Inon Z240 Max Flash Sync Speed

[Tom_Aust]

Hi all,

Wondering if anyone has some advice on the max ttl sync speed of the Inon Z240?

I currently have a RX100 with a S&S YS-D1 strobe (in a nauticam housing) that will sync optically ttl ok up to 1/200 or 1/250 but really struggles past this. I know that I can run it in manual much faster but for flexibility was wondering if other strobes could sync ttl quicker.

I am going to purchase another strobe anyway, and the options that I have are a newer YS-D2 (that has a similar HSS limitation) or an Inon Z240. I cannot find any information on the max ttl sync speed of the Z240 online however. Not sure if this is because a) there is no issue, or b) there are a lot of D1's out there that this issue became apparent.

Thanks in advance for your advice.

Regards,

Tom

 

[bvanant]

It is true that the Rx100 (at least in later versions) can flash sync at fast speeds, i think that TTL coverage at those speeds will be limited by the cameras ability to send out pre-flash then process the data, I am quite sure that it probably is not the strobe
Bill

 

[Tom_Aust]

Hi Bill, of that I am not sure (and thus the question). It is definitely an issue that was found for the purchasers of the original YS-D1 strobe that surprised a few folk who bought the original RX100. The S&S response at the time is that the strobe is not designed for HSS above these limits.
Unfortunately I cannot see any info from those who used a Z240 with the RX100...

Regards,

Tom

 

[bvanant]

Well my Z240 syncs (in slave mode) with my other strobes and I will bring it to our lab and hook it up to a scope and see what the delay times might be.

Bill

 

[watboy]

I understand that max sync speeds are for the most part, determined by the camera and not the strobe. The duration of a strobe pulse is far shorter than the shutter speed. Anyways, I have no problems getting my z240 in sTTL to work on my OMD EM1 at 1/320th a second. On my previous camera, it could only do 1/250th though (EM5).

 

[Tom_Aust]

Fantastic Bill and watboy. I have ended up going with the inon due to suggested high reliability and the potential to sync at higher speeds. The RX100 can sync with a fill flash greater than 1/500 so now I just have to play with the setup to get it all working right, and keep fingers crossed that the inon will run up to 1/500.

 

[bvanant]

I am quite sure that the Z240 will flash at 1/500 with no issue. BUT it is not clear that it will work with TTL. That is the big question.
BVA

 

[watboy]

I don't think this is the correct use of the term High Speed Sync (HSS). Standard sync speeds is determined by the fastest shutter speed where the shutter fully exposes the sensor. for TTL, it would have to fully expose the sensor long enough to have a pre-flash as well, process the data and then the actual flash (i'd assume the strobe would have some minimum delay between pre flash and flash as well). At faster shutter speeds, the second curtains closes so quickly after the first, that the sensor is never fully exposed. In HSS, the strobe fires for the entire duration of the shutter, so even though the sensor is never fully exposed, the strobe is providing light for the entire sensor. I'm not aware of any mainstream UW strobes that can do HSS, but i could be wrong.

 

[bvanant]

For the RX100 cameras there is no standard shutter but only an electronic version (I think) and it can sync at very high speeds.
For traditional cameras you are of course correct, but for the RX100 it is not correct.

Bill

 

[KeithG]

I don't think this is the correct use of the term High Speed Sync (HSS). Standard sync speeds is determined by the fastest shutter speed where the shutter fully exposes the sensor. for TTL, it would have to fully expose the sensor long enough to have a pre-flash as well, process the data and then the actual flash (i'd assume the strobe would have some minimum delay between pre flash and flash as well). At faster shutter speeds, the second curtains closes so quickly after the first, that the sensor is never fully exposed. In HSS, the strobe fires for the entire duration of the shutter, so even though the sensor is never fully exposed, the strobe is providing light for the entire sensor. I'm not aware of any mainstream UW strobes that can do HSS, but i could be wrong.

To add further clarification: HSS is an industry marketing term used to identify flashes that provide specialized operation for mechanical focal plane shutters being used at very short exposures.

In HSS mode the flash operates as a strobe. It emits many short (hence low power) pulses of light during the exposure. Pocketwizard provides a good description here
Understanding HyperSync and High Speed Sync - PocketWizard Wiki

HSS protocols are proprietary to the camera manufacturer and require specialized data exchange communication between the camera and flash.