Hyperfocal Distance & Manual Focus

[dkCambridgeshire]

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I'm planning to use my X1 in manual focus mode with the lens set to the hyperfocal distance, and the image composed using the accessory SBLOO 35mm finder. To facilitate same, the matrix affixed to the top of the SBLOO shows:

 

a) whole lens apertures

hyperfocal distances (meters) rounded to nearest 0.5 meter for each aperture (for a 24mm lens on APS 'C' format)

c) minimum distance from which everything should be in focus, to infinity.

 

 

 

 

 

Unfortunately, the manual focus scale in the monitor is rather crude to effectively set the lens to the required hyperfocal distance accurately - because the scale on the screen is relatively short and thus does not or cannot include the required distance settings (with the exception of the 2 meter indicator)

 

However, I hope to try and guestimate some of the distances and maybe achieve reasonably accurate focus where the focus matters.

 

There are 8 clicks audible when turning the focus wheel between 1 meter and 2 meters through which the focus indicator dot moves along the scale. This appears to suggest that 1.5 meters is 4 clicks away from 1 meter ... but this part of the focus sector is unlikely to be needed as much as the 2 meters to Infinity sector.

 

Between 2 meters and Infinity, the focus scale has 8 clicks through which the focus indicator 'dot' moves along the scale. The 'dot' actually reaches the Infinity mark at the 7th click after which there is an 8th click available enabling the 'dot' to move past the infinity mark ... and then there is a ninth click for which the 'dot' cannot move any further because the 'dot' reaches the end of the scale at the 8th click! The distances that the focus 'dot' moves, with each 'click' are not linear between 2 meters and infinity. And the 2meters to Infinity sector of the focusing scale is only 5mm in width! That is a lot of distance for such a short part of the scale.

 

I'd like to know exactly which distances the clicks between 2meters and infinity correspond to because then I might be able to roughly locate the 2.5, 3.6, 5, 7 and 10 meter hyperfocal distances. And I'd also like to know exactly which actual click corresponds with infinity ... Is it the 7th, the 8th or the 9th?

 

So far, I don't find the manual focus scale adequate.

 

Maybe this is something that Leica could improve in future ie make the scale wider with more distance settings. I wonder if this could be improved via a firmware fix? Somehow I doubt it. Whoever designed the manual focus scale has not taken the needs of the age old 'hyperfocal distance mode ' into account.

 

Cheers

 

dunk

[stkorn]

Great post, very useful! What was Leica thinking when they designed that focus scale??

[damnsharp]

Let's hope someone from Leica is also reading our posts...

[ziggurat]

Hello Dunk,

 

On the M version there are 3, 5, 10 M marks between 2 and infinity. That gives 4 spaces between 2 and infinity. I take your point about it not being linear but you could try two clicks for each space.

 

Bye the way the X1 has more increments than the D3 on the kit lens, so they are getting better.

 

Regards

Johnny

[ziggurat]

"to infinity and beyond"

 

sorry someone had to do the Buzz Lightyear joke.

 

I suppose the only real way to work this out is to take the camera out onto a playing field. Set it up on a tripod, measure out the distances along a measured line and get someone to pose in the relevant positions.

 

Just don't do it near any security guards or police. I would not like to try and explain this one.

 

Regards

Johnny

[dkCambridgeshire]

"to infinity and beyond"

 

sorry someone had to do the Buzz Lightyear joke.

 

I suppose the only real way to work this out is to take the camera out onto a playing field. Set it up on a tripod, measure out the distances along a measured line and get someone to pose in the relevant positions.

 

Just don't do it near any security guards or police. I would not like to try and explain this one.

 

Regards

Johnny

 

 

Maybe Leica will advise exactly what distances the clicks correspond to ... After all, they designed the camera ... At least I hope they did.

 

dunk

[dkCambridgeshire]

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Maybe Leica will advise exactly what distances the clicks correspond to ... After all, they designed the camera ... At least I hope they did.

 

dunk

 

EDIT: I just sent Leica an Email to ask if they can advise.

 

The above two photos clearly show how the focus indicator travels past the infinity mark ... maybe the infinity mark is inaccurately situated? The focus scale is way too minimalist .

 

dunk

[ziggurat]

Hope you have a good response to this Dunk.

 

However, I would not hold my breath if I were you. I've asked similar questions in the past and been given answers with no real substance or meaning; or in other words figure it out for your self kind of thing, we only make the things.

 

The forum is looking to provide more editorial content in the future. Perhaps this subject would be a useful starting point for a lot of people.

 

Regards

Johnny

[dkCambridgeshire]

....

