe to full power and there is fill the gap in the HS curtain moving.

 

Regards

Balazs

Share this post


Link to post
Share on other sites

I'm unable to go past 1/200 on my a7RIII using YS-D2J's, but I'd certainly be interest in any flash trigger that would would expand that...

Hi. The trigger can makes the HS from LED side , but the underwater strobes can not sense these signal. :)

Share this post


Link to post
Share on other sites

Do i understand correctly that someone (Pavel?) is creating a device/converter that will make the SonyA7r3 be able to shoot at 1/250 without the black band (using YSD2J strobes / manual exposure)? I'm using a Nauticam housing.

 

If so, i'm interested. I desperately need 1/250 for better sun ray shots with strobes.

Share this post


Link to post
Share on other sites

You can send a high speed sync signal which rapidly pulses the strobe to allow it to illuminate the whole frame but most UW strobes can't do that, they are purely slaves even TTL they just keep the strobe going for as long as they see light from the trigger. The strobe needs to be setup to recognise high speed sync and be able to rapidly pulse. It needs to start ulsing when the first curtain moves and keep pulsing till the second curtain has closed. This is significantly longer than the time the flash is fired for even at full power for many strobes.

 

So in summary it's not just the trigger it's also the strobe.

Share this post


Link to post
Share on other sites
Posted (edited)

You can send a high speed sync signal which rapidly pulses the strobe to allow it to illuminate the whole frame but most UW strobes can't do that, they are purely slaves even TTL they just keep the strobe going for as long as they see light from the trigger. The strobe needs to be setup to recognise high speed sync and be able to rapidly pulse. It needs to start ulsing when the first curtain moves and keep pulsing till the second curtain has closed. This is significantly longer than the time the flash is fired for even at full power for many strobes.

 

So in summary it's not just the trigger it's also the strobe.

 

I don't think the strobes are the issue in this case, following http://wetpixel.com/forums/index.php?showtopic=56787

Pavel tested YS-D1 at 1/250 and 1/320 on several cameras in TTL, - no problem. Also worked at 1/500 in TTL (Nikon D50 + #11031 TTL-Converter).

Edited by Kasper Prijs

Share this post


Link to post
Share on other sites

It's a combination of camera and strobe capabilities. The camera shutter determines the speed at which it can execute a normal flash sync - the first curtain exposes the sensor, then the flash fires, then the second curtain moves in and closes the sensor. The shutter curtains don't move instantaneously though, and the speed at which they move out and in determines the overall shortest possible exposure - while they're moving, the sensor is still getting some light. In order to provide a shorter exposure, the second curtain starts closing before the front one is fully open, creating a strip of light that races across the image, and this precludes using a normal flash, because if it fires when only part of the sensor is exposed then you get underexposed areas where the curtains were covering the sensor at the moment that the flash fired. Some cameras have shutter curtains that move exceptionally fast, like the Nikon D50 that allows 1/500s flash sync; some are much slower, like Nikon 1 series that are generally limited to 1/60s flash sync speed. Most Sony interchangeable-lens cameras are limited to 1/160s, or, in some limited circumstances as Pavel mentions, 1/200s.

 

Here is an animation showcasing this process: https://cdn.fstoppers.com/styles/full/s3/media/2015/04/fstoppers-high_speed_sync-_shutter-_operation.gif

 

Fixed lens cameras usually have diaphragm or 'leaf' shutters located in the lens - these have a much smaller distance to cover when opening and closing, and thus allow for much faster flash sync speeds. For example, Sony RX100 series cameras can sync flash at up to 1/2000s. Note, however, that full-power flash dumps usually take around 1/320s (for commonly used underwater strobes such as Inon Z-330/S&S YS-D2; figures may differ for land strobes), so syncing your flash faster than that cuts into strobe power at the same rate that it cuts into ambient light power.

 

The way this limitation is overcome for interchangeable-lens cameras with curtain shutter is so-called high-speed sync where, instead of emitting a single powerful pulse, the strobe emits a series of smaller flashes, typically modulated at 40kHz while that thin strip of exposure races across the sensor. Alas, this has the unfortunate effect of massively reducing effective flash power, and in underwater strobes, support for this mode is almost nonexistent. The long since discontinued Olympus UFL-2 was effectively a land strobe (Olympus FL-36) in an underwater housing, and thus inherited its ability to do HSS with select Olympus cameras using their RC triggering. The upcoming Retra Prime and Retra Pro flashes claim HSS capability with triggers that can drive this mode using LEDs, but they are not shipping yet, and neither are compatible triggers. Once they're out (C'mon Oskar!) we'll know more about how useful this mode is in practice. As mentioned above by Pavel, Sea & Sea YS-250 Pros with their long burn time at full power allow for a sort of of pseudo-HSS, but these are also discontinued. With other strobes, including YS-D2s ,you can't sync any faster than allowed by your camera's shutter mechanism.

Share this post


Link to post
Share on other sites

It's a combination of camera and strobe capabilities. The camera shutter determines the speed at which it can execute a normal flash sync - the first curtain exposes the sensor, then the flash fires, then the second curtain moves in and closes the sensor. The shutter curtains don't move instantaneously though, and the speed at which they move out and in determines the overall shortest possible exposure - while they're moving, the sensor is still getting some light. In order to provide a shorter exposure, the second curtain starts closing before the front one is fully open, creating a strip of light that races across the image, and this precludes using a normal flash, because if it fires when only part of the sensor is exposed then you get underexposed areas where the curtains were covering the sensor at the moment that the flash fired. Some cameras have shutter curtains that move exceptionally fast, like the Nikon D50 that allows 1/500s flash sync; some are much slower, like Nikon 1 series that are generally limited to 1/60s flash sync speed. Most Sony interchangeable-lens cameras are limited to 1/160s, or, in some limited circumstances as Pavel mentions, 1/200s.

 

 

...

Thanks for the in depth explanation. The A7R3 is actually capable of syncing up to 1/250 using my regular Metz M-360 flash, not having any issues with a black band above water.

Share this post


Link to post
Share on other sites
Posted (edited)
On 4/1/2019 at 3:19 PM, Barmaglot said:

.... Sony TTL converter release date? ;)

UWTechnics ships Sony TTL Converter for Nauticam A7...A9 housings since 31-July. 

Maximum sync speed is 1/250, tested, no dark strip on images.

 

Edited by Pavel Kolpakov

Share this post


Link to post
Share on other sites
Posted (edited)

It seems it might be the Nauticam mini flash trigger causing the Sony to not go past 1/200. I'll probably order one of these triggers myself and see if they work with my Sea and Sea YSD2J strobes.

Edited by Kasper Prijs

Share this post


Link to post
Share on other sites
Posted (edited)

Nauticam product is manual trigger, it does not use communication protocol with camera. Max sync speed must be 1/160 for this case.  Yes, the 1/200 can be used as a threshold value, small gradient begins at the top of image.  But for 1/250 sync speed, you need any TTL device connected to HotShoe.

Edited by Pavel Kolpakov

Share this post


Link to post
Share on other sites

Sponsors

Advertisements



×
×
  • Create New...