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ibabcock
15-Feb-2020, 14:16
Hello, I have a problem with my architectural shots - I level the camera, use the glass grid along with front rise to get parallel sides, and use the glass grid to check for level against some roofline element. If I have a level camera but not a level roofline, windowline etc, then either the building is not level or I am not square against it's face and need to adjust swing. I usually check for swing-squareness by looking at focus on both sides wide open, and make the rotational adjustments on the tripod head, usually necessitating picking up the tripod and moving left/right to recenter. This method only gets me 50/50 perfect squareness. I have rotated the attached scan to align the left vertical correctly, you can see the error in the other dimensions. I am wondering what are the checks to do in the correct order to keep from making one adjustment throw off something you already checked.
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LabRat
15-Feb-2020, 15:32
All of the elements you listed are correct, and you are looking at the right parameters, but these can be tricky...

I'm thinking this is from a combination of two parameters... First, it is hard to find the point directly in front of this building, and second, the camera rotation on its head throws off the side alignment... You then tend to adjust for one line on one edge of the frame, but other lines start wandering...

A good exercise to demonstrate the phenomenon is to hang a painting or tack a poster to a wall and try to get it square... You will see the other lines wandering as you correct for one, and with some very slight head rotation, things change again... You find camera placement/alignment is key...

Try to find some vertical lines AND horizontal lines to square, and use shift and rise to do final framing... It may take a while, but the critical balance point is there... ;-)

Steve K

Christopher Barrett
15-Feb-2020, 16:11
The left and right verticals are not parallel, indicating that you have a little tilt to the camera. I always start by setting tilt, so that the camera is plumb and then adjust pan to bring the horizontals into parallel. Also, I never trust levels on tripod heads or cameras, but rather use a small torpedo level on the lens and groundglass.

Hope that helps,
CB

Eric Woodbury
15-Feb-2020, 16:30
Never trust a horizontal. Go vertical.

Greg
15-Feb-2020, 16:58
Years ago photographed 46 plus buildings in our town for a historical brochure and walking tour. For a little less than half of the structures I discovered that the building's verticals were not vertical but slightly out of kilter. Rooflines were better but central sagging of the ridge beam/board common. Circa late 1800s factory buildings were mostly brick and one stone. Walls were pretty much vertically true, but with most of roofs that wooden rafters and were anything but level/square. At the time was using a plain GG on my 4x5 and trusted my levels... big mistake. Over the years I have found that camera levels are not very accurate, and the bubbles on the worst offenders took a half minute to come to complete rest. An architectural photographer friend of mine used a set of precision levels. I had started the project with a modern wooden 4x5 view camera because of its portability, but quickly changed to using a Sinar Norma. I doubt that any flat bed camera (Linhof being probably the exception) is a good candidate for architectural subjects... in my opinion.

C. D. Keth
15-Feb-2020, 17:40
You just need the back to be parallel to the building face. Lots of ways to figure that out. You can do it by eye. You can use a compass, sidewalk or parking lot lines. I would use a better level than the little bubbles on the camera. Those are too prone to error.

If I did this shot, I would do the following:

1. Walk to the spot that produces the perspective I want between elements in the desired frame. Put on the lens that will see the amount of that view that you want. Walk in/out as needed.

2. Put your lens where you eyeballed the right perspective from.

3. Level your tripod crown and then your camera bed/rail in every way you can, looking flat at the building. Don’t worry if this doesn’t make the frame you want. The building should look square.

4. Use rise, fall, and shifts to make the frame you want. The building should still look square.

5. Focus, noting that moving the rear standard out of parallel with the building will ruin the formal frame you have painstakingly set.


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ic-racer
15-Feb-2020, 20:31
...I level the camera...I usually check for swing-squareness by looking at focus...


Only one condition need to be satisfied:

1) Film plane parallel to the building


Any issue with the camera base being off 'level' can be easily corrected by rotation during printing, so this is not a critical component and it can be ignored.

Using any means of 'focus' to determine if the film plane is parallel to the building is conditioned upon the front and rear standards being parallel (laser alignment at least) and would questionable in the field.

