Hyperfocal focusing with tilts

[leighperry]

I'm about to make the leap into large format photography and am doing extensive research. I've studied the usual focusing tutorials (Large Format Pages, Merklinger, Simmons, etc) so I have a theoretical grasp, if not practical experience.

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I have been told of a focusing method used by a landscape photographer. The method is attractively simple but strikes me as specious. Here it is:

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<i>"I worked out the hyperfocal distances for all my lenses and recorded them for F11 and F22. I them focused on these distances and marked them on the rail for when I move the back. For most landscapes with a fairly flat field all you need to do is focus on the foreground apply your tilt to the background and refocus to the hyperfocal distance which is marked on the bed."</i>

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I think I can see the rationale behind it. He focuses on foreground, then tilts for background. He then refocuses at hyperfocal, preserving the tilt.

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However, given that tilt creates a conical depth of field around the tilted subject plane, I would have thought that conventional hyperfocal distances no longer apply when a tilt is active. Therefore focusing at the hyperfocal distance is not likely to be optimal.

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What do you think of this approach? Is it just plain wrong?

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Thanks.

[richard_boulware]

With respect....Whatever happened to the time honored technique of

just drawing down the dark cloth around your GG and using a good

louple to tell you if you had sharp focus or NOT. This Techno-stuff

is getting a little bit

tiresome. I'll bet that Brady and Jackson never heard the term,

hyperfocal distance. They did it anyway. (:-)

[mike_mahoney]

Richard has the idea, although a little theory can save some time and

trouble in the field.

 

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My understanding of hyperfocal distance is that it relates only to

film and lens planes that are parallel. Once tilt is applied to

either standard, HF DOF goes out the window.

[thilo_schmid]

Leigh,

 

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the Hyperfocal Distance, i.e. the focus point where DOF extends from

infinity to the nearest most plane, is indeed not applicable to a

tilted view camera in the same way. It's substitute is a more general

DOF-concept, as you have already pointed out.

 

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Regards,

[mark_sampson]

It's much simpler in practice than in theory. Go make some

photographs. Use a loupe to check your focus. You'll understand it

much more quickly and you'll have some pictures too.

[leighperry]

Mark, are you saying that you endorse the hyperfocal method I

described?

[carl_weese]

It's good to know the hyperfocal distance for your lenses because

there are situations where swing and tilt can't be used. Beyond that,

the hyperfocal distance is a good starting point. For many landscape

subjects if you start at the hyperfocal distance and then add a bit of

front tilt you'll immediately have universal focus.

[gary_frost1]

This will get easier once you get your camera and start practicing

what you read about. I assume you have looked at these 2 articles

on the LF page:

 

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http://HTTP.CS.Berkeley.EDU/~qtluong/photography/lf/fstop.html

 

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http://HTTP.CS.Berkeley.EDU/~qtluong/photography/lf/dofknob/

 

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Once you have applied the tilt (use the GG to focus, Merklinger will

just slow you down and confuse here!) select the near & far limits

in your 'wedge-shaped' DOF required, and use the method of measuring

the distance you need to move the focus knob to focus the near and

far limits (the second article above). The nice thing about this

method is it works the same for all focal lenghts.

I don't use a scale, I just go by how many mm per 1/4 turn of the

knob and do it by 'feel', so I can stay under the dark cloth.

As others have suggested, you can also just stop down using a loupe

on the GG until all limits are sharp. Sometimes this can be difficult

in dim light though. I agree with all here who say that the practice

is much easier than the theory!

[philip_sweeney]

I got a kick out of some of the responses! With my 4 x 5 and a 90mm

lense (f6.8) at f22 with the standards parallel, I focus on my cases

at 11 feet. Therefore from 5.5 to infinity (in theory) everything is

in focus. One thing is for sure: from 5.5 out to who knows where, is

in focus. I then use rise or fall for final adjustment; however no

tilts! I do this all the time! This technique is not necessary with my

150, 210, and 305mm lenses. With those I use the movements for focus!!

For me the technique works because all my 90mm shots are done at f22.

It works for me. I hope you find what works for you!