Hyperfocal distance

SnaphaanSnaphaan Registered Users Posts: 25 Big grins
edited April 3, 2012 in Technique
I've been trying to get technically improve some of my landscape attempts by getting as much of the foreground as well as the background in focus. But so far it hasn't been working out all that well. I think it's because I can't get the relationship between f-stop, focus distance and image fuzziness working to optimal - or maybe I'm over thinking it. :D

There seems to be a trade-off with image sharpness vs f-number. According to most sources anything over F11 is bound to soften the image a bit. But to get everything in focus I need to stop down. So I'm thinking, there has to be some point where the image loses all the qualities of good focus due to the fuzziness caused by stopping down. What I mean is, there has to be some sweet spot.

Is there anyway to get everything from 30cm in front of your camera to in finitum in focus? I've used a method where I selectively focus on the foreground area, take the image and then selectively focusing on the more distant objects, taking another image and systematically combining them in PS. Painstaking work especially if there are a lot of small leaves involved!

So maybe someone can explain to me how to best make use of this Hyper Focal Distance method. I've read that you need to focus somewhere 1/3 into the image frame but that didn't quite work so well.

I've download this DOF Chart but I can't really put my head around it. Seems to be a lot more complicated than aiming 1/3 into the frame. :scratch

I'm shooting with a Canon EOS 1100D with kit lens (18-55mm).


Thanks for your time!

Comments

  • NikolaiNikolai Registered Users Posts: 19,035 Major grins
    edited March 28, 2012
    It's not about 1/3 of the frame, as you frame can vary in angle/size (for zooms).
    It's about the distance to the subject, which you can get from your DOF chart. Unfortunately, it also means:
    1) you have to be pretty good at "eye metering". For Canon APS-C sensor type cameras at 50mm and f/10 your chart should show hyperfocal distance at 43ft (13.1m). Meaning everything futher than that would be in focus. You just need to be sure it is.
    2) zooms lenses do not have a good metering scale, less so DOF marks (as they change with f/stop and focal length setting)

    The last but not least (and I'm really sorry to say that) the 18-55 is not the sharpest glass on the block. IMHO, it's one of the dullest. The best use for it would be to sell it and use the money for "fantastic plastic" 50/1.8. Better yet, get 50/1.4 if you can afford is, as it is so much better.
    I know, 50mm is a bit long for landscapes, but unfortunately there is no cheap yet good solution for WA (or tele, for that matter). Every decent landscape-capable glass I'm aware of (EF-S 10-22, EF-S 17-55) is by an order of magnitude more expensive than 18-55, and I'm not even talking about a good 16-35MkII...
    "May the f/stop be with you!"
  • DavidTODavidTO Registered Users, Retired Mod Posts: 19,160 Major grins
    edited March 28, 2012
    A tilt-shift lens can help in getting a longer DOF in landscape shots by tilting the lens down a touch. But that's some serious money.
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  • pathfinderpathfinder Super Moderators Posts: 14,708 moderator
    edited March 28, 2012
    Or one can shoot a series of images and stack them in Photoshop also.

    Most lens are at their very sharpest 2- 3 stops down from wide open. Marc Muench feels strongly enough about this that he rarely uses other apertures when shooting landscapes. For real depth of field, tilt shift lenses are the ideal too, but they are expensive and require learning new skills as well.


    DOF Master will give you the actual numbers you need to find your hyperfocal distance, but most modern zoom lenses do not really let you focus to exactly 43 feet, as they have minimal to no manual focus scale. They are built around AF.

    It is true that diffraction can limit lens best sharpness with crop sensor bodies, at smaller apertures, say smaller than f11 or so.

    But I am with Nik, the kit zoom is not the best glass to choose for this type of image.

    How large do you need your print to be? If you are talking less than 8 x 12 inches, then stop down to f11 or f16 and give it a whirl.

    Are you shooting with a tripod and a cable release to maximize your image quality?

    The cheapest way to improve your glass is a good, stable tripod.
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  • Moving PicturesMoving Pictures Registered Users Posts: 384 Major grins
    edited March 28, 2012
    I would heartly add to the others on the matter of the kit lens. Without a doubt, that's your problem. Kit lens can't do sharp.
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  • OverfocusedOverfocused Registered Users Posts: 1,068 Major grins
    edited March 28, 2012
    Ultra wide angle lenses will greatly increase DOF. The shorter the focal length of the lens the better and wider the DOF since it doesn't compress everything.

    17mm should be plenty wide for you, so I'd go with the others and suggest swapping out that kit lens.
  • SnaphaanSnaphaan Registered Users Posts: 25 Big grins
    edited March 29, 2012
    I'm shooting from a tripod, sometimes with the timer and sometimes with cable release.

    I have to say that with many of my images I am perfectly happy. I've recently printed some of my stuff pretty big (for display) and they look great. But when it comes to those up-close to far away shots I just can't seem to balance everything. That tilt-shift lens thing sounds interesting.

    I've checked around for prices. Yikes. The EFS 10-22mm is about twice my kit lens and body cost! Well, I guess I have another accessory I have to budget for. *sigh*
    I would heartly add to the others on the matter of the kit lens. Without a doubt, that's your problem. Kit lens can't do sharp.

    Wanna bet? After 20 minutes fiddling in PS Kit Lens can do sharp. :) Well, as long as everything in the fore- and background keep their distance...
    Nikolai wrote: »
    1) you have to be pretty good at "eye metering". For Canon APS-C sensor type cameras at 50mm and f/10 your chart should show hyperfocal distance at 43ft (13.1m). Meaning everything futher than that would be in focus. You just need to be sure it is.