John Layton
16-Feb-2020, 05:35
Don't start by looking at the building. Instead, first completely level the tripod head/camera base. Then bring the standards into parallel with each other, and ascertain that the lens is on axis with the film. Now, from your desired vantage point - focus on the building. If the perspective seems skewed, rotate the whole camera to straighten things out (this gets your film plane parallel with your object plane). Then, either work from this position and fine-tune your composition by utilizing lateral (left or right shift, rise, or fall) movements (do not rotate the camera!), or move your position to get closer to your actual preferred vantage point, and fine tune again (if necessary) using lateral movements. IMHO, it is much better to get things straight in-camera if you possibly can.

Edit: For the above to actually work, you must first know that your camera is well enough designed and constructed (and cared for) that it can be brought into known good alignment, in all ways. Often overlooked is that the film plane, after aligned to be "axially" correct and in-parallel with the lens plane/position, can still be very slightly rotated itself...typically the result of poor execution in manufacture or some impact (damage) while in use. Also, if the camera features a rotating back...you need to know that any detents and/or witness marks are correctly aligned.

Also...if you are wet (darkroom) printing the image, be sure to very carefully check your negative before loading it into the enlarger, to ascertain that the image is properly aligned. If the print then looks "off," you will need to consider your enlarger's alignment, and/or that the individual blades of your printing easel are actually square to the other blades.

Doremus Scudder
16-Feb-2020, 12:15
It's not that hard. The trick is to look for pairs of parallel lines at the sides of the image first. Note that you need pairs of lines, one at each extreme of the image. Just using one line to square to will never get you parallel. All you need is a good gridded ground glass. You don't need to worry about camera precision, leveling your tripod or anything else; you'll be adjusting all that. Here's my method:

1. Get the vertical lines parallel: Level your camera back roughly and point your camera at the horizontal center of your desired image (don't worry about the center top-to-bottom, just right/left). Now, use the gridded ground glass and your tripod head front-to-back and side-to-side tilts to position the camera to get parallel lines on either side of the image exactly aligned with the grid marks. Once you've done that, lock down your tripod head and don't touch it anymore. Don't worry about horizontal lines yet. Don't worry about the exact composition yet either.

2. Align the horizontals: Now, find some parallel lines at the top and bottom of the image and swing your camera back to get those exactly aligned with the horizontal grid marks. Note: don't use the pan on the tripod head! Unless you have set up your tripod exactly level, using the pan will move the back away from the parallel vertical position. Once you have horizontals aligned, lock down the camera back's swings and don't touch them anymore. You can't rely on just one line, and especially not a line in the center of the image. If you have to use rise/fall to get some horizontal lines positioned at the top and bottom of the image, do so. You aren't composing yet.

3. Compose and focus: Now, you've got the camera back parallel to the façade, but likely not got the composition you want, so use rise/fall and shift to frame your shot the way you want it. If you've used swing to bring the back parallel horizontally, you'll have to swing the lens stage for focus to compensate. Now, check focus at both sides and at the top and the bottom and adjust the lens stage if needed to get what you want in focus (see, we're not relying on camera precision to preserve focus, but actually focusing).

Voilà.

The only problem that can crop up with this method is that you run out of rise/fall and/or shift before you get the composition you want. If so, you'll have to start over using the "point-and-swing/tilt" method. For example, let's say you don't have enough rise. Zero the rise movement and then point your camera up to get the approximate framing. The verticals will converge, of course. Now, tilt the back to get the verticals parallel with the grid marks and tilt the lens to get everything in focus. Use rise/fall to fine tune. The analogous procedure works for running out of shift. Point the camera, swing back to parallel, swing lens to focus.

One more tip: If you've got foreground in your shot, a tiny bit of front tilt can help with depth-of-field issues quite a bit. Say we have a mansion and a front yard. Pick a focus point low and close (at the top of the ground glass) and one high and close (front of the roof line). Tilt to get both these sharp. Now check the focus spread between close and "far," which will now be at the bottom of the building where it converges with the ground. Often, this will reduce the focus spread a bit compared to having lens and back parallel.

