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Archive 2015 · SB 700 in SU 4 Slave Mode

  
 
peter38a
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p.1 #1 · p.1 #1 · SB 700 in SU 4 Slave Mode


I have a D7000 and am using SB700s. I want one SB700 to fire as a straight slave when I am in Commander Mode (CM).

Goal: To control two SB 700 from the camera in (CM) and one in SU-4 mode that can be set manually giving me in effect three groups.

My setup.

The D7000 is in Commander Mode with the pop up on camera flash set at M, 1/128.

The SB 700 settings.

SU-4

Slider to the left of the screen set at Manual

When I set the output to 1/1 my histogram is all the way right. When I set the output at 1/128 my histogram is the same indicating that the flash output remains the same. There must be a way to manually set output because of what use would a slave flash be that only fired full output. By the way all outputs remain the same as described when I try using TTL instead of Manual.

Does anyone know how to manually set the flash output on an SB 700 when set in SU- 4? If you do, I'll… I'll be your best friend!




May 13, 2015 at 07:19 PM
peter38a
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p.1 #2 · p.1 #2 · SB 700 in SU 4 Slave Mode


Fiddling around (not as Rome burns you understand) I got the answer.

When the SB700 is set to SU-4 and dialed to Remote you DO NOT return to the previous ON screen and set the output. You stay on the Remote screen, click SEL and dial in the output setting you want.

Works great, 'course as Columbus said, "It's easy once you know how."
This by the way gives a shooter three groups when in Commander Mode i.e. A, B (set from the camera), and the slave that is manually set.



May 13, 2015 at 07:56 PM
WayneF
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p.1 #3 · p.1 #3 · SB 700 in SU 4 Slave Mode


Not what you want to hear, but a SU-4 unit combined with Commander is not a good plan. The commander flashes commands many times, to request Each TTL group preflash, and of course Each TTL preflash from remotes, and again to set the remote power level in Each remote. That is a lot of flashing before the shutter, each of which can trigger SU-4. You might be able to shield it from the Commander, but not from the Remote preflashes. But the SU-4 is more sensitive than the Remote mode, shielding won't be easy. SU-4 is an optical slave, designed to trigger when it sees any flash. If you're anywhere near full power, it will run out of power before the final flash. It's not a wise game to play when you need picture results.

Even if all remotes are in Commander Manual mode, Commander still has to flash before the shutter to convey the menu power level to Each remote.

SU-4 mode is designed for all flashes to be in REAL GENUINE Manual mode, the mode called M in the flash menu (no Commander).



May 13, 2015 at 09:25 PM
peter38a
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p.1 #4 · p.1 #4 · SB 700 in SU 4 Slave Mode


Thank you very much for your reply. Let me do some experimenting and get back to you. I have to go out now.


May 14, 2015 at 12:56 PM
peter38a
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p.1 #5 · p.1 #5 · SB 700 in SU 4 Slave Mode


Ok, here are my results. Please highlight any mistakes you see.

My camera a D7000 is in Commander Mode.

Pop up set at M and 128

Group A set at M and 1/8

My SB 700 set to SU-4, slider set to Manual and of course Remote.

There is no SB 700 deployed in group A but that should not affect what the camera sends out nor what the SB 700 SU-4 "sees".

When the SU-4 is set to 1/1 it flashes but does not synchronize so that the output does not illuminate my image.

But at each setting below 1/1 e.g. 1/4, 1/16, 1/128 the flash does synchronize with my shutter and my images show the proper illumination both on the back of the camera and my histogram.

Why SU-4 at 1/1 doesn't sync I don't know. More, I don't care much because this flash will only be used for background illumination.

This leaves me with three groups, two camera controlled and one manually controlled.



May 14, 2015 at 09:06 PM
kaplah
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p.1 #6 · p.1 #6 · SB 700 in SU 4 Slave Mode


peter38a wrote:
Ok, here are my results. Please highlight any mistakes you see.

My camera a D7000 is in Commander Mode.
[...]

There is no SB 700 deployed in group A but that should not affect what the camera sends out nor what the SB 700 SU-4 "sees".


The mistake is "... in Commander Mode".

Put the pop-up flash in Manual, not Commander, and control the SB-700 manually from it's own interface.

Or, the mistake is "... sb 700 su-4" - take it out of SU-4 mode, put it in Group A, and control it manually from the camera.

As WayneF said, Commander (e.g., CLS) and SU-4 don't mix, essentially because CLS sends out multiple control pulses followed by a "fire" pulse, whereas SU-4 mode will cause the flash to fire on the first pulse it sees. So don't mix them.





