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DPChallenge Forums >> Tips, Tricks, and Q&A >> Hyperfocal Distance
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09/26/2003 09:35:52 AM · #1
What is Hyperfocal Distance?

The hyperfocal distance is the point in your composition where everything from 1/2 that distance to infinity is in focus. For instance, if the calculated hyperfocal distance is 25 feet, if you set the focus on your camera to 25 feet, everything from 12.5 feet to infinity will be in focus.

Hyperfocal Distance (ft) = ((FL * FL) / (Ap * CoC)) * 0.0033

FL = Lens Focal Length
Ap = Aperture F Number
Coc = Circle of Confusion size (0.02 is used for most digital cameras)
.0033 = Conversion from millimeters to feet

Example of this calculation with a 28mm lens at F16

HFD = ((28 * 28) / (16 * 0.02)) * 0.0033

HFD = (( 784 ) / ( 0.32 )) * 0.0033

HFD = 2450 * 0.0033

HFD = 8.08 feet

In this example, if you set your focus at about 8 feet, everything from 4 feet to infinity will be in focus in your photo.

Taking advantage of the hyperfocal distance can help you out in several ways. When photographing wide angle scenes where your objective is to have everything in sharp focus, you would normally use the smallest aperture possible for the photograph. The small aperture gives you the greatest depth of field. However, you may still have objects in your image that are out of focus or soft because they are close to the camera. The reason for this is that your point of focus is far away. When your focus is way out in the distance somewhere, your near focus distance is farther away as well, so closer objects in your scene may appear soft or out of focus.

Another advantage of using the hyperfocal distance is that you may be able to work with a larger aperture and faster shutter speed while keeping everything in your image in focus. In the above calculation example using 28mm and an aperture of F16, let's assume that our shutter speed for proper exposure is 1/60". If you are shooting a landscape where there is a bit of a breeze, you could possibly get some motion blur on the tree leaves or in the grass at that shutter speed. If you could shoot the same scene at F8 and a shutter speed of 1/250", you will greatly reduce the chances of blur in your image. Using the above calculation, our hyperfocal distance for 28mm at F8 would be about 16.1 feet. This means that if we focus on something 16 feet out, we will have sharp focus from 8 feet to infinity. If there is nothing within our composition inside of 8 feet, we could change apertures, get a faster shutter speed, and still keep everything in focus.

I have a spreadsheet with a hyperfocal and near focus distance calculator and chart that I will gladly share with anyone who wants it.

John Setzler

09/26/2003 09:37:44 AM · #2
i would love to see that spread sheet...i could take it out with me...great idea john
09/26/2003 09:44:52 AM · #3
If you are interested in all the nasty maths that John didn't mention, //www.photo.net/learn/optics/dofdigital/ has a good overview, without really going through much of the equations, just presenting the results.
09/26/2003 09:45:50 AM · #4
Another good link on Hyperfocal Distance
09/26/2003 09:51:51 AM · #5
Thanks John, now I can see why super wide angle lenses have suck deep DOF.

Edit: I was going to edit my typo, but this is just too funny. I always wondered why I liked Super wide angle lenses so much.

Message edited by author 2003-09-26 10:02:00.
09/26/2003 10:23:50 AM · #6
Originally posted by Jacko:

Thanks John, now I can see why super wide angle lenses have suck deep DOF.

Edit: I was going to edit my typo, but this is just too funny. I always wondered why I liked Super wide angle lenses so much.


The interesting thing is, they dont have any more depth of field than your super telephoto lenses, for the same subject size...
09/26/2003 10:28:49 AM · #7
I would love to see that spreadsheet too John :)
09/26/2003 10:30:02 AM · #8
i keep reading about the f stops and the apertures, but i couldnt find any of it on my camera...what if i dont have that kind of selection?Does it mean I have a low tech camera? MY cam is olympus d550 zoom...
09/26/2003 11:19:21 AM · #9
You dont have to learn all the math to use hyperfocus. I use DEP mode to set hyperfocus distance, remember the settings and turn off autofocus. Turn it to manual and use settings stopped down 1 stop from the DEP sugested aperture. This works for Canon film users. Does the 10D have DEP mode?

Tim
09/26/2003 11:23:35 AM · #10
Originally posted by Niten:

You dont have to learn all the math to use hyperfocus. I use DEP mode to set hyperfocus distance, remember the settings and turn off autofocus. Turn it to manual and use settings stopped down 1 stop from the DEP sugested aperture. This works for Canon film users. Does the 10D have DEP mode?

Tim


It has a watered down A-DEP mode

DEP vs A-DEP
09/26/2003 11:31:23 AM · #11
Originally posted by Niten:

You dont have to learn all the math to use hyperfocus. I use DEP mode to set hyperfocus distance, remember the settings and turn off autofocus. Turn it to manual and use settings stopped down 1 stop from the DEP sugested aperture. This works for Canon film users. Does the 10D have DEP mode?

Tim


Yeah this works pretty well the few times I have used it. Nice feature... Great mention... Dave
09/26/2003 11:36:45 AM · #12
I'd like to see the spreadsheet if you can send it John. My email is tyrkinn@tyrkinn.com
09/26/2003 11:45:54 AM · #13
Compulsory reading for anyone wanting to know about hyperfocal distance and depth of field in general is here :dofmaster
Including a field calculator for Palm, an on-line calculator, and the possibility to make your own DOF scale for your digital camera !!!
09/26/2003 03:11:28 PM · #14
I'll be curious to play with that A-DEP mode... that could be interesting :)
09/26/2003 04:32:51 PM · #15
Originally posted by jmsetzler:

Coc = Circle of Confusion size (0.02 is used for most digital cameras)


Keep in mind 0.02µm is much too large "for most digital cameras", but is close enough for most DSLRs. As an example, the Sony F717's CoC is closer to .008µm and the Olympus C730uz is about .005µm.

