- This topic is empty.
blur
-
The traditional way to blur photos is with the right lens.
There are a number of factors which dictate how much of a photo is in focus, called the “Depth-of-Field”
These are the aperture used (f-stop), focal length, distance of focus and enlargement size of the photo when you view it.Most blurred background shots come from lenses with large apertures eg, f/1.4 or f/2. Lenses which open as wide as this (smaller number = larger hole) can be expensive and large.
You can also use lenses with long focal lengths, and focusing at a close distance.It might be good to look through the articles on this site http://www.dofmaster.com/
A good exercise would be to take the exact same photo it all repects except changing the aperture going down the scale and see the difference. Maybe shot along a wall so that you can see exactly the depth-of-field.There are also software solutions, blurring with photoshop etc.
Martin
Use the aperture priority setting in the camera set it to the lowest number i.e. the largest aperture. what ever you focus on will be in focus the background will be blurred
Deebo wrote:
Or simply use the Gaussian blur in photoshop
You can use that to blur anything digital-
it doesn’t have to be a photograph- which was what the original question referred to- I think-
Using software to that extent might make the photographic element secondary to the ‘digital art’ computer manipulations.Sorry, just came over all of a quiver, went a bit blurry myself-
I’ll be alright, I’ll just sit down, have a glass of water…j
Deebo wrote:
Or simply use the Gaussian blur in photoshop
:shock: This piece of advice I would certainly ignore… a lot of things are achievable in photoshop, but something as simple as a shallow DOF (blurred background) can be easily achieved in camera.
A lot of the tips here are semi-accurate and should put you on the right track (apart from the one above).
Put simply, a camera can only focus on one distance correctly. Anything at that distance will be in sharp focus. Anything closer to the camera than it and anything further away fall out of focus. How quickly they fall out of focus (the depth of field) depend on a number of factors. Aperture is the primary one. However focal length does NOT change depth of field – I’ll come back to that in a second.
So aperture.. by opening your lens up (smaller f number) you decrease the depth of field, so focus falls away quicker. But you don’t need an expensive f1.2, f1.4 or indeed f2.8 lens to achieve this. Remember that the subject is in focus and focus falls away behind it and in front of it. So set your lens to the smallest f-number it has and then simply move your subject away from the background. With greater separation comes greater blur effect.
Focal distance is the second factor, NOT focal length. It is a common misconception to believe that focal length effects depth of field, because telephoto lenses are often used to create a shallower DOF – but it in fact doesn’t. Telephoto zooms make the subject appear bigger rather than the photographer getting closer – so there is a magnification process underway. If you were to take two pictures of an object, one with a telephoto lens and one with a wide lens, in such a way that the subject was the exact same size in both images (would mean getting closer with the wide angle and further away with the zoom), assuming you used the same aperture, the DOF would be identical in both images! So the DOF is constant with focal length, hence disproving the focal length is a factor.
I’d agree with Ciaran’s comments-
in addition, and you wont want to hear this, I’m sure,
you could choose a lens where the optical design contributes to blur-
soft focus designs, which use spherical aberration, such as the Imagon or Verito types,
Petzval designs, which achieve blur through extreme field curvature,
or simple meniscus lenses such as those found on the Holga and other ‘Toy’ cameras-
field curvature again-Panning the camera will produce blur, as will subject movement-
though this is a type of blur that’s seldom welcome…j
To get back to basics you would need a camera where the aperture of a lens can be adjusted. To do this with a point and shoot would be rather difficult to blur the background intentionally. What has been discussed previously makes the assumption that you do own, or have access to such a camera. This might seem overly obvious to some but there is no indication as to what you take your photographs with.
Alan
You must be logged in to reply to this topic.
