SB-28 monitor pre-Flash

[fernando_garcia4]

<p>Hi,<br>

I have a F-4 with a SB-28. I've just gotten an hot shoe optical flash slave (Kaiser) that I want to use with an old flash unit.<br>

I've read that to use the SB-28 (attched at camera) as "master" and the old one (attached at the slave unit) as slave, pre-flashes of SB-28 must be turn-off.<br>

Do you know how I must disable pre-flash? Setting SB-28 in TTL mode (no 3D-multisensor mode)?<br>

Thanks a lot</p>

<p> </p>

[frank_skomial]

<p>Pre-flashes is new iTTL/CLS method for Digital SLR cameras to determine automated flash exposure, so perhaps this is what you do know...?</p>

<p>F4 is an older film camera, and... well, if it does pre-flash for you (?) then you must use flash in Manual mode, but first try it and see. </p>

<p>You will need to use your own exposure determination with the extra Kaiser flash in the picture, anyhow, so Manual flashes settings will be the way to use them, but try other options as well...</p>

 

[Michael R Freeman]

<p>The SB-28 has no pre-flashes for exposure measurement. It is film based OTF flash metering technology. The only pre-flashes that would occur with the SB-28 would be if the flash was used in red-eye reduction mode (I don't recall if the F4 supports this or not). So as long as red-eye mode is not enabled on the SB-28, there should be no pre-flashes.</p>

<p>The SB-28<strong>DX</strong> would (I think) have pre-flashes for exposure measurement when used in D-TTL mode.</p>

<p>As Frank noted, manual settings on both the master and slaved unit are probably the way to go for this set up.</p>

[User_276104]

<p>Just a note on Monitor Preflash - the SB-28 does employ this, but only on cameras that Nikon designates as "Group 1".</p>

<p>From page 24 of the manual:</p>

<p><strong>3D Multi-Sensor Balanced Fill-Flash</strong> <br /> <strong>(Applicable to F5, F100, F90X/N90s, F90-Series/N90, F80-Series/N80-Series, F70-Series/N70)</strong> <br /> <em>This mode automatically controls flash output to keep both subject and<br /> background correctly exposed. The SB-28 fires a series of nearly invisible<br /> preflashes, called Monitor Preflash. These preflashes are detected by the<br /> TTL multi-sensor in Group I cameras and the data is then integrated with<br /> distance information from D-type Nikkor lenses and other exposure data to<br /> determine the optimal flash shooting distance range and flash output level<br /> for balanced fill-flash exposure. This is especially effective for scenes that<br /> include: (1) a mirror, white wall or other highly reflective surface or (2)<br /> unwanted obstacles in front of the subject.</em><br>

<em><br /> </em></p>

[fernando_garcia4]

<p>Hi,</p>

<p>Thanks a lot.<br>

I've also a F-80 (Goup I), so I'll have the problem on pre-flashes.<br>

The reason for my question is as follows: When SB-28 fires pre-flashes, the slave unit cell will detect this pre-flashes, and will fire the slave flash. I've read that only way to fix this problem is to disable pre-flashes. So..¿It's enought to disable 3D-multisensor mode, and work in TTL mode?</p>

<p>I'm very grateful for your help.</p>

<p>Thanks a lot</p>

[Michael R Freeman]

<p>Thanks Eric. I had forgotten about the difference in usages on Group I vs. other cameras. I used my SB-28 primarily on the F4 (Group II), so I never paid any attention to that feature.</p>

[frank_skomial]

<p>"It's enought to disable 3D-multisensor mode, and work in TTL mode?" - perhaps?, but once you add a Kaiser flash as a remote optical slave, the flash in camera hot shoe will not be able to control the power output of it, and entire TTL determination could be incorrect, and you could get inconsistent or over exposed film.</p>

[fernando_garcia4]

<p>Frank, Michael, Eric...thanks a lot.<br>

I'll need to do test to adjust intensity of both flashes.<br>

But my concern was if pre-flashes of SB-28 will fire the slave flash. In accordance with your views, I must to disable 3D-multisensor so that this does not happen.<br>

I'll post my prints to get your opinions.<br>

Thanks a lot.</p>