Nikon FG Malfunction?

[m._howard_edwards]

Why did I lose the lower half of frames 7 thru 24?

 

The exposure of the top of the frames is fine. The lower portion of

each frame is unexposed. The demarcation is fuzzy and almost

perfectly in the center of each frame. I shot two rolls before this

one with no trouble. Looking at the shutter,without film, at 1/60

sec., it appears to be operating properly.

 

I was shooting closeups with a dedicated Vivitar 3700 and a

ringlight (it happened with both light sources), a MD-14 motor

drive, cable release and tripod. Lenses were Nikkor 86 mm zoom and

a Micro Nikkor 105 mm.

 

Can anyone tell me what causes this and how to avoid it?

[david_h._hartman]

It sounds like you are shooting at shutter speed above the FG�s maximum flash sync speed. Check your manual or...

[david_h._hartman]

or try this link<br>

<br>

<a

href="http://mir.com.my/rb/photography/hardwares/classics/emfgfg20/fg/index.htm"

target="_new"><u>Nikon Super Compact Bodies EM, FG & FG-20</u></a><br>

<br>

Regards,<br>

<br>

Dave Hartman.

[jim_gifford]

How to avoid it:

 

<Been there, done that. Almost all of us have been there and done that>

 

You need to be aware of the maximum shutter speed for flash... set the FG to that shutter speed (or slower if you like) whenever using a flash.

 

Brief explanation to answer the "what causes this" part of your question:

 

Remember the way your shutters work: first shutter opens when you begin the exposure, and second shutter begins closing soon thereafter. At speeds faster than the maximum flash synch, the second shutter begins to close before the first shutter has finished its travel. That means there's a sort of moving slit through which light reaches your film. If you're using an electronic flash, it has an extremely short duration so it only "lights up" a portion of the film and the rest of the frame is blocked by the still-moving shutter blades.

 

Have fun...

[roland_larson]

It very much sounds like you're shooting with a higher shutter speed than X but one thing strikes me odd -- I don't know about a Vivitar 3700 and you haven't specified which ringlight yor're using, however, if they are "dedicated", the FG can override its own shutter speed to X even if you set it wrong in Manual mode. Your flash units may not be "dedicated", at least not properly set-up when your took those shots. Please tell us more about your flash units.

 

One more thing : I don't seem to be able to tell whether a shutter is operating properly simply by looking at it at 1/60, anyhow ??

[Robert_Lai]

Only if you are using a dedicated Nikon TTL flash such as the SB-15 or the SB-21b / SB-29 ringlights, will there be automatic setting of the shutter speed to the flash synch speed of 1/90. With a regular flash such as the Vivitars, it is VERY easy to keep rolling the shutter dial to higher and higher speeds, especially if you're trying to balance flash with daylight exposure. There's not much you can do about that except to roll the shutter speed dial to M90. You'll be shooting at the mechanical speed, so no battery consumption will occur. There is no metering at that speed either. That way, if you ever roll the shutter speed dial off M90, you'll either be at 1 second or B. At least your whole frame will be exposed!

[m._howard_edwards]

Many thanks to you all. Sometimes looking for the most complex answer causes us to overlook the most simple. I checked what you suggested, and ...

 

At some point in the session (about exposure 7)I accidently nudged, bumpted, twirled, jiggled, and reset the shutter speed to 1/250 sec. The dial locks on the automatic functions, but there are only slight detents for all the manual ones. Lesson learned: "Measure twice, cut once." It pays to check now and then to be sure all is as desired.

 

Now I'VE been there, done that.