David Kirk wrote:
I think you are trying to keep the light on the sofa and furniture within 1 stop of each other - resulting in them being similarly lit.  Is that correct?

Judging by your diagram, the talent & sofa are about 1/2 way between the furniture and the flash.  This means that the contribution from the flash will be 4 times as much on the talent & sofa as on the furniture.  Therefore, with just flash alone (assuming no ambient) the talent & sofa would be +2 stops brighter than the furniture.

You don't specify what the source of the ambient light is so I would have to assume that it is roughly even throughout the room (or at least the same for the sofa and the furniture). 

If you wish to use the ambient light to even this out then you need to have the flash contributing less light to the scene than the ambient.  Therefore, if ambient is measured at 1/60, f/5.6 then you would want your flash to be at f/5.6.  This way the light on the talent & sofa would be f/8.0 (ambient @ f/5.6 + flash @ f/5.6) and the light on the furniture would be slightly greater than f/5.6 (ambient @ f/5.6 + flash @ f/2.8).

I would measure the ambient with the flash meter to get the initial setting (e.g. 1/60, f/5.6).  Then set your flash to the same aperture value.

I don't understand why you think you need NP Viewfinder for your L358 for this.  Just measure incident light at the furniture and the sofa to ensure they are similar.  Use this reading to set the power of the flash to match.

Hi David all that you say was what I thought.
For sure the flash (although addressed with a grid) will affect to sofa and the backgrounds.
What I was wondering if I could trust in the internal measurement system of the Nikon D700 in spot mode. I would sample various areas of the substrate and ambient light to average. This measure would like under expose one or two stops from the light on the subject (which will be a mix of ambient light and flash).

walterfantauzzi wrote:
Hi David all that you say was what I thought.
For sure the flash (although addressed with a grid) will affect to sofa and the backgrounds.
What I was wondering if I could trust in the internal measurement system of the Nikon D700 in spot mode. I would sample various areas of the substrate and ambient light to average. This measure would like under expose one or two stops from the light on the subject (which will be a mix of ambient light and flash).

I don't have any experience with the D700 specifically to comment on whether it would be accurate or not.  I don't use my camera meter (reflected measurement), but instead use my meter to take an incident reading at the point of interest.

For me I am not sure an average value from different positions in the scene is very useful.  I can't think in terms of an average value for scenes which have significant variation.  Instead I prefer to think in terms of range (darkest to brightest) and then use the flash to brighten areas which are darker than I would like (often using flags and grids).  I tend to light the subject separately with a key light (flash) and then use a second flash as broad fill if I need to compress the light latitude of the scene (make all darker areas brighter without significantly affecting the bright areas). 

I generally take incident measurements with the L358 and find it is a good way to measure multiple small areas in the scene to map out the light.

David Kirk wrote:

I don't have any experience with the D700 specifically to comment on whether it would be accurate or not.  I don't use my camera meter (reflected measurement), but instead use my meter to take an incident reading at the point of interest.

For me I am not sure an average value from different positions in the scene is very useful.  I can't think in terms of an average value for scenes which have significant variation.  Instead I prefer to think in terms of range (darkest to brightest) and then use the flash to brighten areas which are darker than I would like (often using flags and grids).  I tend to light the subject separately with a key light (flash) and then use a second flash as broad fill if I need to compress the light latitude of the scene (make all darker areas brighter without significantly affecting the bright areas). 

I generally take incident measurements with the L358 and find it is a good way to measure multiple small areas in the scene to map out the light.

Yes it's Traditional measurement that I do too
thanks for the exchange of ideas David

Photography by Riddell wrote:
Are you not using flash?

and really only shooting at f5.6?

it was an example