Beginner question about operation of YS-D2J strobes

[WyattGlynn]

I looked through the manual for my YS-D2Js, but it seems lots of UW photography equipment manuals assume you already more or less know what you're doing. As a newbie to all of this, I have a couple questions I'm hoping someone can help educate me on.

1) When shooting in manual mode, I notice the power level dial is measured in f-stop values. I assumed you should match up the strobe dial to the aperture you're using IF you're shooting at the ISO and distance that the guide number is measured at, but I realize that is probably a dangerous assumption.

2) Mode setting: I under stand the Manual modes (flash and pre-flash) and shoot in "DS-TTL" with my fiber optic cables, but there is also a "Slave" mode. Is that an optical slave - i.e., it wirelessly slaves off the other strobe by reading it's pulses? Or something different altogether?

Thanks in advance for any wisdom anyone is willing to share!

 

[Chris Ross]

It is marked in stops and this will be accurate for the difference between the settings. Guide numbers tend be works of fiction and somewhat optimistic and often measured in air, it might be close in air, but I wouldn't count on it.

To start out, set your self up with your rig as you would take it under water (including your interpretation of strobe angles required) in a darkened room with a plastic toy or something about the size of your expected subject position your strobes and take a test shot at your expected aperture, review exposure and adjust till the exposure looks right. That is you starting point for that aperture and distance. If you are shooting macro and somewhere in the range of less than 0.5m (20") from your subject it should be pretty close. You want a darkened room so the lighting in the image has mostly come from the flash.

If you are shooting wide angle and using a m43 or DSLR shooting at f8-11 range and ISO200-400 range start at half power and adjust from there.

Once you are underwater start with that setting and adjust as required to get your exposure where you want it. Shutter speed will likely be 1/125- 1/250 range at maybe f8 and ISO200-400 range for nice background water rendering if you are in clear water and not too deep. I used 1/250 @ f8 ISO400 when I was shooting at Catalina Island and including water as a background . A bit more flexibility with macro as often you are trying to exclude light from the BG or maybe the shot is 100% strobe lit. The advantage of doing your initial dialling in on land is you can get close to where you should be and take that out of the equation when you are UW.

Start shooting at similar distances and keep your f-stop constant till you get used to adjusting flash exposure. Once you have an exposure sorted at a given distance if you stay close to that distance your exposure won't vary. Once you are getting good results branch out to different distances and then different f-stops. Pick you starting aperture according to your sensor format, try f8 for m43, f11 for APS-C and maybe f16 for fullframe this is based on decreasing depth of field as the sensor size increases.

 

[WyattGlynn]

It is marked in stops and this will be accurate for the difference between the settings. Guide numbers tend be works of fiction and somewhat optimistic and often measured in air, it might be close in air, but I wouldn't count on it.

...

Thank you! Some good tips there!

 

[conundrum]

1. Turn your camera to manual mode and fix the ISO to the lowest (100 or 200 depend on camera model)
2. fix you aperture to 5.6 or 8 on compact camera, or 8 or 11 on MFT, DSLR camera.
3. Switch on the strobe to non-pre flash or pre-flash (depend on you camera) .
4. Turn the power adjustment knob to full.
5. Test shot. If the picture too bright, reduce the strobe power. If the picture too dark, increase the aperture to greater number.

 

[WyattGlynn]

1. Turn your camera to manual mode and fix the ISO to the lowest (100 or 200 depend on camera model)
2. fix you aperture to 5.6 or 8 on compact camera, or 8 or 11 on MFT, DSLR camera.
3. Switch on the strobe to non-pre flash or pre-flash (depend on you camera) .
4. Turn the power adjustment knob to full.
5. Test shot. If the picture too bright, reduce the strobe power. If the picture too dark, increase the aperture to greater number.

Thanks. I get the basics of testing my strobes, but I was more so curious as to how the aperture values on the strobe power dial corresponded to the actual aperture of the lens, if at all.

 

[conundrum]

Thanks. I get the basics of testing my strobes, but I was more so curious as to how the aperture values on the strobe power dial corresponded to the actual aperture of the lens, if at all.

The aperture value on the strobe is just for increase and decrease the output power in manual mode. Most of the cases the aperture value on strobe and camera do not relevant. Just think that the more number, the more power output.

 

[ReadyDiverOne]

@WyattGlynn : I think if you research this on this board and on WetPixel you will find a fair amount of guidance (sorry about that) on this topic. Long story short, @conundrum is right: the guide/aperture numbers are really only power levels; they don't correlate in any meaningful way to underwater aperture choices. And, as stated above and elsewhere, the only way to figure out what level to use for a particular underwater shot is trial and error. The advice above is good: if using a compact camera, start at about 1/125 shutter, 100 ISO and F6.3, set the strobes to flash or preflash (one or two lightning bolts) (most compacts are pre-flash), set strobe power to mid-strength, take a shot and see what it looks like, then adjust power up or down or move in or out, etc. I have spoken about this issue at length with the pros at Backscatter and BlueWater Photo and they all agree, the guide numbers are just that, merely a guide/guess.

Happy shooting.

 

[WyattGlynn]

The aperture value on the strobe is just for increase and decrease the output power in manual mode. Most of the cases the aperture value on strobe and camera do not relevant. Just think that the more number, the more power output.

Thanks! I had kind of figured that was probably the case, but figured I should ask if I wasn't sure! I appreciate the response!

@WyattGlynn : I think if you research this on this board and on WetPixel you will find a fair amount of guidance (sorry about that) on this topic. Long story short, @conundrum is right: the guide/aperture numbers are really only power levels; they don't correlate in any meaningful way to underwater aperture choices. And, as stated above and elsewhere, the only way to figure out what level to use for a particular underwater shot is trial and error. The advice above is good: if using a compact camera, start at about 1/125 shutter, 100 ISO and F6.3, set the strobes to flash or preflash (one or two lightning bolts) (most compacts are pre-flash), set strobe power to mid-strength, take a shot and see what it looks like, then adjust power up or down or move in or out, etc. I have spoken about this issue at length with the pros at Backscatter and BlueWater Photo and they all agree, the guide numbers are just that, merely a guide/guess.

Happy shooting.

Thanks. I didn't mean to seem unappreciative of the feedback given above, as that wasn't the case at all. I had tried looking on this forum for the information regarding strobe power as measured by f-stop values, but maybe was naive in limiting my search to YS-D2 strobes. I appreciate the guidance!

 

[ReadyDiverOne]

No worries! Happy shooting!