Hyperfocal technique

[sstanfay]

I've been trying to understand how to set up hyperfocal photos, where you have a perfectly clear foreground as well as clear distance to infinity. So far I'm failing miserably and finding the instructions impossible to decipher. Can anyone help me in plain English?

[inkista]

Get a DoF calculator. It simplifies things drastically. (I blew $1.99 on the AppStore for DoFMaster on the iPhone/iPodTouch. ) You can also print out and use charts, but check that any "for digital" charts you're using are for the sensor size of your camera (i.e., don't use a Nikon one if you're on a Canon crop and vice versa).

Enter in:

• Your sensor size
• Your focal length
• Your aperture

The calculator will spit back your hyperfocal distance. Set your lens to focus at that distance (this is nearly impossible to do accurately, btw, without a distance scale. If you're using an 18-55 kit lens, you don't have a distance scale, and this may be the main reason why you're having problems).

Everything from half the hyperfocal distance to infinity should be in focus, if a hyperfocal distance could be found.

With some focal length and aperture combinations, you may not be able to achieve a useful hyperfocal distance (i.e., with a very long lens, and a very wide aperture, DoF will be limited so that it can't reach infinity).

So, for example, if I'm using my Canon XT, and my 135L, if I set the lens to f/2, there is no hyperfocal distance. If I set the same lens to f/11, my hyperfocal distance is 278.6 ft. Which is only going to get me everything from 139.3 ft. to infinity in focus. Not exactly useful. If, otoh, I'm using my 18-55 kit @18mm, set to f/8, my hyperfocal distance is 7.05 ft, and everything from 3.53 ft. to infinity will be in focus, and that's far more useful.

Achieving what you're asking for: near foreground and infinity in focus, is going to require a pretty wide lens and a relatively small aperture setting, and it's not a given that simply finding the hyperfocal distance will always do it. This is why some of us also lust after tilt-shift lenses.

Another tool you may want to consider using to help you judge DoF, if your camera has one, is the DoF preview button. If you're shooting a Canon dSLR, you have one, but if you're shooting with an entry-level Nikon (e.g., D40/D60), you don't. But essentially when you look through the viewfinder your lens is wide open. This is so you have the most light to see by to compose and focus, but the DoF shown is inaccurate for the picture you're about to take if you're not using your lens's maximum aperture. The DoF preview button stops down the lens to your aperture setting. The viewfinder will get darker, because you're looking through a smaller hole, but the DoF will be accurate to judge for composition.

[sstanfay]

This has been more helpful than any of the many things I've read and tried to comprehend. Thank you so much. I'm hoping I can get that app for my BlackBerry; I'm off to search now.

[kencaleno]

So what is Hyperfocal Distance? It is the point of focus that will give you the greatest acceptable sharpness from a point near your camera on out to infinity. (Up to prints size 11 x 14 inches) The near point is half the distance to your HFD. The wider your lens and the smaller the aperture, the larger the area of acceptable sharpness.

here is a chart I made for 18-55 and 70-300 kit lenses:

For example with 18-55 kit lens @ F8 and focused on hyperfocal distance of 2.04 meters,my depth of field is from 1.1 meter to infinity(as far as the eye can see)

[inkista]

No insult to Ken, but I have a feeling his table is probably only accurate if you have a Nikon 1.5x crop body. If you're shooting a different format, you may want to get charts that are specific to your sensor size (including P&S cameras) and most-used focal lengths, and that can do feet if you're from a backwards culture that doesn't do metric.

[kencaleno]

Originally Posted by inkista

No insult to Ken, but I have a feeling his table is probably only accurate if you have a Nikon 1.5x crop body. If you're shooting a different format, you may want to get charts that are specific to your sensor size (including P&S cameras) and most-used focal lengths, and that can do feet if you're from a backwards culture that doesn't do metric.

If you compare meters to feet-the example I gave matches your example at F8-yes this chart is for DX cameras Regards, ken

[inkista]

Ken, I'm sure your chart is accurate for DX sensors and the given focal lengths.

It's just no good to me as a Canon shooter, because Canon doesn't have a 1.5x crop sensor. With a 1.6x crop sensor, the circle of confusion changes size and all the hyperfocal distances are different. Your chart tells me @55mm and f/8, my hyperfocal is 19m. But on 1.6x crop, it's actually 20m. Your chart is also no good for a four-thirds shooter or someone shooting full-frame, or APS-H (1.3x crop), or using a point-and-shoot.

The DoF/hyperfocal chart generator I linked to can create charts based on any of those sensor sizes and any given focal length.

[kencaleno]

Originally Posted by inkista

Ken, I'm sure your chart is accurate for DX sensors and the given focal lengths.

It's just no good to me as a Canon shooter, because Canon doesn't have a 1.5x crop sensor. With a 1.6x crop sensor, the circle of confusion changes size and all the hyperfocal distances are different. Your chart tells me @55mm and f/8, my hyperfocal is 19m. But on 1.6x crop, it's actually 20m. Your chart is also no good for a four-thirds shooter or someone shooting full-frame, or APS-H (1.3x crop), or using a point-and-shoot.

The DoF/hyperfocal chart generator I linked to can create charts based on any of those sensor sizes and any given focal length.

You're right- Nikon c of c is 0.020mm,and Canon is 0.019,and most point and shoots are.o.006 or 0.007mm Ken

[lee1026]

While DOF calculators are useful, there is another way - simply stop down the lens until the entire picture look like it is in focus in the viewfinder. (depending on the camera, you may have to change a setting to allow you to preview the image) If you are anywhere near as bad as I am at estimating distances, that is a far more useful technique.

[kencaleno]

I do have other charts for canon powershot G3,both dof and hyperfocal.but as most posters here have entry level dslrs I only supplied the ones I have for my nikon D50. But the main thing to realise about hyperfocal distance, is that it is only accurate for prints up to 11" x 14", held at arm's length,so better to focus on subject for near distance, and 1/3 into distance for subjects over 30 feet away. Ken