Edit: Yet another tip (after reading the above post). Even if you don't get everything exactly parallel, you can compensate in the darkroom by propping up the easel accordingly. I do this all the time, either because I've not adjusted the camera as carefully as I could have or because I didn't have the movements to get everything perfectly parallel when making the negative. It helps to leave a little room to crop if you plan on doing this. I've found that I can easily prop up the easel up to 2 inches for both 11x14 and 16x20 prints without worrying about focus issues. More than that and you need to be able to tilt your enlarger lens (my Beseler has a tilting lens stage).

Hope this helps,

Doremus

ibabcock
16-Feb-2020, 13:46
Thank you all, you are appreciated greatly. I have a Berlebach Report 332 wood tripod which has a proprietary ball head-- if I want to change heads I have to first spend 120.00 for a Berlebach flat plate! I'm a little mad at this because so many of the lighter weight ball-heads have a pan base. I believe the fix is to mount a pan base (Feisol) atop the ball head, so that I can follow this workflow:1) level the camera 2) adjust verticals using rise, 3) adjust horizontals with pan (rear swing if necessary) 4) recenter with front shift if necessary. Doremus - I see your note about not using pan for leveling horizontals, but the whole premise is that I am not square face-to-face with the building, and so I want the lens and the film back together as a unit both to be square so shouldn't I use pan to level horizontals before resorting to rear swing? Fix verticals first, then horizontals, then fine tune composition with front movements only.

Doremus Scudder
16-Feb-2020, 18:29
... Doremus - I see your note about not using pan for leveling horizontals, but the whole premise is that I am not square face-to-face with the building, and so I want the lens and the film back together as a unit both to be square so shouldn't I use pan to level horizontals before resorting to rear swing? Fix verticals first, then horizontals, then fine tune composition with front movements only.

Set up your camera as close to final position as possible. Then, use the pan and tilt to get the verticals correct. It doesn't matter if your tripod is level as long as you don't change anything after locking down the tripod head once you have the verticals correct. Then use rear swing to fine-tune the horizontals.

The problem with using pan to get the horizontals correct is that if the tripod is just a tiny bit out of level, panning will skew the verticals that you just worked so carefully on, so you have to go back and re-do them, then you have to check the horizontals again... Using swing at this stage is faster by far. It should be a real time saver with a ball head too. Yes, if you swing the back, you'll have to swing the lens stage too to get focus, but you should be checking that anyway.

Just ask a cinematographer how carefully they have to level their tripods and heads in order to do a decent pan shot. Tripods for still photography are not nearly as sophisticated as good cine tripods/heads either.

With my method, you don't even have to worry about setting the tripod up level (another time saver and a blessing on uneven terrain). Eyeballing is just fine.

Best,

Doremus

Robert Opheim
16-Feb-2020, 18:37
The roof will not be horizontal unless the camera is perpendicular to the wall of the building . I have had this issue for years. Also as mentioned above buildings are not actually built perfectly - things are often out of true.

Doremus Scudder
16-Feb-2020, 18:46
The roof will not be horizontal unless the camera is perpendicular to the wall of the building . I have had this issue for years. Also as mentioned above buildings are not actually built perfectly - things are often out of true.


Maybe you meant parallel? Perpendicular means "at an angle of 90° to a given line, plane, or surface."

Two horizontal (parallel) lines in the scene will only be rendered parallel on the film if the camera back (i.e., film) is oriented so that an imaginary horizontal line in it is parallel to both those lines (e.g., the façade of a building).

Note that we can have converging verticals and nice parallel horizontal lines, so the film only needs to be "parallel" in one axis to get the horizontals right. Same for the verticals; we can have nice parallel verticals and converging horizontals (think an oblique view of a building façade).

Note also that an axis line on the film has to be parallel to two parallel lines in the scene. It's real easy to get one line nice and horizontal, but have all the others converging... In fact, any scene with converging verticals or horizontals has one line it it (imaginary or not) that is parallel to the axis of the film.

