Greetings, volks. Welcome to Hohenfels Volks, THE place for our place! Today we’re going to learn about hyperfocal distance.
What is hyperfocal distance? It’s the distance you focus your lens for to have a maximum DOF. When you focus at this distance, everything from about half that distance to infinity is in acceptably sharp focus. To accomplish this and to define acceptably sharp focus you need to know your circle of confusion (COC.) COC is the largest size that a point or spot can be without appearing out of focus. For an APS-C size sensor, which most of us have, that number is .019. The smaller your COC, the greater your sharpness. Although, for different sensors and films that number is different. For 6cmx9cm film, it’s generally accepted to be .07, and for 35mm or full frame sensors, it’s about .03.
Things get mathematical here, so you may want your calculator. You can calculate the hyperfocal distance for a given lens and aperture using this method. Take the focal length of your lens and square it to get variable a, next take your aperture or f/stop and multiply it by the COC to get variable b. Divide a by b, and there you have your hyperfocal distance. Here’s how it looks in mathematical terms
H =F²/(f x C)
In the equation above
H = hyperfocal distance
F = focal length
f = f/stop
C = COC
As an example, your lens is 50mm, you wish to focus on something 10 meters away, use f/11, and you’re using an APS-C sensor. 50x50/(11x.019). This gives us 2500/(11x.019) or 2500/.209, and finally approximately 11.9 meters. If you focus at infinity on your lens, your DOF will run from 11.9 meters to infinity. If you focus at 11.9 meters, your DOF will run about 6 meters to infinity. By focusing at your hyperfocal distance, you can maximize your DOF in an image and get that winning shot. By using this calculation on a variety of focal lengths and f/stops, you can see why smaller apertures (bigger f-numbers) give you greater DOF.
There are 2 other ways to figure it out. Both are much easier, if you are using a higher end lens with a scale on it, you set the infinity symbol on your lens to line up on your f/stop at the far scale, then everything from the matching f/stop on the near scale to infinity will be acceptably sharp. That allows for Maximum DOF and zone focusing. The other easier way is to look it online. There are so many sites that you can find on Google just searching for hyperfocal distance, that you’ll never be at a loss. I prefer using DOF Master, as they have some great stuff there and it’s too easy. You just enter your info and away you go!
I hope this gives you some idea of how to use your focus for maximum DOF and how to get that extra bit of oomph to make your image stand out. Next time we’ll be calculating DOF, more math so keep that calculator handy!
Don’t forget to post any of your images you’d like to see here at the Hohenfels Volks Facebook page. Of course, commenting on both Facebook and here is always appreciated, too!
Showing posts with label zone focusing. Show all posts
Showing posts with label zone focusing. Show all posts
Thursday, January 19, 2012
Wednesday, January 4, 2012
In the Zone- Zone Focusing
Greetings and welcome to Hohenfels Volks, THE place for our place. I hope you’re ready, Hohenfels, to learn about zone focusing. This is something that can make getting some of those passing moments in the can, as it were, quicker and easier.
First off, let’s explain what zone focusing is. Zone focusing is using a combination of focal length, aperture, and distance to allow for enough depth of field to make a usable print. That’s pretty straight forward, right? Well, there is more to it than that, including knowing your equipment.
Zone focus developed as a way for photographers to focus their equipment, as most older cameras had no viewfinder or way to check your focus. Many of the old time greats used zone focusing to maximize the sharpness and detail in their works. Given the nature of early lenses, high f/stops were often required to get good detail and enough DOF to be worth printing. Remember, sheets of film, and rolls, were costly to purchase, develop, and print, so lots of effort went into taking each shot. Zone focusing grew from the concept and practice of hyperfocal distance, which you use to give you the maximum DOF for each lens focal length. We’ll have more on that in another post.
The technique works best with lenses that have markings on them. A distance scale for focusing opposite an aperture scale with DOF markings as shown in the photo below works best. It’s quicker and easier. Unfortunately, most lenses today are auto-focus, and kit lenses generally don’t have such marking. Higher end lenses do have them, as do pro and manual lenses as a rule.
ISO 200, f/4.5, 1/30, 32mm
Notice the f/stops on the front of the ring. They go out from the diamond marking focal distance, to give you the range, or zone, of acceptable focus.
Referring to the image above, you can see that there is a diamond. That is the distance marker. On the focus ring, there are markers that aren’t shown, that tell you your focal distance. Line up the desired distance, then using the f/stops that radiate out from the diamond, identically on either side, determine your needed aperture and distance. The distance covered will line up with the marks for the desired aperture. It’s that simple, anything in that range will be in sharp enough focus for decent size prints, including 8x10 and 11x14 if your camera has the resolution.
If your lens has a focusing distance scale, much like Canon’s 28-135mm, you can figure out your DOF with a little legwork online. The key when using zone focus, is to turn off your auto-focus. The second factor is to shoot either Aperture Priority or Manual modes only! Any other mode nullifies your efforts!
Know your location, and what’s happening there, and you can figure the ranges you will need. Let’s say for our purposes you’re shooting in a decently lit area at ISO 400 and you need to cover 3 meters and 6 meters, with room to spare. You get you’re framing, that will give you your focal length. You know it’s decently lit and you can get by with f/5.6-f/8. Going with a 55mm focal length, as most kit lenses like to go from 18-55mm, you should be focused at 4 meters for f/5.6 and 3.5 meters for f/8, although 4 meters is adequate, and has the advantage of allowing you to switch over to f/5.6 without losing too much DOF. If your lens doesn’t have a focal distance scale, measure off 4 meters, focus your lens, and mark it. An easy tip for marking your focus, is take 2 fat rubber bands and wrap one around the zoom ring of your lens at the focal length you wish to use, then wrap the other around the focus ring. Mark the one on the zoom ring at the top, focus your camera, then make a mark that lines up with the first mark you made. As time progresses and your lens drifts over the course of events, you always have your focus marked and can return to it in a snap. Then set your aperture and you’re cooking with gas!
