Hyperfocal focusing?

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cherokee1111

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Read an article by Tom Mackie recently where on landscape shots he said not to focus on infinity but on the hyperfocal point:shrug: he never explained how though :thumbsdown:
so basically, what is it? and how do I do it?

thanks
 
if you focus on anything, some parts in front and some behind are in focus
the hyperfocal distance is the point you focus at so the furthest away bit is at infinity

if you think about it, if you focus at infinity, some bits "This side" are in focus
and some bite "beyond infinity" would be in focus

now unless you're taking picture of Toy Story that's a waste

so focus a bit this side of infinity

btw hyperfocal distance varies with aperture
 
bit hard though to use though if your lens doesnt have a distance scale for focusing and markings for the hyperfocal point, it is very useful though
 
Hyperfocal distance is the distance at which you need to focus at a given aperture to get the greatest dof from nearest the camera to infinty wth infinity being in focus.

I agree it's a great pity that they no longer put usable dof scales on lenses.

Generally speaking, depth of field extends about 2/3rds behind the distance at with you focus and about 1/3rd in front of it, so focusing about 1/3rd of the way into your scene will get you in the ball park. Obviously stop down to f8 or smaller if you want max dof. Try using the dof preview before you take the shot to stop down the lens and check the nearest and furthest parts of the image for sharpness. Yes - the viewfinder image goes darker but it's actually quite a useful function contrary to what many people think.

The above is a rough rule of thumb which will serve you pretty well - if you really want to get technical about it you can get printed dof scales for all lens focal lengths and apertures and carry them around in youir bag - together with a very long tape measure! ;)
 
thanks guys, its a bit clearer but I'm still not sure what to do on the scale on the lens ie it would be a Nikon 35mm f/2 prime or a Nikon16-85 lens that both have scales so would I focus using the scales and not the viewfinder?
 
This is a handy little tool >>>> http://www.dofmaster.com/dofjs.html

You can plug in you camera/lens combination and it'll provide you with the calculated depth of field and hyperfocal distance...

Cheers

Phil
 
there is a free app for nokia phones called kmk dof which tells you the hyperfocal distance for any lens aperture and focal length. I guess you would need a tape measure to do it properly though... does anyone really do that?
 
dubcat said:
there is a free app for nokia phones called kmk dof which tells you the hyperfocal distance for any lens aperture and focal length. I guess you would need a tape measure to do it properly though... does anyone really do that?
Click to expand...

Sounds like a bit of fun..... may have to have a look at that - I always feel left out with all the Apps for the iphones

[ sorry for the almost double post above - re the DOF link ]

Phil
 
Oh hay, do you really want infinity in focus? Now THERE's a question to think about.
 
cherokee1111 said:
thanks guys, its a bit clearer but I'm still not sure what to do on the scale on the lens ie it would be a Nikon 35mm f/2 prime or a Nikon16-85 lens that both have scales so would I focus using the scales and not the viewfinder?
Click to expand...

Assuming you have a lens with a DOF scale on it - this is the 50mm lens on my RB67 but the principal is the same with any lens with a DOF scale.

4833607127_d8972f52cd_o.jpg



You can see that the lens is focused at just over 6 feet. The DOf scale is the one on the very front of the lens. You can see that infinity (the red mark which looks like a figure 8 on it's side) is against f16. Now if you look over on the left side of the DOF scale, you can see that f16 is against 3.5 feet on the scale.

What this means is that usng an aperture of f16 we'll get everything sharp from 3.5 feet to infinity and the hyperfocal distance for this shot is just over 6 feet.

This a 50mm lens btw which is quite a wide angle lens on a medium format camera so you get good DOF. You're right - you don't use the viewfinder to focus at all - you focus using the DOF scale only.

Hope that helps?
 
I usually use the bottom focus point (when in landscape) orientation, thats focusing about a third of the way into the scene. The little focusing scale shows that it is usually just before the infinity mark, really simle way of getting it.
 
Unprofessional tip: When you're taking landscapes you (tend to) have all the time in the world, and on digital you get unlimited attempts...so you can find it through trial and error. It'll only take a few shots - start at infinite and work forwards.
 
