MACRO

Need help please. Have just purchased a canon 100mm usm f2.8 macro lens. Using canon 10D with

ikelite housing and one DS- 125 substrobe with diffuser on left arm. Have have 4700 k 20 W video

light on right arm with diffuser also.

Have strobe set to TTL camera in manual mode 1/180 sec F 22 and ISO 100 settings. Note shooting in RAW.Distance 1.5 feet from objects. All photos very underexposed but in focus. Tried with diffuser off

strobe and not much better. EV lights on housing unable to adjust + or -. Yellow TTL LED working on housing.

Just wondering is it best to revert back to manual settings and the formula GN = Fstop * distance.

Any input greatly aprreciated.

Mark.

f22 at iso 100 with a single strobe at a distance of 1.5 feet (camera to subject) might require too much light from the strobe. Try again, start slower (e.g f5.6) and work your way to f22. Make sure your strobe is properly aimed at the subject. Also make sure your strobe is not way out from the lens on long arms ... remember the light has to travel from your strobe to your subject, then back to the lens.

Also, to test the system first, try a shot on land with the strobe and camera aimed directly at a mirror. The strobe should quench very fast. You should end up with a dark photo, but with a very bright spot where the strobe is reflected n the mirror.

I am assuming your Ikelite housing has the TTL circuitry built in?

"EV lights on housing unable to adjust + or -. Yellow TTL LED working on housing."

This worries me a bit. Why can't you adjust the flash compensation? You should be able to adjust it up or down. That might indicate bad/damaged circuitry.

Cheers

James

"EV lights on housing unable to adjust + or -. Yellow TTL LED working on housing."

 

This worries me a bit. Why can't you adjust the flash compensation? You should be able to adjust it up or down. That might indicate bad/damaged circuitry.

 

Cheers

James

Thanks to both of you for your help.

Have set up camera over weekend. Took photo with port facing mirror and strobe in TTL. Have white

spot in centre of photo.Strobe quenched fast.

Now flash compensation on housing working.Maybe hot shoe connection issue don't know?

Note after taking pic against mirror the strobe tried to recharge giving a lot of high pitched beeps.Then

died after 4 more flashes.Usually it just squeels up to point of recharge...?

Thanks,

Mark.

Hi Mark,

If you look on page twenty of your strobe instruction manual you will see a chart for manual settings for your strobe. At ISO 100 and F/22 it shows that the strobe needs to be one foot or less from the subject without any diffusers on the strobe. In TTL the power is not going to get any stronger so I would suggest you move the strobe more like eight or nine from the subject and test again.

Learning to shoot in manual will go a long way to helping you understand how the TTL will work at any given setting.

Phil Rudin

Now flash compensation on housing working.Maybe hot shoe connection issue don't know?

 

 

Mark.

That will typically be a problem with the hot shoe connector being pushed backwards when pushing the camera into the housing. Test the compensation before diving, and if it doesn´t work, open and push connector forwards.

Bent C

You are too far away. Even the sunny 16 rule gives you a only 1/100th at F16 on a sunny day. Slow down your shutter speed, water works great as the poor diver's image stabilizer. Try 1/125 or 1/100 Shutter speed.

s.

1/60th @ f8 is my starting point for macro I then bracket around that depending on what I am trying to achieve. 1/100 @ f22 seems a bit extreme plus I tend to stay away from f16 so that I can get most out of the optics of the lens.

You are too far away. Even the sunny 16 rule gives you a only 1/100th at F16 on a sunny day. Slow down your shutter speed, water works great as the poor diver's image stabilizer. Try 1/125 or 1/100 Shutter speed.

 

s.

I certainly agree with getting getting closer. As for slowing down the shutter speed that is partially correct in that it would of course increase the exposure of the ambient light. The strobe exposure however is independent of the shutter speed. If a picture was taken in total darkness, any shutter speed in the strobe's sync range would produce the same exposure. OK I am just being picky

Oy

What ISO are you shooting at? Here's why I ask........

I had one guy getting an all yellow cast in his close macro photos from the DS125 modeling light. His DS125 WAS putting out a "blip" of strobe power as you indicate. He was also shooting at ISO 200 which for being on top of a macro subject isn't necessary.

Try ISO100 and move your modeling light BACK so the camera / strobe combination doesn't think there is so much light already, thus the TTL camera to strobe calculating to not put out much of a flash.

Also back off a bit to F16 and see if the DS125 puts more of a proper flash.

Finally, at ISO 100 and even at F16 there is a MINIMUM distance the strobe needs to be for TTL to work and quench your flash avoiding overexposure. Pushing in closer is often not the answer

Good luck and let us know how it works out!

dhaas