Does aperture affects hyperfocal distance?

[Gaurav Prabhu]

I've heard that focussing a lens on its hyperfocal distance ensures perfect sharpness throughout the frame. So if one focuses on the hyperfocal distance of a particular lens, what aperture should be used? Will it matter if one uses a wide or a narrow aperture when the lens is focussed at hyperfocal distance?

[RichardTaylor]

Aperture affects hyperfocal distance.

See here & plug in some numbers.

Online Depth of Field Calculator

Sharpness depends on the lens IQ at a particular aperture (usually a couple of stops down from wide open), the depth of field, the lighting, the subject texture, and the photographers technique (no effects from camera shake or flare).

[Gaurav Prabhu]

Still its not clear to me. Which aperture should be used to ensure DOF all throughout the image(hyperfocal distance)?

[sk66]

In reality, aperture is less important than focal length for hyperfocal distance use. Use a short lens with small aperture for maximum results. Otherwise just us a small aperture (f/8-16) and focus about 1/3 into a scene.

[RichardTaylor]

You are using a P&S which most likely will not stop down past F8.

There is only one area when the picture will be sharpest, however the zone of acceptable sharpness will depend on the aperture, shooting distance and focal length (and the size of the final image and viewing distance)

As sk66 says focussing 1/3 of the way into the scene will do the trick, especially with the lens at the wide end. F5.6 or F8 should be OK for shooting scenes.

Examples - all taken with a point & shoot camera.

(1) 'scape. (I can't remember where I was focussed)


Camera Canon PowerShot G11
Exposure 2
Aperture f/5.6
Focal Length 6.1 mm
ISO Speed 100
Exposure Bias 0 EV
Date and Time (Original) 2011:04:30 06:01:52+10:00


(2) Here I would have been focused on the lady

Camera Canon PowerShot G11
Exposure 0.002 sec (1/500)
Aperture f/4.0
Focal Length 6.1 mm
ISO Speed 200
Exposure Bias -2/3 EV

(3) However for extreme close up your depth of field will be in mm or fractions of an inch.
I think I would have been focussed on the bug (this is the inside of a Nasturtium)


Camera Canon PowerShot G11
Exposure 0.005 sec (1/200)
Aperture f/8.0
Focal Length 6.1 mm
ISO Speed 400
Exposure Bias +1 EV
Flash Off, Did not fire

[Gaurav Prabhu]

Now I got what you meant to say. Yes, my P&S has the max aperture as f/8.0.

[crockny]

If I can horn in on this discussion, I had the same question. I do mostly birds and closeups and haven't gotten the hang of what to focus on in a big scene. If there's nothing in particular a third of the way into the picture, but stuff in the front and mountains or whatever in the back, where do you focus? Still a third of the way in? And for f-stop, do you use the middle ground or use the smallest aperture you can?

[RichardTaylor]

For 'scapes I am usually (not always) using around F11-F16 (on a DSLR) or F5.6-F8 for a P&S
However it also depends on the lighting, the focal length I am using and if I am using a tripod.
The only time I tend to use very small apertures is when shooting macros.

I tend to focus on a contrasty significant object object about 1/3 way into the scene however if the main subject is in the distance that is what I will focus on.

Here are some examples from my Flickr stream, where larger pics can be seen..

(1) Here I focussed on the lights on the first bridge (close to infinity)

Camera Canon EOS 5D
Exposure 3.2
Aperture f/8.0
Focal Length 45 mm
ISO Speed 200

(2) Here I was probably focussed on the man (it was a while ago)

Camera Canon EOS 5D
Exposure 0.003 sec (1/320)
Aperture f/13
Focal Length 50 mm
ISO Speed 200
Exposure Bias -4/3 EV

(3) Here I was focussed on the surfers.

Camera Canon EOS 40D
Exposure 0.167 sec (1/6)
Aperture f/8.0
Focal Length 100 mm
ISO Speed 100

(4) Here I would have been focussed on the gate.


Camera Canon EOS 5D
Exposure 0.006 sec (1/160)
Aperture f/14.0
Focal Length 105 mm
ISO Speed 800
Exposure Bias -1 EV

Hope this helps.

[sk66]

One thing to keep in mind, there can be a significant difference between using hyperfocal distance and focusing 1/3 into a scene.

Here's an example (using quick swag math):
using a 50mm lens on a crop sensor the hyperfocal distance is aprox. 12m @ f/11
If you focus 1/3 into a scene (say 30m) then everything from around 12m on out will be in focus.
If you focus at 12m (the hyperfocal point) everything from 6m on out will be in focus.

It can make a difference in particular instances.

[crockny]

Who knew math was going to be a prerequisite for photography? I'm not good with millimeters or even approximating distance in feet ... but this is obviously something I need to learn to get the sharpest pictures ... eventually I'll get a wide angle lens, but for now landscape pictures are being done with my Tamron 18-270 zoom which means my focal length could be almost anything ... is there a cheat sheet somewhere????