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03-23-2007, 09:36 AM   #1
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Hyperfocal distance

I am struggling with how to determine the distance to the optimum focal distance. Let's say I am shooting with the 43 LTD at f5.6. The hyperfocal distance is 53.8 feet. That will give me an in focus photo from 27 feet to infinity which is what I want. Other than pacing off the 54 feet, how do you determine what is that distance away from you? I've thought of using range finder binoculars but those suckers are about $200. How do you determine the distance? Thanks for any ideas. Just trying to learn a little more.

Regards,

03-23-2007, 09:54 AM   #2
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Hi Ken, I haven't done this in a very long time, but you can train your eye to measure this to a fair degree of accuracy. Back so long ago it seems like a previous incarnation, I was a surveyor. The crew chief I was attached to would set us a series of exercises to improve our eye. First he would measure off 25, 37.5 and 50 feet and flag them with marked flags, and have us look at them. Then he would remove one and make us tell him which one. Then he would have us direct him in replacing it. When we could properly locate the flags within 3-4 feet of where they should be fairly consistantly he did the same for 62.5 to 87.5 feet and then 100 to 125 feet. By the end of three weeks I was pretty good a judging distances up to about 150 feet. Not quite theodolite accuracy, but good enough for plane table mapping. I'd suggest marking off a course and practice looking at how it appears at known measured distances. It may take a while but once your eye is "in" it will stay that way if you continue to use it.
Of course if your lens has range markings on it you can open the aperture select a somewhat distant subject, focus and read the markings on your lens.

NaCl(your eye can be calibrated)H2O
03-23-2007, 10:18 AM   #3
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Cardboard Distance Meter

QuoteOriginally posted by regken Quote
How do you determine the distance?
An Interesting Distance Meter
03-23-2007, 10:38 AM   #4
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QuoteOriginally posted by Mr. The Guy Quote
Thanks. That is interesting. Wish I was handy with my hands.

Regards,

03-23-2007, 12:20 PM   #5
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Do note that the hyperfocal distance stems from the 35mm days. In the digital era, the hyperfocal distance most likely cannot stand up to pixel peeping. There was an article in luminous landscape which did some testing. So do prepare to significantly reduce the distance if you want everything to be "sharp" by pixel peeping standard.
03-23-2007, 12:47 PM   #6
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OK, I found the article:

Digital Focusing Part One
03-23-2007, 01:03 PM   #7
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QuoteOriginally posted by regken Quote
[...] That will give me an in focus photo from 27 feet to infinity which is what I want. [...]
In this particular case you could use DOF scale engraved on your lenses: just align center of the infinity mark with tick mark equivalent to the current f-number and you could immediately read the DOF range and hyperfocal distance.

Example: with my A28/2.8 to set hyperfocal distance at f/8 I align infinity mark with f/8 tick mark on the left. The equivalent tick mark on the right points at 1.5m/5ft. The meaning: everything between 1.5m/5ft and infinity will be in focus. It is easy to see if you have anything closer than 1.5m/5ft. The actual hyperfocal distance is in the center and reads 3m/10ft, but you don't actually need to know that, the range is of primary importance. (DOF scale engraved on the lens is in fact a mechanical calculator!)

Note that on both A28/2.8 and your K28/3.5 there is a reminder of the most convenient aperture/hyperfocal distance combination: f/8 and 3m/10ft. These numbers are marked in RED. So if you align f/8, center triangle, and m/ft scale at 3m/10ft -- all in red -- your infinity mark will land precisely at f/8!

WARNING: hyperfocal distance and acceptable DOF had been established a long time ago using film and older lenses. Modern lenses and high resolution sensors could render details better, so it is safe to assume that by using engraved DOF scale you may actually overestimate DOF. For best results I recommend you to use DOF scale with one aperture wider then your set aperture. For example if you set f/11 use DOF scale as if you have f/8 set.
03-23-2007, 04:58 PM   #8
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Hi Nosnoop,
Thanks much for the link. Looks like I have some studying to do, but it's Friday night and I hear my friendly corner Irish bar calling me.

Maybe this will seem clearer after I return, or not. But thanks. I'll study this weekend.

Regards,

03-23-2007, 04:59 PM   #9
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and really you could not totally pixel peep in the same way with film, so the acceptable sharpness tolerance distance is defintiely much smaller now in digital era
03-23-2007, 05:03 PM   #10
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Hi Ivan,
Thanks. That's cool! Need to think about this but not until the morning. Need to go and start enjoying the weekend with my friends at the local Pub right now.

I'll try it this weekend.

Thanks,
03-23-2007, 06:56 PM   #11
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No need to think to much though, just adopt it as is. To summarize: (1) set aperture; (2) align infinity mark with the right mark on the DOF scale indicating the same aperture; (3) read distance aligned with the right mark: "acceptable" DOF would be that distance to infinity. That would give you the best "average" sharpness. (There are better approaches though, depending on the situation.)
03-24-2007, 03:31 PM   #12
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Sometimes when taking candid photos while using manual focus, I find it handy to "pre-focus" the lens using the distance scale, so I am at least in the ballpark and have a chance to fine-focus prior to the subject noticing me and ruining the candid nature of the shot. It's always pleasant those rare times when I raise the camera and find that I have guessed the range spot-on. Like anything else, practice would probably increase my success rate at doing that.

In my work I haul intermodal containers, which are either 20 or 40 feet long. I find that I have a pretty good feel for how far both 20 and 40 feet are, so when eyeballing a photo subject I find that guesstimating the range based on how much the distance varies from either of those distances helps.
03-25-2007, 05:31 PM   #13
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A problem these days though, and I think it may only apply to zooms, is that the aperture numbers and dof markers are no longer put on the lenses. So one can't put the infinity marker beside the f stop value!
03-26-2007, 12:02 AM   #14
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I agree. The most stupid thing camera/lens manufactures did is remove the DOF markings on lenses. I guess it was just another step in the dumbing down of photography.
Photography took off with the Kodak Brownie - now it has returned to its popular roots with the "let the camera do all the work" mentality.

Check out Hyperfocal Distance and Depth of Field Calculator - DOFMaster - Great tool allows you to rebuild DOF markings for lenes of nearly any size. And it provides insight into how DOF is calculated with suggestions for use.

PDL
03-26-2007, 02:11 AM   #15
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Thinking further - it may be because we have the twist zooms instead of push/pull zooms. Not sure how possible it would be mark those up properly.
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