Does a ikelite strobe work on a PT-23 housing, TTL ?

[AUTiger]

For best results, you'll still be using manual settings (ISO, aperature, shutter, maybe exposure compensation) no matter what camera you choose. Some hard core photographers still use manual flash output control on top of the rest.

David

I was thinking of buying his set up. I don't like all these manual settings with the Olympus housing's. By the time I spend another $250 changing the bulk head, i could have just bought a Ikelite housing

 

[bobf]

..........everything is coming out white, from way to much strobe light..................

I'm afraid you are not using the manual controller properly. Follow this link:

http://www.ikelite.com/web_pages/mansenswitch.html

You'll notice a passage on the right hand side that states:

The SubStrobe must be set to TTL mode when used with the Manual Controller to receive the predetermined quench signal for the power chosen.

I know it sounds confusing, but TTL is the correct setting on the strobe head when using a Manual Controller to dictate how much influence the strobe will have in manual mode. Do not set the strobe to F, 1/2, 1/4, 1/8 when using the EV manual controller.

......because the Ev controller is set to 4.5 , which is the lowest setting, and the strobe set to 1/8th power, which is less then 30 watts, and I'm still overexpossing the background with to much light.

I don't think it works that way. Also, 1/8th power relates to strobe intensity whereas watt-seconds (the correct term is Ws, not watts) refers to stored energy.

And if the background is indeed also being overexposed, then that is a function of shutter speed and aperture (and ISO)............unless the "background" is within reach of the strobe's light.

Next time out, try setting your ISO to its lowest available setting on your camera (100 or 64 is fine). Attach the diffuser to the DS 125. Set your camera to manual (not "P"). Choose an aperture of f/4 and a shutter speed of 1/125 sec. Set the Manual Controller to somewhere in the middle of the offerings (2.5?). Then follow the digital mantra..........Shoot, Review, Adjust, Shoot Again.........

Too much light in the foreground? Dial the manual controller a click or two closer to 4.5. Not enough light illuminating the foreground? Choose a setting on the Manual controller closer to F (full dump). But I doubt you will need "F"..............

Background too light? Try a faster shutter speed. Background too dark? Try a slower shutter speed.

You can practice this topside in a dimly lit room...........or outside just after sunset......just remember the settings will not be exact once submerged because light travels much easier through air than it does water.....

hth,
b

 

[bobf]

With my C-5060, which is similar to the 8080, I followed the settings on this page:

http://www.splashdowndivers.com/photo_gallery/underwater_photography/up_settings.htm

They got me off to a good start. I agreed that f/5 and 1/100 is a pretty good starting point. I used a DS-125 with a slave sensor and the Oly housing for a year.

As I think was mentioned, look at the exif data for your picturs and see what the shutter speeds and aperatures were. Compare them to f/5 and 1/100. If the f stop is smaller, then the picture will more exposed (eventually being overexposed as you get too wide). If the shutter speed is faster, then the backgrounds (non-flash zone) will be darker and they will lighten up as the shutter speed decreases.

David

Dave,

Sorry I missed this while I was writing my reply...........good advise.........I agree with all.........and Peter Schulz's web site is chock full of great info.....

......If the f stop is smaller........

To clarify, you mean if the f/stop "number" is smaller than f/5.......knowing that a smaller number actually means a larger opening (aperture)...........then the picture will become more exposed........for instance f/4 is a smaller number than f/5, but actually refers to a wider aperture..........

regards,
b

 

[bobf]

...........
To clarify, you mean if the f/stop "number" is smaller than f/5.......knowing that a smaller number actually means a larger opening (aperture)...........then the picture will become more exposed........for instance f/4 is a smaller number than f/5, but actually refers to a wider aperture..........

how about a clarification of my clarification..........(and traditionally speaking*)........

When stating f/stops you'll notice I always include the "/" sign. The reason is because when stating f/stops, we are actually describing a fractional calculation.......based on division...........a relationship between the focal length and aperture. For instance:

f/4 refers to the fact that the aperture's diameter is the focal length divided by 4.

Say the focal length we chose for compositional reasons was 100mm and the diameter of the chosen aperture measured 25 mm...........100 divided by 25 equals.........4..........or stated in photographic terms f/4.

iow, we chose an aperture diameter that was 1/4 the length of the lens' focal length

If the focal length was 100mm and the aperture was only 20mm wide, the f/stop would then be described as f/5 (100/20=5).

So you see, 5 is a larger number than 4, but it actually refers to a smaller opening......just as 1/4 is larger than 1/5.

One more example..........

Say the aperture remained at 25mm, but the focal length was shortened to 50 mm.....
focal length/aperture
50/25=2
or f/2!

hth,
b

*covering myself against new fangled products that through advancements in technology do not limit themselves to "the old ways"...........