CoC also depends on what one would consider acceptable sharpness in a print, usually about 5 lp/mm, though some now recommend upwards of 8 lp/mm. Your CoC will be much, much smaller if you use the aggressive 8 lp/mm; the D60 at 7.5 lp/mm brings the CoC down to .01µm! It matters little though if you can't see the difference.

This chart of CoC values for some popular digicams might be useful, though values have been rounded and it looks like it is based on 3-4 lp/mm as the standard of acceptable sharpness.
09/26/2003 04:38:42 PM · #16
Originally posted by jmsetzler:

I'll be curious to play with that A-DEP mode... that could be interesting :)


Or annoying. There's so little control with A-DEP that you're practically better off bringing a laptop/palm to do your DoF calcs, then finding objects at the right HFD (with a laser rangerfinder perhaps).

And Canon didn't even fix it with the 10D! Lame.
09/26/2003 09:38:45 PM · #17
Hey John, I would like a copy of your spreadsheet. I understand Hyperfocal Distance but I don't have the numbers. I usually guess or focus at 2 or 3 meters with no zoom. Thanks in advance.
09/26/2003 09:43:00 PM · #18
HERE is the spreadsheet. You can enter your own values for aperture and focal length at the top if they do not appear on the chart as you like...


09/26/2003 10:45:27 PM · #19
John, why are you using .02µm as your CoC value? Even for your camera, it's not an accurate value to use.
09/26/2003 11:18:19 PM · #20
Originally posted by dwoolridge:

John, why are you using .02µm as your CoC value? Even for your camera, it's not an accurate value to use.


It was the suggestion I found.. I know the 10d would actually use 0.019 but it's close enuff. I'm not even planning to attempt hpyerfocal distances with my Sony...


Message edited by author 2003-09-26 23:18:57.
09/26/2003 11:25:49 PM · #21
My digital gets everything in focus(like it or not) but I understand that the DSLRs work more like real cameras.

Tim ;)
09/27/2003 12:48:47 AM · #22
Here's a site with some pertinent tools. Especially nice is the HfD chart generator, which allows you to enter a custom CoC. On the page is also a CoC calculator, but it hasn't been updated for digital sensors. For the D60, I always use a CoC of .01845mm.

Note: In my previous posts I used µm instead of mm, but I don't imagine anyone cared much about the units.
09/27/2003 01:36:38 AM · #23
John,

Yeah A-DEP on the 10D isn't overly useful, as it's only bringing the 7 AF points into focus. The better EOS film cameras have a proper DEP mode, where you can select focus points one after the other and it'll do the calculation. This is where prime lenses are more advantageous as a photography too. Whereas on the digicams aperture is often little more than a metering tool, with the DSLR it becomes a critical composition tool. When you're used to a prime you'll develop an A-DEP mode in your head, which is infinitely more useful. With a single focal length you'll really get to know the focal length and be able to compose images without the camera. With a zoom, it's much more convenient but there are almost infinite variations of composition available. I think this is why most zooms get used most often at the extreme telephoto - people buy the lens for the length, learn to see at that length, think of it in terms of a 200 rather than a 28-200 and end up using it as such.

When I first got the 10D I was shooting it wide-open at first (and with the 50 1.4 that's VERY wide) playing with the short DOF that I'd never experienced before. However, you'll take a shot of two people and if their faces are not perpendicular to the camera, or if they're not pretty much exactly side-by-side, both their faces won't be in focus...and that's at 10 feet away.

I know you've got film cameras so you know all this...but you'll be rudely awakened to the fact that, much more than with the F7x7, aperture is a compositional tool as well as a metering tool. My advice is to get a prime (get the 50 1.8 if the 1.4 doesn't interest you first) and learn how to use the camera with it before deciding on a zoom lens and making things more complicated. You'll get the 50 1.8 anyways (everyone should have it) so why not start with it...

James.

Originally posted by dwoolridge:

Originally posted by jmsetzler:

I'll be curious to play with that A-DEP mode... that could be interesting :)


Or annoying. There's so little control with A-DEP that you're practically better off bringing a laptop/palm to do your DoF calcs, then finding objects at the right HFD (with a laser rangerfinder perhaps).

And Canon didn't even fix it with the 10D! Lame.
09/27/2003 01:38:28 AM · #24
Hmmm...I thought the CoC variable was based on an 8x10 print, and thus camera-independent?

Originally posted by jmsetzler:

Originally posted by dwoolridge:

John, why are you using .02µm as your CoC value? Even for your camera, it's not an accurate value to use.


It was the suggestion I found.. I know the 10d would actually use 0.019 but it's close enuff. I'm not even planning to attempt hpyerfocal distances with my Sony...
09/27/2003 09:07:57 AM · #25
Originally posted by jimmythefish:

Hmmm...I thought the CoC variable was based on an 8x10 print, and thus camera-independent?



I believe that it is based on a print size, but the print size and quality is also based on the 'negative' size. The value associated with a 35mm negative is 0.03 Larger negatives use a larger number and smaller digital sensors use a smaller number. This Article discusses it a little more...


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