Portrait Background Bluring - A little help please?

Complete123 · Dec 30, 2012

New to the photography scene. Not new to the IT scene ( vetted in photoshop ) however a slight dilema.

Purchased: Sony DSC-f828 (mint condition!) On the cheap (bargain)

Read tutorials Apeture, Iso etc etc.

One thing confuses me though - there are many tutorials on how to take gorgeous photo's with blurred backgrounds. But I can not find anything about altering the amount of blur in the background. While I have managed to take some great profile shots; what I'd like to be able to do is only slightly blur things out of the focus target.

For instance if I have a crowd of people, and I'd like to target one while bluring the people behind .. but only slightly in such a way the faces are recognisable as faces rather than a blur.

Any tutorials how to adjust background blur? Tips? Tricks? This is one of those 'I can't fix with photoshop' situations. Is my best option just to take a photo without any blurring and photoshop it?

480sparky · Dec 30, 2012

Shoot at longer focal lengths.

Shoot with a large aperture (smaller f/number).

Dao · Dec 30, 2012

To increase the background blur effect, you can ....

- Use a longer focal length. (longer the better)
- Use a wider aperture. (smaller the f number, wider the better)
- Shorten the subject to camera distance. (shorter the better)
- Find a background that is far away from the subject. (farther the better)

Complete123 · Dec 30, 2012

Thank you! Just what I was after.

KmH · Dec 30, 2012

You need to understand the ins-and-outs of Depth-Of-Field (DoF) - Understanding Depth of Field in Photography

Image sensor size and focus distance are major influences on DoF.

Longer focal lengths give the same DoF as shorter focal lengths if subject scale in the image frame is maintained, and the lens aperture is the same.
In other words, with a longer focal length you move further away from the subject to maintain subject scale.
If you use 2x the focal length, you would be 2x further from the subject.

Dao · Dec 30, 2012

You are correct the DoF is the same with the longer focal length lens. However, the "effect" of the blur background is better when view it in a narrower angle of view.

Lets take an example.

1. Subject is 20 feet from the camera. Take a photo with 24mm.
2. Subject is 20 feet from the camera (same place as 1). Take a photo with 200mm.
3. Shoot with 24mm and subject move much closer to the camera to a point that the frame of the subject is the same as shoot with 200mm (2).
4. Crop the photo in (1) so that the subject framing is the same as (2).

You will notice the background blur of (4) and (2) is the same because same DoF, but I will use method (2) instead of (4) to achieve the same angle of view. For (3), the angle of view of the background is too wide to be good as a blur background.

justiceischeap · Dec 31, 2012

There are some great video tutorials on YouTube as well, if you're a visual learner like me. Just search for "bokeh tutorial."

weepete · Dec 31, 2012

Bokeh is different to depth of field, so they'd be better off searching for depth of field tutorials.

Complete123 - the easiest way of changing the amount of blur in the background is to change your aperture size. You may have to experiment a bit with the distance between the subject and the background too, as this will also affect how blurred the shot is.

Duckysaurus · Dec 31, 2012

Everything Dao said in the first response here. Whereas you CAN get good background blur (bokeh) with a short lens, it's harder to do so, and usually the wider lenses that can cost a bit to a lot more.

Also, you don't necessarily need a small f-stop (aka LARGER APERTURE like 1.4 or 1.8) to get good background blur if the separation between subject + background is good. Can even get a nice blur up to f/4 to f/8. Most pros usually use f/1.4-2.8 lenses. Sometimes the f/4 lenses if there is VR.

Also note, if you want nicer bokeh, use a lens at it's smallest f-stop so the blades will be fully recessed. For example, the bokeh on a 50mm 1.8 at 1.8 is better than the bokeh on a 50mm 1.4 at 1.8.

ph0enix · Jan 2, 2013

Despite the F828 being a decent camera it is still a "point and shoot". It might be difficult to achieve the exact effect you're looking for due to its small sensor and manual settings limitations. With that being said I have never used the F828 but I own the F707 (its predecessor - two generations behind yours). I find the 707 to be a great "Auto" camera but it is very frustrating in the A, S and M modes. Perhaps the F828 is much better. I would love to see your results.

fokker · Jan 2, 2013

ph0enix said:
Despite the F828 being a decent camera it is still a "point and shoot". It might be difficult to achieve the exact effect you're looking for due to its small sensor and manual settings limitations. With that being said I have never used the F828 but I own the F707 (its predecessor - two generations behind yours). I find the 707 to be a great "Auto" camera but it is very frustrating in the A, S and M modes. Perhaps the F828 is much better. I would love to see your results.

Yeah this. ^
That camera is incapable of ever achieving the type of shot you talk about "For instance if I have a crowd of people, and I'd like to target one while bluring the people behind .. but only slightly in such a way the faces are recognisable as faces rather than a blur."
For that, you need a camera with a bigger sensor like dslr with a nice f/2.8 telephoto lens...

bratkinson · Jan 3, 2013

One of the lessons I learned the hard way was when I wanted to isolate 1-2 people in a crowd with the rest out of focus, one really needs to know how to select AF focus points (center AF point only is the easiest) and shoot at or near wide open to get a thin depth of field (DOF). I take a couple of manual focus shots as well, if time permits, just to make sure I got a keeper.

JTPhotography · Jan 3, 2013

What everyone has said is spot-on. Blur is related to aperture and focal length. Bokeh is specifically the quality of the blur. Extreme shallow depth of field photography has become popular. I have heard from many beginners who see, like it, and it causes them to want to take up photography....without realizing that much of what they see is being done with superwide aperture lenses like the 1.2s and even the lens babies. Two things to keep in mind. First, these lenses are very expensive. Second, if this is a style of photography that you want to explore, you still have to learn and fully understand the basics of exposure (shutter speed, aperture, ISO, and depth of field). I know several "pro" portrait photographers who own one camera body, one big aperture lens and shoot the same photos over and over and over, over-exposing and blurring out the background. There is nothing wrong with that effect, but they are doing a disservice to their client and to themselves by placing themselves in a box like that.

That being said, I have a sigma 85 1.4 that I shoot almost exclusively wide open. It is a very sharp lens, half the price of the canon 85. Very fun but the autofocus is useless wide open. You have to know what you are doing to get good photos with it.