Another very basic question
After watching lot of videos I decided to put my camera on a tripod and capture pictures starting from minimum aperture - 2.4 camera supports.
However I am not seeing bokeh effect at same aperture the way I see in these videos. Almost everything stays in focus.
At the same aperture, is the effect same for every lens? I am guessing the reason why I am not getting effect is because of lens limitations.
What focal length is the lens? You’ll see more bokeh with longer lenses.
Besides focal length, the focus distance also matters, the closer you focus, the bigger the blur.
Besides aperture (expressed as an f-number), the physical (not equivalent) focal length also matters. Or, worded differently, the aperture expressed in absolute terms (e.g. millimetres). f/2.4 on a compact, with a 50 mm ‘equivalent’ lens (that would be 11 mm on many phones and small-sensor compacts) and a 50 mm lens on a full-frame camera will look very different.
the DOFs are in inverse proportion to the absolute aperture diameters
Image sensor format - Wikipedia
Camera is Sony RX10 IV. Focal length is listed 24mm to 600mm. For my testing I did not zoom in, just turned on the camera and left the lens at startup position. That’s the only position where I could get 2.4 aperture.
Hi
I’ll hazard a guess that anything beyond 2 metres, 6ft, at 24mm is gonna be in focus.
To expand on @Pizzacutter comment, keep the distance between camera and subject much smaller than subject to background.
Also bokeh effects will diminish with shorter focal lengths.
Then there’s the lens minimum focus distance.
And the effects of sensor size…
Hhmm, bit of a rabbit hole.
Experiment.
I shoot a 24mm on my full frame often, and blur and bokeh is not something that lens does.
200mm at f5 and focus on something close to the lens will likely give you way more blur than 24mm ever can.
A 24 mm lens at f/2.4 has an aperture diameter of 24 mm / 2.4 = 10 mm.
A simple kit lens, like my 18 - 105 Nikkor at 105 mm, f/5.6 has an aperture diameter of 105 mm / 5.6 = 18.75 mm, and has a shallower DoF (as long as both can focus on the subject, and they are the same distance from the subject). Going further, my 70 - 300 mm, when fully zoomed in, at f/5.6, has an aperture diameter of 53.57 mm. Of course it delivers a much shallower DoF than the 24 mm lens at f/2.4 (or the 18-105 at f/5.6).
DoF is a function of aperture, but in my view the true focal length of the lens is a more critical starting point. If you want a nice artistic blur (bokeh) then you must avoid short focal length lenses. In my experience I would say a 50mm lens is the shortest I would consider, but it would need an aperture of at least F1.8. A 55mm kit lens with a F 5.6 aperture would be insufficient for a nice bokeh. Even longer lens with with large enough apertures work very well.
50mm lens with F1.7 works
200mm lens with F4 works very well
As others have said, bokeh is a function of the depth of field. For a given focal lent, focal point, and aperature, there will be a range where the subject is in focus and a range where it is out of focus (both in front of and behind the subject. There are many online calculators for this such as here
https://www.cambridgeincolour.com/tutorials/dof-calculator.htm
Play around the variables to get a feel for it.
I may have missed it if someone has mentioned this, but that Sony camera has a “1 inch type” sensor. The wide end of the lens is something close to 9mm in real focal length. At f/2.4 that aperture is less than 4mm across.