Hyperfocal Focus

[Btreize]

Hello dear friends,
Now that i know that Landscape will be my main subjects, having sharp photos is important and started practicing all techniques to give me sharpest photos possible.
I have just started reading on Hyperfocal distance focusing and i even have a calculator on my mobile. I have to input the focal length, my f-stop value, subject distance then it gives me the Hyperfocal value

an example:
Focal lenght (mm): 18mm
Selected f-stop: f/11
Subject distance (meters): 10m

Results:
Near limit: 1.31m
Far limit: 10000m
Hyperfocal: 1.525m

I understand that i must focus on a point that is 1m5 from where my camera is placed (front lens), then from 1m31 from my camera to 10000m (infinity) should be in focus. Am i right or missed something somewhere?
Also, how to focus with this method? Manual focus or auto focus? If AF used, i guess we focus at the hyperfocal distance, then recompose the scene without refocusing..

So manual focus on an object 1m50 from me should keep the foreground and the far background in "focus"

huh the 1m50 seems a bit near to focus on, but i think that with an aperture of f11, it should be good.

I would really appreciate some guides from some more experienced here.

Regards

Btreize

[RecurrentNerve]

Personally I wouldn't bother with going through all the calculations, unless you're walking around with a measuring tape all the time.

The rule of thumb is to focus a third of the way 'into' the shot (yup, the rule of thirds again), which will usually be pretty close to the correct distance. You can use autofocus for this; if you need to recompose the shot, simply autofocus on the correct spot, flick the camera to manual focus, and recompose.

Always use a tripod so the only thing you need to worry about is aperture. Standard settings for me are A-priority f/16ish, ISO 200 and whatever shutter speed the camera works out. Using a remote or timer will also help to get pin-sharp images by reducing any camera shake. And of course you can always take a shot then check the image on the LCD.

[zona5101]

you would need to manually focus at the hyperfocal distance you calculate. (Because chances are there isn't anything there to autofocus on!). Some lens these days don't have a distance scale and even ones that do the marking probably aren't as precise as you will need them to be. You most probably will either measure this distance or pace it off as an estimate, oplace an object there to focus on, set your focus, remove the object and take the picture. Obviously the more accurate your measure, the more your focus will align with what you predetermined on your calculator. The question will be do you need that level of precision (and hassle)?

[sk66]

I just "swag" hyperfocal distance in the field..

square the focal length and divide by 200 for a crop sensor fr hyperfocal distance at f/10. Or even simpler take the first number (rounded) of the focal length squared and divide by two...
i.e. 18mm= 1.8, rounds up to two. 2x2=4. 4/2=2...hyperfocal distance =2m @ f/10.
50mm= 5, 5x5=25, 25/2= 12.5m @f/10
Hyperfocal distance doubles or halves for every full stop change in aperture.
(Divide by three for a FF sensor)

Hyperfocal distance can be significantly different than the "1/3 into the scene" rule of thumb when we are talking about deep landscape shots that include near foreground.

[navcom]

I agree with sk66. I know where you are coming from Recurrentnerve (and no offense here at all!), but "1/3 into the image" is not really a good rule to work by if you want to consistently get sharp landscape photos. Composition-wise, most landscapes work better if there is something prominent in the foreground versus just a shot of a mountain or a pretty sky. If you just focus 1/3 into the image, you will deny a crucial part of many (if not most) interesting compositions.

Turn off the auto focus and use manual mode. Do not get in the habit of using AF with this method. Determine the distance to your closest subject you need in focus and which f/stop you want to use. Use your calculator to determine where to set the focus ring on your lens (the lens focus ring will have distances marked on it. If it doesn't, you will have a hard time using hyperfocal distance).

You don't have to be +/- 1/2m on your calculations or anything like that, but you should be more precise than 1/3 of the image.

My two cents anyhow.

[inkista]

Originally Posted by Btreize

...
Focal lenght (mm): 18mm
Selected f-stop: f/11
Subject distance (meters): 10m

Results:
Near limit: 1.31m
Far limit: 10000m
Hyperfocal: 1.525m

I understand that i must focus on a point that is 1m5 from where my camera is placed (front lens), then from 1m31 from my camera to 10000m (infinity) should be in focus....

Ok, slight correction. You're misunderstanding part of what your software is telling you. Your near limit of 1.31m is if you are still focused at 10m (the "subject distance" you input).

If you set your subject distance to the hyperfocal distance, 1.525m, your near limit would then become half of 1.525, or 0.762m, and your far limit should be infinity. Hyperfocal gives you the greatest DoF for that focal length/aperture combination.

The reason focal length is important here is that the symmetry of your DoF shifts with your focal length. With a wide angle lens, you typically have something like 30% of the DoF in front of the focus point and 70% behind it--hence the "1/3 of the way into the scene" rule of thumb. But if you're using a longer lens, say a 200mm, then the DoF is distributed much closer to 50/50 around the point of focus.

[sk66]

Another interesting note is that when you focus inside the hyperfocal distance your DOF rapidly gets thinner...this is why "working distance" is so important to DOF...
When you focus beyond you loose foreground focus, but it retains sharpness to infinity.

The 1/3-2/3 rule applies most correctly to when you focus inside the hyperfocal distance.

[Michael_2010]

Just when I think I have a good understanding of this I realize I don't! lol

[inkista]

Originally Posted by sk66

Another interesting note is that when you focus inside the hyperfocal distance your DOF rapidly gets thinner...this is why "working distance" is so important to DOF...

Oh the wikipedia entry for hyperfocal distance I found out that there's this really cool math thing that happens which you focus within hyperfocal, which I just think is neat. If H is your hyperfocal distance,

If you focus at H, then everything from H/2 to infinity is in focus.

If you focus at H/2, then everything from H/3 to H is in focus.

If you focus at H/3, then everything from H/4 to H/2 is in focus.

in other words, for any given (positive) integer x, focusing at H/x means that everything from H/(x+1) to H/(x-1) is in focus.

[Btreize]

Hi everybody,

i thank you all for the rich info you shared here. So the calculations are good. It is just a matter of practice and focusing on the right spot provided by the calculations.

Does anyone have any illustrated photo of where we focus to obtain wanted results or something like this?
i will try to make mine tonight.

thanks to all

Btreize