HSS using my A7S and A7R2 with Phottix Odin with 1:1 flash power & TTL

[SpanishFlyer]

Dear friends,

 

I'm having trouble in making both my sony (A7S & A7R2) cameras work in High Speed Synch (HSS) when I set my Sony HVL-F43M flash to HSS and TTL in manual mode at max output 1/1, the Phottix Odin set to HSS and TTL and both cameras set to wireless flash mode; the main problem is that the flash won't give the full 1/1 full power unless I set my shutter speed to 1/250 or less. I try to raise the speed higher and on the A7R2 it has the shutter speed limited to 1/250 and on the A7S it will allow me to select a higher speed, but then the flash will give a much lower power output...

 

I'm sure I am doing something wrong when setting both my cameras, but have tried changing settings through my menus, without any luck, success, or what is worse, not knowing how to set it up.

 

The whole idea is to use the flash as a fill-in flash to lighten up daylight photography, needing at the same time to freeze the subject (mainly wild birds) moving fast.

 

If I press the test button on the ODIN transmitter it will give the full power burst each and every time, but when I press the camera's shutter button it all goes to hell 

 

I would really appreciate it if someone could tell me how to configure my cameras so I manage to achieve what I need.

 

Best regards,

 

Spanish Flyer

[michelb]

As soon as you dial in HSS, the power of the flash gets reduced as you increase shutter speed. Check your owner's manual at the end in the specs section, there is a chart where GN for HSS is shown relative to the shutter speed selected. It goes down fast 

 

GN at 50mm at 1/250 sec: 14

GN at 50mm at 1/1000 sec: 7

GN at 50mm at 1/4000 sec: 3.5

GN at 50mm at 1/8000 sec: 2.5

 

This is due to the fact that as HSS is engaged, the flash has to supply multiple invisible bursts of flash to cover the slit caused by the way focal plane shutters operate at higher speeds. The faster the speed, the more flash bursts the flash has to provide but the power is limited to what is in the capacitors so it is dividing its power on every burst to cover the whole frame. 

This is why you are not getting the same power as your shutter speed goes up, the flash is dividing its power to ensure even coverage of the small slit your focal plane shutter is using to increase its speed.

 

HSS was designed as fill flash possibility for subjects not too far from the flash . This is why with the first flash units providing this, if you bounced up the flash head, it would revert to normal since the power is definitely not enough to provide the power necessary for proper exposure

 

HSS is not really a stop motion feature as these multiple low power flash bursts will show you multiple images with very fast subjects like Hummingbirds wings. 

It was demonstrated somewhere on Dyxum that using multiple flash units of the same power and model connected together by the same TTL cables is the best way to obtain very fast flash bursts in the area of about 1/12000 sec but in a single burst which is faster than the 1/8000 of your camera.

[SpanishFlyer]

Thanks a lot michelb,

 

I now fully understand why this is happening to me; no way my small-ish flash unit could deliver full blast multiple bursts in fractions of a second. Problem of course is that most of my shots over the flash synch speed of 1/250 s come out totally dark and unrecoverable.

 

Just wonder if apart from the option of using more flashes you mention, I can use other means of lighting, because I cannot afford spending more in flashes (have three Sony flashes, not the same model and three Nikon SB's). Instead of that I do have two AlienBees, B400 & B1600 and I could try with them.

Must explain that I am shooting from my home to the trees nearby, so have no problem in power source for them; only thing is that I can only shoot in manual mode, no TTL and plugged wirelessly with my PocketWizards I had for my Nikon gear. Good thing is that they will trigger both A.Bees and with the AC3 I can adjust the power output from my camera, without fiddling with the strobes themselves.

 

Thanks again 

 

Spanish Flyer

[michelb]

Just  small detail: What lens are you using ?

