Techniques/Procedure for front tilt and focusing

[AdamD]

***First off, I'm not 100% sure this is the correct forum subsection, so if this is the wrong place, maybe the moderator can step in....this is a technique question, really about any camera***

Okay with that, maybe some of you can shed some light on this subject for me. What is your procedure for using front tilt and ensuring the full depth of field is in focus?

Here is my procedure. I have found it to be pretty good, but for some reason I get screwy results from time to time. It's either that my method is flawed or my skill sucks and just needs practice. Maybe both... Anyway, here's the way I do it.

Assumptions:
1. Cambo monorail 4x5
2. Always focus by moving the back standard
3. I use a 4X loupe
4. Within 8 feet or so, there's an object that needs to be in sharp focus
5. The subject is typically beyond that at 15 to 30 feet away
6. The screen typically has a sky background with distant mountains
7. Typically shoot at f22-f32

Procedure:
1. Generally I will focus on the close in object like a plant.
2. Tilt the front standard and get the objects in the midrange of the scene in focus.
3. Refocus the plant that's in close (~8feet).
4. Stop down until the distant object sharpen up.
5. Lock it down.

Again, I've found this to work well, but I get a few misses in there even though I think I've got it right.

What do you think? What's you procedure and do you see any problems with mine?

I will post a good example and a not so good example so you can see what I mean.

Any comments (mostly constructive) would be most appreciated.

Thanks,
Adam

[AdamD]

[Vaughn]

I work differently. I see a point where you might be giving yourself some issues.

Set focus about 1/3 into the scene (not mid-range), then tilt to get the foreground and background close to focus.
Close the lens down while looking at the GG. The foreground and background should come into focus at the same time (at the same aperture). If they don't, move tilt and/or focus until they do.

In your examples, you have middle ground hiding directly right behind the foreground instead of an even transition from near to far. No way to alight a plane of focus evenly across the scene.

Another way is to focus on the closest thing you want sharp, note where the back standard is...then do the same with the far distance -- then move the back standard right in the middle. Start there for focus before you start to tilt, etc.

[AdamD]

This is super interesting to me. Thank you!!

[Vaughn]

I think the Cambo has a number scale on its rail, so using that last method I mentioned above should be quick and easy to get your standards in a good starting position.

I typically use the front standard to focus in the landscape...but that is because I use wood folding field cameras. At landscape distances, it does not as significant which standard one uses to focus.

[Alan9940]

I'm sure there are many different approaches to using front tilt, but here's what I do (this assumes base tilts and that there are no significant verticals in the scene):

1. With the lens wide open, focus on the far.
2. As you tilt the front standard forward, slowly focus on the near until both near/far are in focus.
3. Lock tilt.
4. Adjust focus, as needed.
5. Watch gg while stopping down to ensure all important elements are in focus.

If you have some vertical elements, you will need to play with the focus and aperture settings to zero in on the correct focus point. If you have tall verticals, especially if they're close to camera position, then forget tilts and play with DOF ensuring that the most important elements are in focus.

Since I've never worked with any LF camera having other than base tilt, I can't offer any suggestions for other styles of camera movements.

[Doremus Scudder]

The way you apply your front tilt depends on the type of tilt you have, axis tilt or base tilt. Axis tilt means that the front lens standard tilts around an axis that runs through the center of the lens, i.e., the lens revolves around an axis running through it. With base tilts, the axis of the tilt is lower than the lens, either at the rail connection or the camera bed (with field cameras, etc.).

Technique for axis front tilts:
1. Focus on something in the middle of the ground glass that lies on the axis around which the lens revolves.
2. Tilt the lens standard until the desired objects in the foreground and background are both in focus (or as close as they are going to get to each other - more later about this).
3. Recheck focus on the object in the center (the one on the axis). Refocus if necessary and repeat the above.

Technique for base front tilts:
1. Focus on an object to the bottom of the ground glass. This is usually the farthest object, except when you're photographing cave ceilings, etc.
2. Tilt the standard until both of your chosen near and far objects are equally unsharp.
3. Refocus on the far and check the near object with your loupe. If the near object is unsharp, tweak the focus one way to see which way you need to further adjust your tilt (you only need one way to decide this). If, for example, you focus closer (moving the bellows longer) and the near object gets sharper, then you need to adjust your tilt by tilting forward a small (very small) amount. If it gets less sharp, then you need to adjust the tilt by tilting backwards a tiny bit. (Note: if you start by tweaking focus farther, i.e., shorter bellows, then the inverse of the above applies. The basic rule is: If the object you are checking gets sharper when you tweak focus, you adjust tilt in that same direction; if it gets less sharp, you adjust in the opposite direction.
4. Repeat the above till both near and far are in acceptable focus.

