COC - DOF - X1D Hyperfocal

[hcubell]

Leica's S(007) displays near and far focus distances.

--Matt

How does that work? Based upon where you focus the camera, there is a readout that shows the near and far points in feet that would be in focus?

 

[Godfrey]

Leica's S(007) displays near and far focus distances.

As does the Leica SL as well. It's a great feature when you're using the dedicated lenses. Of course, using adapted manual focus lenses, they all have distance scales and DoF markings too.

Hopefully Hasselblad will incorporate a similar readout into the X1D. Another feature enhancement request to send in...

G

 

[Godfrey]

How does that work? Based upon where you focus the camera, there is a readout that shows the near and far points in feet that would be in focus?

On the SL with a dedicated AF lens: When you're using manual focus, hold the shutter release at the halfway position and watch the top LCD as you turn the focusing ring. Critical focus plane is displayed, bracketed by near and far focus limits dependent on the focal length setting and aperture.

It's extremely handy! You can set the focus by scale very precisely, and the hyperfocal if you desire.

G

 

[siddhaarta]

I was sort of making a sort of a joke in my previous post above, but thats basically what I suggested as the easiest work around for the time being. Namely a cheat sheet (laminated and foldable). Used to do this with lenses that lacked DOF scales on the barrel.

Cell phone app/spreadsheet is another way to go. Heck, a middle of the night phone call (while shooting) to one of the Hasselblad lens designers is always an option .

Dave (D&A)i

Torgers iOS app "Lumariver DOF" is very nice and very flexible... maybe in combination with the Leica DISTO :ROTFL:

 

[algrove]

The XF system isn't all that amazing. I watched a one hour webinar in which they didn't point out that judging focus on a MacBook Pro screen was going to be different from various print resolutions, and in which I learned that after all the calibration process, you can only set one hyperlocal distance per lens and that it does not vary according to aperture. So in reality it is very simple. The math exists to start from intended print size and viewing distance, use the corresponding COC and determine for each aperture what the hyperlocal distance should be - especially when the lens is a known factor.

Tim. I can assure you that using the XF is much more than a video where who knows what they covered. In addition to the hyper focal feature one can always use the "in focus" feature where I have it set to indicate in focus areas in green. It can be toggled on and off.

Suggest using an XF where one might change opinions instead of video views to form opinions.

 

[tashley]

Torgers iOS app "Lumariver DOF" is very nice and very flexible... maybe in combination with the Leica DISTO :ROTFL:

I just tried the app and I found it less easy to use than True DOF Pro. However, if you give both apps the exact same parameters, that give quite widely different results. Hmmm.

 

[tashley]

Tim. I can assure you that using the XF is much more than a video where who knows what they covered. In addition to the hyper focal feature one can always use the "in focus" feature where I have it set to indicate in focus areas in green. It can be toggled on and off.

Suggest using an XF where one might change opinions instead of video views to form opinions.

I take your point. But I have tried one in-store (liked it very much - it's still a tank but it needs to be to meet its use-case) and the Webinar (an official Phase one) at an hour long on nothing but using the hyperfocal feature was a great deal more detailed than anything I was able to discover playing with the real thing. The simple fact is that though it might be very useful, it is constrained by the needs to

1) Do the calibration oneself - understandable but a pretty tedious routine, probably requiring one to tether whilst at the same time having access to an infinity view.
2) Only store one hyperfocal per lens when one might need one for infinity/landscape work and another for studio
3) Only store one hyperfocal per lens meaning that you have to make your aperture decision whilst making the calibration rather than whilst shooting.

I also regard the on my IQ180 the green shimmering in-focus guide as a rough guide only. I wouldn't trust it for critical work because I haven't chosen the COC myself. Which is fine.

But, the math seems to be 'out there'* for a given sensor size, pixel pitch, output size, viewing distance, focal length and aperture to determine which hyperfocal distance will achieve acceptable infinity focus with closest possible near distance. It's not quite rocket science and if it can be run on an iPhone it could be run in-camera. But that would require that camera to have the ability to display, save and recall focus distance...

*notwithstanding that two very convincing looking apps when fed the same parameters give me different results!

 

[siddhaarta]

I just tried the app and I found it less easy to use than True DOF Pro. However, if you give both apps the exact same parameters, that give quite widely different results. Hmmm.

Will try this app. Thanks !

And true ... I tried - when I had the Leica S - to compare the results from the app Lumariver DOF, with the results from the camera itself. I could NOT come to the same results with any CoC dialed in ?!?

Must be some secret mojo in the math ...

But anyway ... I am waiting for my Hasselblad X1D and want to use it for landscape. I am a little bit worried about the scale-less focus-by-wire lenses and the lack of a clear commitment from Hasselblad to implement something, even simple, in future firmware.

