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XT1 hyperfocal distance


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steveinakayak

Hoping someone can thrown some light on an issue i'm having with the new XT1, with either the 18-55 or 10-24. maybe me or maybe the camera....

Part of the reason for getting the 10-24 (which i'm loving) was to maximise depth of field for landscape shots. Example settings might be f/11 at 10mm, which i'd expect to give a good DOF if focussed reasonably close. All the resources i've found suggest a hyperfocal distance of 0.45m, with near and far limits of .42 and infinity respectively.

So far so unsurprising.......however, looking at the distance and blue DOF indicator on the camera give a DOF WAY shallower than this and to get the far limit out towards infinity requires focussing metres and metres further out.

Any thoughts on this discrepancy would be appreciated!

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There is no such thing as exact DOF, it all depends on what is considered sharp and how big a print we have in mind. What are "all the resources" you are referring to? If they are calculated for 135 size film/sensor, they are much too "optimistic" for APS-C sized sensor X-T1 has. Fuji is also known to have much more conservative DOF calculations than usual. Maybe because people now pixel peep with screens, where photos do not look as sharp as on a 8*10" print, and they do not want ignorant buyers writing on the Net that the lenses are not sharp if the DOF markings promise too much, meaning as much as was customary in the old days.

There is only so much DOF you can get with any system, only ways to get more is either use a tilt lens (not natively available for Fuji) or use focus stacking. Closing the aperture down past f/5.6 starts to add diffraction also, something to remember when aiming for the sharpest possible photograph.

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...All the resources i've found suggest a hyperfocal distance of 0.45m, with near and far limits of .42 and infinity respectively...

however, looking at the distance and blue DOF indicator on the camera give a DOF WAY shallower than this and to get the far limit out towards infinity requires focussing metres and metres further out.

The estimates you cite are, indeed, the standard calculations using the commonly adopted assumptions for circles of confusion, etc (as used in the dofmaster.com calculator,say). Use these as a basic guide, rather than the Fuji display: it uses a VERY conservative estimate for DoF, and does not employ the standard methods of estimating DoF.

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steveinakayak

thanks for the comments.....i'm sure you weren't referring to me as "ignorant buyer writing on the Net that the lenses are not sharp".

the resources i'm referring to are all the online DOF/hyperfocal calculators that factor in the senor size. this one seemed more user-friendly than most:

http://www.dofmaster.com/dofjs.html

but others do the same thing.

I wasn't aware that Fuji use conservative estimates for DOF but now that I am, I'll go out and have another play without getting too caught up with the camera display.

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"Circle of Confusion" is defined as eight optical engineers sitting around a table arguing about depth of field.

Fuji has chosen a very conservative figure that pretty much guarantees results for most photographers. Individual photographers must test to see where their tolerance lies. For some, much wider standards may be acceptable, and for others—pixel-peepers—Fuji is not sufficiently conservative.

Do your own tests, and set your own standards that satisfy you.

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As apt as Larry's description is, "circle of confusion" was a standard

where a point of light diverged to a circle 1/30th of 1mm in diameter

(on a 35mm film frame). That may not look good in largish prints.

The last line of Larry's post is what counts.

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It's a coincidence you've wrote this post as I'm having my own issues with Hyperfocal distance and focussing in general on some shots. I've had an X-E1 since last September and it was my first "proper" camera for many years.

I enjoy landscape type photography also and can get some results I'm happy with when focussing on foreground interest at around f8/f11 etc.. with the background out of focus by choice (like this: Dunstanburgh Castle). But when I'm trying to get the whole shot in focus (as best possible) on a general landscape type shot I seem to struggle and get frustrated.

In the past I've used F16, which I know now is a bad move, so stick to F11 and use the hyperfocal distance/depth of field calculators with the circle of confusion setting for the X-E1. As an example I did a shot today which was at 18mm, F11 and focussed at 1.45m yet the background of the shot was soft and not as sharp as the front. I played around with a few things and using manual focus w/ focus peaking I got it sharper but still not perfect.

