Range for SB-900 as commander

[penn10]

<p>I have one of my SB-900 flash on the camera, used as commander; another SB-900 on a lightstand, as remote. I find that if I move a little away from the remote, it won't trigger. I have to be really close. But if I use my SU-800 controller, it works with a much farther distance.<br>

Exactly what is the distance limitation a SB-900 commander can trigger a remote? I can't seem to find this number.<br>

Thanks!</p>

[Matt Laur]

<p>There are many factors, here. Out of curiosity, have you tried rotating the slave strobe's body so that the sensor is facing the commander, rather than having to work off of reflected light pulses? That can dramatically increase the effective distance. Because the SB-900's head can swivel 180 degrees, there's never a stand-mounting situation in which you can't get the sensor to point in the most optimized direction. In doing the same tests with SB-600 and SB-800 speedlights, I found that the slave's useful distance could sometimes double just by orienting the sensor differently. The results were all over the map, depending on whether you're using the rig outdoors, or in sunlight, or in a reflective room, or a large space, etc. I think that the reason you won't find hard numbers on this is because there are so many variables that impact the results (is the commander shooting directly? bouncing? is there a diffuser in use? etc).<br /><br />If I'm getting into even slightly dicey territory, out come the radio triggers.</p>

[penn10]

<p>Thanks so much Matt, I think you are dead on. My slave was pointing forward, just like my commander, so their path of communication is probably relying on walls/cerlings. I will try to rotate the slave to point to my commander.</p>

<p>Thanks again!!</p>

[frank_skomial]

<p>It is that simple, read specifications of SU-800 and SB-900. See the diagram for SU-800 and SB-800 in their manuals. One major factor is that SU-800 commander has twice longer range than the SB900 as a commander. SU-800 generates much more commanding IR energy light for the extended range of 20 meters or 66 feet.</p>

<p>It is actually a pitty since the SB900 used as a commander (or not commander) and extended head zooming capability is not fully utilized by the in-camera auto light determination and CLS limited range in iTTL and iTTL/BL mode, while SB900 when zoomed can throw exposure time light much farther, but is limited by the faint preflasf light output during CLS testing that is predetermined by the CLS range, and that range is different for different commanders.</p>