avoiding Blurr

[Yasser]

Hello All Experts .

i'm new to this and to the DSLR world. but i'm a fast learner. i just have a quick Quiz . how can i avoid bluring the items in the picture . i mean if there is three ppl standing right to each other . can can i get them all in the foucs? i cant get the camera to put all the Red Dots on all of them . i'm using a 50MM 1.8 the nefty fifty Glass. :)

please help . thanks yall

[Quad]

You need to focus on the middle subject and close the aperature to a smaller number (remember the numbers are fractional so 16 is 1/16 and 1.8 is 1/1.8 ) this will increase Depth-of_Field and make more stuff in front and behind the point of focus appear sharp.

[aacmckay]

I have this lens as well. It's a bit touchy with the focus. Try using a smaller aperature. Something like f/5 or smaller. At f/1.8 it won't be able to focus everyone in the shot.

[Mark_Cohran]

You need to focus on the middle subject and close the aperature to a smaller number (remember the numbers are fractional so 16 is 1/16 and 1.8 is 1/1.8 ) this will increase Depth-of_Field and make more stuff in front and behind the point of focus appear sharp.

Apertures are indeed a ratio, but they are the ratio of the focal length of the lens to the diameter of the opening in the lens. Thus, as the diameter of the lens opening gets larger, the aperture number gets smaller ( FL/Diameter).

As indicated, as smaller aperture (bigger number) will increase your Depth of Field which is the range of acceptable sharpness behind and in front of the point of focus. Of course, if you make the aperture smaller (let less light into the camera), you'll find that the camera will reduce the shutter speed (let the light in longer) to get the same exposure. If you don't want the shutter speed to change, you need to adjust your camera's ISO setting (sensitivity to light) to compensate.

Mark

[inthedeck]

Basically, here's the way to do it, in layman's terms...though the description from Mark, above, is great.

This is all subject to what the lens offers in terms of f-stop:

f2 - wide open aperture, more light, not much depth of field -- i.e., in your situation, all three people will not be sharp.

f4 - almost open, or wide open, sufficient light in daytime, not much DOF -- i.e. in your situation 1.5 people may be sharp

f8 & f/11 are very common, and will alow for enough light in daytime - sufficient DOF -- i.e. in your situation, the three people will be in focus, as will some of the background.

f/16 & f/22 allow low levels of light , and therefore, will slow down the shutter speed. Maybe 0 seconds, 2 seconds, 4 seconds, etc. You do NOT want to take a moon shot with a small aperture...as the moon will look blown out.

Shutter speed is a whole different story... which is usually 1/focal length, so, for an image to not be shaky, generally if you use a 50mm lens, it would be 1/50 shutter speed, to be mostly sharp (unless camera operator is shaky). Though, some people can hold the camera still, even at 1/20 with a 50mm lens, so, again, this depends on user.

Hope that helps a little more.

[Yasser]

thank you very much everyone for the help. but i need to know as well . which mode do i use (TV or AV or M) if i'm trying to shot like 3 or 4 ppl wich foucs. when i do that the Pic comes out of foucs and its like the Object is moving.
i just need numbers .like
use AV with F4 or f8 and ISO #? flash ? no flash ( i take the pics indoor)

thanks allot for all this great help

[John_B]

Yasser,
There really isn't a direct answer as the photo depends on the light available, distance from subject etc.....

f/8 with flash with 1/200 iso 100 in Manual mode is a good starter for indoor portrait photos.

You have a DSLR so try different settings, you get a preview of the results immediatly. Learn by doing is the best way in my opinion :)