 

I'd like to know exactly which distances the clicks between 2meters and infinity correspond to because then I might be able to roughly locate the 2.5, 3.6, 5, 7 and 10 meter hyperfocal distances. And I'd also like to know exactly which actual click corresponds with infinity ... Is it the 7th, the 8th or the 9th?

 

So far, I don't find the manual focus scale adequate.

 

Maybe this is something that Leica could improve in future ie make the scale wider with more distance settings. I wonder if this could be improved via a firmware fix? Somehow I doubt it. Whoever designed the manual focus scale has not taken the needs of the age old 'hyperfocal distance mode ' into account.

 

Cheers

 

dunk

 

Contrary to my previous assertion I've read elsewhere that the focus scale problem might be fixable with a firmware update ... if so, the sooner the better. The focus scale in its current form is very "unsatisfactory" ... and that is being polite

 

BTW in the above pix the monitor has a self adhesive screen protector attached ... which avoids nose grease marks on the actual screen when using the accessory finder

 

Cheers

 

dunk

[lars_bergquist]

I'm sorry but the monitor scale seems to be just like the scale on a lens -- i.e logarithmic and not linear. So you cannot just count the clicks to infinity and then divide.

 

But 4m will be exactly at half the distance between 2m and infinity. Similarly, 8m is halfway between 4m and infinity. Check on any decent camera with a manually focusing lens.

 

A far more burning problem is that, to the best of my knowledge, the camera goes completely amnesiacal when it goes asleep automatically, and when you wake it up, you have to go through the monitor rigmarole again. Not what you want for street shooting.

 

Then a piece of pedantry: 'Hyperfocal focusing' and 'zone focusing' are not the same thing. What you mean is zone focusing. Hyperfocal is when the further limit of your zone of acceptable sharpness ends at infinity.

 

The old man from the Age of Tape Measure Focusing

[lars_bergquist]

BTW in the above pix the monitor has a self adhesive screen protector attached ... which avoids nose grease marks on the actual screen when using the accessory finder

 

Cheers

 

dunk

I got over the nose grease complex about six months after acquiring my M8. The resolution of the screen is much too coarse for any reasonably amount of nose grease to make a difference.

 

Snot is a different matter of course, especially the frozen variety, as you will find when you work as close to the North Pole as I do.

 

The old man from the Age of Tape Measure Focusing

[earleygallery]

Just out of interest have you tested the accuracy of the scale as it is, i.e. if you set the focus at 1M, and shoot a test object 1M away, is it in accurate focus?

[dkCambridgeshire]

I'm sorry but the monitor scale seems to be just like the scale on a lens -- i.e logarithmic and not linear. So you cannot just count the clicks to infinity and then divide.

 

But 4m will be exactly at half the distance between 2m and infinity. Similarly, 8m is halfway between 4m and infinity. Check on any decent camera with a manually focusing lens.

 

A far more burning problem is that, to the best of my knowledge, the camera goes completely amnesiacal when it goes asleep automatically, and when you wake it up, you have to go through the monitor rigmarole again. Not what you want for street shooting.

 

Then a piece of pedantry: 'Hyperfocal focusing' and 'zone focusing' are not the same thing. What you mean is zone focusing. Hyperfocal is when the further limit of your zone of acceptable sharpness ends at infinity.

 

The old man from the Age of Tape Measure Focusing

 

Thank you for pointing out the 'count the clicks' anomaly. Unfortunately' the infinity indicator on the scale does not coincide with the end of the scale. And the moving dot which travels along the scale does not at any point stop halfway between the 2meter mark and the end of the scale. From the 2meter mark, it stops at a further 9 positions the first four being approximately four equal increments apart; then there is a relatively bigger jump to the fifth position, followed by two similar jumps to the end of the scale ... and then (and this is the mystery) two further clicks at the end of the scale when the moving dot does not move at all. And at no stage does the moving dot ever stop directly under the infinity marker of the scale ... and the infinity marker is a few mm. before the end of the scale. How are we are supposed to interpret what distances these clicks correspond to?

 

Regarding your assumption that I meant 'Zone focusing" I did in fact mean 'Hyperfocal' ... which is why this post commences "I'm planning to use my X1 in manual focus mode with the lens set to the hyperfocal distance, and the image composed using the accessory SBLOO 35mm finder ... etc "

 

I'm beginning to realise that this is probably not a camera for fast ever ready and thus candid street photography.

 

But will reserve judgement until have actually had the opportunity to try it.

 

dunk

[dkCambridgeshire]

Just out of interest have you tested the accuracy of the scale as it is, i.e. if you set the focus at 1M, and shoot a test object 1M away, is it in accurate focus?

