exposure and development time for black background

[andrew_goliszek]

As a beginning large format photographer, I am struggling with an

exposure and development problem. When taking a closeup of a white

flower against a black velvet background using a 500amp halogen, do I

meter on the flower, increase exposure 2 stops to place it on zone 7

and give the film N, N-1, or N-2 development? Anyone experienced with

this please tell me exactly how you expose and develop. Thanks much.

 

Andy

[rob_tucher]

I'd worry about the local contrast in the white flower. I'd meter there, increase exposure by two stops, do N-1 development, and make sure no light falls on the background (scrims, shading, etc.) so it goes black naturally. You say you're shooting "against" the velvet. I've shot hundreds of thousands of archaeological artifacts against black velvet and I off-set the subject from the velvet by at least half a foot, shade it from the light that falls on the subject and usually shoot with a piece of smoked gray glass between (artifacts on glass and camera shooting down)to take down the velvet "zone" even more.

[alan_bucknam]

You know the mantra: Expose for the shadows, develop for the highlights.

 

i.e. meter the shadows of your subject (not the background...that should be shaded from

your light source and should be darker anyhow). Say you want the shadows in the subject

2 stops darker than medium grey (zone 3). So, stop down 2 stops, and make your

exposure. Meter your highlights, too. If your highlight is where you want it to be, develop

normally. If it's too high, reduce your development. If it's too low, increase development

time.

[eric rose]

Gee I think there was this old fart photographer who did a pretty decent picture of some white flowers once. Saw it in a book somewhere. Anyway he metered the petals of the flowers, placed them on zone 6.5 and gave it n+1 development. Mind you it was an overcast day and the light was very diffuse.

 

I hope you are using some kind of diffuser inbetween the lamp and the flowers.

 

Take several photos and try different stuff and let us know how it turned out.