SU-800 vs SB-900

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I have both, but don't use the SU-800 at all. I searched and read all over, but still can't make up my mind.

In thinking about it, I could only come up with 2 reasons to have the SU-800 - the weight of the SB-900 (which does not bother me) and the pre-flash/blinking issue (which I can cure using the FV lock). Is there any other reason to have the SU-800?
 
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I have both, but don't use the SU-800 at all. I searched and read all over, but still can't make up my mind.

In thinking about it, I could only come up with 2 reasons to have the SU-800 - the weight of the SB-900 (which does not bother me) and the pre-flash/blinking issue (which I can cure using the FV lock). Is there any other reason to have the SU-800?

In a word, no.
 
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If you ever buy a D3, D3s, or D3x, the SU-800 comes in handy as a flash commander if you are using multiple flash units.
 
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Sorry, I should have been more clear - I have several SB's, so off camera is not a problem. And the SB-900 will act as a commander for 3 groups in addition to being able to act as a 4th, on-camera or even off camera with a cable. That is whatgot me thinking that the SU-800 may just be taking up room in my bag at this point.
 
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Sorry, I should have been more clear - I have several SB's, so off camera is not a problem. And the SB-900 will act as a commander for 3 groups in addition to being able to act as a 4th, on-camera or even off camera with a cable. That is what got me thinking that the SU-800 may just be taking up room in my bag at this point.

I concur.
 
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Since the SU-800 does not send out a flash or pre flash it reduces the chance of blinking. With FV Lock enabled it almost eliminates people blinking.
 
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Would using a piece of exposed film like a gel cure that all together by blocking much of the light, but letting the signal through? (Of course that is only if the on-camera SB-900 is only being used as a commander.)
 
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I have both, but don't use the SU-800 at all. I searched and read all over, but still can't make up my mind.

In thinking about it, I could only come up with 2 reasons to have the SU-800 - the weight of the SB-900 (which does not bother me) and the pre-flash/blinking issue (which I can cure using the FV lock). Is there any other reason to have the SU-800?

Weight and being able to use the SB-900 off camera instead of an expensive trigger device. Also, FV lock does not work for manual flash power mode, for some very silly, rather stupid reason.
 
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Also, FV lock does not work for manual flash power mode, for some very silly, rather stupid reason.


? The only reason is that there is nothing for FV Lock to do then. The commander menu already knows what the remote manual flash power levels should be, it's already directly set in the commander menu. So there is no logic to do preflashes to find out what the flash level should to be. So FV Lock does nothing then, it is simply ignored for manual level groups. FV Lock remembers the flash level for TTL remotes, and the Commander menu remembers flash level for manual level flashes.

You can see this happen by setting Rear Curtain sync, and setting a slow shutter speed, like one second, to be able to distinguish the flashing.

Then pressing the shutter button will see:

TTL groups:

1. Commander flashes immediately, and the remote TTL flash respond with a preflash, to be metered to set flash level. FV Lock remembers this metering to be able to set power level. This delay also causes the subject to blink (and the remote preflash does not help), so FV Lock just gets it over a relatively long time before the shutter. The FV Lock button also triggers this step 1, in which case Step 1 is remembered, instead of subsequently executed again.
2. Then there is a commander flash immediately before shutter opens, to set the power level in the remote flashes.
3. Then the shutter opens, and delays open to nearly finish, and then the remote flashes are triggered.

Manual groups:

1. Not done. No point of it.
2. There is a commander flash immediately before shutter opens, to set the power level in the remote flashes. This is in the menu, Commander already knows levels.
3. Then the shutter opens, and delays open to nearly finish, and then the remote flashes are triggered.

Step 1 is a delay, longer for multiple TTL flash groups, which causes the subject to blink by the time the final flash is triggered. The TTL preflashes can contribute to it too.

In front curtain sync, and manual flash levels, the flash in Step 2 is too close to the final flash to allow blinking to be photographed. Rear Curtain sync and a slow shutter could put the blinking back, but that is nothing FV Lock could have helped anyway.
 
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Thanks. I actually sold the SU and have enough flashes that the SB-900 has taken its place and works great. Its a slightly more expensive trigger device, but I love the UI.
 
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From what I have read and used my SB900 & SU800, The SB900 can be ZOOMED out to 200mm and the flash can be turned to bounce off walls when you do vertical shots and the SU-800 can not. Also Joe McNally states that in his videos & on the flash tour. I also asked him in person, cause I could not make up my mind to keep or sale?

later....
 
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? The only reason is that there is nothing for FV Lock to do then. The commander menu already knows what the remote manual flash power levels should be, it's already directly set in the commander menu. So there is no logic to do preflashes to find out what the flash level should to be. So FV Lock does nothing then, it is simply ignored for manual level groups. FV Lock remembers the flash level for TTL remotes, and the Commander menu remembers flash level for manual level flashes.

You can see this happen by setting Rear Curtain sync, and setting a slow shutter speed, like one second, to be able to distinguish the flashing.

Well I am no sure what you are saying exactly. Of course there is no test flash to measure and set the power with manual mode. However, the remote flash still needs to know what manual power to flash at for each picture. Very likely, it will change from shot to shot. This has to be communicated in some manner wirelessly.