May 15, 2015 at 07:15 AM
WayneF
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p.1 #7 · p.1 #7 · SB 700 in SU 4 Slave Mode


peter38a wrote:
Ok, here are my results. Please highlight any mistakes you see.

My camera a D7000 is in Commander Mode.

Pop up set at M and 128

Group A set at M and 1/8

My SB 700 set to SU-4, slider set to Manual and of course Remote.

There is no SB 700 deployed in group A but that should not affect what the camera sends out nor what the SB 700 SU-4 "sees".

When the SU-4 is set to 1/1 it flashes but does not synchronize so that the output does not illuminate my image.

But at each setting below 1/1 e.g. 1/4,
...Show more



Yes, the mistake is "in Commander mode". Nothing wrong with Commander mode of course, the actual problem is mixing in SU-4 with Commander. Very different systems.

If you want to use manual flash (the SU-4), then turn Commander off, and use manual flash.

It does not sync at 1/1 because the commander signal (to relay the commander menu's manual power level info to the remote flash before the shutter opens) is triggering the SU-4. The SU-4 is supposed to trigger when it sees any flash... and it does. And with its full power expended before the shutter opens, it does not have any power left to trigger again in a few milliseconds when the shutter opens and it is supposed to fire.

You can visually see this two ways. Watch through the viewfinder as you push the shutter button. You will get a strong glimpse of the SU-4 firing just BEFORE the mirror goes up to be ready for the shutter.

Or easier to see, set Rear Curtain Sync, and set a slower shutter speed, like one second (flash is not affected by shutter speed. Ambient may be, but we don't care about exposure for this test). So this means the commander (and the SU-4) will flash just before the shutter opens, and then after one second rear curtain delay, we see the Remote flash trigger, and the SU-4 again (it might be able do something after the one second recycle).

Seems a poor way to run the lighting.

Different subject:

You said "Pop up set at M and 128"

This really makes no sense, Your goal must be that you want it to trigger the remote, but you don't want it to contribute to the picture lighting. But the commander triggering signals do their own thing, before the shutter opens, and this setting does NOT affect the commander in any way.

The 128 power does prevent the popup from contributing much, but the proper way to do that is to set the popup MODE (in the Commander menu), to be "---". This MODE turns the flash part OFF, and but commander still does its own thing before the shutter opens.

There is still the weak trigger signal after the shutter opens, but unless the subject is very close or very reflective, or the aperture is very wide, it is normally totally negligible.

More about all of these subjects at http://www.scantips.com/lights/awl.html
(mostly on the second page there)



May 15, 2015 at 09:51 AM
peter38a
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p.1 #8 · p.1 #8 · SB 700 in SU 4 Slave Mode


Thank you all for your posts. As a guest here, and with limited photo experience, I want to take care not to trod on any toes or seem unappreciative.

To reiterate I wanted my SB 700 to work in SU-4, controlled by my camera popup. No camera shop here in Phoenix could help, nor Nikon USA and I posted to this site as my last hope for help. Shortly after my original post I noticed that when the SB was switched to Remote the screen presented an M and an output number. Duh, I never noticed it before but when I clicked SEL and changed the power output to anything other than 1/1 it does give an output as set, perfectly!

In Commander Mode I changed the pop-up to "--" from 128 and everything works consistently as above. The link to the article on flash is wonderful and I will be pouring over it for the next few days but when it says that Commander and SU will not work together it is mistaken because it works here for me, the day before yesterday, yesterday and today.

Here's something a camera store guy passed on to me. I carry a chrome knob and when I don't have direct line of sight I use it as a reflector and so it far has triggered any flash out of direct line of sight.

Please allow me to say thank you again for your interest and input. May I respectfully suggest that you try what I've described and see for yourself?



May 15, 2015 at 01:07 PM
WayneF
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p.1 #9 · p.1 #9 · SB 700 in SU 4 Slave Mode


peter38a wrote:
Thank you all for your posts. As a guest here, and with limited photo experience, I want to take care not to trod on any toes or seem unappreciative.

To reiterate I wanted my SB 700 to work in SU-4, controlled by my camera popup. No camera shop here in Phoenix could help, nor Nikon USA and I posted to this site as my last hope for help. Shortly after my original post I noticed that when the SB was switched to Remote the screen presented an M and an output number. Duh, I never noticed it before but when
...Show more

It gives some output, but probably not the full effect you imagine.

The usual plan is for optical slaves (SU-4) to be triggered by the other manual flashes. It does not need the popup unless there are no other flashes. But usually, one manual flash is triggered some other way (either PC sync cord or a radio trigger), and it triggers the optical slaves on all the other flashes in sync.

