Why is there little background blur at 50mm f/1.8?
Asked 12/4/2013
2 views
2 answers
0
I shot a wave at f/1.8 with a 50mm lens, and the boats in the background still look fairly sharp. I expected much stronger background blur. Why would there be so little bokeh at such a wide aperture?
Originally by Photography Stack Exchange contributor. Source · Licensed CC BY-SA 4.0
Photography Stack Exchange contributor
12y ago
2 Answers
31
Depth of field depends not only on aperture but also on distance to the subject. Depth of field increases as the subject gets farther away. If the wave and boats were all relatively far from the camera, but not terribly far from each other, then it's not surprising that they were all reasonably sharp.
You can use DOFMaster to run the numbers yourself. Some examples using a 50mm lens at f/1.8 on a full frame camera:
at 15m (50 feet) to the subject, you get a total of 11m (36 feet) of depth of field
at 30.5m (100 feet) to the subject, you get 68.5m (225 feet) of depth of field
Originally by user4262. Source · Licensed CC BY-SA 4.0
user4262
12y ago
0
Generated from our catalog & community — verify before relying on it.
A wide aperture helps, but bokeh/background blur also depends heavily on subject distance and focal length.
With a 50mm lens at f/1.8, depth of field becomes much deeper when you focus farther away. If the wave was fairly distant, and the boats behind it were not much farther away than the wave, they can all appear reasonably sharp even at f/1.8.
In practice, stronger background blur comes from combining:
- a wide aperture
- a closer focus distance to the subject
- a larger distance between subject and background
- often a longer focal length
So in your scene, the limiting factor was likely distance: the wave and boats were all relatively far from the camera, and probably not separated enough in depth to create obvious blur.
If you want more blur, try moving closer to the subject, increasing the distance between subject and background, or using a longer lens.
Recommended products
UniqueBot
AI12y ago
Your Answer
Related Questions
Will an 85mm prime give me more background blur than a 50mm f/1.8 on a Nikon D3100?
Why am I not getting very blurry backgrounds at f/1.8 with a 35mm lens?
Are 50mm f/1.8 lenses less sharp than 50mm f/2.8 lenses of similar design?
Why are small apertures usually recommended for landscape photography?
Why doesn’t changing aperture blur the background on a Fujifilm FinePix S4000?