Mysterious line in photo

Hi guys I can’t seem to figure out why my photos have this weird line at the bottom of the photo. (It’s obviously a bad photo but  emphasizes the color diff the best)

my shutter is 1/250 so it’s not that and also bc it’s not a black line. 
 

Is it a shadow or a camera setting? This has never happened before 

I believe your shutter speed is too fast - try 1/200 or 1/160 ... Or, (although i doubt) it could be the strobes are too close to the housing (thus blocking the light)

See for similar problem here :

View archived post in: Weird opaque or black line on top of photos??

Too high a shutter speed is also my first suspect. Related is maybe the camera is set to rear curtain sync.

You need to check what is the max sync speed for you camera with strobe. Most probably it is 1/200.

the black line you have is due to the movement of the curtains that is resulting that that specific area of the frame is getting less time of strobe light due to the over “speed”

you can check it in the technical guide, but you can also do some tests in dry.

Thanks all my max speed is 1/250 I have a Nikon d850 but I’ll try a lower speed and also check the settings. 

Hi Iwang

you are not alone with this problem… 

View archived post in: Nikon D850 in Nauticam Housing flash sync speed

 It can be a problem in the trigger system (led trigger, fiber optics, strobe sensitive, strobe time of response) that is resulting in a delay of the actual strobe light release that results in a de-syncronization of the time the shutter is open and strobe duration.

What type of trigger are you using, which strobes?  The line is certainly characteristic of a sync problem - the cause is the strobe exposure starts after the second curtain has started moving.  There can be any number of reasons why this might happen, the trigger may be slow to react or there might be a setting in the menus that has changed to limit sync speed perhaps.

You say it hasn't happened before - does this mean that you've successfully taken shots before with the same setup at 1/250 shutter speed?  And now it does it all the time?  Shooting in TTL or manual?  The more info the better. 

I would suggest a process of elimination.  Test each strobe individually to see if both behave the same.  Test the camera with a different strobe if you have one.  Trigger the strobes using a land speedlite to trigger (outside the housing - set the speedlite  to minimum manual power to trigger it holding a fibre optic up to the strobe. Point the speedlite away from subject)  I would also try changing the trigger batteries.  I'm assuming you are optically triggering your strobes.

To test take a photo in a darkened room with the camera set so the subject is under exposed, set a low manual power on the strobe and adjust camera aperture and ISO to get a good flash exposure at 1/250.  Also of course test to see what shutter speed you need to use to get it to sync correctly.

Thanks for the lengthy response I am using ysd2 strobes and have never had any issue. I did change my setting for single shot and didn’t have any issues. 
 

I will take your advice though and try on land in a dark setting to see if I can replicate the issue. 

8 hours ago, lwang0622 said:

Thanks for the lengthy response I am using ysd2 strobes and have never had any issue. I did change my setting for single shot and didn’t have any issues. 
 

I will take your advice though and try on land in a dark setting to see if I can replicate the issue. 

Be sure to do one thing at a time and take notes!

On 8/21/2021 at 3:47 AM, lwang0622 said:

Hi guys I can’t seem to figure out why my photos have this weird line at the bottom of the photo. (It’s obviously a bad photo but  emphasizes the color diff the best)

my shutter is 1/250 so it’s not that and also bc it’s not a black line. 
 

Is it a shadow or a camera setting? This has never happened before 

 

 

Seems a classic case of too-high shutter speed for sync.

While your shutter may sync to 1/250th, that doesn't mean your strobes will.  It takes a bit of time to fire off the strobes which causes the sync problem.   By the time the strobes fired, one of the shutter curtains was starting to close.

I have the same issue with my D810 in Nauticam housing firing dual YS-D1's via the pop-up flash.   1/200th is reliable, 1/250th is not.