Am I just being unrealistic? I'm not an expert like many of the other users on here so I might be missing something but I'm getting increasingly frustrated and resorting to doing shots with good foreground interest with the background soft by choice.

I've read a few guides like this, Hyperfocal distance, and think to myself right I've cracked it. Then get out in the field and get frustrated when I can't get the image I want.

How do others here focus when shooting landscapes- manual focus with focus peaking until it "feels right"? I'd appreciate any help... I'm going to the Isle of Skye next month and fearful I'm not gonna be able to get the shots I want or do it justice. :-/

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Don't forget that atmospheric conditions play a part in how well landscape shots appear to be in focus at distances. If you have smog or other crap in the air it is going to affect how sharp things in the distance look in a photo. There is not much the camera or the photographer can do other than wait for more suitable weather.

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I've noticed on several occasions when shooting hand held panos that when switching to manual focus, with Focus Peaking enabled, the highlighted, In Focus portion of the image tends to move along with the selected F stop. i.e. as aperture is closed down on a lens the depth of the plane with In Focus highlights deepens.

Don't know how accurate it is but it does help visualize the front and back edges of the plane of focus.

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Example settings might be f/11 at 10mm, which i'd expect to give a good DOF if focussed reasonably close. All the resources i've found suggest a hyperfocal distance of 0.45m, with near and far limits of .42 and infinity respectively.

The DOF app you are using, with these parameters, states a near limit of 0.23 when focused at hyperfocal length.

Btw, when you do your own trials, suggest you also try comparing handheld with tripod mounted exposures.

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Am I just being unrealistic?

Quite possible. DOF calculations were traditionally done for 8x10" prints, now we are looking at the files at 100% magnification on the screen.

When the print/picture gets bigger and other factors stay the same, DOF gets smaller.

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Maybe I'm doing something wrong or being overly realistic,but I get what I view as

excellent DOF at mid-range apertures. I can use f/11 on my old f/3.5 Micro-Nikkor

without discernible diffraction because f/11 is a mid-range aperture for an f/3.5

lens just as it was with a 65mm f/3.5 Leitz Elmar I wish I still had.

The value of conservative-aperture lenses is mostly overlooked by those with a

perceived need for speed. Don't get me wrong;fast lenses have have a reason to

exist. They are often outperformed in specific applications by slow, boring,

old, and uninteresting models.

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Maybe I'm doing something wrong or being overly realistic,but I get what I view as

excellent DOF at mid-range apertures. I can use f/11 on my old f/3.5 Micro-Nikkor

without discernible diffraction because f/11 is a mid-range aperture for an f/3.5

lens just as it was with a 65mm f/3.5 Leitz Elmar I wish I still had.

The value of conservative-aperture lenses is mostly overlooked by those with a

perceived need for speed. Don't get me wrong;fast lenses have have a reason to

exist. They are often outperformed in specific applications by slow, boring,

old, and uninteresting models.

Well, now, diffraction is fully aperture dependent, it does not matter what the maximum aperture of the lens is. With 135 size sensors diffraction starts to diminish the sharpness from f/8, with APS-C sized sensors like we have in X-Trans Fujis diffraction kicks in at f/5.6. It is just fairly simple math.

It is true, though, that many older slower lenses perform just as good as new expensive fast ones at real "landscape" working apertures. Some landscape photographers have started asking for new slow lenses optimized for landscape work, which would be lighter and cheaper than the new fast offerings.

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@Petrus:Do you genuinely believe what you just said?

A given aperture, say f/11, does not translate into a given level of diffraction

in disregard of other factors. My f/3.5 Micro has no discernible diffraction at f/11

while the f/2.8 is by my standards unuseable at f/11 for general photography.

The reason for the difference is the much greater relative incursion of the aperture blades into the light path of the /2.8 lens. Hence, the f/2.8 Micro has much greater diffraction at f/11 than the f/3.5. It's just fairly simple optical science.