Keep in mind, that when you apply tilts and swings (front or back) you are repositioning the plane of sharp focus in the scene. If you have chosen three objects, like in the first example, they all might not line up in one plane, so you'll have to compromise. Depth-of-field should be enough to get everything in sharp focus most of the time. With only two objects, you can always find a tilt that works.

Mistakes to avoid: Don't place your plane of sharp focus at the extremes of where you want the boundaries of your depth of field to be. For example, a common mistake is to tilt to get both the top of a near boulder and the top of a distant mountain in focus. However, when you stop down, the whole top half of the depth-of-field ends up being above the plane of sharp focus, i.e., where there's nothing and is wasted, and often, the base of the distant mountain or the ground below the near boulder will not be included in the depth-of-field and be out of focus.

Instead, focus on the middle of the boulder and halfway up the distant mountain so that when you stop down, you get both the area below the plane of sharp focus (the ground) and that above it (the mountaintop) in your area of acceptable sharpness.

For deciding how to choose the f-stop for a particular scene, I really recommend using the focus spread method described in the article, "How to select the f-stop" on the LF-forum homepage, here: https://www.largeformatphotography.info/fstop.html

Hope this helps,

Doremus

[Alan Klein]

Doremus: My Chamonix 45H-1 has asymmetrical axis about 1/4 to 1/3 up on the read standard. So I can do asymmetrical focus adjustments using the back standard.

1. How would you adjust your instructions for this camera?
2. Why couldn't;t I use asymmetrical with the front standard?
https://www.chamonixviewcamera.com/cameras/45h1

[Doremus Scudder]

Doremus: My Chamonix 45H-1 has asymmetrical axis about 1/4 to 1/3 up on the read standard. So I can do asymmetrical focus adjustments using the back standard.

1. How would you adjust your instructions for this camera?
2. Why couldn't;t I use asymmetrical with the front standard?
https://www.chamonixviewcamera.com/cameras/45h1

Alan,

The discussion here was about front tilts, where asymmetrical movements aren't usually available. I don't know of a camera with asymmetrical front movements. I can't really see how they would be accomplished, since you wouldn't have any reference lines for the axes and the axes would move about with any shift or rise. I imagine your camera simply has either axis or base tilts on the front standard (maybe both?).

Asymmetrical back movements are essentially axis tilts/swings with the axis simply being off-center a bit. So, exactly the same techniques we use for axis tilts/swings works for asymmetrical movements. Simply focus one of your chosen reference points on the axis (the off-center reference lines on the ground glass shows these) and then tilt or swing till the other desired reference point is in focus.

The problem with using back tilt in many cases is that it moves the back out of plumb, a real no-no for most architectural work, where you want parallel verticals not to converge and often not desirable in landscape work for the same reason (converging trees, etc. plus the near-far rendering).

So, we should learn to deal with front tilt so we can better handle such situations.

Best,

Doremus

[Alan Klein]

Alan,

The discussion here was about front tilts, where asymmetrical movements aren't usually available. I don't know of a camera with asymmetrical front movements. I can't really see how they would be accomplished, since you wouldn't have any reference lines for the axes and the axes would move about with any shift or rise. I imagine your camera simply has either axis or base tilts on the front standard (maybe both?).

Asymmetrical back movements are essentially axis tilts/swings with the axis simply being off-center a bit. So, exactly the same techniques we use for axis tilts/swings works for asymmetrical movements. Simply focus one of your chosen reference points on the axis (the off-center reference lines on the ground glass shows these) and then tilt or swing till the other desired reference point is in focus.

The problem with using back tilt in many cases is that it moves the back out of plumb, a real no-no for most architectural work, where you want parallel verticals not to converge and often not desirable in landscape work for the same reason (converging trees, etc. plus the near-far rendering).

So, we should learn to deal with front tilt so we can better handle such situations.

Best,

Doremus

I'm trying to understand why in theory, front asymmetrical tilts will or won't work. Here's the link to my camera. You can see both the front and rear standards' axises are about a third up. So couldn't you focus the initial far setting on the axis for either. Then tilt the front or rear to get the near point in focus? Why is the camera limited to tilting the rear only for asymmetrical? (Of course, you can use the front to tilt in typical fashion)
https://www.chamonixviewcamera.com/cameras/45h1