"By Jove I think I've got it!"

well thanks CT for taking the time to add a pic and explain it to me, makes sense now, now I will try it out without using the cameras auto focus and maybe my landscapes will improve.
Thanks again:thumbs:



QUOTE=CT;2839785]Assuming you have a lens with a DOF scale on it - this is the 50mm lens on my RB67 but the principal is the same with any lens with a DOF scale.

4833607127_d8972f52cd_o.jpg



You can see that the lens is focused at just over 6 feet. The DOf scale is the one on the very front of the lens. You can see that infinity (the red mark which looks like a figure 8 on it's side) is against f16. Now if you look over on the left side of the DOF scale, you can see that f16 is against 3.5 feet on the scale.

What this means is that usng an aperture of f16 we'll get everything sharp from 3.5 feet to infinity and the hyperfocal distance for this shot is just over 6 feet.

This a 50mm lens btw which is quite a wide angle lens on a medium format camera so you get good DOF. You're right - you don't use the viewfinder to focus at all - you focus using the DOF scale only.

Hope that helps?[/QUOTE]
 
This is how I set hyperfocal distance, and it's really easy. This is what I have printed inside the lens cap of my 17-40L (numbers apply to full frame) and it's all I need to know.

HFD f/5.6 f/11 f/22
17mm 5.6ft 2.8ft 1.4ft
24mm 11.2ft 5.7ft 2.9ft
35mm 24ft 12ft 6ft

Bear in mind that you only need a few guide figures to work from because a) depth of field, although seemingly a very precise business, actually isn't because it's based on a lot of assumptions that may or may not apply, b) sharp focus doesn't stop and start at specific points within the zone of DoF, it fades gradually, and c) HFD usually only applies to short focal length lenses and higher f/numbers.

Things to note.
You can guess inbetween f/number and focal lengths pretty easily with reasonable accuracy. When in doubt, use a stop higher f/number to make sure.
The most useful thing I ever learned about HFD is that the near point of the hyperfocal range is always exactly half the HFD. That is, if your HFD is 6ft, then everything will be sharp from 3ft to infinity.
Also note that depth of field calcs always measure from the front of the lens, whereas focusing distances marked on the lens barrel are from the focal plane (sensor). Might be relevant if you're working very close.

Download all the number you want from www.dofmaster.com :thumbs:
 
HoppyUK said:
.
The most useful thing I ever learned about HFD is that the near point of the hyperfocal range is always exactly half the HFD.
Click to expand...

Now that is useful! I probably knew that that - I must have forgotten. :D
 
CT said:
Now that is useful! I probably knew that that - I must have forgotten. :D
Click to expand...

It is very handy Cedric! That's actually how I use HFD focusing.

Example, near object that I want sharp, framed up on 24mm. Say it's 3ft away and I know therefore that the HFD I need is 6ft. Check the table for 6ft (or slightly less to be safe) and it tells me f/11. Done :)

There's another rough and ready method you can adopt with this bit of knowledge, without the need for any tables. Similar situation, and I want everything sharp from 3ft away, then I know that focusing at 6ft and using the highest f/number I dare will be there or thereabouts, within reason.

Chimp to check, then add a stop for luck :D

BTW, just adding to my previous post, trying to set the focusing distance manually from the lens scales is near impossible, bearing in mind my 17-40L only has three distance markings in total (1ft, 1.5ft and 3ft - that's it!). But I reckon I can visualise 4, 6, 8ft or whatever reasonably accurately, so I AF on something at that distance :thumbs:
 
HoppyUK said:
BTW, just adding to my previous post, trying to set the focusing distance manually from the lens scales is near impossible, bearing in mind my 17-40L only has three distance markings in total (1ft, 1.5ft and 3ft - that's it!). But I reckon I can visualise 4, 6, 8ft or whatever reasonably accurately, so I AF on something at that distance :thumbs:
Click to expand...

I hear you- I have the 17-40L - that's pretty much what I do.
 
Hyperfocal focusing definitely can be useful but focusing at this point is designed to produce the maximum DOF throughout the image - bear in mind this may not always be what you want.
If you have a very close foreground element then using HF may well result in it being "unsharp". If something in the distance is a little unsharp its far less noticeable than it would be for the foreground.