As you suggest with a quick test, using rear curtain sync and slow shutter speed AND using FV prior to pressing the shutter. Also, using either SB900 or SB800 as master. I am not sure if the SU800 has the same problem. With IR, it is not as big of a deal anyway.

1) iTTL mode on master flash: RESULT > No pre-shutter flash. All information that is needed for the flash has been communicated during the FV procedure. One firing signal is sent and a micro-second later the power flash is delivered. Just one power flash seen at end of shutter period because the trigger flash and power flash can not be discerned due to the short time. In standard front current mode, almost instantaneous response of exposure flash power.

2) Manual power mode on master flash: RESULT > Always uses an extra pre-shutter flash to communicate which manual power setting for the remote to use. Then, wait, wait, wait, then the main power flash at end of shutter period. The wireless system does not give you an option to communicate this simple power setting ahead of time using FV button. And, this gets repeated each time wireless manual power mode is used. This actually causes a slight delay in the shutter response as the camera waits for the communication flash to finish so the second trigger flash can go off. If you do happen to use rear curtain sync with a somewhat slow shutter, then the communication flash is just another pre-flash that can cause blinks. The net result with FV mode as an option, is that the very complicated iTTL-BL mode is more responsive and more nimble than manual mode is.

Nikon's Advanced Wireless Lighting is not as advanced as it could be in this regard. They should have given the option to communicate the manual power setting wirelessly using the same FV button (however, you have it programed) and just as importantly lock the setting once so it stays the same until changed by the photographer. This reduces the value of the wireless feature if you like to use manual mode a lot like I do. It forces me to use iTTL and old fashioned auto mode more than I would like when I need very quick flash response and no pre-flashes of any kind (assuming I use FV for iTTL).

= Tom
 
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Just a quick clarification regarding my comment about FV mode and wireless manual.

What I meant to suggest to Nikon is:

The FV button does the following I believe in iTTL mode. It triggers a test flash for the body metering system to measure. The exposure calculation is made and the body sends the information to the master which then sends out a second flash, which I call a communication flash to tell the remote flash(s) how much light to send out when the final trigger flash is received during the shutter release.

IMPROVEMENT: It would be easy for the system to also use FV for manual power mode. The master could be programed to simply skip the test flash but still send out the communication flash for the manual power setting one time until FV button is pressed again. If the FV button is not used, then the regular communication flash is sent prior to each shutter activation as it is done now.

Seems simple to me.

= Tom
 
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Well I am no sure what you are saying exactly. Of course there is no test flash to measure and set the power with manual mode. However, the remote flash still needs to know what manual power to flash at for each picture. Very likely, it will change from shot to shot. This has to be communicated in some manner wirelessly.

Manual power levels should never change power flash to flash. If the commander menu specifies it should be at 1/4 power, it should be at 1/4 power.

The remote flash is informed of its power level setting at my step 2 above, always immediately before the shutter opens, for both TTL and manual levels.


As you suggest with a quick test, using rear curtain sync and slow shutter speed AND using FV prior to pressing the shutter. Also, using either SB900 or SB800 as master. I am not sure if the SU800 has the same problem. With IR, it is not as big of a deal anyway.
SU800 is the same sequence. The IR advantage only helps minimize subject blinking (but the TTL remotes still fire their visible preflash of course). You can also use FV Lock for other reasons, to meter flash at one place and focus another, or to prevent the TTL from remetering and varying at every shot.


1) iTTL mode on master flash: RESULT > No pre-shutter flash. All information that is needed for the flash has been communicated during the FV procedure. One firing signal is sent and a micro-second later the power flash is delivered. Just one power flash seen at end of shutter period because the trigger flash and power flash can not be discerned due to the short time. In standard front current mode, almost instantaneous response of exposure flash power.
Not sure I am following. I think you mean no more remote preflash happens at shutter after FV Lock.

FV Lock itself preflashes and meters the TTL remotes, but it does nothing for manual level remotes (no need then, commander menu already has the manual power level setting). That is my step 1.

Then yes, at shutter button, there is no more preflashing . All that happens is my step 2, when the power level is sent to the remote groups, for both modes. For TTL groups, this level comes from the remembered metered preflash. For the manual level remotes, this level comes from the commander menu.

2) Manual power mode on master flash: RESULT > Always uses an extra pre-shutter flash to communicate which manual power setting for the remote to use. Then, wait, wait, wait, then the main power flash at end of shutter period. The wireless system does not give you an option to communicate this simple power setting ahead of time using FV button.
You perceive problems I do not imagine. It communicates power level in same way for both TTL and Manual flashes. It is immediately before the shutter, and immediately before Front Curtain flash, so it is too quick to cause any blinking issue. Blinking comes from the more distant earlier peflash stuff.


And, this gets repeated each time wireless manual power mode is used.
You possibly might change the commander power setting between shots. It does the same for manual as it does for TTL - communicates the power level to be used, immediately at any shutter button.

