Editing a single channel

Some PS tutorials suggest choosing and editing a single channel for better results. After choosing a channel, how do I go about editing it only? Getting a bit ahead, after editing that channel, will the old channel be automatically replaced?

After choosing a channel, how do I go about editing it
only?

If you are in the Channels palette and have clicked (selected) one of the channels then all edits occur on just that channel. Note it is greyscale so there are a lot of things you can't do ...

after editing that channel, will the old
channel be automatically replaced?

If you didn't make a copy and edit the copy (which is probably the smart way to do it) then you are editing the original channel, so it's not exactly "replaced", it's changed by your edits.

wrote in message

Some PS tutorials suggest choosing and editing a single channel for better results. After choosing a channel, how do I go about editing it only? Getting a bit ahead, after editing that channel, will the old channel be automatically replaced?

It's a technique that's often used for getting better selections - look for the channel that has the most contrast between the item you're selecting, and the background.

Each channel (as you probably know) represents one of the primary colours, but you can set PS to display the channel in monochrome or in the primary colour.

Whilst in the channels pallette, you can right-click and choose to duplicate the channel - it's always a smart move to work on a copy.

Bill Hilton wrote:

After choosing a channel, how do I go about editing it
only?

If you are in the Channels palette and have clicked (selected) one of the channels then all edits occur on just that channel. Note it is greyscale so there are a lot of things you can't do ...

after editing that channel, will the old
channel be automatically replaced?

If you didn't make a copy and edit the copy (which is probably the smart way to do it) then you are editing the original channel, so it's not exactly "replaced", it's changed by your edits.

I do know how to edit and duplicate a channel as you and CJ described. Perhaps my question should be: can I edit a single channel in the Layer palette so that the edits are not permanent (or destructive). For example, can I edit a channel using adjustment layers and using layer masks?

C J Southern wrote:

wrote in message

Some PS tutorials suggest choosing and editing a single channel for better results. After choosing a channel, how do I go about editing it only? Getting a bit ahead, after editing that channel, will the old channel be automatically replaced?

It's a technique that's often used for getting better selections - look for the channel that has the most contrast between the item you're selecting, and the background.

Each channel (as you probably know) represents one of the primary colours, but you can set PS to display the channel in monochrome or in the primary colour.

Whilst in the channels pallette, you can right-click and choose to duplicate the channel - it's always a smart move to work on a copy.

Getting a good selection from a single channel is certainly one good reason to work with only one channel. The tutorials typically are pretty good at how to do this. They suggest to increase the contrast drastically for a good selection separation, and then to delete the channel after the selection is made. In this case the use of the channel is temporary and no changes are made to it.

But for tonal correction or noise removal, etc., there will be changes made to a channel, and it would be nice to keep the changes non-destructive as in adjustment layers. How can that be done?

writes ...

Perhaps my question should be: can I edit a single channel in the Layer palette ...

I don't know how to edit a channel in the Layer palette ... did you mean Channels palette?

can I edit a channel using adjustment layers ...

I don't know how to do this, I don't think you can but maybe someone else has a method ...

... and using layer masks?

You can save a layer mask as a selection, which means it's an alpha channel, and then you can combine this alpha channel with other channels using Channel Mixer, but I don't think that's what you're asking.

If I understand your Q the best way to do it (edit channels without changing the original) would be to just make a copy of the image and do whatever you need to do on the channels, then move the result over to the original image.

In article , wrote:

I do know how to edit and duplicate a channel as you and CJ described. Perhaps my question should be: can I edit a single channel in the Layer palette so that the edits are not permanent (or destructive). For example, can I edit a channel using adjustment layers and using layer masks?

No. You can not work in layers in a single channel, and you can not create adjustment layers or layer masks that affect only a single channel.

This has been a gripe I have had with Photoshop for years. Not because i work in channels using layers--there are other ways to do that--but because Photoshop treats a spot color as a special case of a channel, which means you can not work in layers when you work with spot colors.

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wrote in message

But for tonal correction or noise removal, etc., there will be changes made to a channel, and it would be nice to keep the changes non-destructive as in adjustment layers. How can that be done?

I'm not aware of any ways.

Best work-around would probably be to duplicate the channels, and work on the duplicates - turning them off and on as you require.

Thanks to all for confirming that editing a single channel in a layer is not possible.

C J Southern wrote:

wrote in message

But for tonal correction or noise removal, etc., there will be changes made to a channel, and it would be nice to keep the changes non-destructive as in adjustment layers. How can that be done?

I'm not aware of any ways.

Best work-around would probably be to duplicate the channels, and work on the duplicates - turning them off and on as you require.