Flash Sync Problem

[gsgary]

The strobes are hooked from the opas transceivers via PC sync. The speedlight is mounted to the hotshoe

The pixel opas transceivers are compatible with the King system up to 1/8000. They're about 95% reliable. The King receiver....mehhh not so much

How long between each shot are you waiting for the flash to get back up to full power ?

 

[lennon33x]

I was initially popping them off about every 5 seconds. I then realized my issue and waited up to a full minute or 2. No improvement.

 

[Derrel]

The miscommunication is coming from the terms High Speed Sync or HSS as opposed to flash synch at high shutter speeds. It's kind of neat how with various monolights, it's possible to use flash at VERY fast shutter speeds, and basically use the long, slow "tail" part of a monolight flash's duration, to shoot at ridiculously-high shutter speeds. I'm so old that I often forget about that being a possibility. Paul C. Buff himself, in his old forum that he used to run, had some posts and diagrams/illustrations showing how he was able to synch his Alien Bee lights at really fast shutter speeds.

 

[lennon33x]

Additional Update:
While I understand that based on my current setup, the strobes and flash have limited capabilities regarding HSS. And further research indicates, that unless I want to sell my kidneys, getting studio strobes for HSS is a hit-or-miss situation and also a huge investment, financially. Essentially, I'm trying to optimize my equipment to know what I can push as far as sync speed. I like shooting fast apertures, so higher shutter speeds are what I'm needing. Thankfully, with my 5D, I can drop my ISO lower than I did on my Rebel.

 

[lennon33x]

The miscommunication is coming from the terms High Speed Sync or HSS as opposed to flash synch at high shutter speeds. It's kind of neat how with various monolights, it's possible to use flash at VERY fast shutter speeds, and basically use the long, slow "tail" part of a monolight flash's duration, to shoot at ridiculously-high shutter speeds. I'm so old that I often forget about that being a possibility. Paul C. Buff himself, in his old forum that he used to run, had some posts and diagrams/illustrations showing how he was able to synch his Alien Bee lights at really fast shutter speeds.

<--- THIS is essentially what I'm going for.

I have two goals with this approach:
1.) Freeze motion (i.e. freeze the pouring of scotch into a glass, while lighting the scene with strobes)
2.) Use fast apertures for shallow DoF in not-so-dim light (i.e just before the golden hour in the afternoon).

 

[gsgary]

The miscommunication is coming from the terms High Speed Sync or HSS as opposed to flash synch at high shutter speeds. It's kind of neat how with various monolights, it's possible to use flash at VERY fast shutter speeds, and basically use the long, slow "tail" part of a monolight flash's duration, to shoot at ridiculously-high shutter speeds. I'm so old that I often forget about that being a possibility. Paul C. Buff himself, in his old forum that he used to run, had some posts and diagrams/illustrations showing how he was able to synch his Alien Bee lights at really fast shutter speeds.

<--- THIS is essentially what I'm going for.

I have two goals with this approach:
1.) Freeze motion (i.e. freeze the pouring of scotch into a glass, while lighting the scene with strobes)
2.) Use fast apertures for shallow DoF in not-so-dim light (i.e just before the golden hour in the afternoon).

Freezing motion with flash depends on the speed of your flash and not shutter speed

Sent from my GT-I9100P using Tapatalk 2

 

[lennon33x]

Freezing motion with flash depends on the speed of your flash and not shutter speed Sent from my GT-I9100P using Tapatalk 2

Then why am I able to still get flash at 1/8000 with non-HSS strobes?

 

[table1349]

Take a picture with your sync speed on your camera at 1/8000 and see what you get.

 

[gsgary]

Freezing motion with flash depends on the speed of your flash and not shutter speed Sent from my GT-I9100P using Tapatalk 2

Then why am I able to still get flash at 1/8000 with non-HSS strobes?

If you are shooting flash with no ambient light shutter speed make no difference to the exposure, if you are shooting flash with ambient light your shutter speed controls the ambient exposure and aperture controls the flash exposure

 

[lennon33x]

If you are shooting flash with no ambient light shutter speed make no difference to the exposure, if you are shooting flash with ambient light your shutter speed controls the ambient exposure and aperture controls the flash exposure

So, when I turn up the intensity of the strobe, am I increasing or decreasing the duration of the flash? Or does it actually make it brighter?