    I've got a 50mm 1.8 I bought for a few bucks. Never thought of using it for landscapes.
    Ultra wide angle lenses will greatly increase DOF. The shorter the focal length of the lens the better and wider the DOF since it doesn't compress everything.

    17mm should be plenty wide for you, so I'd go with the others and suggest swapping out that kit lens.

    Makes perfect sense about wide-angles and DOF but a 17mm?! Hope I'm not pulling a stupid on myself but how's 1mm going to make a difference?
  • OverfocusedOverfocused Registered Users Posts: 1,068 Major grins
    edited March 29, 2012
    Snaphaan wrote: »
    Makes perfect sense about wide-angles and DOF but a 17mm?! Hope I'm not pulling a stupid on myself but how's 1mm going to make a difference?


    Im not saying 1mm will make a huge difference, Im just saying in general (17 or 18, whatever) has a fairly deep DOF already
  • angevin1angevin1 Registered Users Posts: 3,403 Major grins
    edited March 29, 2012
    Snaphaan wrote: »
    I've been trying to get technically improve some of my landscape attempts by getting as much of the foreground as well as the background in focus. But so far it hasn't been working out all that well. I think it's because I can't get the relationship between f-stop, focus distance and image fuzziness working to optimal - or maybe I'm over thinking it. :D

    There seems to be a trade-off with image sharpness vs f-number. According to most sources anything over F11 is bound to soften the image a bit. But to get everything in focus I need to stop down. So I'm thinking, there has to be some point where the image loses all the qualities of good focus due to the fuzziness caused by stopping down. What I mean is, there has to be some sweet spot.

    Is there anyway to get everything from 30cm in front of your camera to in finitum in focus? I've used a method where I selectively focus on the foreground area, take the image and then selectively focusing on the more distant objects, taking another image and systematically combining them in PS. Painstaking work especially if there are a lot of small leaves involved!

    So maybe someone can explain to me how to best make use of this Hyper Focal Distance method. I've read that you need to focus somewhere 1/3 into the image frame but that didn't quite work so well.

    I've download this DOF Chart but I can't really put my head around it. Seems to be a lot more complicated than aiming 1/3 into the frame. headscratch.gif

    I'm shooting with a Canon EOS 1100D with kit lens (18-55mm).


    Thanks for your time!


    Everyone replying in here has given you really good info and advice! One thing not mentioned is that sweet spot thing with YOUR lens. 18-55mm, right? your sweet spot ought to come in about 30-ish mm on that lens if memory serves. What I've read and found is that indeed there is a zoom sweet spot and it is typically around half or a bit less of your Zoom range.

    Stopping down is good as is tripod! but really...try that 50 1.8II you have. that thing stopped down to f/8 is pretty good, and perhaps better than your zoom. Mine is garbage when wide open and just amazing stopped down....where I tend to use it for video!

    Check list:

    1) STURDY TRIPOD.
    2) DOF master. And yes, I will pull a tape if needed and did my last shoot!
    3) Wide angle of view gives deeper acceptable Sharpness; provided other items are tended to.
    4) Metering Scale. Your lens is not really detailed enough to tell you..."Oh we're at 27 ft. now"..hence why I use a measuring tape.
    tom wise
  • QarikQarik Registered Users Posts: 4,959 Major grins
    edited April 3, 2012
    Here are simple rules of thumb so you don't have to use DOF calc all the time.

    1) the shorter your zoom the the bigger the DOF
    2) the farther the subject of focus is the the bigger the DOF
    3) the smaller your apeture the bigger the DOF

    You want 30cm to infinity? use the widest end of the appropriate zoom, f/11 is a good aperture if you want to avoid diffraction effects focus farther away. If you can't achieve your DOF you want then you have to sacrifice something..use a wider zoom, go beyond f/11.
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  • DeVermDeVerm Registered Users Posts: 405 Major grins
    edited April 3, 2012
    Snaphaan wrote: »
    I'm shooting from a tripod, sometimes with the timer and sometimes with cable release.

    Check on mirror lock-up and or live-view shooting with focus checking at the 10x zoom on live view display. If it's windy, observe the camera on the tri-pod... I just spent serious $$$ on a better tripod and still see shake...
    I've got a 50mm 1.8 I bought for a few bucks. Never thought of using it for landscapes.

    Makes perfect sense about wide-angles and DOF but a 17mm?! Hope I'm not pulling a stupid on myself but how's 1mm going to make a difference?

    I think they mean that the EF-S 17-55mm is like the EF-S 10-22mm : very good IQ and a hefty price tag to go with it. If budget is tight I would go for the 17-55mm though because most landscape shots are in that range I think and it's a great lens for much more. Selling the 18-55mm helps a bit while you can't do that when buying the 10-22mm

    Or use the 17-55mm or 50mm prime and put the camera in portrait orientation and shoot a panorama. I think somebody else meant that although I'm not sure if he meant focus stacking instead... another option for DOF :D
    ciao!
    Nick.

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  • pathfinderpathfinder Super Moderators Posts: 14,708 moderator
    edited April 3, 2012
    While it is frequently stated that wide angle lenses offer much greater depth of field than telephoto lenses, for a given format size, as long as the subject size is the same in each image, then the depth of field is almost exactly the same for very wide angle and very telephoto lenses.

    As a reference see this link - http://www.luminous-landscape.com/tutorials/dof2.shtml

    Or from Wikipedia's long article on DOF here - http://en.wikipedia.org/wiki/Depth_of_field#Moderate-to-large_distances

    There is this brief quote from the above article clarifying a lot of math - "Stated otherwise, for the same subject magnification and the same f-number, all focal lengths for a given image format give approximately the same DOF. This statement is true only when the subject distance is small in comparison with the hyperfocal distance, however."
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