A great online DOF calculator that just requires your focal length, camera model, and scale used (feet or meters) is DOF Master's DOF table. They also have some great information on hyperfocal distance and some nifty little software to play with!
If your shooting with a flash, your f/stop will be dictated by the flash when you use manual flash. TTL and E-TTL are great for using flash, but to use it right, you need a sync cable that’s designed for your camera maker or line to get it off camera. You can get a good one that’s about a meter reasonably priced. Add in a Flashbender or Sto-fen to diffuse the light some, and you’re off to the races. This allows you to hand hold your flash off camera and get some directional TTL or E-TTL light in your images that just adds to the quality.
Zone focusing is great for street photography, event photography, candids, and may other things. Try it out in your works and see how it can help you! You can also use it for this week's theme, as it will allow you to appear less obtrusive when shooting work getting done!
Enjoy the rest of your day, and remember to cast your vote for next week’s theme. Get yours in to have a say! Don’t forget to get your pics posted at the Hohenfels Volks Facebook page. Of course, commenting on both Facebook and here is always appreciated, too!
First off, let’s explain what zone focusing is. Zone focusing is using a combination of focal length, aperture, and distance to allow for enough depth of field to make a usable print. That’s pretty straight forward, right? Well, there is more to it than that, including knowing your equipment.
Zone focus developed as a way for photographers to focus their equipment, as most older cameras had no viewfinder or way to check your focus. Many of the old time greats used zone focusing to maximize the sharpness and detail in their works. Given the nature of early lenses, high f/stops were often required to get good detail and enough DOF to be worth printing. Remember, sheets of film, and rolls, were costly to purchase, develop, and print, so lots of effort went into taking each shot. Zone focusing grew from the concept and practice of hyperfocal distance, which you use to give you the maximum DOF for each lens focal length. We’ll have more on that in another post.
The technique works best with lenses that have markings on them. A distance scale for focusing opposite an aperture scale with DOF markings as shown in the photo below works best. It’s quicker and easier. Unfortunately, most lenses today are auto-focus, and kit lenses generally don’t have such marking. Higher end lenses do have them, as do pro and manual lenses as a rule.
ISO 200, f/4.5, 1/30, 32mm
Notice the f/stops on the front of the ring. They go out from the diamond marking focal distance, to give you the range, or zone, of acceptable focus.
Referring to the image above, you can see that there is a diamond. That is the distance marker. On the focus ring, there are markers that aren’t shown, that tell you your focal distance. Line up the desired distance, then using the f/stops that radiate out from the diamond, identically on either side, determine your needed aperture and distance. The distance covered will line up with the marks for the desired aperture. It’s that simple, anything in that range will be in sharp enough focus for decent size prints, including 8x10 and 11x14 if your camera has the resolution.
If your lens has a focusing distance scale, much like Canon’s 28-135mm, you can figure out your DOF with a little legwork online. The key when using zone focus, is to turn off your auto-focus. The second factor is to shoot either Aperture Priority or Manual modes only! Any other mode nullifies your efforts!
Know your location, and what’s happening there, and you can figure the ranges you will need. Let’s say for our purposes you’re shooting in a decently lit area at ISO 400 and you need to cover 3 meters and 6 meters, with room to spare. You get you’re framing, that will give you your focal length. You know it’s decently lit and you can get by with f/5.6-f/8. Going with a 55mm focal length, as most kit lenses like to go from 18-55mm, you should be focused at 4 meters for f/5.6 and 3.5 meters for f/8, although 4 meters is adequate, and has the advantage of allowing you to switch over to f/5.6 without losing too much DOF. If your lens doesn’t have a focal distance scale, measure off 4 meters, focus your lens, and mark it. An easy tip for marking your focus, is take 2 fat rubber bands and wrap one around the zoom ring of your lens at the focal length you wish to use, then wrap the other around the focus ring. Mark the one on the zoom ring at the top, focus your camera, then make a mark that lines up with the first mark you made. As time progresses and your lens drifts over the course of events, you always have your focus marked and can return to it in a snap. Then set your aperture and you’re cooking with gas!
A great online DOF calculator that just requires your focal length, camera model, and scale used (feet or meters) is DOF Master's DOF table. They also have some great information on hyperfocal distance and some nifty little software to play with!
If your shooting with a flash, your f/stop will be dictated by the flash when you use manual flash. TTL and E-TTL are great for using flash, but to use it right, you need a sync cable that’s designed for your camera maker or line to get it off camera. You can get a good one that’s about a meter reasonably priced. Add in a Flashbender or Sto-fen to diffuse the light some, and you’re off to the races. This allows you to hand hold your flash off camera and get some directional TTL or E-TTL light in your images that just adds to the quality.
Zone focusing is great for street photography, event photography, candids, and may other things. Try it out in your works and see how it can help you! You can also use it for this week's theme, as it will allow you to appear less obtrusive when shooting work getting done!
Enjoy the rest of your day, and remember to cast your vote for next week’s theme. Get yours in to have a say! Don’t forget to get your pics posted at the Hohenfels Volks Facebook page. Of course, commenting on both Facebook and here is always appreciated, too!
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