 

[Derrel]

Paul C. Buff, Inc. - Flash Duration

As you can see, with "MOST" studio flash units, the higher the flash power, the longer the flash duration. FOr example, with my Speedotron studio flash units, 2,400 Watt-seconds, the flash duration is around 1/225 second. At lower power outputs, like 400 Watt-seconds, the same flash generator and flash head give a MUCH faster flash pop.

With IGBT style flash units,like Buff's newer "Einstein 640" units, the highest power levels give VERY quick aka "short" flash durations.

When you are synchronizing studio flash units like the Neewer units at high shutter speeds, you are working on the long, low-intensity "tail" of the flash, and so you do not gain the full benefit of the flash's PEAK power, so raising the intensity of the flash might not produce as much extra "oomph!" as you might hope.

 

[lennon33x]

Paul C. Buff, Inc. - Flash Duration

As you can see, with "MOST" studio flash units, the higher the flash power, the longer the flash duration. FOr example, with my Speedotron studio flash units, 2,400 Watt-seconds, the flash duration is around 1/225 second. At lower power outputs, like 400 Watt-seconds, the same flash generator and flash head give a MUCH faster flash pop.

With IGBT style flash units,like Buff's newer "Einstein 640" units, the highest power levels give VERY quick aka "short" flash durations.

When you are synchronizing studio flash units like the Neewer units at high shutter speeds, you are working on the long, low-intensity "tail" of the flash, and so you do not gain the full benefit of the flash's PEAK power, so raising the intensity of the flash might not produce as much extra "oomph!" as you might hope.

Derrel, now that we've got that squared away (and yes I agree that the sensor is capturing the tail end of the flash), on to my next question.

Let me also interject that I appreciate all of the replies. I would rather take the time to make the mistakes and to learn the process, than to fly by the seat of my pants and hope I get the correct exposure/flash exposure. That is evidence of learning.

So my question is this. If, based upon my settings and the settings of the Neewer strobes and the Opas transceivers, which are not employing HSS, but are rather utilizing high shutter speeds with flash, then why am I allowed to get full exposures without banding (seeing the curtain) with these receivers rather than the King Transmitter/receiver. I ran into this issue early on with my Rebel. The Transceivers, when one is employed as a transmitter, but the other is a receiver, set strictly as RF triggers, would only allow up to about 1/250 SS without banding. When I switched to the King Transmitter and used the Opas(es) as receivers, I could get as high as 1/4000 (on my Rebel) and up to 1/8000 on my 5D.

My understanding is that the transmitter tells the receivers (in HSS) to repeatedly fire small flashes of light to compensate for the quick curtain closures. But, if there is no indication that that information can be received from the Opas to the Neewer strobe, then how does it happen? Theories?

 

[gsgary]

Are you shooting outside with ambient light and flash or in the studio ? In the studio you dont need fast shutter speeds, just buy a flash meter to set your lights up

Sent from my GT-I9100P using Tapatalk 2

 

[lennon33x]

Are you shooting outside with ambient light and flash or in the studio ? In the studio you dont need fast shutter speeds, just buy a flash meter to set your lights up

Sent from my GT-I9100P using Tapatalk 2

I'm not a fan of flash meters. Yes they serve their purpose, but I cannot justify a purchase of one, as I wouldn't use it as often as one might think. Fans blowing hair, water droplets, pouring liquids...all of these would/could require fastER shutter speeds to freeze motion. I also like doing outdoor portraits at night with flash. I did one recently where myself, my sister and my wife were all jumping mid-air. Fastest SS I could get was 1/250 and there was still motion blur. No ambient.

 

[gsgary]

Are you shooting outside with ambient light and flash or in the studio ? In the studio you dont need fast shutter speeds, just buy a flash meter to set your lights up

Sent from my GT-I9100P using Tapatalk 2

I'm not a fan of flash meters. Yes they serve their purpose, but I cannot justify a purchase of one, as I wouldn't use it as often as one might think. Fans blowing hair, water droplets, pouring liquids...all of these would/could require fastER shutter speeds to freeze motion. I also like doing outdoor portraits at night with flash. I did one recently where myself, my sister and my wife were all jumping mid-air. Fastest SS I could get was 1/250 and there was still motion blur. No ambient.

I always use a flash meter i will have done my shoot will you are still messing with settings, you dont need fast shutter speeds to stop motion in a studio why can't you get your head round it ? It is down to flash duration

Sent from my GT-I9100P using Tapatalk 2