When it flashes at a power lower than 1/1, then less than full power means there is some capacitor energy left, not totally expended. You might assume that it could do two half power flashes (1/2 + 1/2 = 1), but not quite. It will flash twice quickly, but the second won't have full 1/2 power output, because it was not recycled fully to full capacitor voltage again. Flash energy is C * (V squared). V squared is pretty important to full output. Full power output requires full recycle to be Ready again. That takes a little time at higher power levels.

Speedlights always fire at full voltage and full power intensity, and then a timer cuts them off, at say the 1/2 or 1/128 designated power point. At low power, they get short and fast, is why they are called speedlights. But a quick second flash before it can fully recycle will not then be at full voltage, and thus not full power, and then it provides less than expected output (since it was not fully recycled)

It possibly might do two proper flashes at maybe 1/8 power or less. Guessing about the available recycle time, but some flashes (SB-910, SB-800) have a Repeating flash mode, and at 100 ms recycle time (ten per second), they can do 1/8 power. I am not making it up, there are charts in the manuals about this property, about what it can do. It cannot do two proper 1/2 flashes that fast.

But do you really want to run your flash session that way, always double firing the SU-4 unit?


In Commander Mode I changed the pop-up to "--" from 128 and everything works consistently as above. The link to the article on flash is wonderful and I will be pouring over it for the next few days but when it says that Commander and SU will not work together it is mistaken because it works here for me, the day before yesterday, yesterday and today.

Here's something a camera store guy passed on to me. I carry a chrome knob and when I don't have direct line of sight I use it as a reflector and so it far has triggered
...Show more


The flash sensor is more sensitive in SU-4 mode than it is in Commander Remote mode.
Same sensor, but the commander signal is 1) a complex binary encoded signal that must be properly decoded, and 2) is at very low power (probably a bit less than 1/128 power), so that the flash will have some power left for the final contributing flash (see concept above).
It can recycle fast at very low power.

But the SU-4 trigger signal is 1) a very simple detection of any flash at all, and 2) from the strong full working power of the other other flashes. SU-4 is quite sensitive, and the trigger is very powerful, and line of sight should NOT be any concern at all (for SU-4). I put them anywhere in the room without any concern, and they always trigger (not true of Commander).

Did you not determine yet that it was in fact flashing twice (as outlined above)?

So OK, you are not yet a believer, but as you get more experience, you will realize this mixing is the very hard way to do it. Simply not designed to be used that way. Real Genuine Actual Manual Flash Mode (the mode called M in the flash menu, with the commander turned off) works really great, and is simply unbeatable. Might as well do it right, the way things are designed.

Buy a $28 Yongnuo RF-603 radio trigger (transmitter and receiver units), Amazon. Trigger one remote flash that way, with all the other flashes in optical slave mode (SU-4 on Nikon flashes). That should work great, and consistently.

Or if you want to use the commander, then use the Commanders system, which does NOT include any real manual flashes, and certainly no SU-4.

Make your choice, and go with that system. Trying to be helpful.


Good luck.




May 15, 2015 at 03:18 PM
peter38a
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p.1 #10 · p.1 #10 · SB 700 in SU 4 Slave Mode


Let me chew on all this and get back. Thank you for you posts.


May 16, 2015 at 02:46 AM
kaplah
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p.1 #11 · p.1 #11 · SB 700 in SU 4 Slave Mode


peter38a wrote:
Let me chew on all this and get back. Thank you for you posts.

To be frank, here is a better idea: set the D7000 pop-up to Manual 1/128, and try it with your SB-700 in SU-4 all Manual. It will work exactly as you expect it to.You can then chew on that additional data and get back.

You are only wasting time and energy trying to mix Commander (CLS) and SU-4. But don't waste more time chewing on all of the (accurate) info presented: Try Manual and SU-4 for yourself, for the marginal cost of a shutter click.



May 16, 2015 at 12:31 PM
peter38a
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p.1 #12 · p.1 #12 · SB 700 in SU 4 Slave Mode


Ok, I've been at this for two hours or so.

D7000 set to "Rear", Manual settings and shutter speed to one second aiming for my SU-4 which is set at M and output, 1/1. The shutter clicks, there is a pause and the SU fires once, shutter closes and SU recovers in about a second. The SU will fire in 1/1 if my popup flash, Commander is set to 128, not "--".

If I set to Commander and the flash from Group A and the flash is strong enough it will fire a second SB set in Manual, Group C.

Gentlemen, you are princes' to have contributed your time to this problem. I think best is to set all flashes to Manual and work from there.

Thank you all again.



May 17, 2015 at 01:47 AM





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