OCF, Settings on flash and camera, etc. ???

OK, Just when I think I know what's going on things don't work like I think they should.

Camera: D7100
Flash: Yongnuo 568EX

I want to use the flash in Manual Mode and use the CMD mode of the camera to trigger it. (In all reality I'm probably confused on the functions I want to use. Ha!) Right now I am trying to stay away from iTTL so I can get a feel for the flash power levels and camera settings.

Looking at the camera E3 custom menu
I have tried setting the
"Built in flash" to CMD, --, .
Group A to M, 1/1 to 1/128 and settings in between

The 568 is set to Sn2 and M with various power and zooms to look at changes. (I did also have the flash set on Sn1 but it fired from the preflash on the camera, I think.)

All in all the various changes do not seem to work. It is like the flash power has a mind of it's own.

I have been able to use the flash with the D5300 and have it triggered by the Built in Flash (set at minimum power) and adjust the power output of the flash at the flash.

Is the CMD mode on the D7100 only good for iTTL and to shoot with the Flash in iTTL mode?

I have done some searches, but most of the info is how to get the flash to work in iTTL mode, nothing in manual.

Any help in plain English will be appreciated. Ha! I know wireless triggers (which are probably in my future) are another answer. I think what is mostly confusing me is the CMD mode vs a flash built in or otherwise firing the remote 568.

I don't think I've tried exactly what you are wanting to do with CLS, but have done similar with radio triggers.

Did I understand right that you have the 568 set as TTL and set to be triggered by CLS? The master control of settings still uses the TTL signalling, it's just sending your manual power settings to the remote vs having the camera Pre-flash and send its suggestion to the light.

If you set the 568 to M, then it would just be taking an optical trigger and would need the setting to be set directly on the speed light (and it could be triggering on the CLS Pre-flash instead at the time of shutter release.


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Thanks Charlie for your feedback.

Really, I am scratching my head which now has more cleared areas than it has hair. Ha!

If the camera is set to CMD mode for the built in flash, the options that exist are:
1. Set to -- means that it will send a signal to the OCF but it will be very, very low power.
2. Set to M the built in flash power can be changed and still trigger the OCF (Optically)
3. Set to TTL the built in flash's power will be adjust according to what the camera reads for exposure and will trigger the OCF (Optically)

Group A
1. Set to -- means any OCF set to Grp A will not be fired
2. Set to M means that the OCF will...................... I'm not sure but I assumed it would vary the power on the OCF by what ever was set on the camera ie 1/1 - 1/128
3. Set to TTL means that the OCF will have the power adjusted by what the camera decides needs to be done exposure wise

Group B--Ditto to Group A only the flashes set to Grp B will be the ones affected.

Now for the flash.
If the mode is set on the OCF to iTTL, (matching the group A or B) then when the camera also set to TTL for Group A, it will flash with the power determined by the camera.
If the mode is set on the OCF to Sn1 or Sn2 does the camera settings ever change the power output of the flash or is it all done at the flash?


I'm trying to get this straight because the shot that I submitted in the weekly challenge, Leaves, was a disaster using the flash. Nothing seemed to increase the power much. I ended up using an LED work light and light from a dining room over the table light to get what I was looking for.

I hope this gives some better insight into my confusion. Ha!

cwgrizz said:

I want to use the flash in Manual Mode and use the CMD mode of the camera to trigger it. (In all reality I'm probably confused on the functions I want to use. Ha!) Right now I am trying to stay away from iTTL so I can get a feel for the flash power levels and camera settings

Click to expand...

You cannot use the commander to trigger optical slave triggers. The Commander is a very different system entirely. Remote flashes must be in REMOTE mode to use Commander.

Because, the commander does lots of flashing before the shutter opens for the final flash, for example, flashing commands to set each remote flash group to its proper power level. This flashing will trigger the optical slaves too early, before the shutter opens. Won't be useful. S2 mode can ignore simple TTL preflash, but it cannot ignore all of the Commander flashing. Simply very different systems.

To use the remote S1 optical slave system, and trigger with internal flash, then instead set the internal flash to Manual (not Commander) and set a very low Manual power level for it, which should be sufficient for triggering.

Commander system is simply NOT to be mixed with other manual flash gear.

There are a few ifs and buts (see Using the Nikon CLS Remote Wireless Flash System - Part 2 ), but why fight the right way?

Thanks @WayneF for your info. I am going to go back and read your article again. It should "soak" in better now that I have been playing and am somewhat familiar with the different settings. In my mind, I was confusing what the CMD mode was. I felt it was a "better" trigger as in more reliable than the optical mode I used with the D5300. I see now that I will have to shoot the D7100 in the same way as I do for the D5300 for the manual OCF. I will look into the CMD mode and remote setting on the OCF to see how things change.

After I read your article, I am sure I will have more questions.

The Commander is just the same optical mode, however it is extremely more complex data, dealing with all the complex binary signals the Commander has to deal with (in the Nikon Commander system). For one example, the Commander has to relay the manual power settings from the Commander menu to all the remote flashes. Or TTL metering and setting those power levels too. That is a lot of flashing, before the shutter opens.

All of this flashing is all close together, humans only recognize one big flash, but Commander does very much flashing of commands before the shutter opens. We can better recognize there are two groups by setting Rear Curtain sync with a long shutter duration (like one second), and then we at least see the two groups, right before the shutter opens, and again before it closes. But the first group has lots of flashes in it.

You COULD set the mode of all commander groups (A & B) to mode "- -" (off), and set the internal flash mode to MAN and lowest power, and that probably works to trigger S1 optical mode. It suppresses most of the data signals. But why? When you can simply set the internal flash to real Manual mode at lowest power, to be compatible with the design.

The S1 optical mode in the flash merely needs to see a simple flash, any simple flash. Best not to confuse it, especially before the shutter actually opens.

Re Questions: I hate to post and then leave, but after this morning, I won't here be for several days now.

WayneF said:

Re Questions: I hate to post and then leave, but I won't here be for several days now.

Click to expand...

No problem. That will give me a lot of time to play and formulate my questions that I am sure I will have.