Focusing a third of the distance into the scene is a decent starting point, bringing it a bit closer if you have important foreground whilst choosing a smaller aperture too - you might find that you don't need HF 90% of the time doing this once you've perfected it.

Simon
 
simonkit said:
Hyperfocal focusing definitely can be useful but focusing at this point is designed to produce the maximum DOF throughout the image - bear in mind this may not always be what you want.
If you have a very close foreground element then using HF may well result in it being "unsharp". If something in the distance is a little unsharp its far less noticeable than it would be for the foreground.
Click to expand...

That's true. If you have say a 20 foot high wall 20 feet behind your subject, then as far as your lens is concerned that wall is infinity and you can focus closer than the hyperfocal distance to get nearer objects more in focus.
 
simonkit said:
Hyperfocal focusing definitely can be useful but focusing at this point is designed to produce the maximum DOF throughout the image - bear in mind this may not always be what you want.
If you have a very close foreground element then using HF may well result in it being "unsharp". If something in the distance is a little unsharp its far less noticeable than it would be for the foreground.

Focusing a third of the distance into the scene is a decent starting point, bringing it a bit closer if you have important foreground whilst choosing a smaller aperture too - you might find that you don't need HF 90% of the time doing this once you've perfected it.

Simon
Click to expand...

I disagree. You can't focus 'a third in' to a scene for hyperfocal distance setting. What is a third of infinity? It doesn't work. The 'one third in' rule of thumb, and it's a very rough one, only applies when the near and far points can be measured/estimated.

The hyperfocal distance setting is quite specific aspect of depth of field. It only applies when you want maximum DoF in terms of the total distance, so must always include infinity. In fact that's how it works - it sets infinity at the extreme edge of the acceptable circle of confusion and works that backwards.

And that is really the rub with the HFD. By definition it puts the far distance right at the limit of acceptable sharpness, and with modern hi-res digital there is some debate as to whether that's acceptable, given that quite often those dramatic snow capped mountains are actually the most important part of the scene and you want them not just acceptably sharp, but maximum sharp.

That's another thread altogther but there is a school of thought amongst landscapers that says in such a situation you should forget about HFD and simply focus on infinity, then stop down as far as you can before diffraction hits too hard, and then accept whatever depth of field that gives you to cover near objects.

I guess there's a third option which is to focus somewhere beyond the HFD but a bit short of infinity. Haha, you can argue that all night! Personally it doesn't bother me much - I know where the HFD is and stop down as much as I reasonably can. You can make too much fuss about something essentially very simple and useful, but is yet quite a crude guide and when in reality there's only so much you can do anyway.
 
dcash29 said:
Similar to what you mentioned Richard.....HERE focusing at infinity
Click to expand...

Cheers Dave. Yes, I've seen that link before. Some forums are full of endless debates on this.

The problem at the heart of it is that there is no absolute answer to the question of what is sharp, and what is not. There is an international standards agreement, but that's not quite the same thing.

And then secondly, there is the question of how that standard should be interpreted and applied in practise, so plenty of scope for argument there too!
 
HoppyUK said:
I disagree. You can't focus 'a third in' to a scene for hyperfocal distance setting. What is a third of infinity? It doesn't work. The 'one third in' rule of thumb, and it's a very rough one, only applies when the near and far points can be measured/estimated.
Click to expand...

Hi,

You misunderstood my thread...my point was that Hyperfocal is probably not needed 90% of the time, as I mentioned here:

"you might find that you don't need HF 90% of the time doing this once you've perfected it."

I adjust my focus point to make sure what I want sharp in the scene is sharp, usually the foreground. The joy of digital is that you can experiment with this without having to rely on Hyperfocal distance. As you say the "technique" is designed to produce "acceptable sharpness" throughout the scene but it may well not be acceptable for a close foreground element, which sometimes appear unsharp as a result of using HF. Implementing Hyperfocal with modern crop sensor DSLRs/lenses isn't 100% accurate anyway due to lack of decent distance scales etc.

