First attempts

The important bit to grasp is quite simple, it's the first diagram in the article Joanna linked to, the Scheimpflug Principle. You need to mentally envisage the film plane, lens plane and plane of focus converging at the same point, With no movements that's at Infinity.

It's best to practice (visually) with extremes, applying movements isn't difficult when you've understood the basic principle.

Joanna's second example is the odd tough one where you have to balance slight movements and also rely on lens DOF and using smaller apertures like f32 or even f45.

Movements aren't difficult and soon become second nature, I'll often use front tilt and rise/fall when working hand held. It's just takes practice.

Ian.
 
Ian Grant said:
The important bit to grasp is quite simple, it's the first diagram in the article Joanna linked to, the Scheimpflug Principle. You need to mentally envisage the film plane, lens plane and plane of focus converging at the same point, With no movements that's at Infinity.
Click to expand...
As long as you can find something to play them on, the .mov files on this page can be quite useful in demonstrating how things change as tilt and focus change.

Unfortunately, I haven't yet found a (free) converter and what I have got only plays them at a small size low resolution

Correction. I've managed to get them into M4V format, which should be playable.

If Ian or Martin can let me have an upload location, I will transfer them.
 
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Ian Grant said:
With LF where possible it's best to use lenses at f22 for overall sharpness, that's the sweet spot LF lenses are designed for and in general where edge sharpness matches central sharpness, This is particularly noticeable with older lens designs like Tessars and type, Xenars Skopars, most of the Kodak Ektars, etc.

f32, f45 and smaller begin to suffer diffraction limitation which impacts sharpness, but in reality sometimes you need the extra DOF of these apertures so it's a trade off, It's also about knowing your lenses because that sharpness drop off might be measurable on an optical bench but unnoticeable in final prints etc. I will use f32 if needed, and at a push f45, someone noted the Apertures John Sexton used in one of his books and while most images were shot at f22, some were f32 and the odd one or two f45, and John Sextons image quality is superb.

It's not that DOF is no longer a priority rather that use of front/rear tilt can shift the plane of focus allowing foreground through to background to be brought into focus at the full aperture of the lens, that's the extreme we'd struggle with without movements, then DOF brings into sharpness the parts of the image that deviate from the new plane of focus.

Ian
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Got it. SO when I read that the DOF handles the "midpoint" between the two extremes that are in focus by tilts, then DOF takes over to help in the middle. RIght?

So my first lens on 4x5 is a Schneider 150mm APO Synnar MC. Would anyone know itf f/22 is the "sweet" spot for it?
 
f22 is the sweet pot for most 5x4 lenses including all varieties of Symmar.

The DOF helps with the points that deviate from the plane of focus, so in Joanna's second example that would be the first building front right. That's the tricky area as it's closest to the camera/lens where DOF is more critical and you also need the steps sharp.

Most people learn to use movements very quickly, it become intuitive. I demonstrated for someone two years ago and had instinctively used the approx 45º tilt needed, and on focussing it was spot on. Remember that often with tilt or swing we use rise/fall or shift to keep in the centre of the image circle. This is crucuially important with lenses with smaller image circles, like say a 90mm Angulon, 135mm Xenar/Tessar etc, and far less important with a 150mm Symmar or 90mm Super Angulon/Grandagon.

Ian
 
If you want front- to- back sharpness then tilt can achieve this, as is well known. But it can't be easily used if you have a tall object in the foreground. Then you have to forget tilt and stop the lens down to get more depth of field, as is also well known. The question is, how much do you stop down? For many years I have used a simple strategy to determine this. It's not my own idea, but I can't remember where I got it from. To make it work you need a millimetre scale on the camera bed, and a mark on the moving front to allow you to read how much extension is being applied when changing focus.
First focus on the furthest object you want to be sharp in your picture. Note where the mark is. Then focus on the nearest object you want sharp. Note where the mark has moved to, showing how many millimetres of extension has been applied. Then refer to the following table to find how much you need to stop the lens down.

0.7mm extension. F16
1.3mm ext. f2
2.7mm ext. f32
5.4mm ext. f45
11mm ext. f64

Then you stop the lens down to suit the amount of extension, and re-focus the camera at the mid-point between the closest and furthest extension, using the scale.
It all sounds a bit long-winded, but in practice is very quick and easy to do.

Alan
 
Alan Clark said:
If you want front- to- back sharpness then tilt can achieve this, as is well known. But it can't be easily used if you have a tall object in the foreground. Then you have to forget tilt and stop the lens down to get more depth of field, as is also well known. The question is, how much do you stop down? For many years I have used a simple strategy to determine this. It's not my own idea, but I can't remember where I got it from. To make it work you need a millimetre scale on the camera bed, and a mark on the moving front to allow you to read how much extension is being applied when changing focus.
First focus on the furthest object you want to be sharp in your picture. Note where the mark is. Then focus on the nearest object you want sharp. Note where the mark has moved to, showing how many millimetres of extension has been applied. Then refer to the following table to find how much you need to stop the lens down.