 

Odin's don't work well with un-chipped adapted lenses and this could worsen your situation

[SpanishFlyer]

Hi again michelb,

 

Right now and for this situation I'm using the 70-400 mm F4-5.6 G SSM II with either adapters LA EA3 or LA EA4. I also have the FE 70-200 mm F4 G OSS,  but it doesn't have enough reach..

  I am looking for a Minolta 300 f 2.8 SSM, but there are very few for sale out there and as I mentioned earlier, the Sony 300 f 2.8 G II is out of my budget. 

 

I could try using the FE 70-200, just to see if I get a better response, but I doubt it.

 

Best regards,

 

Spanish Flyer

[Guest all8]

With my A7ii and F43M attached, the rear LCD showing all parameters, when the shutter speed is beyond 1/250 ... I get a "HSS" next to the flash icon and the same "HSS" is showing on the Flash unit. Do you see that on your F43M? If not, try a long press of the Fn button, this gives some menus (which I know nothing about) and there seems to be an entry to turn HSS On or Off.

 

The photos taken at the higher shutter speed are correctly exposed.

 

Not that it matters, but I tried this with 70-200G4.

[Golem]

Think of HSS as a strobe doing its best to imitate an LED. 

  

Since firing the HHS strobe is consuming battery reserve

and also wearing/aging the strobe, them clever designers

couple it to distance, shutter speed, f/stop, and ISO data

from the camera to predict proper exposure. It can work

in simple point and shoot mode using such info. That is a

generalization about all brands of HSS. I can't speak of

any Sony peculiarities cuz ......

 

I would rather NOT use an imitation LED. A real LED is

is simpler, cheaper, more versatile, not so busy wearing

itself out, etc etc. And if you want auto exposure, just use

any mode you want, since an LED is just a light, and not

some component of an artificial intelligence regime. So if

you wanna be old school, metering it manually, just do it.

  

Another old school benefit of a real LED is that you can

see the lighting .... just by switching it on and looking :-)

[Al Pha]

Just wonder if apart from the option of using more flashes you mention, I can use other means of lighting, because I cannot afford spending more in flashes (have three Sony flashes, not the same model and three Nikon SB's). Instead of that I do have two AlienBees, B400 & B1600 and I could try with them.

Must explain that I am shooting from my home to the trees nearby, so have no problem in power source for them; only thing is that I can only shoot in manual mode, no TTL and plugged wirelessly with my PocketWizards I had for my Nikon gear. Good thing is that they will trigger both A.Bees and with the AC3 I can adjust the power output from my camera, without fiddling with the strobes themselves.

 

 

Hi, Try the following experiment: 1. Point one of the A.Bees (in slave mode) at the subject with the correct power setting for the subject distance; 2. Use one Sony flash on camera to fire another Sony off-camera flash in HSS mode; 3. Point the off-camera Sony flash at the A.Bees to fire it but not contribute to the exposure. The A.Bee should react fast enough in slave mode to give you the right amount of light necessary for the correct exposure.

[SpanishFlyer]

Thanks a lot guys,

 

And Al Pha, since I have all the elements will no doubt try to carry out your experiment; still, I will have to make several arrangements to avoid the A.Bees burst get into my lens, since I can only plant the strobe slightly ahead of the lens and can easily create some flare. With the Sony F43M I had made a kind of black snoot that only sent light forwards towards the trees about 16 feet/ 5 m away from my window.

 

Best regards,

 

Spanish Flyer

[IamJF]

So you have 8 flashes an no one does what you really need? Maybe get rid of a few and think about a nice studio flash with a Sony wireless system, there are a few new players on the field. With the right lightformer you should get plenty of power?

(btw - are there spezialiced light formers for tele shooting? Maybe something with a lens?)

[Golem]

..........

(btw - are there spezialiced light formers for tele

shooting? Maybe something with a lens?)

Yes. and you can make your own.

[IamJF]

White tube? With grid?

[tsenior]

If you can't get HSS to work, another alternative would be the use of a ND filter to allow larger apertures.