Split Channels

[pixelarte]

I currently use Photoshop CS6 to create digital negatives by splitting the colour channels and apply apply correction curves. Is there any way to do this Affinity Photo?

[Andy Somerfield]

Hi,

 

Can you explain the process a little more? How do you split the channels?

 

If we don't have a similar feature, we can certainly consider adding it :)

 

Thanks,

 

Andy.

[pixelarte]

In all recent versions of Photoshop there is a split channels option available from the channels tab. This is the sequence used to produce digital negatives:

 

Tricolor RGB negatives

1. Start with a color digital image that has been edited and is in Adobe RGB (1998) and 16 bit depth.
2. Flatten the image to a single layer, then size it to 360ppi and the correct dimensions.
3. Invert the sized image to negative (Image/Adjustments/Invert).
4. Save at this step since the next step cannot be undone.
5. Go to Window/Channels. This will open the Channels panel. In the upper right corner, click on the small stack of lines to open the Channel Options window. Scroll down and select Split Channels. This will cause the color image to disappear and be replaced by three grayscale images, one for the Red, one for the Green, and one for the Blue channel.
6. Rename the Red separation as imagename_BLUEneg.psd, the Green separation as imagename_MAGENTAneg.psd, and the Blue separation as imagename_YELLOWneg.psd. Make a practice of also marking each negative as it comes out of the printer as Blue, Magenta, or Yellow since they look nearly identical.
7. Be sure that each negative file has Gray gamma 2.2 embedded in it (Edit/Convert to Profile/Select Gray Gamma 2.2 as the Destination Space).
8. At this point there are two options. If the correct negative contrast has already been determined the negatives can be printed in the gum layer of choice at the Basic Exposure Time determined in Step 1 of the 3-step method and the Printer Settings determined in Step 2, including the correct Color Density setting for contrast.
9. On the other hand if more fine-tuning of the midtones is necessary, a midtone correction curve as described in Step 3 will be necessary, but when applied to the RGB separations, it must be applied to the positive. Since at this point the RGB splits are negative, it is necessary to invert each file back to positive, apply the correction curve, flatten, then re-invert to negative. Print the corrected negative using the Exposure and Printer Settings determined in Steps One and Two.

[pixelarte]

Andy do you you think you will be able to add this feature? As much as I like Affinity Photo without this feature I'll have to continue with PS CS6 as making digital negs is one of my main uses of PS.

 

Richard

[Andy Somerfield]

Yes,

 

First up, the new build coming Monday has the ability to separate any channel into a new greyscale layer - which I think will then enable you to do the rest of your recipe :)

 

We might add a "split all channels to greyscale layers and delete the original layer" button one day too - could be useful..

 

There might also be a possibility for a "Filters -> Create Negative" thing - something like Frequency Separation, but to make your negative workflow a little shorter with this stuff - I'll give that some more thought..

 

Thanks,

 

Andy.

[pixelarte]

Hi Andy,

That sounds good. I have the new build but cant see how to separate a channel into a new greyscale layer?

 

Thanks again,

Richard

[Andy Somerfield]

Hi pixelarte,

 

Look in the "Channels" panel - there will be a small button to the right of each channel - it looks like a grey gradient icon - press that :)

 

Thanks,

 

Andy.

[pixelarte]

Thanks Andy.

[pixelarte]

Has the latest update changed the channels palette and got rid of the button to separate the channel into a greyscale layer?

[pixelarte]

Has the latest update changed the channels palette and got rid of the button to separate the channel into a greyscale layer?

My mistake the button hasn't disappeared I forgot the layer controls what shows.

[nghenry]

I'm using affinity photo and I can't find the way to separate the different channels into greyscale layers. Is that something that didn't make it out of the Beta or am I missing something?

[pixelarte]

I have just purchased Affinity Photo 1.4 after not using the software due to to the beta expiring. However I see there is still no option to split the RGB channels into seperate greyscale files and the method described above no longer seems possible. Does anyone know of a way to separate the RGB channels in seperate greyscales files in this latest version. I find it hard to believe that AP doesn't offer a straight forward method to do this as it has been available in Photoshop now for many years.

[MEB]

Hi pixelarte,

Go to the Channels panel, right click the Background Red, Background Green or Background Blue channel, in the second section of the panel - not the composites on top - (assuming you have a layer called Background) and select Create Grayscale Layer.

[paolo.limoncelli]

 

 

..has the ability to separate any channel into a new greyscale layer...

 

Wait, wait, wait, wait...   :)

Reading this old thread carefully again the "new grayscale layer" sounds interesting...

Does it mean that it will possible to have different colour sampling/depth per layer?

[pixelarte]

Thanks for the quick reply. The only problem I have now is importing curves created in Photoshop - is this likely to be added in a future update.

[blupace]

Hi, 

 

So I'm thinking of moving from Photoshop to Affinity Photo and Affinity Designer.  I found this thread and wondered if it is easy to separate the colour channels. I need to do this for designs I am submitting. If this can be done easily then I will download and tryout the software.

