Starting F-stop

ajroahkni

What do you seasoned photogs use as your starting f-stop for portraiture - you know, the jumping off point setting to get the person tack sharp with enough bokeh on the other bits?

Thanks,

John

crockett

http://www.dofmaster.com/dofjs.html

Way to many variables here.

Studio stuff is usually done at smaller aperatures (f8-f11) primarily because they have so much control over the background and this is a common sweet spot for just about all lenses.

Outdoor stuff is usually done up against the limit walking the delicate balance between bokeh and an out of focus subject.

If you twisted my arm and made me say a value I would say f4 for non studio stuff, but I'm far from seasoned.

The easiest and best go to thing to get great bokeh. Create space between model and background. The more the better. Of course combined with wide aperatures. But even with a enough space between model and background and a long lens, f5.6 can look fabulously creamy.

jdryan3

Depends upon the lens (length) you are using, the distance between you and the subject and the distance between the subject and objects in the background. Classic case of of DOF. Check out this guide. Assuming that the person's head is about 12 inches deep and you want all of it in focus with a 5D, a 85mm lens and you are 12' away, f/5.6 has a 2' depth of field.

So this should get their entire head in focus and everything behind them goes OOF. But those specific calcs leave little room for error: you move up, they move back, etc. and only part of them image is in focus

Oh, and don't forget that most lenses are sharpest about 2-3 stops smaller than their largest aperature. So an f/2.8 is usually sharpest at f/5.6 -f/8. Without being overly artistic, most portraits are supposed to be as sharp as possible. So f/8 in the example above may be the safer option since it allows more margin for error, and may give you a sharper image. Just make sure nothing in the background is close.

Of course, YMMV. Plus your artistic vison may be completely different. So practice. It is the only way you will know for sure.

ajroahkni

Thanks for the input guys.

I was thinking for shots outside, using a pentax 50/1.7 lens. Checked that neat dof site...6' range and only 1 foot of clarity at f8. Didn't expect that. I think my aperatures have been way too small.

zoomer

I normally use f4 (never higher unless I want the background to be in focus which is practically never).
With some at f2.8 only if using the 70-200 of 24-70 Nikon as they look just as sharp at 2.8 as they are at other f-stops.

I use 2.8 more often with the 24-70 because of the shorter focal length it naturally has more depth of field that the larger focal length lens.

My favorite is to shoot at 200mm at f4 sometimes 2.8. The background just disappears into swatches of color and I get plenty of depth of field for a portrait.

With the d700 I seem to get shorter depth of field that I did with the d300, must be something to do with the full frame sensor.