Posts tagged "Channels"

June 14, 2011

LR3 – Previewing “Clipped” Channels in an Image

Hovering your curser over the triangles in the upper left and right of the Histogram panel in Lightroom’s Develop module displays a red or blue preview of the clipped values in the image preview. To toggle on this clipping preview (so that it remains displayed as you move your cursor to other areas), tap the “J” key. The red overlay shows where information in one or more channels (R, G or B) of the image is pure white. The blue overlay shows where information in one or more of the channels (R, G or B) of the image is pure black.

To preview (more specifically) which channel is being pushed to pure black and white, Option (Mac) / Alt (Win) + drag the Blacks/Exposure sliders. Where the image preview is pure black or white, all of the channels are clipped, the various colors show which individual channels (or combination of channels) are clipped.

 

4:21 AM Permalink
January 17, 2011

New Spot Channels

Command (Mac) / Control (Win) -click the New Channel icon on the Channel panel to create a new Spot Color Channel (instead of a new regular channel).

5:08 AM Permalink
August 24, 2010

Viewing Individual Channels

During a Free Transform, using the Place command, and /or when Cropping, the opacity of layers as well as the visibility of individual channels can be changed on their respective panels. Note: this can be especially useful when using alpha channels and/or with alignment of layers.

5:22 AM Permalink
July 30, 2010

Working with Quick Mask

• “Q” will toggle between Quick Mask and Normal Mode.
• Double click the Quick Mask icon on the tool panel to view Quick Mask Options.
• Command (Mac) / Control (Win) + 2 to view the Quick Mask, yet edit the composite image. Note: You can view the Channels panel to see what’s happening under the hood – notice how Command (Mac) / Control (Win) + 2 targets the RGB image instead of Quick Mask and that Command (Mac) / Control (Win) + 6 will target the Quick Mask).

5:17 AM Permalink
July 15, 2010

Legacy Channel Shortcuts

PSCS5 – If you prefer to use the legacy channel shortcuts (from Photoshop 3 and before) select Edit > Keyboard Shortcuts and check the Use Legacy Channel Shortcuts option.

5:37 AM Permalink
July 2, 2010

Selecting Multiple Alpha Channels

PSCS5 – Shift -click to select multiple channels in the Channels panel in order to move, delete transform etc. them.

5:00 AM Permalink
June 18, 2010

Legacy Shortcuts for Displaying Channels

In Photoshop CS4 we changed the keyboard shortcuts for viewing channels:
“The shortcut to display an individual channel in Photoshop CS3 was previously assigned to Cmd (Mac) / Ctrl (Win) +1, 2, 3, etc. Cmd+1 would show Red, Cmd+2 would show Green, etc. Those shortcuts, in Photoshop CS4 were shifted two places to the right. Therefore Cmd+3 shows Red, Cmd=4 shows Green, etc. (Cmd + 2 shows the composite).”
For those who still prefer the legacy shortcuts for switching among channels, (i.e. you want them set back to PSCS3), select Edit > Keyboard Shortcuts and use the check box to enable “Use Legacy Channel Shortcuts”.

6:46 AM Permalink
December 16, 2009

Displaying Different Channels in Curves

When the Curves Adjustments panel is active, Option (Mac)/ Alt (Win) + 2-6 to toggle through the different channels (2 = composite, 3 = Red, 4 = Green, 5 = Blue or 3-6 for CMYK etc.)

4:19 AM Permalink
June 5, 2009

Viewing Layer Masks

To view a layer mask, Option (Mac) / Alt (Win) -click on the mask thumbnail in the Layers panel. Tapping the “\”(backslash) toggles the display of a layer mask on and off (as a red rubylith overlay). (Looking at the Channels panel, you can see that this shortcut toggles the channels visibility.)

5:44 AM Permalink
April 9, 2009

Spot Color Channels

Command (Mac) / Control (Win) -click the new channel icon to create a new Spot Color channel. (Spot Color channels are used primarily for printing using additional “spot colors” on the printing press.)