Getting both horizontals and verticals parallel requires the film plane to be parallel to the façade (assuming the façade is true...). Or, put another way, it requires that we have imaginary horizontal and vertical lines on our film plane that are parallel to two parallel lines horizontally and two parallel lines vertically, respectively, in the scene. It's a two-part procedure: get the verticals right, then get the horizontals right.


Your camera back can be perpendicular to ground while doing this... :)

Best,

Doremus

C. D. Keth
16-Feb-2020, 19:07
He said it right. A horizontal roofline will only look perfectly horizontal when the lens axis is on a plane perpendicular to it. That satisfies the same conditions as your method of explaining the same thing.


The verticals will only be parallel when the film plane is also vertical.


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Ari
17-Feb-2020, 08:45
I often work in carpentry so levels are plentiful in my house, but the top-shelf ones are quite expensive, not to mention unwieldy and not practical for photo use.
I've found that Ebisu card levels give a good combination of accuracy and portability.
Digital inclinometers are hit-and-miss for accuracy, even the more expensive ones are a bit of a gamble.
Camera/tripod/ball head levels are ok to get you in the ballpark, but not very useful beyond that.

200781

Doremus Scudder
17-Feb-2020, 11:26
He said it right. A horizontal roof line will only look perfectly horizontal when the lens axis is on a plane perpendicular to it. That satisfies the same conditions as your method of explaining the same thing.

The verticals will only be parallel when the film plane is also vertical.

Of course! The camera axis (really, a perpendicular line from the film plane) does need to be perpendicular to parallel lines in the scene in order for them to be rendered parallel on the film. I think so regularly in terms of film plane and "lens plane" (a là Scheimpflug, i.e. a plane perpendicular to the lens axis running through the optical center of the lens) that when someone says "the camera has to be perpendicular" I immediately think of the plane, not the axis. My mistake for misunderstanding and apologies to Robert!

For getting parallels right, imagining the film plane, or the axis lines on the film plane, is easiest for me. It is really the horizontal and vertical axes of the film plane that have to be parallel to horizontal and vertical parallel lines in the scene, respectively, in order for them to be rendered parallel on the film. When both axes are parallel to the vertical and horizontal lines in the scene, the film plane is parallel to the plane in the scene. (Thanks Euclid...). Adding the extra perpendicular lines to the mix just makes it more complicated for me.

The lens axis, on the other hand, can be tilted or swung away from perpendicular to the scene for whatever reason without affecting the parallel rendering on the film. The lens position determines the focus plane only; the film plane position relative to the scene determines the perspective and whether or not parallel lines in the scene are rendered parallel on the film. I use front tilt when photographing architecture often and the parallels are just fine :)

Note further that you can get a roof line exactly horizontal even if the horizontal axis on the film plane is not parallel to the horizontal lines in the scene. Even with convergence, one line in the scene will always be parallel to the horizontal axis of the film plane. If we use the side-to-side tilt function of the tripod head to align a roof line with a horizontal grid line on the ground glass, but the film plane is not parallel horizontally to the scene, all the other horizontal lines in the scene will converge. This is a problem for beginners, who many times just align one line in the scene. The result is often that all the other horizontal lines in the scene converge slightly, which can be disconcerting (this applies equally for verticals, just rotated 90°).

By making sure two parallel lines in the scene are correctly aligned with the grid on the ground glass, either vertically or horizontally or both, we automatically get the film axes in the right position. When we align both vertical and horizontal parallels this way, the film plane is then parallel to the plane in the scene.

It sure is a lot harder to describe all this precisely that to do it!

@Ari: I have levels on all my cameras and use them when setting up. However, I've found that no matter how good the levels are, orienting the scene to the grid on the ground glass is almost always needed. Sometimes it's just a little tweak, sometimes more. Plus, as mentioned above, buildings are not always plumb or level. Visually compromising the elements (lines) in the scene is often needed and using the ground glass helps get things as pleasing as possible.

