Beginner Hyperfocal Distance - Totally Confused

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LumixNoob

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I had the afternoon to myself so decided to have a play around with hyperfocal distance focusing and came away baffled. I was using this site - http://www.dofmaster.com/dofjs.html - and set my lens to f8 @ 15mm and focused (manually) at just under 5ft, which according to the site was the hyperfocal distance for those settings. The resulting pictures were out of focus completely.

I tried again, but this time set the focusing to 5m instead of feet by accident - the picture came out exactly how I expected it to at 5ft! What the hell is going on?!


Edit: I think the 5m focus was a fluke, it just happened to be along the lines of 'focus a third of the way into your scene' rule of thumb.
 
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Well, when you think of it, f8 15mm and focused at 5' should put objects roughly from 2 to 3' up to 10'.

If you are wanting infinity to be at the upper end of your hyperfocal distance I would imagine you would have to focus somewhere roughly about 5 or 6 metres...
 
And if infinity is absolutely your priority hyperfocal probably isn't the best approach.
 
The problem with hyperfocal distance, is that most modern lenses to not have a decent distance scale. I just focus around 1/3 into the frame and it works for me.

My App shows a hyperfocal distance of 5.21ft which should give you acceptable focus from 2.60ft to infinity, but I can guarantee your distance scale will not allow you to accurately focus at 5.21ft.
This was for a crop canon body. It will differ for full frame
 
I think I would've been better just going out with the camera + pen/pad, I'm more confused now than when I started!
 
Have you found the depth of field preview button on the camera yet, its under the lens mount on the left side.
If on a tripod, you can zoom in on LCD in liveview while depressing the preview button and see exactly what's in focus, or not.
 
Hi Steve, yeah but to be honest I forgot it was there! Saying that though, I've only really got into the habit of using live view for awkward angles and not much else. I should probably change that...
 
LumixNoob said:
I had the afternoon to myself so decided to have a play around with hyperfocal distance focusing and came away baffled. I was using this site - http://www.dofmaster.com/dofjs.html - and set my lens to f8 @ 15mm and focused (manually) at just under 5ft, which according to the site was the hyperfocal distance for those settings. The resulting pictures were out of focus completely.

I tried again, but this time set the focusing to 5m instead of feet by accident - the picture came out exactly how I expected it to at 5ft! What the hell is going on?!


Edit: I think the 5m focus was a fluke, it just happened to be along the lines of 'focus a third of the way into your scene' rule of thumb.
Click to expand...

HFD on your 1.6x crop format camera, with 15mm lens at f/8, is 4.9ft. That will deliver everything acceptably sharp from 2.45ft to infinity (according to the internationally agreed standard). DoF varies by camera format so be sure to input that correctly (it changes the Circle of Confusion at bottom-right of the DOFmaster settings panel) and set the HFD position by visually estimating the distance and focusing on something at that distance using centre-point AF.

Other methods, such as a 'third up the frame' or a 'third into the scene' are unlikely to be near optimum, and will usually result in a loss of potential near-ground sharpness. The depth-of-field preview button is usually a poor guide to DoF as the viewfinder gets very dark at higher f/numbers. But live view works well, or even easier is to quickly take a test snap and then zoom in on the LCD magnifier.

The point that Ned makes is worth bearing in mind. Basically HFD technique puts both the furthest and nearest subjects right on the limit of acceptable sharpness, as opposed to optimum sharpness.
 
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LumixNoob said:
I had the afternoon to myself so decided to have a play around with hyperfocal distance focusing and came away baffled. I was using this site - http://www.dofmaster.com/dofjs.html - and set my lens to f8 @ 15mm and focused (manually) at just under 5ft, which according to the site was the hyperfocal distance for those settings. The resulting pictures were out of focus completely.

I tried again, but this time set the focusing to 5m instead of feet by accident - the picture came out exactly how I expected it to at 5ft! What the hell is going on?!


Edit: I think the 5m focus was a fluke, it just happened to be along the lines of 'focus a third of the way into your scene' rule of thumb.
Click to expand...
My initial thought is that you guestimated 5ft wrong, getting it slightly wrong under the hyperfocal distance can throw it right off, for example in the above scenario focus at 4ft and you only get focus to 21ft rather than infinite. I use the hyperfocal distance but err on the side of caution. If it says 1.5m for example I would focus at 2m just to make sure, at 1.5m near range is 0.75m and at 2m it's only just further at 0.85m and I'd rather lose 10cm DOF in the foreground and make sure it had focus to infinite than the other way around. I doubt I'd notice 10cm difference in the foreground, and if for some extreme reason I did I could always crop it a touch.

Not saying this is right for everyone, just the way I do it. I always err on the side of caution ;)
 
OK, a quick demo (not much time atm). BTW I have a distance window on my lens so i can't be that far out.

