Why is my shutter so slow even under bright light?

Zephrus

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Hi all, been trying to find an answer to this for a while and it's been driving me nuts.
I often get very slow shutter speeds (like 1/10 sec or less) when shooting indoors under bright lighting (non flash). For example, I may have a person or object in front of a backdrop ... I have my aperture wide open (maybe 1.8 with my 50mm prime lens) and am throwing anywhere from 500 to 1000 watts of continuous light onto the subject, from 2 soft boxes or shop lights.

Usually I'm shooting in a program mode at 100-200 ISO and am no more than 10 feet away from the subject, sometimes much less, and get VERY slow shutter speeds. Sometimes as slow as 1/4 sec! And strangley enough throwing more light at the subject does not help.

At first I though it might be my camera (Nikon D80) so I tried it with my cheaper little Konica Minolta Z3. Same thing! Very slow shutter speed. What gives? Is the camera being fooled by something? How can I be using plenty of light but still have such a slow shutter speed?
 
It may strike you as bright, but you'd be surprised. 1000 watts from 20 feet away is not that much light. Shoot at a higher ISO.

...but somehow I still feel I'm missing information. Not sure, something seems off.
 
...but somehow I still feel I'm missing information. Not sure, something seems off.

Definitely something is off, I agree. Not talking continuous light, but if current conditions are F11, ISO 200, 1/200th, 12-14 feet to subject), and I take my 1000 W/s studio head, I can set the camera to F/22, ISO 100, 1/250th and still be over exposed by 2 stops... and that is from 12-14 feet away.

F22+at+ISO+100b.jpg
 
...but somehow I still feel I'm missing information. Not sure, something seems off.

Definitely something is off, I agree. Not talking continuous light, but if current conditions are F11, ISO 200, 1/200th, 12-14 feet to subject), and I take my 1000 W/s studio head, I can set the camera to F/22, ISO 100, 1/250th and still be over exposed by 2 stops... and that is from 12-14 feet away.

F22+at+ISO+100b.jpg



I agree it seems off, but why would I get the same effect with two different cameras?

I usually use a full frame or "matrix" metering mode when shooting. I've speculated that maybe it's a "hot spot" somewhere that's fooling the camera into thinking the scene is much brighter than it really is, thereby reducing the shutter speed.

I've tried moving closer and further away, moving the lights, etc. Still I get the same effect. Yet if I were to turn off the lights, open the blinds and shoot indoors just from the ambient outside light coming in, I'll get a higher, more normal shutter speed. Everything seems perfectly normal the rest of the time.
 
With the slow shutter speed, were the photos still correctly exposed?
 
I don't suppose by any chance you have access to a light meter?
 
Remove the lens cap :D


Lol....or remove the ND filter. This sounds like you have an ND filter stuck to the front of your lens that you forgot about. Posting one of the pictures you took with the above settings might help us figure it all out.
 
With the slow shutter speed, were the photos still correctly exposed?

Yes they were correctly exposed. In the case of an object it wasn't so much of a problem because the camera was tripod mounted. But in the case of a person they have to hold quite still to avoid motion blur.
 
Post an example. Are you sure you were at f1.8 and not f18? If they were correctly exposed then it's obvious that the settings used were correct based on the amount of light. Post an example and we can see the exif data to see what all the settings were and if there was something you maybe overlooked.
 
With the slow shutter speed, were the photos still correctly exposed?

Yes they were correctly exposed. In the case of an object it wasn't so much of a problem because the camera was tripod mounted. But in the case of a person they have to hold quite still to avoid motion blur.

Well, if they were correctly exposed, and assuming you've eliminated ND filters (which presumably you wouldn't have had on both cameras) then the only conclusion is that the camera's metering system is functioning correctly and that is, indeed, the correct exposure.

Remember that light fall off varies with the square of the distance of the light source from the subject.

So 1000w at 10 feet is equivalent to 10w at one foot which suddenly doesn't sound very bright.
 
With the slow shutter speed, were the photos still correctly exposed?

Yes they were correctly exposed. In the case of an object it wasn't so much of a problem because the camera was tripod mounted. But in the case of a person they have to hold quite still to avoid motion blur.

Well, if they were correctly exposed, and assuming you've eliminated ND filters (which presumably you wouldn't have had on both cameras) then the only conclusion is that the camera's metering system is functioning correctly and that is, indeed, the correct exposure.

Remember that light fall off varies with the square of the distance of the light source from the subject.

So 1000w at 10 feet is equivalent to 10w at one foot which suddenly doesn't sound very bright.

What this guy said. :thumbup:

Try moving your lights closer half the distance between where they were at that time and your subject and see if your shutter speed doesn't shoot up a bit.
 

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