Getting Portrait Bokeh..

[RSisco]

I am obviously new to this forum and to photography. I have a new D5100 and two lenses, both in my sig. One is the kit lens (18-55) and one is a 55-300. They seem to work well for some things, but if I want to take a portrait with a backdrop the backdrop is in focus as well as the subject. I want the backdrop to blur so it's nice and smooth and doesn't distract from the subject. I tried a few setting and came to a conclusion that I need another lens!?. Right?

I did a bit of reading and I think what I want is either the..

AF-S NIKKOR 50mm f/1.8G

or the

AF-S NIKKOR 35mm f/1.8G

Suggestions? comments?

 

[Kbarredo]

If you want more bokeh the longer focal length has more. the longer the focal length the shorter the dof. A 300mm 1.8 will be much shallower than a 25mm 1.8

 

[willis_927]

Not necessarily... There is a few other ways that you can obtain a nice blurred background (although, yes getting a lens with a larger aperature can also do this).

A few other things to consider are:

1) Increase focal length- with your 55-300 you have a good amount of focal length. Shooting at 300mm, (given a set aperature and shutter speed) vs shooting at 55mm (given the same aperature and shutter speed), will result in the background being much more out of focus (at 300mm).
2) Focusing Distance - focusing on the subject when you are closer to it will make the background much more blurred than if you focus on the subject from a long distance away.

 

[willis_927]

Kbarredo beat me to some of that.

 

[mrpink]

More distance between your subject and background will help as well.

Bokeh is not DoF.






p!nK

 

[SwiftTone]

You should note that the 35mm 1.8G is a DX lens and the 50mm 1.8G is a full frame lens, which really acts like a 75mm. Out of these 2, the 50mm should be better, however, its not even released yet so no one can speak of the optical quality, though it should be good.

 

[seekinglight]

The bigger the aperture, the more bokeh. This is not the same as the f-stop. A 100mm f2 lens has twice the aperture size as a 50mm F2 lens. So between your two choices, the 35mm will not have as much bokeh as the 50mm.

The 85mm lens is popular for portraits because of the compromise of having a big aperture and still being able to take portraits in a normal sized room. With the 50mm, see if you can be closer to the subject than the subject is to the background.

 

[RSisco]

The 85mm lens is popular for portraits because of the compromise of having a big aperture and still being able to take portraits in a normal sized room.

I think that is the issue I am having. I am shooting in a livingroom at the moment, so I am limited on space. I have the backdrop against the wall, the subject 4 or 5 feet from that. So I have about 10 feet of room left to work in.

 

[MWG]

More distance between your subject and background will help as well.

Bokeh is not DoF.






p!nK

This.

The infinity point gets farther from the camera as the focal length increases, meaning the shallow depth of field becomes more proclaimed on longer lenses.

 

[RSisco]

Thank you all for the input. I will mess around with the camera some tomorrow. Everyone is in bed and I don't want lights to wake the babies.

Rick

 

[MissCream]

Didn't read any of the above posts. Put your subject a lot further away from the background and put your f# as low as it will go. If you're still not getting bokeh with the lenses you have then move the subject even further away from the background!

 

[Dao]

If you shoot indoor inside a small room with a backdrop, I think it is kind of tough to create a nice blur background. You maybe able to make the background out of focus, but may not be able to create creamy blur background. But why do you want to do that? You have a very ugly looking backdrop?

 

[The_Traveler]

Didn't read any of the above posts.

Ditto

 

[KmH]

If you want more bokeh the longer focal length has more. the longer the focal length the shorter the dof. A 300mm 1.8 will be much shallower than a 25mm 1.8

Not if the subject scale in the frame is the same. With a longer focal length lens, you have to be further back from the focal point to maintain the same subject scale in the frame.

If the subject scale is the same the DOF range of distance will be the same for both focal lengths. What the longer focal length does is compresses the background making it appear closer to the subject, which makes the blurred elements appear larger in size, not more blurred. Obviously, in a studio or home setting there may not be enough space to use longer focal lengths.

Everyone seems to concentrate on lens aperture, and ignore the fact that the focal point distance from the camera has a lot to do with DOF. In other words you can also change the DOF by moving away from, or getting closer to your subject with the same focal length.

Four things effect DOF, so you need to consider all 4 when setting up a shot:

1. Focal point to background distance.
2. Focal point to camera distance.
3. Lens focal length.
4. Lens aperture.

As mentioned elsewhare bokeh and a blurred background are not the same thing.

Bokeh is a subjective visual quality of the blur that a particular lens produces. That subjective visual quality is a function of the "circle of confusion' a lens produces. The circle of confusion a lens produces is affected by the number and shape of the lens aperture blades, and by how the lens maker controlled the spherical aberration the lens produces. http://en.wikipedia.org/wiki/Circle_of_confusion

From http://en.wikipedia.org/wiki/Bokeh

Although difficult to quantify, some lenses enhance overall image quality by producing more subjectively pleasing out-of-focus areas. Good bokeh is especially important for large-aperture lenses, macro lenses, and long telephoto lenses because they are typically used with a shallow depth of field. Bokeh is also important for medium telephoto "portrait lenses" (typically 85–150 mm on 35 mm format) because in portraiture photography, the photographer typically seeks to obtain a shallow depth of field to achieve an out-of-focus background and make the subject stand out.

 

[Derrel]

The 35mm 1.8 AF-S G-Nikkor is known as a lens with atrociously poor bokeh. Bokeh is the quality if the out-of-focus regions in an image. Not "how out of focus the background or foreground" is, but how pleasingly the OOF areas are rendered by the lens.

You are looking to create "selective focus". Unfortunately, with a limited shooting area, with the subject quite close to the background, it is going to be exceedingly difficult to well and truly separate the focus on the foreground from the background's degree of focus. THIS IS A PROBLEM with small-sensor cameras!!! They have greater depth of field at each angle of view and at each subject size in the picture, compared against cameras that use BIGGER sensors or bigger film to capture their images.

Do what you can.