Julieanne Kost's Blog

A percentage of my Essential Training videos on Lynda.com are available for free. Click here to learn the Difference between the Resize and Resample options in Image Size.

Selecting Image > Image Size and changing the size of the image will scale the Effect/Style (as long as the Scale Styles option is checked), keeping the Effect/Style in proportion to the layers to which they are applied. However, when using Free Transform to scale an individual layer that has a Layer Effect/Style applied to it,  it will not scale the Effect/Style. To scale the layer style, note what percentage the layer was scaled using Free Transform and then enter that value in the Layer > Layer Style > Scale Effect dialog box. Or, before using Free transform, convert the layer to a Smart Object and resize.

Don’t forget that in Lightroom you aren’t committing to a specific output size when cropping. Instead, you specify the actual number of pixels that are going to be created when you use the Export feature or one of the Output modules (Slideshow, Print or Web) to create a raster (pixel) based image.

While using the Crop tool, you can select from the list of default/preset aspect ratios, or choose Enter Custom from the list and create your own. Lightroom will save the last 5 custom aspect ratios entered.

In addition:

• “X” flips the crop (horizontal to vertical).

• “A” will lock or unlock the aspect ratio.

In dialog boxes referencing width and height (New File, Image Size, Canvas Size, etc.) if you change units of measurement for one of the dimensions Photoshop will automatically match the units for the other dimensions (i.e. if you select pixels as the units for width, Photoshop automatically changes the height to pixels).  If you need to enter in two different units of measurement, holding down the shift key will override this feature to allow different units for each value.

When using the Image Size dialog box in Photoshop, there are several different resampling options including those used most by photographers — Bicubic Sharper, Bicubic, and Bicubic Smoother. These different options have an impact on the perceived sharpness & smoothness of the resulting image. When changing image size relatively small amounts (say scaling up or down less than 10%), it may not be necessary to change the default setting of (Bicubic), but when making large changesbe certain to choose the appropriate option for the maximum quality. For example, if you have a high resolution scan and need a low resolution version to place on the web, make sure to use the Bicubic Sharper option. If you have a low resolution capture from your phone and want to resize it to print as a poster, use the  Bicubic Smoother option.

If you are going to need to resize a photograph significantly larger or smaller than it was originally captured, it is better (in theory) to use the Crop tool and the Workflow options in Adobe Camera Raw to interpolate up (resample) the photo as oppose to opening the file in Photoshop and then using the Image Size command to interpolate. This is because ACR does its resampling adaptively, based on the difference in size between the original image size (e.g., 5616) and the target image size (e.g., 2096). So, although there will be slight differences between the two images,  (one from ACR, the other from PS) in many cases, it would be very hard to see the difference to the naked eye. The main difference, then, in practice, is the convenience and the workflow. (Thank you Eric Chan for this information!)

When a layer is larger than the canvas size (maybe you dropped a larger file into a smaller composite), Photoshop keeps track of the information beyond the visible canvas. This provides added flexibility if the image needs to be repositioned. However, when working with really large files (for example when I create my digital illustrations, each layer is 24 x 24 inches at 300 ppi and the files often reach greater than 1.5GB very quickly). In order to keep my file size down, as soon as I am certain that I will not change my mind and reposition the image, I choose Select > All and then Image > Crop. This crops any extraneous information beyond the visible canvas size (which is typically significant for my images as I photograph in a 2:3 aspect ratio but my final images are 1:1). Of course you do loose some flexibility so make sure that you are happy with each layer’s position before cropping!

To make a document the same size as another open document, while in the Image Size or Canvas Size dialog box, select the other open document from the bottom of the Window menu (PS will automatically fill in the values).

To make a document the same size as another open document, while in the Image Size and Canvas Size dialog boxes, select the other open document from the bottom of the Window menu and Photoshop will automatically fill in the values.

To use the dimensions of one image to crop another, select the document with the desired crop (width, height, and resolution) and click the “Front Image” button in the Options bar (this will enter the height, width and resolution for the document). Then, switch to the document that needs to be cropped and use the Crop tool to make your selection. The aspect ratio will be constrained while dragging the crop and, when applied, the image will be resized to the desired width, height and resolution.