I'm not saying for anyone not to give it a go, I did and it's a useful technique to know about...having said that I find that I rarely use it :shrug:

Simon

[EDIT] Just had a quick look around the web for something that describes my point a little better than I can, it adds an interesting point that print size affects percieved sharpness too...here's a link...it also happens to criticise the "always focus at 1/3 technique" too !!

http://www.cambridgeincolour.com/tutorials/hyperfocal-distance.htm




.
 
HoppyUK said:
This is how I set hyperfocal distance, and it's really easy. This is what I have printed inside the lens cap of my 17-40L (numbers apply to full frame) and it's all I need to know.

HFD f/5.6 f/11 f/22
17mm 5.6ft 2.8ft 1.4ft
24mm 11.2ft 5.7ft 2.9ft
35mm 24ft 12ft 6ft
Click to expand...

That's rather useful is that, I think I will stick that inside a 17-40 when I get one soon.
 
simonkit said:
Hi,

You misunderstood my thread...my point was that Hyperfocal is probably not needed 90% of the time, as I mentioned here:

"you might find that you don't need HF 90% of the time doing this once you've perfected it."

I adjust my focus point to make sure what I want sharp in the scene is sharp, usually the foreground. The joy of digital is that you can experiment with this without having to rely on Hyperfocal distance. As you say the "technique" is designed to produce "acceptable sharpness" throughout the scene but it may well not be acceptable for a close foreground element, which sometimes appear unsharp as a result of using HF. Implementing Hyperfocal with modern crop sensor DSLRs/lenses isn't 100% accurate anyway due to lack of decent distance scales etc.

I'm not saying for anyone not to give it a go, I did and it's a useful technique to know about...having said that I find that I rarely use it :shrug:

Simon

[EDIT] Just had a quick look around the web for something that describes my point a little better than I can, it adds an interesting point that print size affects percieved sharpness too...here's a link...it also happens to criticise the "always focus at 1/3 technique" too !!

http://www.cambridgeincolour.com/tutorials/hyperfocal-distance.htm

.
Click to expand...

Sorry Simon. Still not sure I agree but that's the subjectivity of this kind of debate! And it's always interesting :)

Sure HFD focusing is not what you need for everything, or even most things. It's just one particular application of DoF theory, and all the variables that go with that.

But as I think you have discovered with the CambridgeInColour link (v good website that, especially since I was punting on the Cam only last weekend :D ) the 'one third in' rule of thumb is perhaps more prone to variables than most other DoF theories.

The only hard fact about DoF range is that here is always more distance in focus behind the subject than there is in front of it. But within that, at close distances it's more like 49/51%, and at the other extreme if you analyse HFD settings in the same way, you find that it's typically under 1/99%.

So 33/67% is highly dependent on the subject distance. Having said that, I use it a lot and for general shooting it works very well! FWIW, I use just three DoF applications - for small stuff like table top, head and shoulders portraits and things at close range, I use 50/50%; for general walkabout the one third in rule works pretty well; and for deepest DoF landscapes that little HFD table I posted above tells me what I need to know.

In addition, I chimp the LCD a lot and there I have the advantage of a very good screen on my 5D2. It's 1m pixels and on max zoom I can look at a section of the image equal to a 24in wide print. I find that's plenty good enough to asses the real live DoF that I've actually got and I certainly don't lament the absence of DoF scales on my zoom lenses. They still have them on most primes but TBH they are so small and the markings so sparse that in practise they can't hold a candle to looking at the zoomed image on a decent LCD.

trencheel303 said:
That's rather useful is that, I think I will stick that inside a 17-40 when I get one soon.
Click to expand...

:thumbs:

It works well for me. It looks a bit rough and ready, being just a handful of key numbers with some quite big gaps inbetween, but in practise that's usually good enough.

It works on the principle that the reality of depth of field is that it's hard to set with absolute accuracy anyway, and even when you can, not everybody accepts that the agreed DoF standards are appropriate and are variable according to final ouput.

But make what you like of DoF standards, they are at least universally accepted and make an excellent starting point on which to base your own settings.
 
HoppyUK said:
Sorry Simon. Still not sure I agree but that's the subjectivity of this kind of debate! And it's always interesting :)
Click to expand...

Like you say, makes life interesting although having read through the rest of your post it seems we basically do the same thing...choose the appropriate method for the results we want:)


Simon
 
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