Placement

Placement decides where the photo lies on the sheet and how much of it is used. Nothing here changes the photo's pixels, only where they fall. But where they fall changes what gets traced, and a crop changes what the machine counts.

What it does

Under the Placement heading are tiles, each with a small picture of what it does. Four are covered here; Skew and Unskew have a chapter of their own.

• Fit (“Whole photo visible”) centers the photo on the sheet, as large as it can be with all of it inside. A new photo starts this way.
• Fill (“Covers the sheet”) centers it so that it covers the whole sheet, running off two opposite edges unless it has the sheet's own proportions.
• Move photo (“Drag · resize corners”): drag to move it; drag a corner to resize it, with its proportions kept and the opposite corner held still. It can't be made smaller than 10 of the app's units, about a tenth of an inch (the app counts 96 units to the inch). A skewed photo can only be moved as a whole.
• Crop (“8 handles · drag to set”): the whole photo appears, uncropped, with the crop box on it. Drag any of the eight handles to move an edge or a corner, or drag inside the box to slide it. The box can't leave the photo or get smaller than about a tenth of an inch. Whatever you keep stays exactly where it was on the canvas.

Fit and Fill both clear any skew. Crop is off while the photo is skewed; its tooltip says “Unskew the photo to crop it”.

Move photo and Crop borrow the canvas until you finish. A pill at the top of the canvas says what to do. For a crop, Done or Enter applies it, Cancel or Escape discards it, and Whole photo removes any crop at all; the same three buttons appear under the tiles while you crop. Choosing another tool cancels a crop in progress. A move needs no applying: it happens as you drag, and Done, Enter or Escape simply end it. Pressing the tile a second time is the same as Done.

Starting either one zooms the view out, if it has to, so the whole photo shows clear of the pill, and on a phone it closes the settings sheet so the canvas can be seen. None of this is in Undo, because the photo never is; the place is kept with the photo in this browser instead.

Why it works this way

Proportions are always kept because a stretched photo would stretch every shape traced from it. A circle photographed would come back an ellipse.

Where the photo lies changes the result. Below its finest setting, Detail measures size as a share of the sheet, not of the photo. Enlarge the photo and a speck covers more of the sheet, so it may now survive; shrink it and small shapes drop sooner. (At 100, the default, only specks a few pixels across go, wherever the photo lies.) Trace also keeps only what lies on the art board around the sheet: the rest of a big photo is no part of the design.

A crop changes more than the frame. The histogram, and Auto's choice of threshold, count only the pixels in use. Crop away a black border or a bright window and Auto's split can move, because the tones it is balancing have changed. Cropping is often the quickest way to a better split.

Crop comes before Skew. A crop is a rectangle in the photo's own terms. Once the photo is skewed, its rectangle is no longer a rectangle on the canvas, and a crop box would have nothing square to work in. So crop first, then skew; Find sheet sets its own crop for the same reason.

Fit on arrival because the safest start is the whole photo with nothing hidden.

The metaphor

Crop borrows the art director's cropping L's: two L-shaped pieces of card slid over a print until the frame looks right, then crop marks drawn in the margin with a grease pencil. The print itself was never cut. That holds here exactly: the photo is untouched, and Whole photo is the same as rubbing out the marks.

Move photo borrows registration, the printer's business of putting the paper in the same place every time. Fit and Fill borrow the mount-cutter's choice between showing the whole picture with a border and letting the mat cover its edges.

The metaphor breaks in one telling place. An art director's crop only changed what was printed. Here a crop also changes what the machine counts, and so what it decides. There is no paper equivalent of cropping a picture and finding that the remaining part has changed its mind about where dark ends.

A history

In art

Placing and scaling an image has always needed a system. Egyptian artists of the Middle Kingdom drew their figures over a grid, with a standing figure measuring 18 squares from the soles of the feet to the hairline. The grid kept proportions right at any size, from a sketch to a tomb wall. Renaissance painters did the same when they “squared up” a small drawing to transfer it, cell by cell, to a large cartoon.

