Aperture/DoF: my error or the camera?
Discussion
Hi,
I've been thinking of updating my approx 7 yr old bridge camera for an SLR recently (fuji finepix S5600), however before I spend the money I wanted to see if I could get more out of the bridge camera and save myself the cash. At the South Cerney steam rally this weekend I though I'd have a play with the aperture to get a narrower depth of field. The intention was to get the subject in focus and the background out of focus.
The top picture was taken using F8 and 1/75, the bottom picture was taken using F3.2 and 1/450 (the limits of aperture on this camera). Focal length on both was 6.3 (is this relevant?). I'd have expected the bottom picture to show the organ in the background to be blurred. This is not the case - have I done something wrong? or is this a limitation of the camera that would be rectified with an SLR?
Thanks,
Ralph
I've been thinking of updating my approx 7 yr old bridge camera for an SLR recently (fuji finepix S5600), however before I spend the money I wanted to see if I could get more out of the bridge camera and save myself the cash. At the South Cerney steam rally this weekend I though I'd have a play with the aperture to get a narrower depth of field. The intention was to get the subject in focus and the background out of focus.
The top picture was taken using F8 and 1/75, the bottom picture was taken using F3.2 and 1/450 (the limits of aperture on this camera). Focal length on both was 6.3 (is this relevant?). I'd have expected the bottom picture to show the organ in the background to be blurred. This is not the case - have I done something wrong? or is this a limitation of the camera that would be rectified with an SLR?
Thanks,
Ralph
Due to the size of the sensor in a bridge camera and the relatively slow lenses, it's often impossible to get a nice depth of field when focusing on objects that aren't directly in front of the camera.
A DSLR doesn't automatically mean pictures with a shallow depth of field, although with an APS-C sized sensor or larger, it's far more possible with slower lenses.
A DSLR doesn't automatically mean pictures with a shallow depth of field, although with an APS-C sized sensor or larger, it's far more possible with slower lenses.
A slow lens is one with a narrow max aperture. A fast lens is one capable of a wide max aperture.
So a 1.8 50mm prime is classed a fast lens.
A 1.8 50mm prime will be limiting in some situations but perfect for others. This is why bridge cameras have the lenses they do. They are designed to be a jack of all trades but unfortunately suffer from being a master of none.
Each lens for a DSLR will have it's own advantages and will also have it's own disadvantages. Of course, you can still get jack of all trade type lenses with a wide angle and a superzoom and reasonable aperture but then you will likely end up with the same issues you do with your bridge.
So a 1.8 50mm prime is classed a fast lens.
A 1.8 50mm prime will be limiting in some situations but perfect for others. This is why bridge cameras have the lenses they do. They are designed to be a jack of all trades but unfortunately suffer from being a master of none.
Each lens for a DSLR will have it's own advantages and will also have it's own disadvantages. Of course, you can still get jack of all trade type lenses with a wide angle and a superzoom and reasonable aperture but then you will likely end up with the same issues you do with your bridge.
I think you are reaching the limitations of compact cameras 
Narrow dof at-distance from a small sensored camera is a tough ask.
You can promote narrow dof by using as long a focal length as possible (zoom in), but that'll be difficult with the given subject. Can also focus as closely to the camera as possible - also not really possible given the subject. So using a wide aperture is really your only tool in this case.
But dof is also effected by sensor size. There is a comparison on wikipedia:
http://en.wikipedia.org/wiki/File:Sensor_sizes_ove...
Your camera has a 1/25" size sensor, most normal DSLRs have a APS-C sized sensor. There is quite a difference in area...
I'd say neither you or your camera were in error
Narrow dof at-distance from a small sensored camera is a tough ask.
You can promote narrow dof by using as long a focal length as possible (zoom in), but that'll be difficult with the given subject. Can also focus as closely to the camera as possible - also not really possible given the subject. So using a wide aperture is really your only tool in this case.
But dof is also effected by sensor size. There is a comparison on wikipedia:
http://en.wikipedia.org/wiki/File:Sensor_sizes_ove...
Your camera has a 1/25" size sensor, most normal DSLRs have a APS-C sized sensor. There is quite a difference in area...
I'd say neither you or your camera were in error
In my opinion, a shallow depth of field is what makes a layman regard a photograph as 'professional'.
Now I know that's a sweeping statement, but having taken tens of thousands of pictures over the years there is no doubt in my mind that it's true.
Big apertures are pretty much exclusive to pro-lenses, and as discussed, it's only those big apertures that can really achieve this.
Now I know that's a sweeping statement, but having taken tens of thousands of pictures over the years there is no doubt in my mind that it's true.
Big apertures are pretty much exclusive to pro-lenses, and as discussed, it's only those big apertures that can really achieve this.
budfox said:
In my opinion, a shallow depth of field is what makes a layman regard a photograph as 'professional'.
Nothing wrong with that if it makes us rank amateurs with a nifty fifty look good.It's not the be all and end all but I can see why people appreciate it - it isolates the subject from the background much more effectively than most compacts and mobile phones can manage, which in turn makes photo's stand out from everything else that turns up on Facebook etc. It might not attract kudos from the tog community but if it makes everyone else go 'ah, that's a great shot' (sometimes follow with, 'you must have a really good camera') then I don't see a problem with that.
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