SLR Experts

[553 Bridgeton]

How do you get a shot like this? Im talking about the blurred backround with the subject in the photo standing out more. Is it photoshopped? Or do I need a macro lens with long zoom?

 

BTW the pic was taken by trevor.

 

[St Louis Car 09]

How do you get a shot like this? Im talking about the blurred backround with the subject in the photo standing out more. Is it photoshopped? Or do I need a macro lens with long zoom?

 

BTW the pic was taken by trevor.

 

Big kudos for giving credit when credit is due.I know with point and shoots,its just a matter of selecting macro and focusing on the target.

[Y2Julio]

How do you get a shot like this? Im talking about the blurred backround with the subject in the photo standing out more. Is it photoshopped? Or do I need a macro lens with long zoom?

 

BTW the pic was taken by trevor.

 

The "blurred" background you're talking about is what's called bokeh.

Read the article on Wikipedia about it http://en.wikipedia.org/wiki/Bokeh

and also from Kenrockwell.com

http://www.kenrockwell.com/nikon/bokeh-comparison.htm

http://www.kenrockwell.com/tech/bokeh.htm

[Joe]

Longer focal length (in that example the FL is 300mm) results in a thinner depth of field which therefore gives you the "one part sharp, everything else blurry" look.

[error46146]

i remember reading somewhere if you zoom in and use a lower f-stop you will get a blurred background while if you use a higher f-stop everything tends to be more clear. that proved somewhat true in my experience and tests you could try it yourself if you have the manual settings

[Joe]

i remember reading somewhere if you zoom in and use a lower f-stop you will get a blurred background while if you use a higher f-stop everything tends to be more clear. that proved somewhat true in my experience and tests you could try it yourself if you have the manual settings

 

That is 100% correct, error.

 

What we see in the photo is a thin depth of field. Depth of field depends on three variables: aperture, focal length and focal distance.

 

A larger aperture (smaller f/number) yields a thinner depth of field than a smaller aperture (larger f/number).

 

A shorter focal length yields a wider depth of field than a longer focal length.

 

A closer focal distance yields a thinner depth of field than a more distant focal distance.

 

What is depth of field may you ask? Depth of field is a measure of the distances in front of and behind the plane of focus that will be rendered "acceptably sharp".

[Joe]

To amend my last post, the following is also true, though i'm including it separately because it opens a whole other can of worms...

 

Depth of field also depends on sensor size, with smaller sensors offering wider depth of fields per f/stop; larger sensors offer a thinner depth of field per f/stop. This is why little point and shoot cameras often won't close down any further than f/8 whereas I have lenses for Nikon F that close down to f/11 and f/22. On a P&S camera you simply don't need anything slower than f/8...you get amazing DoF at f/3.5 and f/4.

[css9450]

Not to hijack the thread, but the photo included in the first post is a good example of what I'm asking: Why do the LEDs sometimes (often?) not all appear illuminated in photos? A lot of my NY photos looked like that too. Something to do with the LEDs "flashing" (or something) faster than the eye can see?

[Y2Julio]

Not to hijack the thread, but the photo included in the first post is a good example of what I'm asking: Why do the LEDs sometimes (often?) not all appear illuminated in photos? A lot of my NY photos looked like that too. Something to do with the LEDs "flashing" (or something) faster than the eye can see?

 

Has to do with the shutter speed.

[Joe]

Not to hijack the thread, but the photo included in the first post is a good example of what I'm asking: Why do the LEDs sometimes (often?) not all appear illuminated in photos? A lot of my NY photos looked like that too. Something to do with the LEDs "flashing" (or something) faster than the eye can see?

 

The display device has a certain refresh rate. The refresh rate is the time it takes the device to completely re-draw itself. A refresh rate of 60Hz indicates that the display completely refreshes in a cycle of 1/60s (x Hz = 1/x seconds).

 

What we see on the R143s and R160s is that people take a photo with a shutter speed faster than the refresh rate of the route indicator display. On this equipment, the display refreshes at a rate of 125Hz (1/125s). A camera shutter speed of 1/125s will capture this perfectly, whereas a shutter speed of 1/250s will only show half of the display.

 

This is also why when CRTs were more prevalent as computer displays and a news camera would film them, they would appear to "scroll".

[css9450]

Makes sense! When I was in NY, I shot a few trains just before sunrise (or in the subway) at lower shutter speeds, and their LEDs were complete. The sunny daylight stuff at 1/640 or whatever looked like some of the lights were burned out.... just like the TV analogy.

[553 Bridgeton]

The "blurred" background you're talking about is what's called bokeh.

Read the article on Wikipedia about it http://en.wikipedia.org/wiki/Bokeh

and also from Kenrockwell.com

http://www.kenrockwell.com/nikon/bokeh-comparison.htm

http://www.kenrockwell.com/tech/bokeh.htm

 

Thanks!

 

Thanks everyone for all the great info!

 

And im working with a Nikon D3000.