In 1603 the Jesuit astronomer Christoph Scheiner devised the pantograph, a linkage of four rods that copies a drawing larger or smaller as you trace it, and he published it in 1631. It enlarges and reduces while keeping proportions, the same promise the corner handles make.

Cropping became an expressive act in the nineteenth century. Edgar Degas cut figures off at the frame's edge as if by accident, a way of seeing that art historians connect both to Japanese prints and to photography. The crop was no longer where the picture stopped; it was part of what the picture said.

In printing

Japanese woodblock printers placed each sheet against kentō: a right-angled notch carved at one corner of the block and a straight mark along an adjoining edge. With them, block after block of color landed on the same paper in the same place. Full-color prints of this kind appeared in the 1760s, with Suzuki Harunobu.

On the picture desk of a newspaper or magazine, a photograph was cropped with marks in its margins, and a proportion wheel, two concentric discs of numbers, told the editor what percentage to enlarge or reduce it to fill the space on the page. Crop and scale were separate, deliberate decisions, which is how they are separated here.

In technology

Fit and Fill are the two answers to a question every screen asks: what to do when a picture's shape doesn't match its frame. Web designers know them as contain and cover, two values of CSS's object-fit and background-size. Television met the same question when wide cinema films came to squarer screens: letterboxing showed the whole frame with bars, and “pan and scan” filled the screen and cut the sides. Both are here, one tile each.

Image editors made cropping undoable and then non-destructive, keeping the cut-away pixels so that a crop could be widened again later. This crop works that way: nothing is thrown away until you choose Whole photo, and then nothing is lost.

In professional software

Bringing a photo into a document is called placing it, or in CAD attaching it. Scaling it with its proportions kept, and cropping it without destroying pixels, are the same good habits in every program.

• Adobe Photoshop. ‘File › Place Embedded’ copies a photo into the document and ‘File › Place Linked’ refers to the file on disk; either way it arrives as a Smart Object inside a transform box, and Enter or Return commits it. ‘Edit › Free Transform’, ⌘T (Ctrl+T), resizes it later, keeping its proportions as you drag a corner. The Crop tool (C) keeps the cut-away pixels, so the crop can be widened again, only while ‘Delete Cropped Pixels’ is unticked.
• Adobe Illustrator. ‘File › Place’, ⇧⌘P (Shift+Ctrl+P), links the photo when ‘Link’ is ticked and embeds it when it is not. A clipping mask, ⌘7 (Ctrl+7), hides the edges without harming the photo, much like Crop here. The ‘Crop Image’ button, by contrast, cuts the photo for good, and embeds it if it was linked.
• Autodesk Fusion (formerly Fusion 360). ‘Insert › Canvas’ puts the photo on a plane or a face. To bring it to true size, right-click the canvas in the Browser, choose ‘Calibrate’, pick two points and type the real distance between them.
• Autodesk AutoCAD. ATTACH places an image at an insertion point, scale and rotation you give. SCALE with its Reference option then sets true size: pick the two ends of something you know, and type its real length. IMAGECLIP hides part of the image behind a boundary without changing the file.

What carries over. Keep proportions, and crop in a way you can take back. Studio Notan does both for you; elsewhere they are settings to check. One pitfall: a linked photo is only a reference, so if you move or rename the file, Photoshop and Illustrator report it missing. Embed it when the document has to travel.

Try this

• Press Fill, then Trace, and notice that the traced shapes stop at the art board around the sheet, however far the photo runs on.
• Crop out a dark border or a bright sky and watch where Auto puts the threshold line before and after.
• Set Detail to about 50, then enlarge the photo with a corner handle and watch the count of small shapes dropped, in the note above Trace, go down.

Going further

See Skew and Unskew and Adjusting the photo on the canvas. Harold Evans, Pictures on a Page. Josef Müller-Brockmann, Grid Systems in Graphic Design.