Problems with shutter speed and strobe. Help!

Hello All. I am a Novice underwater photographer and recently got a macro setup. I have a nikon d100, a nikon 60mm ikelite housing and ikleite ds150 substrobe. In my photos with shutter speeds upward from 250 or so I am getting black on the upper half of the image from where the shutter is starting to close. the bottom half will be a distinguishable image illuminated by the strobe. the faster shutter speed i use the larger the black area will obvioulsy be. In order to produce and acceptable image i have to use a very small aperture to compensate. This is not ideal. Its almost like my strobe is a fraction too slow, but it shows no signs of malfunctioning and fires seemingly normally when the shutter is released. The strobe connectors seem to be fine, and no corrosion etc. I have taken my system out with 2 separate d100 bodies. so it seems very unlikely that the problem lies there. Any suggestions?

cheers,

Kevin Stephens

Your camera can't sync with a flash at a shutter speed higher than 1/180 ... but ... that's ok.

For the subject light by your strobes, the only thing that matters is aperture and strobe power.

Shutter speed will influence the exposure of the background NOT light by the strobes, but is irrelevant to the subject in the foreground.

Hello All. I am a Novice underwater photographer and recently got a macro setup. I have a nikon d100, a nikon 60mm ikelite housing and ikleite ds150 substrobe. In my photos with shutter speeds upward from 250 or so I am getting black on the upper half of the image from where the shutter is starting to close. the bottom half will be a distinguishable image illuminated by the strobe. the faster shutter speed i use the larger the black area will obvioulsy be. In order to produce and acceptable image i have to use a very small aperture to compensate. This is not ideal. Its almost like my strobe is a fraction too slow, but it shows no signs of malfunctioning and fires seemingly normally when the shutter is released. The strobe connectors seem to be fine, and no corrosion etc. I have taken my system out with 2 separate d100 bodies. so it seems very unlikely that the problem lies there. Any suggestions?

 

cheers,

 

 

Kevin Stephens

Use a shutter speed less than 200. Strobe can't seek faster that that. Apeture and ISO exposes for you foreground and background exposure. The shutter speed is for the back ground exposure and the stobe power is for the foreground exposure.

With your maco setup try this: ISO 200, Apeture F16 or F22, Shutter speed 200, Flash in Manual at 1/2 to 1/4 power. Take a shot and adjust from there. i.e. if the back ground is too dark, then lower the shutter speed. If the foreground is blown out, reduce the strobe power.

Kirk

Use a shutter speed less than 200. Strobe can't seek faster that that. Apeture and ISO exposes for you foreground and background exposure. The shutter speed is for the back ground exposure and the stobe power is for the foreground exposure.

 

With your maco setup try this: ISO 200, Apeture F16 or F22, Shutter speed 200, Flash in Manual at 1/2 to 1/4 power. Take a shot and adjust from there. i.e. if the back ground is too dark, then lower the shutter speed. If the foreground is blown out, reduce the strobe power.

 

Kirk

Sorry ... that's just bad advice.

A) The limitation is the camera, not the strobe - my D700 will sync at 1/320th and cameras with electronic shutters (like Point & Shoots and (I think) the Nikon D70) can sync at any shutter speed

B) The D100 can't sync faster than 1/180th - look it up

In my photos with shutter speeds upward from 250 or so I am getting black on the upper half of the image from where the shutter is starting to close.\

 

cheers,

 

 

Kevin Stephens

like Jeremy said, this is normal behavior, don't shoot with a faster shutter speed than 1/180th

Sorry ... that's just bad advice.

 

A) The limitation is the camera, not the strobe - my D700 will sync at 1/320th and cameras with electronic shutters (like Point & Shoots and (I think) the Nikon D70) can sync at any shutter speed

 

B) The D100 can't sync faster than 1/180th - look it up

Didn't know that the D100 syncs at 1/180. I thought it was 1/200th. I was trying to get him a starting point. What I should have said was to set the Shutter no higher than the fastest synch speed.

Kirk

thanks alot guys. this has been very helpful. its kind of a shame the camera cant synch with faster shutter speeds. i thought i was using my strobes' lowest power setting and it was still overexposed so i guess i'll have to master all the settings in manual including ISO to achieve the exposure i want. I got my setup second hand so i didnt get a manual with my strobe. can anyone quickly explain the power settings and what the numbers really mean or how they relate?

Other options off the top of my head, as a similarly ignorant noobie though so take for what they're worth:

What ISO are you shooting? Drop it to ISO100 or 50 if the camera allows it.

Diffuser on the strobe? Angle it away a bit, etc.