For me it would be sufficient to have a digital indication of m/ft in focus (I understand this is lacking). The rest (DOF, hyperfocal distance) can be done with experience and trial and error for the specific viewing needs. Surely I wont walk around with a DISTO with a camera like the X1D ...

 

[ejpeiker]

So, one thing I noticed yesterday was that at F8 one has to place focus very carefully (or luckily) on the 30mm lens in order to get acceptably sharp foreground (and bottom corners) and yet maintain good infinity resolution.

So this morning I did some math that others might find useful

I am 5'9" tall (175cm). At that height, with the camera to my eye and held level according to the camera's built-in level, the nearest point in the frame is approximately 3 metres away (flat ground, ground level point).

Assuming I want a print that is 46" wide (in other words printed to 180DPI which will work perfectly well although it is of course always better to print at higher resolutions) and that the viewing distance is 24 inches, the required Circle Of Confusion is 23µ. That means that the hyperfocal distance is 5.55 metres.

Being phenomenally anal retentive, I took a tape measure and set it to that distance, focussed on the mark, set it to F8 and levelled it and fired away.

It doesn't quite work. It's pushing it a touch, but 6.55m does work. Now I just need to work out a way of telling the camera to focus on that distance... or of memorising that distance so well that I can always pick a point.

Hope that helps someone!

I can totally relate to the anal retentiveness here - for me on my XF-IQ3100 system, I need a CoC of 0.013 or 13 microns, which of course makes the hyperfocal distance way bigger than generic tables give you which are usually based on a 3 micron CoC resulting in more focus stacks than I'd ideally want to do. I am constantly doing measurements like the ones you described.

By the way, the green focus mask on the XF and in C1P if you are tethered are nowhere precise enough for critical sharpness, you can really be lulled into getting just sort of sharp foregrounds or backgrounds if you rely solely on that. It's good enough for a lot of uses but not critical uses.

 

[KeithL]

So, one thing I noticed yesterday was that at F8 one has to place focus very carefully (or luckily)
I am 5'9" tall (175cm). At that height, with the camera to my eye and held level according to the camera's built-in level, the nearest point in the frame is approximately 3 metres away (flat ground, ground level point).

My question is, why would a 5' 9" photographer want to stand bolt upright and hold the camera perfectly level to his/her eye and need to know the nearest point in the frame is 3 metres away assuming as he/she does that the ground is perfectly level?

Is this the key to photographic nirvana?

:ROTFL:

 

[algrove]

I take your point. But I have tried one in-store (liked it very much - it's still a tank but it needs to be to meet its use-case) and the Webinar (an official Phase one) at an hour long on nothing but using the hyperfocal feature was a great deal more detailed than anything I was able to discover playing with the real thing. The simple fact is that though it might be very useful, it is constrained by the needs to

1) Do the calibration oneself - understandable but a pretty tedious routine, probably requiring one to tether whilst at the same time having access to an infinity view.
2) Only store one hyperfocal per lens when one might need one for infinity/landscape work and another for studio
3) Only store one hyperfocal per lens meaning that you have to make your aperture decision whilst making the calibration rather than whilst shooting.

I also regard the on my IQ180 the green shimmering in-focus guide as a rough guide only. I wouldn't trust it for critical work because I haven't chosen the COC myself. Which is fine.

But, the math seems to be 'out there'* for a given sensor size, pixel pitch, output size, viewing distance, focal length and aperture to determine which hyperfocal distance will achieve acceptable infinity focus with closest possible near distance. It's not quite rocket science and if it can be run on an iPhone it could be run in-camera. But that would require that camera to have the ability to display, save and recall focus distance...

*notwithstanding that two very convincing looking apps when fed the same parameters give me different results!

If one is serious to REALLY know what the XF offers then get out of the store and into your capture comfort zone if even by renting one for a few days. Once I set items in the XF I can always recall them since the "gear wheel" settings (called MCU) for hyperfocal and focus stacking can be recalled without much fuss and recalled by f stop. Most often I would try for f8, f11 and perhaps f16 for longer lenses. Of course distance requirements can change with each different capture.

Just my 2 pence.

P.S. Just read another post about the focus mask green. Sure I never use it as absolute, but as a starting point just to see where the heck I am AFA the XF is concerned. Forgot to mention all my discussion about this assumes one has spent serious time focus trimming each lens.

 

[tashley]

My question is, why would a 5' 9" photographer want to stand bolt upright and hold the camera perfectly level to his/her eye and need to know the nearest point in the frame is 3 metres away assuming as he/she does that the ground is perfectly level?

Is this the key to photographic nirvana?

:ROTFL:

It so is. The path is long....