5metres:

5m by James Howard, on Flickr

5feet:

5ft by James Howard, on Flickr


I don't get it, 5ft is not even close to being sharp anywhere other than at about 3 - 8ft, I know there's no real horizon but I can't even get near distance in focus focusing at 5ft (OK, so it says 4.91ft on the DOF chart). I've tried it slightly under 5ft, slightly over 5ft, at 7ft...it gets better nearer 10ft:


10ft by James Howard, on Flickr

The information on that site seems to make no practical sense whatsoever, or distance windows mean absolutely nothing (probably explains why a lot of lenses dont have them).
 
snerkler said:
My initial thought is that you guestimated 5ft wrong, getting it slightly wrong under the hyperfocal distance can throw it right off, for example in the above scenario focus at 4ft and you only get focus to 21ft rather than infinite. I use the hyperfocal distance but err on the side of caution. If it says 1.5m for example I would focus at 2m just to make sure, at 1.5m near range is 0.75m and at 2m it's only just further at 0.85m and I'd rather lose 10cm DOF in the foreground and make sure it had focus to infinite than the other way around. I doubt I'd notice 10cm difference in the foreground, and if for some extreme reason I did I could always crop it a touch.

Not saying this is right for everyone, just the way I do it. I always err on the side of caution ;)
Click to expand...

Agree. Trying to focus accurately using the distance scale on pretty much any zoom is very hit and miss - that's probably the OP's problem. Estimate the distance by eye (it's always going to be quite close) and focus on something at that distance using the centre AF point, then lock focus.

Erring on the side of caution is prudent :) Another way of doing that is, instead of using say f/5.6 that a HFD calculator suggests, just go one stop higher, to f/8.

Edit: crossed post with above. What focal length are those at James? Are they cropped? Cropping throws out all calculations (it's effectively a change of camera format).
 
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LumixNoob said:
OK, a quick demo (not much time atm). BTW I have a distance window on my lens so i can't be that far out.

5metres:

5m by James Howard, on Flickr

5feet:

5ft by James Howard, on Flickr


I don't get it, 5ft is not even close to being sharp anywhere other than at about 3 - 8ft, I know there's no real horizon but I can't even get near distance in focus focusing at 5ft (OK, so it says 4.91ft on the DOF chart). I've tried it slightly under 5ft, slightly over 5ft, at 7ft...it gets better nearer 10ft:


10ft by James Howard, on Flickr

The information on that site seems to make no practical sense whatsoever, or distance windows mean absolutely nothing (probably explains why a lot of lenses dont have them).
Click to expand...
Tbh the DOF site makes a lot of sense to me, you just need to learn what it all means. Plus make sure you've chosen the right camera as it will change the value whether full frame ,crop body etc (y)

Distance scales on lenses are useless these days, my 18-35mm goes up in increments to 1m then the next measurement is infinity, what use it that, no way of knowing where 3m is or 5m is. Old manual lenses with proper distance scales and hyperfical scales were so much better. Nowadays I have to guesstimate how far 5ft, 8ft etc is focus on this with the centre point, lock focus and then recompose the shot :rolleyes:
 
HoppyUK said:
Agree. Trying to focus accurately using the distance scale on pretty much any zoom is very hit and miss - that's probably the OP's problem. Estimate the distance by eye (it's always going to be quite close) and focus on something at that distance using the centre AF point, then lock focus.

Erring on the side of caution is prudent :) Another way of doing that is, instead of using say f/5.6 that a HFD calculator suggests, just go one stop higher, to f/8.

Edit: crossed post with above. What focal length are those at James? Are they cropped? Cropping throws out all calculations (it's effectively a change of camera format).
Click to expand...

The above ones are crops of 15mm images, but I uploaded the full size originals as well.
 
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snerkler said:
Tbh the DOF site makes a lot of sense to me, you just need to learn what it all means. Plus make sure you've chosen the right camera as it will change the value whether full frame ,crop body etc (y)

Distance scales on lenses are useless these days, my 18-35mm goes up in increments to 1m then the next measurement is infinity, what use it that, no way of knowing where 3m is or 5m is. Old manual lenses with proper distance scales and hyperfical scales were so much better. Nowadays I have to guesstimate how far 5ft, 8ft etc is focus on this with the centre point, lock focus and then recompose the shot :rolleyes:
Click to expand...

Yep, the site has a drop down chart to choose your camera body/crop factor (1.6 in my case).

Re: the distance scale, I suppose it doesn't matter; I could still use it to focus manually if I know where on the scale I actually do get best focus, where ever it says. As you say though, I don't have to anyway.
 
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LumixNoob said:
I can't even find focus distance in the exif data.
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Can't say I've ever seen the distance at which the lens focussed in the EXIF either tbh, only the focal length used.
 
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i have a small chart printed/laminated at 7'' x 5'' for your camera bag - only 2 spare though

shows HF Distance for each focal length vs f-stop

Pm me your address if you want one....:)
 
Thanks for the offer yardbent, it's a good idea. I'll let you hang onto them though or give them to someone else, I have the stuff to do one myself :)
 
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