Explain the blue bubbles in this photo?

[Aussie Nan]

Hi,

I am hoping someone can tell me why I have blue bubble like texture on this image? The bubble area was actually bright blue sky with strands of thin twiggy branches crisscrossing it.

If I remember correctly I had the camera on auto setting because I wanted to take the pic quickly before he flew away.

thanks in advance from a new SLR struggler, Toni

[TonyW]

Toni: I think you'll find that is "bokeh" . It's because the background is out of focus (you had a short depth of field and were focussed on the bird). Bokeh is what lenses do to out of focus parts of an image. Some will look more like a gaussian blur, some will look more like bubbles. You will notice more with a DSLR because of the shorter depth of field you have compared to a typical point and shoot. There is supposedly good and bad bokeh depending I guess on what effect you like.

Here's a somewhat less technical explanation than some you'll find.

http://www.luminous-landscape.com/essays/bokeh.shtml

The key thing I picked up on in is that the eye sees evrything in focus, cameras don't do that, so out of focus areas in photographs don't look like what the eye is used to seeing.

Tony

[Aussie Nan]

Thanks Tony. I have seen comments about the 'bokeh' on images on the net, but didn't know what they meant. I don't like it much.

The link you gave was interesting, but still a bit too complicated for this twirling brain. I got the gist of it though, and thanks to you I have now learned about bokeh.

[mljrbg]

Toni, I like your pic. I think you did a great job on it. I never would have noticed the bubbles.

Tony, I will read your article later. I never knew bokeh existed!!

Mary Lou

[Not4wood]

AussieNan,

Great image, real sharp.

To keep it simple so far to add what Tony mentioned:
Think of it this way. The shape of the shutter passing out of focus light inside gives it a shape on the sensor/film. This shape depending on the light is either round (like bubbles) or it can have a hexagon or flat sides to it which is in itself not natural. Its the shape of the out of focus light that is Bokeh. Some are more pleasing to the eye/mind some are not. Yours is very nice btw........

You will find shooting thru a DSLR is a very long process and learning curve. The eye/mind is very selective in both color, focus and of course subject. The camera sees it all, and you now have to take control of what your new tool does.

You could list your new tool in your sig..... and how bout your shooting EXIF info?

[Not4wood]

Here is an example of my Bokeh from my long lens:



Date/Time: 2008:07:29 07:45:58
Camera Model: NIKON D80 Flash Used: No Lens: 70-300VR Focal Length: 300.0mm (35mm equivalent: 450) Exposure Time: 0.0040 s (1/250) Aperture: f/11.0 ISO Equiv.: 400 Whitebalance: Cloudy -1 Metering Mode: matrix Exposure Mode: Manual
--
I wanted a fast shutter speed to make sure I got a good shot with no Movement from the Butterfly as well as a good mid level f: stop. I wanted good focus with no distortion in the extreme end of this 300mm zoom. At this end my zoom is 5.6 at the fastest so I picked 2 stops in which brings me to f:/11 so I had to increase my ISO to 400 on this heavy cloudy day. Remember, this lens is a VR lens and I dont have to worry about hand holding a long 300mm at 250/second with this VR on. I always have it on the back of my mind to be careful for extra Noise when its not necesary like pushing the ISO up higher especially with a darker background like I do here.

[ladybug]

Toni i love the birdie. Great picture as is.

[Aussie Nan]

Thanks for the advice and comments everyone. This is such a great place for beginners like me.

Mark, thanks for your explanation. And also the info on your gorgeous butterfly image. I won't pretend to understand it all yet, that's what my learning curve is all about. One step at a time. Or should that be one stop at a time?

Your bokeh is not evident to me, is that because it comes across as blur (depth of field?) rather than my 'bubbles'?

Toni

[Not4wood]

Originally Posted by Aussie Nan

our bokeh is not evident to me, is that because it comes across as blur (depth of field?) rather than my 'bubbles'?

Toni

Yes, if you look to the top right the pink flower is way out of focus. The way this is handled by the shutter makes it look like it does. It is very pleasing to the eye and doesn't detract from the overall whole image.

This is also shot at f:/11 and on this lens there are 9 blades for the shutter to make a very nice rounded Bokeh.

[mljrbg]

Originally Posted by mljrbg

Toni, I like your pic. I think you did a great job on it. I never would have noticed the bubbles.

Tony, I will read your article later. I never knew bokeh existed!!

Mary Lou

If I had known bokeh was Japanese for blurry I would have known it existed!! I have always been very intrigued by depth of field, or now as I know it, bokeh. Thanks Toni and Tony for bringing this up and defining it.

Mary Lou