 

I'll try that tomorrow James ... and check the result.

 

Thanks

 

dunk

[earleygallery]

I'd be interested to know, if the scale is accurate or more of a 'cosmetic' feature. Clearly not much thought has been put into the design of the scale - maybe the designers just thought people wouldn't bother with it.

 

Of course maybe in practice the AF will work out well enough that you won't want to use the MF function anyway.

[dkCambridgeshire]

I'd be interested to know, if the scale is accurate or more of a 'cosmetic' feature. Clearly not much thought has been put into the design of the scale - maybe the designers just thought people wouldn't bother with it.

 

Of course maybe in practice the AF will work out well enough that you won't want to use the MF function anyway.

 

If Leica could not be bothered to fully calibrate the manual focus scale then I'll have to do it myself ... and publish the results here in the X1 Forum. And maybe anyone else interested in establishing some calibration data might also consider doing the same themselves and then comparing results. I hope to establish which distances the clicks focus at ... partly using the Manual Focus Assist function ... but will be a time consuming task to do it properly whilst making notes. I'll have to use a tape measure and a tripod .. and probably a loupe even with the manual focus assist. Not sure what will be used as a target at thus stage. Also a possibility might be able to get hold of an ultrasonic distance meter which would make the task easier.

 

Battle on ...

 

Cheers

 

dunk

[diogenis]

Leica, with the X1 needs to publish a firmware that will show a better scale, more detailed, with clear DoF markings, both adjusted for the particular aperture chosen. When someone tries to focus manually, the zone of DoF should clearly be shown in the scale as well.

Apparently there is no big need to indicate distances greater than 2 meters, because after all it is a wide lens.

Also in favor of simplicity, what is the reason of showing both meters and feet measurements, both at the same time? You choose one or the other from a menu setting and thats it. You never see the other.

 

Edit: Also, as I hear, the camera uses whatever aperture things is best for a balanced live view, but that is not helping when one tries to manual focus. I don't know if they can fix this with a firmware release though...

[lars_bergquist]

Regarding your assumption that I meant 'Zone focusing" I did in fact mean 'Hyperfocal' ... which is why this post commences "I'm planning to use my X1 in manual focus mode with the lens set to the hyperfocal distance, and the image composed using the accessory SBLOO 35mm finder ... etc "

Right. The comment was not directed specifically at you. But as you surely know, the term 'hyperfocal' has come to largely supplant 'zone focusing' recently, probably because these not-very-technically-savvy people think it sounds more "scientific". But it is a misuse of the term.

 

A negligible matter? Not really. Without a functioning language, we can't communicate.

 

Just for the fun of it, I dug out the formula for hyperfocal depth of field. It is a bit difficult to write math directly here, so pardon the clumsiness:

 

z = (f x f) / (n x k)

 

where z is the diameter of the circle of confusion, f is the focal length, n is the close limit of the sharp zone (the far limit being infinity of course) and k is the f-stop.

 

The old man from the Age of Tape Measure Focusing

[dkCambridgeshire]

Right. The comment was not directed specifically at you. But as you surely know, the term 'hyperfocal' has come to largely supplant 'zone focusing' recently, probably because these not-very-technically-savvy people think it sounds more "scientific". But it is a misuse of the term.

 

A negligible matter? Not really. Without a functioning language, we can't communicate.

 

Just for the fun of it, I dug out the formula for hyperfocal depth of field. It is a bit difficult to write math directly here, so pardon the clumsiness:

 

z = (f x f) / (n x k)

 

where z is the diameter of the circle of confusion, f is the focal length, n is the close limit of the sharp zone (the far limit being infinity of course) and k is the f-stop.

 

The old man from the Age of Tape Measure Focusing

 

I found a published matrix showing hyperfocal settings for a 24mm lens on an APS C format ... and used those figures after 'rounding' them.

 

Maybe the Leica X1 design team are under the impression that all X1 users requiring manual focus will jiggle the focus wheel whilst using the 'Manual Focus Assist' facility ie the magnified central part of the monitor image. Using the M/F Assist does not really require the photographer to see the actual focused distance. However, for the street photographer seeking quick candid images, jiggling the focus wheel is not fast enough. Street and event photographers need to be able to use the good old proven hyperfocal distance method in conjunction with an accessory finder to minimise delay before the shutter fires.

 

Cheers

 

dunk

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[diogenis]

But the problem is, that the X1 does not retain its distance on the lens. Meaning, if you say place the lens manually to hyperfocal dist, it will move past this setting, even if in manual. Otherwise you would be using an aperture of 8-16: anything after 2m comes in focus. But can you maintain 2m in your lens?