Nikon CLS - builtin vs. SU-800 vs. SB-600/800/900

Canon EF 17-40mm f/4L USM

11/15/2009 01:59:42 AM · #1

I've been googling and reading the various arguments of what's "better" (i.e. stronger or more effective over a distance) among using the builtin flash vs. SU-800 vs. SB-600/800/900 for commanding a CLS group... until I'm cross-eyed. Yet, I have yet to find any real hard data over which method is truly, measurably more effective.

Does anyone have, or can anyone find, any real data comparing the actual effective distance for commanding a CLS remote with 1) the builtin flash, 2) the SU-800 commander, and 3) a speedlite (600/800/900) acting as commander?

I've seen plenty of "gut-feel" articles, etc -- I'm looking for any real data or testing that's been done to scientifically compare the three methods.

Alternatively, does anyone with access to all three feel like doing some controlled tests and posting the results? ;)

wanjun

Canon EOS-400D Rebel XTi

11/15/2009 04:52:40 AM · #2

I recommend more googling! d= "guide number" and then "inverse square law". Or visit strobist.com, they have a lot of very helpful articles regarding those specific flashes.

Canon EF 17-40mm f/4L USM

11/15/2009 05:27:19 AM · #3

Nope, that's not entirely related to my actual question. Using these units for *commander* mode in CLS. The effective visible light output is somewhat-related-to, but not at all the same, as their use a command module. The SU-800, for example, does not emit any visible light whatsoever, nor has any application in a standard flash guide value.

Even if those values had any bearing for this scenario, the effective use of a commander unit is also limited by the receiver's sensitivity.

I've poured over strobist as well -- that's where I started, in fact. I'm asking something pretty specific and "niche" here, and no one that I can find seems to have any hard data to compare these.

wanjun

Canon EOS-400D Rebel XTi

11/15/2009 05:50:11 AM · #4

Oops I misread the original post. Sorry I can't help, not familiar with nikon's CLS.

Shutter-For-Hire

Nikon D90

Nikon AF Nikkor 24mm f/2.8D

11/15/2009 09:14:58 AM · #5

i do have a "gut feel" answer for you... just to keep in mind if you do get an answer... remember... the SB-900 is several years newer than both SB/SU 800's so it's probably better than both... =)

OdysseyF22

Panasonic DC-G9

Olympus 12-45mm /f4.0 Pro

11/15/2009 10:19:45 AM · #6

I'm speaking from a Canon perspective here, but I'd have to think the results would be very much the same between systems, since they are essentially built the same.

The SU-800 is like Canon's IR commander module: I think they'd both suffer from the usual IR limitations, meaning that they have to be in line-of-sight of the slave units, and that range is limited (especially outside).

Either the built-in flash or a SB-800 unit would have the benefit of transmitting the signals with light. There's still the line-of-sight rule, but indoors you can often bounce the commander signal and gain a bit more coverage than with just IR. And of course a hotshoe flash commander unit will have more power than the built-in flash, so it should be able to throw the commands farther.

I know with my setup, the built-in flash has been fine for any of the indoor uses I've tried so far. But if I were going to work in a school gym, or outside, I might switch to my Speedlight commander just for the extra power.

11/15/2009 02:21:31 PM · #7

Wanjun - No problem, that's for trying to help. I understand where you wanted to go with this, but comparing the actual visible flash output isn't a 1:1 comparison for use as a CLS commander, especially when you compare to the SU-800, which is using only infrared communication.

Originally posted by OdysseyF22:

The SU-800 is like Canon's IR commander module: I think they'd both suffer from the usual IR limitations, meaning that they have to be in line-of-sight of the slave units, and that range is limited (especially outside)...Either the built-in flash or a SB-800 unit would have the benefit of transmitting the signals with light.

Originally posted by Shutter-For-Hire:

i do have a "gut feel" answer for you... just to keep in mind if you do get an answer... remember... the SB-900 is several years newer than both SB/SU 800's so it's probably better than both... =)

I agree in concept with both points, but they are in conflict with two specific "studies" (and I use the term loosely) I've seen --

First, more than one independent test I found online states the SU-800 has almost twice the effective commander range as an SB-800 flash. Neither site gives any details on how this conclusion was derived, nor cites any specific data to support it. But, you can trust everything you read on the Internet, right? :P

Second, Joe McNally's present recommendation, according to his blog as well as his lastest books, is to use an SB-800 with a diffuser to scatter the output. As much as I trust and respect Joe, I haven't seen him cite any particular data to support this, nor have I read where he actually comes out and says why he thinks this is the "best" setup. However, it raises the questions -- if the SU-800 has a longer range, why use an SB-800 with diffuser? If the SB-800+diffuser works better than an SU-800, why wouldn't an SB-900+diffuser work even better than that? (Remember, Joe essentially has access to everything, so I doubt he's worrying about any "cost" savings one way or the other).

This gets back to what I asked for in the OP -- any actual test data comparing the three scenarios -- CLS command via builtin flash, SU-800, SB-600/800/900 (which could be treated as five scenarios, if you actually compare each speedlight body).

[ edited, as sometimes spelling makes a big difference... ;) ]

Message edited by author 2009-11-15 14:25:34.

Nikon AF-S DX Zoom-Nikkor 16-85 f/3.5-5.6G ED VR

11/17/2009 12:38:00 PM · #8

One last bump, in case anyone has any input?

thompp1

Nikon D500

11/18/2009 12:20:43 AM · #9

Just a note: The SB-600 can't be used as a commander. On camera flash or slave only.

scope

Nikon D700

Nikon AF Nikkor 50mm f/1.8D

11/18/2009 06:45:24 PM · #10

I don't have an answer, but I thought I'd weigh in on whether it's the right question, even though you sound like you know what you're talking about. :)

I use CLS a lot, and for me the big draw of the SU-800 would be that it doesn't throw visible light. If there were an option to delay the remotes and the exposure to give the command light time to fade, it wouldn't matter, but using a visible commander light means having an on-axis flash contribute to the shot, and sometimes it's not what I want. (An IR filter over the commander flash would work too.)

Similarly, I think the big advantage of commanding with an SB-800 or SB-900 is getting one more slave channel compared to the pop-up. Probably more range too, since those lights can be brighter, but I've never run into range problems with CLS.

If you frequently run into range or visibility limitations in the kinds of shots you set up, you might be better off with radio triggers instead of trying to squeeze another 5% out of CLS. I think the new Radiopopper P1 or PX systems will basically turn CLS into radio.