I don't know if setting the strobe (did you mean DS160?) to TTL and using the TTL-compensation to bump the power down to the minimum available in that mode might work better than manual at low power...I'm guessing not since at macro ranges and subject sizes (considering the spherical 'power distribution' of the light hitting a small close subject vs. the 1/r^2 dropoff hitting a larger, slightly more distant subject) there's just not time for the strobe to be quenched. [sCRATCH THAT - just read that the Ike D100 housing didn't have TTL at all, so nevermind...]

yeah i said ds150 strobe i meant ds-50 of course

Good question,

If you have a manual connection between the strobe and camera, the camera doesn't "know" there is a strobe and will fire at any shutter speed. The shutter curtain will begin to appear in the frame once you exceed your camera's sync speed. The D100 uses D-TTL and many of the Ikelite housings came out before the D-TTL was "deciphered" (thus manual strobe control only).

This should never be an issue when shooting macro - just set your camera at the max shutter speed (in simple terms).

Cheers

James

can anything be done to get it to work with D-TTL?

I don't know that it would make a difference, aside from the camera at least 'knowing' a strobe was attached and not pushing the exposure time too fast. At macro distances, there's not enough time to 'quench' the strobe to drop the subject lighting, I don't think. So you'd still be controlling subject illumination by dropping the strobe power (or going to a smaller aperture).

So to clarify, you have the DS50 which has only "manual" or "TTL" selection on the strobe, and no power options? You have the Ike D100 housing, which has only the sync cord connection for the hotshoe adaptor, but also has no power settings on the housing? So you are 'dropping' strobe power solely with in-camera settings, if your menu has a strobe power adjustment feature (which most do, but don't have much range on them)? And now that you know to use a minimum 1/180th exposure, you're concerned about subject overexposure because your aperture can only get so small, or because you also want to preserve a narrower DOF?

If all the above is correct, then the only new suggestion I'd have is to add a manual controller to the chain: http://www.ikelite.com/web_pages/mansensors.html ...the controller can connect between your camera and the DS50 and be used to drop the strobe power (as well as having a built-in slave sensor for optical triggering, but I don't think you'd be using that). Or upgrade to the DS51 which has TTL and manual with power level options on the strobe itself.

You could also go 'low tech' and make a thicker diffuser out of a couple layers scissored from a plastic milk jug, to drop the strobe power further and spread it out a bit.

Or how about moving the strobe back - lol. Come on now - the brain trumps technology every time :-) Every foot you move the strobe back is one stop of light = cutting the power in half.

The suggestion to use the diffuser is a good one too.

A good starting point for macro w/ the D100 (I used to own one btw) is ISO200, F16 or f22, and a shutterspeed of 1/180th

Cheers

James

Shooting macro, I didn't think moving the strobe 'back' was usually an option, as then your port gets in the way of the illumination, hence the use of ring-flashes? But you have a point about using technique vs. technology...I wasn't really promoting the 'upgrade your gear' options as the best choice, just trying to understand what his current limitations were and give him the options.

Shooting macro, I didn't think moving the strobe 'back' was usually an option, as then your port gets in the way of the illumination, hence the use of ring-flashes? But you have a point about using technique vs. technology...I wasn't really promoting the 'upgrade your gear' options as the best choice, just trying to understand what his current limitations were and give him the options.

Back when the earth's crust was still warm, that IS the way I would backet macro with a Richon R/F camera (in ikelite) or Nikons IVa and Vivitar strobe (in ikelite). One shot close, the next about even with the camera focal plane, the last about a foot futher back. I rarely wanted the light to be flat. I would angle the strobe to the subject to create some depth to the shot. With an angled strobe the shot will not be blocked.

Bob

The earth's crust is still warm today, just not everywhere. And by that token, I'm still covered with a thin gooey layer of amniotic fluid, photographically speaking, and have zero personal experience with macro U/W. So I for one bow to my decrepit macro-shooting overlord's advice.

Yeah I have a manual controller to adjust the power output. It goes F, .5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5. so Is "F" full power and is .5 the lowest? I was using .5 which i assumed was the lowest setting with ISO200 1/180 and F22 and was still getting a bit of an overexposed image but i think i can sort this out. it just doesnt seem that i'm gonna have much freedom choosing narrower depth of field options.

Aha! You have a manual controller! Now that changes everything :-)

No, .5 is essentially 3/4 power. 1 (really -1) is half power. Try experimenting out of the water and take a series of shots at the same Fstop and shutter speed, but adjust the flash power in each shot.

Cheers

James

Yeah, those settings are "F-stops down" from full (F). So on the controller the 4.5 is the "lowest" power setting, I believe.

So looks like if you were shooting at ".5" (the first setting down from full) you actually do have a lot more control range than you thought. Give it a try above water in a controlled environment sometime and see.

I don't have one of those anymore, but I used to use one back when I had a DS50 and was using it to optically slave to my little Canon point and shoot.