 

Thanks 

[MikeLawless]

Howdy y'all

I'm new to Affinity, but I've been a long (LONG) time Illustrator/Photoshop user.

 

This particular topic is relevant to what I need to know about Affinity Photo. I use channels in Photoshop to create spot color POSITIVES for screen printing. Similar to the original poster using the channels as negatives. In photoshop, a channel can be assigned a spot, or Pantone color. Then when the channels are split, you have your positives for screen making.

 

Is this do-able with Affinity Photo?

[tleaf]

Recently learnt how to do colour separations in Photoshop for screen printing purposes. It allowed me to split the channels, grayscale the images, convert to bitmaps, alter the dots and use a halftone screen. It was all very straight forward and allowed me print off the separations and begin screen printing straight away.

 

I simply cannot find ways to do any of this in Affinity and disappointed. Tried some of the suggestions above and they didn't work. Right clicking on the background of each separation didn't allow me to go any further.

 

It's a shame as my school will be using Affinity from September and I was hoping to use this process with my photography classes to reproduce their photos in a new and creative way.

 

 

[tpa.creative.designs]

I too and considering moving over to Affinity and trialing it. yet I find myself as fustrated as MikeLawless and Tleaf..

I normally use Photoshop (cloud subscription) and use the CYMK colour separation into split channels (new documents with channel name ie; CYAN) thus allowing a black and white image of that particular channel ie CYAN. then convert to Bitmap, alter dots to half screen, save to PDF. to print.and repeat for the rest of CYMK...

So far loving Affinity. Except that.. Maybe another Persona could be added just for this exact reason.. there are a lot of Screen printers out there.

or is there any tips that you can help with.

I tried to open a combined file I put together in Photoshop but Affinity Photo does not recognize the differences in channels and shows the same image repeated.. for days I have tried numerous ways to achieve the seperation..  ahhh. frustrated.. my trial is nearly finished and if I am unable to work it out. Im not sure what I will do. Im at uni and the project I am working on uses this process, I do not want to go back to Adobe. Can you help???

Please

Cheers T

 

[BobM10]

Sorry to come to this thread rather late.  I'm wondering if there is a resolution.  There is clearly a demand from some albeit a minority of users.  The demand is still there in screen printing and to a diminishing extent in other printing.  As well as PS there is other specialist software to create colour separations but usually fearfully expensive for what they do.  I confess I have no idea technically how the colour channels work and I haven't got a grip of the pixel greyscale layer yet so not sure exactly what it is doing. 

 

I need a greyscale layer for each of the colours which I can save as separate files.  Is that possible?

 

 Personally I am happy with a less efficient process than PS.  All I really want is to be able to look at the CMYK channels and open separate files for C, M, Y and K separately either as single colour or greyscale files.  At a push I can then apply the halftone filter to each of those separate files.  For my own personal creative use that would be fine.  The halftone filter may not be sufficient for commercial printers compared with the bitmap feature in PS.

 

 

[denk]

I believe there is no resolution to this.  Imagine how powerful this would be if we can color separate efficiently in affinity photo for iPad with the pencil.  Design on iPad then color separate then send to a rip.  Maybe the developers need pictures to better understand what screen printers need.  I mean why design on affinity photo then have to move it to photoshop to color separate when it should be done within affinity.

 

Also if and when affinity designer comes out for iPad, even more powerful if we can design in affinity photo then color separate and then drag and drop to affinity designer to add text.  Or the other way around, design in affinity designer then move to affinity photo to color separate.

 

I will be posting again on the subject.

[evtonic3]

I think you can do it. I work in the food industry hence the pizza as an example, I imagine screen prints will always be solid vector colors but the idea is here. I would still need to find a few more shortcuts to make the workflow seamless even maybe a macro. But I don't think I can get to that anytime soon. Hope this reflects what some of you are needing to do.

[fde101]

For those still trying to figure this out, you need to select a pixel layer in the Layers palette, then scroll down in the Channels list - there are "Composite Red" and the like on top, then another section with the channels of the selected pixel layer: right-click on one of those (second group) and choose "Create Grayscale Layer" to create a layer with a grayscale mapping of that color channel of the selected pixel layer.

To get this for an entire image that consists of multiple layers, first right-click one of the layers and choose "Merge Visible" to create a pixel layer from the document, then use the merged layer that is created to create the grayscale layers.

It would be kind of nice if they also had the "Create Grayscale Layer" option on the composite channels (not sure why that should be a restriction?), but this works in the meantime.

[Themelis]

On 4/12/2018 at 11:06 AM, evtonic3 said:

I think you can do it. I work in the food industry hence the pizza as an example, I imagine screen prints will always be solid vector colors but the idea is here. I would still need to find a few more shortcuts to make the workflow seamless even maybe a macro. But I don't think I can get to that anytime soon. Hope this reflects what some of you are needing to do.

How you do this?

[Sullyman]

Now we just need halftone output that is accurate