0.7mm extension. F16
1.3mm ext. f2
2.7mm ext. f32
5.4mm ext. f45
11mm ext. f64

Then you stop the lens down to suit the amount of extension, and re-focus the camera at the mid-point between the closest and furthest extension, using the scale.
It all sounds a bit long-winded, but in practice is very quick and easy to do.

Alan
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Would it be helpful to do this even on ordinary shots. You do this first to determine the best f stop. Then you use tilts and then set the f stop to what was determine in the first place.
 
Sinar provide scales to adjust both the optimum focus point for maximum DoF and also for tilt.

Somewhere towards the end, I think. (The Wolf [Alpina in USA?] has a small sliding plastic scale.)

I suspect that most of use will a favourite aperture for every shot and deviate only when circumstances demand. It might be very dark indeed; we might really want some out-of-focus blur for creative reasons; or we might need all the DoF we can muster, at any cost.
 
Alan, the method I described is for when you are not using tilt.

Alan
 
Alan, it might but I'm not sure how you would do it, or even if it could be done!

Alan
 
ALan, I was think along the lines that first you don't do tilts. Just use your "best aperture for DOF" setting procedure. Then note the f stop you calculated. Second, go back to initial settings. Then do the normal tilt procedure. When done set the f stop to the one originally calculated.

Does that make sense?
 
Hello Alan. Not really - to answer your question. If you can get front-to - back sharpness simply by stopping down i.e. not using tilts, then you don't need to use tilts anyway. And if you are using correctly applied tilts to tilt the plane of sharp focus to the horizontal, for a landscape, for e.g. then you only need to stop down enough to increase D.O.F. to cover the height of vertical objects, such as trees in the middle-distance. How much you need to stop down depends on their height and distance from the camera...This is where we get into all kinds of variables. For this reason it is far better to learn the principle behind the thing, then you can apply it in any situation. Just learning something by rote without understanding why you are doing it will leave you scratching your head at times. But I am sure you know this.

Alan


Alan
 
Thanks, I just got the 4x5 and still practicing without film waiting for the backpack. My camera also comes with asymmetric tilts in front and back (Chamonix 45H-1). Since I don't really shoot architecture but rather landscapes, I'm focusing on tilts of course to maximize DOF as my first lesson with movements. I've tried the asymmetric focusing method and the traditional method of back and forth jumping from the distance focus point to the nearest. I understand the need for DOF in the middle. But this is all new to me. Lots to absorb. (PS My method with medium format was to calculate the DOF I needed or use the DOF scale on the lens. Then stop down one stop for good measure. Don;t know if that makes sense with large format and tilts. What do you think?

Also, with large format, I don't know when it's better to use the back standard rather than the front. Maybe you can help answer that?
 
One question I can answer. You can use swings and tilts on either the back or front standard to move the plane of focus. The difference is that moving the rear standard alters the shape of the image. Easy to understand if you remember that moving the film plane away from the lens increases the size of the image.
In architecture it's almost a cast-iron rule that the back is kept vertical but there's no reason why is shouldn't be swung, perhaps to exaggerate the size of a nearby pillar or tree, or to straighten the perspective of a terrace if you can't put the tripod in exactly the right place.
Rear backward tilt is used by some landscape photographers to exaggerate a photogenic rock or trickle of water in the foreground. A side effect of this is that these images can have the appearance of using a much wider lens.
 
If you use the back standard to exaggerate a nearby object, which standard(s) do you use to focus?
 
It should also be pointed out that if you tilt the front(lens) standard, then your framing/composition will change, hence the preference to use the back standard for brining the subject into focus.

Tilting the back standard is well used and if you look at landscapes shot on sheet film, there is a tendency for 'looming' objects in the foreground.

Whether you use the front or rear standard for focussing depends on how long your arms are, especially with long lenses. ;)

Mike
 
For your information, this is the kind of shot that required swing rather than tilt to get everything in focus

BourgesCathedral.jpg

The plane of focus was through the lamp at the left of the image to the right tower on the cathedral
 
Some cameras have moveable front and rear standards. Many field cameras have only front focus. In general photography, it does not matter which one you use, but for close-up work, it's best to use rear focusing, because moving the front standard changes the lens-to-subject distance which then needs re-focussing... Anyone who's done this will remember being trapped in an endless loop.
Mike's comment about long arms rings a bell.
 
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