Technique for focusing "into your scene"

[Doremus Scudder]

Here you go—

https://www.largeformatphotography.i...-to-focus.html

Couple that with: https://www.largeformatphotography.info/fstop.html and you're good to go.

A few observations:

The "1/3-in" rule doesn't really work. The amount of depth of field in front of and behind the plane of sharp focus varies with the distance being focused on. There are better ways to work with a view camera.

The "focus near - focus far and split the distance method" works well only if you use it intelligently. You have to get the proper f-stop to provide you with the desired depth of field and you need to consider where the plane of sharp focus will end up and adjust if needed. For example, you might want to cheat toward better focus for a distant horizon line at infinity and stop down more with many scenes, etc.

And, the "near" and the "far" can end up being above and below the plane of sharp focus if you use tilts; you really need to be able to visualize where that plane of sharp focus is in order to effectively choose your near and far focus points.

Mastering movements is an essential part of working with the view camera if you want to optimize sharpness and depth of field. You really need to be able to assess a situation, decide where you want the plane of sharp focus to lie in the scene so you can use the optimum f-stop, and then know how to best achieve that with movements. Choosing focus points for your plane of sharp focus and applying movements is equally, if not more, important that "focusing" your camera.

Knowing how to deal with out-of-focus areas is important too. Sometimes, they are unavoidable; sometimes desirable (although I don't really like glaring out-of-focus areas in my work). Knowing how to tweak movements and focus so an unavoidable soft area is placed unobtrusively in the scene is important too.

Best,

Doremus

[Alan Klein]

Put aside all of the math and theory and consider that there is truly only one slice of "focus" for a given focus distance. The "depth of field" is merely the area which appears, at a given print size, to be "in focus" or in other words, not obviously out of focus.

The closer you get to the edge of that depth of field, the less in focus it is. And if you print to a different size, it may become obviously out of focus once inspected.

In my opinion, it's much better to maximize the usage of your depth of field by putting what is most important in the image as close to the actual focus "slice" than do the whole "into the scene" focusing technique. This is made even easier with LF and movements, where often I would choose to focus on a foreground subject, and using tilt, make sure it and the horizon at infinity are both in reasonable focus. Then, stop down to get more perceived DOF. And when it doubt, stop down a little more. The perceived sharpness of your negative will really not be much different at f/22 or f/45, but having 1/3 of your negative clearly out of focus will definitely be obvious to a viewer. Don't worry about diffraction - that is mostly an overblown issue.

For small formats, using hyperfocal focusing makes a bit more sense to me - mostly for speed of shooting. But I'd still rather have a sharp subject with a slightly out of focus background than a kinda-sorta in focus subject with slightly sharper background, with the sharpest focus in the image somewhere behind the subject.

You focus on the near and tilt for the far?

[AdamD]

Couple that with: https://www.largeformatphotography.info/fstop.html and you're good to go.

A few observations:

The "1/3-in" rule doesn't really work. The amount of depth of field in front of and behind the plane of sharp focus varies with the distance being focused on. There are better ways to work with a view camera.

The "focus near - focus far and split the distance method" works well only if you use it intelligently. You have to get the proper f-stop to provide you with the desired depth of field and you need to consider where the plane of sharp focus will end up and adjust if needed. For example, you might want to cheat toward better focus for a distant horizon line at infinity and stop down more with many scenes, etc.

And, the "near" and the "far" can end up being above and below the plane of sharp focus if you use tilts; you really need to be able to visualize where that plane of sharp focus is in order to effectively choose your near and far focus points.

Mastering movements is an essential part of working with the view camera if you want to optimize sharpness and depth of field. You really need to be able to assess a situation, decide where you want the plane of sharp focus to lie in the scene so you can use the optimum f-stop, and then know how to best achieve that with movements. Choosing focus points for your plane of sharp focus and applying movements is equally, if not more, important that "focusing" your camera.

Knowing how to deal with out-of-focus areas is important too. Sometimes, they are unavoidable; sometimes desirable (although I don't really like glaring out-of-focus areas in my work). Knowing how to tweak movements and focus so an unavoidable soft area is placed unobtrusively in the scene is important too.

Best,

Doremus

Doremus, this is all very well said. But this is what I'm trying to understand better.

How about this....here's a link to 4 shots I just took the other day. You can download them and zoon in further than SmugMug will allow. Anyway, you will see soft spots in these images even though all of these areas fell within my near and far focus points on the rail. It would have been my expectation that everything should have been pretty much the same sharpness, but not so....I'm trying to understand why.

Of course one possibility is that I THOUGHT all the areas were within the near and far focus points of travel, and maybe I was wrong. But I'm thinking by moving the standard to the mid-point of the near and far points on the standard rail markings that I caused the problem and I should have set the standard closer to the max extension point.

Anyway....take a look at let me know if anyone can detect any potential causes.

https://fountainphoto.smugmug.com/Fi...umb-3-27-2021/

Image 1: 150mm Rodenstock f/5.6. 1/15 sec @ f/25 orange filter
Image 2: 150mm Rodenstock f/5.6. 1/15 sec @ f/20 orange filter
Image 3: 90mm Rodenstock f/6.8. 1/15 sec @ f/20 orange filter
Image 4: 90mm Rodenstock f/6.8. 1/8 sec @ f/22 orange filter

Arca-Swiss F-Line Classic with the MicroOrbix. Focus in the highest farthest point, MicroOrbix tilt for the nearest lowest. Image 4 was the easiest to get this clean.

