How to obtain enough depth of field

[albert_martinez]

I've been shooting with my Toyo 4x5 for about a year now and I love it. Unfortunatley, some of us don't have mechanical depth of field calculators built in to our view cameras and that's where the frustrations begin.

 

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I purchased Rodenstocks View Camera calculator, it helped some because your focusing on two points and it then chooses for you your optimal f/stop. I need more info!!!!

 

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So, assuming the cameras level, tilt,swing,shift all set at 0 deg, and you just dropped your Rodenstock calculator in the lake, where

would you go from there? Should I give up and set everything to f45.

 

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Rodenstock also claims you should set your focus point to

half the distance between to objects, instead of the first third I always assumed was correct.

 

If anyone out there has been through this stage in there photographic

journeys and could shed some light, or shall we say-some depth of field on the subject,I would truly appreciate it.

 

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Thank you for your time,

 

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Albert

[doug_paramore2]

Albert: Go the the Schneider Optics web site and they have listed the

depth of field charts for their lenses, listed by focal length. It

doesn't matter who made your lens, focal length and f-stop determine

depth of field. You can figure hyperfocal distance from these charts.

Rather than depending on extras like depth of field calculators, I

would study the ground glass and get everything sharp as possible

with a loupe, then stop down until everything appears sharp, then go

one stop more. It will make your LF work much faster and more

pleasant. With swings and tilts, you can tailor the depth of field

for your LF lenses to match the subject you are shooting.

 

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Regards, Doug.

[lee_nadel1]

react to your gg thats were the magic happens

[robert_a._zeichner]

There is a technique that was beautifully described in an article in

Photo Techniques a couple years ago that I think will help. It

involves taping or gluing a mm scale to the focusing bed and observing

the exact point at which the nearest and furthest subjects come into

focus with respect to a mark you can make on the front standard or

other moving part of the focusing mechanism. The difference or focus

spread determines the aperture you'll need to achieve acceptable

sharpness. You simply place the front standard smack in the middle of

that range, set the lens and expose your film. I don't remember the

exact issue this appeared in, but I 've been using this technique for

at least two years with great success. It also allows you to use

swings and tilts and any focal length of lens. Hope it helps.

[chris_patti1]

My answer: don't drop the Rodenstock calculator in a lake.

 

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Robert Zeichner's method works on the same principal (determining

aperture from the amount of movement of the standard on the focusing

rail necessary to get near and far points into focus). You can

calculate a factor (either by experience or working backward from the

Rodenstock calculator) by which you multiply the amount of movement in

mm on the rail to get the right aperture. The Rodenstock

calculator gives you the additional ability to refine this

calculation when the focusing rail is not level or when you are doing

close-up work (both of which allow a larger aperture for the same

amount of movement on the rail).

 

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Personally, I find DOF tables extraordinarily unhelpful in practice.

The method you are using is much easier.

[chris_patti1]

One last thought: Anyone who can tell whether the image is sharp when

the lens is stopped down to f/45 has a much better ability to see in

the dark than I do.

[qtluong]

I don't think using depth of field calculations in object space

is a good idea with

the view camera. First, unlike on helicoidal-mounted lenses used on

rigid

cameras, you don't have a focussing scale indicating at what distance

your lens is focussed, neither do you have a depth of field

scale. Second, tables can be used only when the standards are

maintained parallel. Third, why use a method based on guessing, when

you can fairly easily use an exact method ?

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For several years I have relied on stopping down the lens and

inspecting the ground glass. I eventually found that this yielded

results less sharp than I wanted. The problem is that it is not that

easy to make a good judgement of sharpness on the ground glass. The

image is grainy, and when you stop down, the image on your ground

glass gets pretty dim. The magnification depends on the lupe you use.

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The idea to relate the focus spread to depth of field was first

implemented by Sinar in their cameras. As their patent ran out, other

manufacturers, including Arca-Swiss came up with a similar device.

Articles which explain in detail how to use the relation in practice

include a draft by Guy de Riencourt, <A

HREF="http://www.micronet.fr/~deriencg/DOFforLF.pdf">Depth of field

and the view camera</A>, the article by Joe Englander,

<a href = "http://www.englander-workshops.com/documents/depth.pdf">

<i>Apparent Depth of Field: Practical Use in Landscape

Photography</i></a>, and the article

by Stephen Peterson, <i>Image sharpness and focussing the view

camera</i>,

Phototechniques March/April 96.

 

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The idea of combining the effects of diffraction and defocus to find

the optimal f-stop was explained by Paul Hansma in the article

<i>View camera focussing in practice</i>, Phototechniques March/April

96. This method seems to make the most sense to me and the article

will be available soon on the LF page,

courtesy of Paul Hansma. However,

Paul Hansma's use of

<samp>N/750</samp> has been criticized by

Bob Wheeler, in his

<a href = "

http://www.bobwheeler.com/photo/ViewCam.pdf"><i>Notes on view camera

geometry</i></a>, section 9.3, where he said it should be

<samp>N/1500</samp>. I am still trying to understand clearly the

issue, before writing an article on depth of field for the LF page.

[larry_huppert1]

I don't believe the Rodenstock calculator tells you to focus at the

half-way point between the near and far points. If I remember, it

tells to to set the rear standard 1/2 way between the near and far

points. For middle distances, this point on the rail approximately

equates to the 1/3 - 2/3 rule in object space. The 1/3 - 2/3 rule

does break down at the extremes. For example, if your doing table

top work, it is closer to a 1/2 - 1/2 rule.

 

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My advice - read different articles and understand the techniques and

then choose ones which work for you. For example, I'm not a big fan

of the two point focusing techniques. There is nothing wrong with

it; many people swear by it. When shooting interiors, I'd rather

determine the distance and f-stop needed, and then focus on something

at that distance. For critical work, I use Bob Wheeler's Vade Mecum

program and PCAM on the Palm Pilot to calculate these parameters (and

others).

[jason l.]

Albert

 

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DOF is really only half the problem. You will have a difficult time

getting the sharpness you want if you do not get the best plane of

focus to begin with.

 

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Someone posted that you should react to your ground glass. I really

agree with this philosophy. Take your camera out and play with the

front and rear tilts and swings. Make notes on what points come into

focus together as you adjust the swings and tilts and re-focus.

 

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Once you are comfortable with the procedure of placeing the plane of

focus to maximize sharpness in the foreground and the background,

then just shoot at the smallest aperature that suits your goal for

the photograph. Remember that smaller is not always better. With

4X5, if you go much smaller than f/32.5 you start to get into

diffraction problems.

 

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Regards,

 

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Jason