Best,

Doremus

Renato Tonelli
17-Feb-2020, 11:56
The Ebisu Card Levels are quite good.
Th carpentry levels I have (not cheap ones, not super expensive) have not been as reliable; I only trust one of them at this point; the rest are for making straight lines.


I often work in carpentry so levels are plentiful in my house, but the top-shelf ones are quite expensive, not to mention unwieldy and not practical for photo use.
I've found that Ebisu card levels give a good combination of accuracy and portability.
Digital inclinometers are hit-and-miss for accuracy, even the more expensive ones are a bit of a gamble.
Camera/tripod/ball head levels are ok to get you in the ballpark, but not very useful beyond that.

200781

Greg
17-Feb-2020, 12:30
Top digital level (no brand name) stay away from. Bottom pocket level... went to the hardware store many years ago and they had a bunch FS. Most were faulty. Bought 2 good ones. Brand is Stevens. One resides in a stream under a bridge in Granville, Ma. If you come across any FS, test them and if they are accurate definitely buy them. Mine normally has a piece of fluorescent webbing tied to its pocket clip, so I hopefully won't accidentally leave it in the field. Much prefer it to camera levels. FYI, when I bought my Sinar X, two of its levels were off "out of the box".

Ari
17-Feb-2020, 13:14
@Ari: I have levels on all my cameras and use them when setting up. However, I've found that no matter how good the levels are, orienting the scene to the grid on the ground glass is almost always needed. Sometimes it's just a little tweak, sometimes more. Plus, as mentioned above, buildings are not always plumb or level. Visually compromising the elements (lines) in the scene is often needed and using the ground glass helps get things as pleasing as possible.

Best,

Doremus

Hey Doremus,
I remember a post of yours (in reply to my questions) from a long time ago where you said exactly the same thing, and I've remembered it ever since.
That is, use the levels to get you in range, but in the end always trust what you see in your viewfinder/GG to determine correct leveling.
Great advice that I tell everyone to this day.

C. D. Keth
17-Feb-2020, 13:56
It sure is a lot harder to describe all this precisely that to do it!

Isn’t that the truth? These are things that so many of us just know but are surprisingly hard to define and explain. I TA’d an introductory cinematography class in college and almost everything was like that. I had to help define things that are more often just felt and known. It was often a surprisingly difficult task.


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Drew Wiley
17-Feb-2020, 14:09
Never assume a building (even new) is level, square, or plumb; many are not. Never assume film is resting square and truly flat in your holder; it probably isn't. Never assume little toy levels are truly level; they almost never are - use a pendulum-style angle finder instead. And even with grid markings, the ground glass might not be evenly centered in the back. A full-featured monorail camera makes life easier; I did most of my architectural shooting with a Sinar. Shift can be dicey with most flatbed cameras. But things tend to get intuitive and easy with practice. If you can back off from the subject and use a longer lens, do it; there will be less risk of distortion than using a wide-angle lens.

Bruce Watson
17-Feb-2020, 14:33
Getting the image "distortion free" is largely an exercise in using camera movements. To get the level of control you seem to want can be daunting. And it can take quite a while; these aren't 10 minute setups, especially when you are in the learning phase. I remember working some setups for an hour or more, and often just tore it all down and either started over from scratch or packed it up and walked away because I couldn't get it right.

What's somewhat humorous to me about my history with this sort of thing is that coming out the other side of the learning curves I found that getting it "perfect" didn't get me the look I wanted either. Completely distortion free doesn't look "natural" to me. So I found that my last adjustment was often a little back tilt to bring back in a touch of keystoning. Completely counter-intuitive I know, but I didn't discover it; many architectural photographers have come to similar conclusions apparently.

It's odd how perfection isn't... perfect. But there it is.

Drew Wiley
17-Feb-2020, 15:00
A lot depends on whether you're working commercially representing an architect or builder, or doing personal work. I violate all kinds of rules with the latter, but not with the former unless they specifically encourage that. I don't think the builders of SF's tallest new highrise would appreciate it being depicted as it actually is - 18 inches out of plumb! On the other hand, that's exactly the kind of shot a class-action lawyer would want.