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@farrel: Yes, I do.

The math behind diffraction is neat in a way that while smaller (absolute) aperture causes more diffraction, like f/8 on 50mm lens versus f/8 on a 200mm lens (the later has an opening which is 4 times bigger in diameter), the fact that the 200mm lens makes an image four times larger exactly compensates the difference on sensor. In the end focal length, maximum speed of the lens etc do not matter at all, the amount of diffraction can be calculated from the relative aperture (a.k.a. f-stop) alone.

Here is something worth looking at: http://www.luminous-landscape.com/tutorials/resolution.shtml

If nothing else, go to table #3 at the end, which is an eyeopener. Notice that only the f-stop is needed to calculate the effect of diffraction.

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My f/3.5 Micro has no discernible diffraction at f/11

while the f/2.8 is by my standards unuseable at f/11 for general photography.

At the same focal length?

Edit: just read the previous post. I'm surprised the focal length does not matter but here we go, cannot argue with Maths.

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boulevardier

My impression from practical testing, is modern lenses are optimised for IQ closer to maximum aperture than older glass. The X10 shows diffraction beyond f4, though the small sensor represents considerable DoF at that aperture. My Canon 40mm f2.8 pancake also peaks somewhere round f4 - 5.6, on full frame, whereas older lenses tend to be at their best around f8-11.

I agree that slower lenses are often 'better' optically, and certainly cheaper than wide aperture lenses, plus less likely to show focus shift and other flaws. The old f2 50mm Nikkors and later 1.8 versions were exemplary optics, as are similar Olympus 50mm's, but money chases the wider versions.

This isn't to say lenses are bad at small apertures, IQ is all relative and people place too much emphasis on pixel peeping and not enough on taking great pictures. However zoom lenses tend to operate best at a narrow aperture range of a couple of stops in a way prime lenses do not.

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@Petrus: Thanks for the link;ironically, it was Luminous Landscape that I used to

refresh what I thought I already knew, that is, the greater the incursion of the

aperture blades into the light path, the greater the diffraction. How far that is

depends on maximum aperture. I never intended to redirect the original discussion

to diffraction and it's causes. Math rules in DOF calculations;diffraction is

an anomaly unaccounted by math.

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@boulevardier;You have reminded me of my rookie days 50 years or so behind me

when I paid 3X the USD for the 50/1.4 Nikkor because it looked more impressive

than the f/2. I use an old 50/1.8 to send pix to an ex-workmate to demonstrate

the exemplary perform of a modest lens that is without visible distortion,unlike

the f/1.4. I have long since outgrown my fascination with the expansive front

elements of blunderbuss lenses, as fine as they probably are today.

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andyfromboston

This isn't at all surprising, it has to do with different people having different standards for what counts as being in focus.

Only the exact distance you focus at is perfectly in focus. Anything closer or farther is at least somewhat out of focus. Of course, the further from the focus distance, the more out of focus. To calculate the amount of DOF you have, you need to first choose a tolerance - that's the amount of out-of-focusness (which is measured as the size of the "circle of confusion" for a point when printed at a chosen size) that you are willing to accept.

The stricter your tolerances (which is to say, the more sharpness you require), the less DOF. So if you have two DOF calculators that disagree, and you've entered the same frame size, focal length and aperture, chances are what's happening is that the two calculators have different tolerances.

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the greater the incursion of the

aperture blades into the light path, the greater the diffraction. How far that is

depends on maximum aperture.

No and no and no. Diffraction is caused by the light bending in a small hole edges. It is the size of the hole which determines the amount of bending, not how big the blades, wall, screen, whatever is where the hole is located. And the math concerning diffraction is just as precise as DOF calculations, and it is not an anomaly, it the nature of light or any wave actually, even waves in an ocean.

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If it is non-anomalous, there must be mathematical formulas to account for

for it and calculate it, as with DOF.

As for small hole edges, I'm not saying they don't exist but only that I've

never heard of them.

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