Any thoughts??

[Drew Wiley]

Maybe this particular thread query is really about how to efficiently use view camera movements. That comes first, in any event.

[Oren Grad]

It would have been my expectation that everything should have been pretty much the same sharpness, but not so....I'm trying to understand why.

DOF theory does not imply that everything within the calculated limits is uniformly sharp. Simply from the laws of optics, the degree of unsharpness necessarily increases as you move away from the plane of focus. However, depending on your circle-of-confusion criterion, up to the calculated distance limits the portions of the picture away from the plane of focus are judged acceptably unsharp. Again, not uniformly unsharp, just acceptably so to a varying degree as you move away from the plane of focus.

[Oren Grad]

Maybe this particular thread query is really about how to efficiently use view camera movements. That comes first, in any event.

Best to keep movements out of it until the basic concepts of focus behavior are adequately understood, else one doesn't really understand what is and isn't being accomplished with movements.

[Drew Wiley]

No topic is as confusing as "circle of confusion". How confused do you want to be? - just depends how much magnification your loupe happens to have! It's all relative. Unless you're printing a book, you don't even need to know that particular expression, or the likewise irrelevant nonsense of, "normal viewing distance". Your own eyes can do it all, spontaneously and far more meaningfully. Yes, once in awhile it's nice to know about hyperfocal theory and so forth; but I can't think of a single instance I ever applied it to large format work. No need. The whole concept of sharpness is itself a plastic concept - and I'm known for very "sharp" prints! No - they are not in fact in acute focus everywhere - it's nuanced, but with some particular portion deliberately in most acute focus; and that comes about as a compositional choice, not via any rote formula. We each have our particular strategies. It's just that the option of view camera movements opens up an entire new toolbox. It takes some time and experimentation to get weaned from small camera methodology, especially if it's digital. So, in my opinion, it helps to erase the blackboard first, and start fresh.

Yes, Oren, I get it. It's like me at 16, trying to learn to drive while also trying to learn how to side-handle gear shift an old GMC truck at the same time. My dad put me out in the middle of the pasture because he figured I couldn't get in any trouble that way. I made it as far as the ditch, and it took him the rest of the day to winch the truck out. Plan B. ...Going from SLR cameras to a view camera was analogous for me. One just has to jump in at some point and learn via some inevitable bellyflops, or else tag along with somebody who already knows the ropes, and watch what they are doing. Hopefully that opportunity will arise in this case.

[otto.f]

I wonder what your goal is: everything sharp, landscape, portrait, stills? Esthetically, I mostly go for 1/3 front, 2/3 background and I’m seldom in for everything sharp, except with landscape.

[reddesert]

Hi all,

Question about 4x5 focusing. But first, to set the stage, let's talk digital for a moment.

When learning about focusing a digital camera I have read many times and in many places, to maximize overall image sharpness and depth of field, focus 1/3 of the way "into" your scene.

By all accounts this works pretty well and reliable.

Now, let's shift gears to 4x5. Here, I have learned from others and have read, basically do the following:

1. Focus on the near/far
2. Tilt for the near/far
3. Note the standard position on the metric scale
4. Then hunt around the scene and find the most out of focus area, focus on that area, then note that position of the standard on the metric scale
5. Then, here's the catch....place the standard at the mid-point of the near and far focus points

The last step is the one I want to talk about. Positioning the standard on the mid-point....doesn't that equate to focusing 50% "into" the scene? Shouldn't we be focusing at the 1/3 point "into" the scene? I know the math is harder, but, thoughts on that?

Thanks!!

Other people have explained that the 1/3 rule of thumb isn't really accurate. It also predates digital BTW. But anyway, the simple explanation for the difference in these rules of thumb is that the 1/3 rule applies to the distance in the subject space, like your subject is from 10 to 40 feet away so you focus at 20 feet. The rule you quote for 4x5 of focusing at the mid-point is in the image space, where you're splitting the positions of the standard corresponding to near and far in half.

Because the relation between image distance from the lens and subject distance from the lens is not linear, these rules of thumb are less different then you might imagine. The difference is not that 35mm/digital has a different DOF from 4x5. Rather, it's mechanical: in 35mm/digital you're usually looking at the focusing distance scale of a lens that gives subject distance, while with an LF camera you can more easily measure the position of the image (the standard).

[GRAYnomad]

Image 1: 150mm Rodenstock f/5.6. 1/15 sec @ f/25 orange filter
Looks good front to rear but soft top right, which implies to me that you had some swing in place as well.

Image 2: 150mm Rodenstock f/5.6. 1/15 sec @ f/20 orange filter
Same thing really. Good overall but soft on the left side.

Image 3: 90mm Rodenstock f/6.8. 1/15 sec @ f/20 orange filter
Looks like it's focused on the dead tree and no tilt has been used so the midground is slightly soft and the background is very soft.

Image 4: 90mm Rodenstock f/6.8. 1/8 sec @ f/22 orange filter
Foreground sharp, background sharp, midground soft. Classic effect you get when the shape of the terrain is like this. Your cone of focus expands as it moves away form the camera but it's not big enough to encompass the midground.

I might not be right but as all these appear to have been shot wide open (or close to that, I'm not familiar with those lenses) I would not be surprised by any of the above.

As an example of #4, here's one of mine I posted on the forum yesterday.



I put the plane of focus as best I could through the heads of all the grass, those in the foreground are sharp as are those at the back, but in between, lower down on the grass stems, it's not in focus. And this is at f45.