This actually causes a slight delay in the shutter response as the camera waits for the communication flash to finish so the second trigger flash can go off. If you do happen to use rear curtain sync with a somewhat slow shutter, then the communication flash is just another pre-flash that can cause blinks. The net result with FV mode as an option, is that the very complicated iTTL-BL mode is more responsive and more nimble than manual mode is.
This timing is nothing in normal front curtain mode, but yes, rear curtain could be another significant delay. Rear Curtain is a slow shutter thing.

Nikon's Advanced Wireless Lighting is not as advanced as it could be in this regard. They should have given the option to communicate the manual power setting wirelessly using the same FV button (however, you have it programed) and just as importantly lock the setting once so it stays the same until changed by the photographer. This reduces the value of the wireless feature if you like to use manual mode a lot like I do. It forces me to use iTTL and old fashioned auto mode more than I would like when I need very quick flash response and no pre-flashes of any kind (assuming I use FV for iTTL).

= Tom
Yes, the design probably could have communicated power level as part of the FV Lock process, but it doesn't. I don't see any down side if it did it.

The commander system does have a few performance issues. Blinking of course, limited range, obstacles, sunlight, shutter lag, limited number of flashes allowing individual control, the on camera trigger is visible in close reflective subjects, etc. Those all seem bigger problems. :smile:

Other regular real manual systems (non-commander) do offer a lot of control, but the Commander does provide an automatic point&shoot wireless remote TTL multiple flash system.
 
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Then yes, at shutter button, there is no more preflashing . All that happens is my step 2, when the power level is sent to the remote groups, for both modes. For TTL groups, this level comes from the remembered metered preflash. For the manual level remotes, this level comes from the commander menu.

You perceive problems I do not imagine. It communicates power level in same way for both TTL and Manual flashes. It is immediately before the shutter, and immediately before Front Curtain flash, so it is too quick to cause any blinking issue. Blinking comes from the more distant earlier peflash stuff.


You possibly might change the commander power setting between shots. It does the same for manual as it does for TTL - communicates the power level to be used, immediately at any shutter button.

This timing is nothing in normal front curtain mode, but yes, rear curtain could be another significant delay. Rear Curtain is a slow shutter thing.

Yes, the design probably could have communicated power level as part of the FV Lock process, but it doesn't. I don't see any down side if it did it.

You are stating a lot of obvious information that I am aware of. Thanks. I am making a simple point that happens to annoy me and possibly others. There is a problem in the manual power wireless mode if you use flash a lot with people. Is it worse than the shutter delay caused by regular wireless iTTL not using FV that people complain about? Of course not. But since manual mode is so simple, why delay it when it is not necessary. My idea would even save flash batteries and we all like that.

Any extra communication flashes prior to the final trigger GO flash signal from the master can and often are a problem due to the delay created. This is one of the reasons FV was developed. You can feel the shutter delay in your finger very easily in manual wireless mode when compared to basic on camera manual with the flash not in master mode. The benefit of a micro-second shutter delay that FV provides for wireless iTTL could have also been available for manual power wireless mode. I am still rather new to Nikon and am generally very happy with the great job they do. Likewise, I am always surprised when the occasional simple/low cost, obvious feature is overlooked.


= Tom
 
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The benefit of a micro-second shutter delay that FV provides for wireless iTTL could have also been available for manual power wireless mode.


I don't understand this part of your argument, in fact, I think it is wrong. Both cases sure look identical to me, in TTL or Manual level. Either way, the commander must tell the remote flashes what level to use, and it does the same thing for both modes. As suggested, Rear Curtain and slow shutter clearly differentiates to show this.

And the shutter is never "micro-second". D300 has about 57 millisecond shutter lag anytime, and my older D70S is double that, or 114 milliseconds (important to measure and know to time water drop splashes). If you don't half press first to turn off rear LCD (to ready it), D300 shutter lag becomes variable and much longer, from about 140 to 200 milliseconds.

This measures from external shutter trigger (ten pin port) to actual triggering of a real manual flash (front curtain). Mirror rise does not cause any part of that, mirror rise simply occurs during the shutter lag, and it never influences shutter lag. Probably this part does too. I can measure that this commander signal occurs 2.5 milliseconds after shutter is activated (much less than shutter lag), and my imagination thinks the flash will still be triggered at the normal time.

So this part doesn't bother me, the timing is nothing (Front Curtain). Certainly it seems the least of any issues, that is to say, several other things bother me much more. I was never concerned about this part.

Maybe you should tell Nikon what you think?
https://www.nikoncafe.com/vforums/showthread.php?t=303493
 
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I have both, but don't use the SU-800 at all. I searched and read all over, but still can't make up my mind.

In thinking about it, I could only come up with 2 reasons to have the SU-800 - the weight of the SB-900 (which does not bother me) and the pre-flash/blinking issue (which I can cure using the FV lock). Is there any other reason to have the SU-800?

Was in same situation like you. Sold my SU800 and kept my SB900. It works both as a flash and a commander. Better yet, SB900 can increase or decrease power of the remote flashes at 1/3rd increment but SU800 does it at 1 full increment. Way less control if you ask me. This is the part I liked least about SU800.
 

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