6:58 AM Permalink
April 8, 2009

Loading Channels as Selections

After saving selections as channels, those channels can be loaded back into a selection with the following shortcuts:
• Command (Mac) / Control (Win) -click on the icon for a channel to load the channel as a selection.
• Command (Mac) / Control (Win) + Shift to add additional channels to the selection.
• Option-Command (Mac) / Alt-Control (Win) to subtract another channel from the selection.
• Option-Command (Mac) / Alt-Control (Win) + Shift to create the intersection of two channels.

7:22 AM Permalink
April 7, 2009

Saving Selections

After making complex selections, it is possible to save them for use again later but choosing Select / Save Selection. This saves the selection as an alpha channel. Alpha Channels can be saved in several file formats including Photoshop and TIFF (they can not be saved as part of a JPEG file however).

7:20 AM Permalink
April 6, 2009

Viewing Channels

A few shortcuts changed in Photoshop CS4 when we simplified the way that adjustments worked by taking them out of modal dialog boxes and putting them into panels. Because a modal dialog box is it’s own little world, it can use shortcuts that are already used in Photoshop “proper”. However, when we put adjustments like Curves, Levels, etc. in the Adjustment panel, we no longer have that isolated context. As a result:

• The shortcut to display an individual channel in a Photoshop file was previously assigned to Cmd (Mac) / Ctrl (Win) +1, 2, 3, etc. Cmd+1 would show Red, Cmd+2 would show Green, etc.  Those shortcuts, have now shifted two places to the right.  Therefore Cmd+3 shows Red, Cmd=4 shows Green, etc. (Cmd + 2 shows the composite).

• Previously, when targeting a channel in a modal dialog box (such as Curves, Levels, etc.), you used Cmd (Mac) / Ctrl (Win) +1, 2, 3, etc.  Cmd+1 would target Red, Cmd+2 would show Green, etc.  Just like the shortcuts for displaying channels, those shortcuts have all shifted two places to the right.  When using the panel-based adjustments, the shortcuts have changed to Opt (Mac) / Alt (Win) +1, 2, 3, etc.

 
• The Hue/Saturation and Selective Color commands are slightly different as they don’t map to just RGB/CMYK, but the same general rules apply: Opt+2 selects the Master channel, and Opt+3, 4, etc. select the subsequent items in the list.
If you prefer to return to the shortcuts found in Photoshop CS3, you can download a ZIP file containing a plug-in (Mac)/registry entries (Windows) that remap the channel keys to CS3 behaviors courtesy of Adobe’s John Nack.

Having read all this, you might reasonably say, “Fine, but Photoshop offers a keyboard shortcut editor, so let me switch things back if I’d like.” That’s not possible, for a couple of reasons. One, the change from modal dialogs to non-modal panel simply means that some commands would now conflict (e.g. hitting Cmd-1 can’t both display a channel & target a channel), so just restoring the old behavior isn’t an option. Two, the shortcut editor frankly isn’t robust enough to handle certain special-purpose keys (numbers, tilde, etc.), and we didn’t have time to enhance it for CS4.

We have, however, created a solution: you can download a file containing a plug-in (Mac)/registry entries (Windows) that remap the channel keys (http://blogs.adobe.com/jnack/files/Use_Old_Shortcuts.zip). That is, you give up using Cmd-~ to switch among open documents, and you lose Cmd-1 for zooming to 100%, but tilde will go back to selecting the composite channel and 1, 2, 3, etc. will go back to selecting/targeting the first, second, third, etc. channels. The Mac plug-in just needs to be dropped into your Photoshop plug-ins directory, and on Windows you can enable/disable the behavior by double-clicking the reg entries.

Thanks to John Nack for this detailed shortcut information! (blogs.adobe.com/jnack)

7:18 AM Permalink