Aperature and Group Portraits

Discuss photography techniques, equipment, etc. here.
Member
Posts: 3
Joined: Tue Jan 27, 2009 2:14 pm

Aperature and Group Portraits

Postby Termiky » Wed Jan 28, 2009 9:29 am

How do you get everyone in a group portrait in focus. I took a group of 10 people some in front and some in the back. The ones on the end look out of focus. I'm using a Nikon D-80 18-135 lens. Is it the aperature? Any suggestions?

Honorary ProShow PHD
User avatar
Posts: 560
Joined: Sun Aug 31, 2008 5:58 am
Location: Tonbridge, Kent. UK

Re: Aperature and Group Portraits

Postby Studio7Productions » Wed Jan 28, 2009 9:39 am

If you have Auto Setting on it, choose the Infinity Setting, if not, pre focus on the mid row then without changing the focus, re-frame your shot and take
PSP v 5: Adobe CS5 Extended:Sony Soundforge Pro 10: Canon 50D: Canon EOS 1000D: Nikon D40:

" Success is the ability to go from one failure to another with no loss of enthusiasm. "
Sir Winston Churchill

.
User avatar
Posts: 7501
Joined: Wed Nov 29, 2006 6:35 pm
Location: Kirkland,Wash, USA, Earth

Re: Aperature and Group Portraits

Postby gpsmikey » Wed Jan 28, 2009 10:20 am

The "depth of field" (circle of confusion) is determined by a number of things under your control. Aperature is one of them - the higher the F-stop, the greater the depth of field for a given focal length of the lens - that said, you have to lower the shutter speed to compensate for the higher F-stop. The focal length of the lens also has a big influence on the depth of field -- if you are back a ways shooting at 135mm, you will have a much shallower depth of field for a given F-stop than if you were up close at a wide angle (like 28mm) on your zoom lens. Another trade-off you have to deal with is on the shutter speed vs the focal length -- the longer you are zoomed (higher number), the more it magnifies any motion of the camera and as a result you need to use a faster shutter speed to stop the motion. One thing you can do to get a higher shutter speed and still keep a decent f-stop is to increase the ISO setting in the camera - recognize that the higher the ISO, the more noise you will see in the image (looks like fine grain sand or something). Each camera has it's own limit as to what you can get away with in the ISO range. My Nikon D-70 does quite well up to about ISO 600 under most conditions. I know that is a bunch of information, but you need to understand how they all relate to each other to make the decisions on what you can do to change the image you get. Sometimes you want a shallow depth of field so the background is out of focus, other times, like you have where you have 2 or more rows of people, you need more depth of field to get everybody in focus.

mikey
You can't have too many gadgets or too much disk space !!
mikey (PSP6, Photoshop CS6, Vegas Pro 14, Acid 7, BluffTitler, Nikon D300s, D810)
Lots of PIC and Arduino microprocessor stuff too !!

ProShow Hall of Fame
User avatar
Posts: 3143
Joined: Mon Nov 13, 2006 7:42 pm
Location: Northern Virginia

Re: Aperature and Group Portraits

Postby DickK » Wed Jan 28, 2009 10:35 am

Termiky wrote:How do you get everyone in a group portrait in focus. I took a group of 10 people some in front and some in the back. The ones on the end look out of focus. I'm using a Nikon D-80 18-135 lens. Is it the aperature? Any suggestions?

You didn't tell us what the distance was from you to the group or the lighting conditions. Without that we're going to be speculating but...

If it's really the ones on the outside (ends, not back/front) that are soft, then I'd guess you were in close, shooting much nearer the 18mm end than the 135mm end and there was limited ambient light. That's a recipe for potential trouble. You need to get back so the lens is operating closer to it's best range, and increase the depth of field by shooting with more light (close the aperture down) and that also keeps the shutter speed up so you don't get motion (camera or people).

Dick
"It is the mark of an educated mind to be able to entertain a thought without accepting it." Aristotle ((PSG, PSE & Fuji HS20 user)) Presentation Impact Blog

.
User avatar
Posts: 3745
Joined: Thu Aug 17, 2006 11:21 am
Location: Parker, CO

Re: Aperature and Group Portraits

Postby im42n8 » Wed Jan 28, 2009 1:49 pm

These might help. They don't directly answer your question directly tho.

The first two items below will probably help a lot though if you don't already have these links. You can capture item 2 from the page source so you can have it to use on your laptop or desktop ... and have all the information you need available to you.

Then, you can use item 4 (even editing it in a graphical editor to customize it for your camera) to create a tool that can help f-stops and apertures (information that you can then use with item 1).

1) http://dofmaster.com/dofjs.html
2) http://www.bobatkins.com/photography/te ... _calc.html
3) http://www.uscoles.com/fstop.htm
4) http://www.uscoles.com/exposures.pdf

Dale

Return to Photography

Who is online

Users browsing this forum: No registered users and 10 guests