Power Commander Mode - help/tips/a few questions

2WheelPhoto · May 30, 2011

Hi, I have a D7000 and am crazy about this power commander mode. I want to learn how to use it and the manual doesn't explain any tips, only how to configure.. I'd appreciate if you could help me out and share your expertise with any or all of the follow. I tried searching the forum and youtube but couldn't find the info. Maybe its so simple its just not addressed. Thanks in advance for help!

a) I need more gear, last night i spent time using a remote sb-600 and also using the flash on cam (not disabling it). Are there any "aftermarket" or ebay non-Nikon flashes that are cheaper than the SB's that will work? Or are there some that will receive the fire command but may won't do TTL, but work great as just back-light or lighting the inside of a building or such that I can use instead of the SB series?

b) when shooting a person on car/motorcycle or downtown near glass buildings or such, do you control flash glare by angle of the light or is it suggested to use the same polarizing filter on lens as when shooting water and such in daylight?

c) I don't understand "groups" yet and it seems if my remote SB-600 was far or if it was directly behind something such as hidden "behind" a tree trunk facing up into tree it failed to fire. Can I use a group "A" SB master flash to relay to an even more distant group "B" flash, or is this a silly thought?

Big Mike · May 30, 2011

There are probably some off-brand flash units that are compatible with your Nikon TTL/CLS system. They are all pretty much 'reverse engineered', so they may not have 100% compatibility.

You certainly can use about any flash unit without TTL and just have it fire. You may have to have a way for it to be triggered. One way is an optical slave cell. Some flashes have this built-in, but you can buy cheap ones to add as well. The problem with this, is that your Nikon TTL system, uses pulses of light from the master flash to communicate with the slaves....and these will trigger any optical slaves prematurely.

The most common solution that photographers use, it radio flash triggers. They have been talked about extensively on the forum, so just look around.

b) polarizing filters won't remove all of the reflections from glass etc. Sometimes none...so they aren't really a solution. Careful placement of your subject, lights, camera etc. are the way to control the situation.

c) The groups are for setting power levels, and thus lighting ratios. For example, you could set all lights in group B, to fire at less power/exposure than group A.
Your problem of the light not firing behind the tree, goes back to the communication. It's light from the master to the slave...and if the slave is behind a tree, it doesn't have line-of-sight...so it may not work. This is another reason why we like to use radio flash triggers. They are more more reliable than optical/flash communication.

2WheelPhoto · May 30, 2011

thank you very much

KmH · May 30, 2011

It's just Commander mode. Your SB-600 user's manual has a fair amount of information about CLS, and how to use it.

Get this book: The Nikon Creative Lighting System: Using the SB-600, SB-800, SB-900, and R1C1 Flashes

Nikon's CLS is an IR (InfraRed) optical system that uses light to work. So it is limited to line-of-sight, which is why " if it was directly behind something such as hidden "behind" a tree trunk facing up into tree it failed to fire".

CLS also has fairly limited range because of the Inverse Square law, and in direct sunlight CLS's IR signal is overwhelmed by all the IR light the Sun puts out, and range is seriously reduced.

That's why so many shooters use an RF (Radio Frequency) system instead.

I made this image using CLS a SB-800, and a SB-600;

2WheelPhoto · May 30, 2011

Thanks for putting me on the book, I will have it. Beautiful pic, I have to assume one cam in the booth one out, and a long shutter speed to capture the background?

KmH · Jun 1, 2011

If you look close at the lower right corner of the phone booth you can see the SB-600 I used to light the interior of the phone booth. Note, the phone booth door is opened just enough for the SB-600 to shoot inside.

The phone booth used to be right outside my store. On my way to the post office one day I realized there weren't very many phone booths around anymore, and that this one would also one day disappear. (it is now gone)

So, I stood there and thought about how I would want the shot to look, and how to shoot it to make it look as I invisioned.

I set up my lighting gear early, waited till the light looked about like I wanted, and made the shot at dusk with the Sun setting well to camera right. The shutter speed I used was 1/200 to make the sky darker than it really was at that time.