Please tell me where I'm going wrong with lighting

[canasta]

OK...
Would REALLY like some help to save what little hair I have left

So it's night-time..
I'm in a room lit by 6 x 60 watt bulbs so I can see what I'm doing

I have my sb-900 off camera set to auto and remote
Nikon d700 is set to commander mode
(Built in flash - Mode -- to stop the on board flash affecting anything)

I ALSO have 2 x these (http://www.interfitphotographic.com/Lighitng/Product%20Pages/EX150mkii.php)

I ALSO have an illuminated background (http://www.warehouseexpress.com/buy-lastolite-hilite-background-6x7-feet/p1016777)

YET.....the only way I can get anything half decent is to chuck the ISO up to about 1000 which I dont really want to do.

I'm trying to get this sorted for a few portrait shots on Wednesday night - ideally I want to shoot at 125 with f5.6 to f8
but to get ANYTHING correctly exposed tonight I have to shoot at 3 or 4 with widest aperture (2.8)

Can anybody help ....are these lights just not powerful enough to illuminate the room at night??

It is a large sunroom....during day catches loads of sunlight

I've been sat here for 3 hours trying all sorts of angles and settings....and am nearly banging my head against the wall.

regards
Doug

[jerryph]

You will be pulling out the last few hairs after I tell you what the issue is for not thinking about it and how simple it is to address... lol

You cannot mix CLS/AWL and manual studio lighting (well you can but NOT the way you are doing it!). What is happening is very simple... your D700 is using pre-flashes to trigger your SB-900 and it is those pre-flashes that are triggering your monolights which I am willing to bet you have in slave mode.

Here is how you do things:

- Set the SB-900 into SU-4 mode
- Set the power of the SB-900 manually to something like 1/4 or 1/2 power.
- Set the power of your monolights to something like 1/4 to 1/2 power

Here is the trick...

Set the D700 to ISO 200 and the D700's built-in camera flash to FULL MANUAL MODE and set it to something like 1/64th.

Take a test picture and enjoy seeing everything extremely overexposed. Turn down your lights until you get the effect you need... all manually. If you do not want your on camera flash to contribute to the scene, set it to a low number like 1/64th or 1/128th. As long as the other lights can detect that one single flash, they will all trigger in sync.

Now, here is why it is happening... you did not understand how the D700 flash in TTL mode works.

It sends out several pre-flashes that tell the SB-900 at what power to set it self, fire off a test preflash of it's own, the D700 then meters off of that preflash, adjusts the power on the remote flash with another preflash, the remote flash reads that flash from the camera, then adjusts it's power to match what the D700 needs and on a final pre-flash synchronizes itself to the flash on the camera to fire that last flash that will expose the frame for you when the camera shutter opens. Now, it is a little more involved than that, but that is the gist of it.

During this process, your monolights see the FIRST pre-flash, fire off their own flash BEFORE the camera shutter opens, leaving you with an underexposed picture and no matter what power settings you adjust the monolights to, it changes nothing. They do this because they do not speak CLS, they do the job properly which is fire at the same time (or within a few thousands of a second) of the first light they detect in the room... whether that is your camera or someone else's camera.

Time to do some more reading Doug... so that you better understand how your camera works. I really suggest that you get the eBook from Thom Hogan about your camera. :)

[canasta]

Aww gee....BIG THANKS Jerry!!

Yes - got that book (its awesome)...now need to READ IT!!!
But that will probably take until December ....it's HUGE.

Once again - thanks for taking the time to explain this
Don't need to buy a wig now....

[canasta]

WHOO HOOO!!!!!!!!!!!!!!

Glorious white blinkies covers my screen at 80

You ARE the man!!!

[jerryph]

LMAO... never saw someone so happy to get a completely blown pic!

Glad I could help. :)

[canasta]

Thanks again Jerry!

Had a great two hours with this model and got some great Hi Key shots in. I learned loads!! BUT...wish i'd got her out another few inches from the background (or turned the backlights down a tad)...its JUST blown out her fine hairs (which I've learned is a good reason to go thethered when in studio - the LCD just didnt show me that detail was lost)

I since got myself a couple of Pocket Wizards and an extra speedlight (which is why I've kinda been quiet on here trying to get to grips with them...)