Manual Alignment & Merging In Photoshop

[groberts]

Can somebody please point me to a simple (short)  description / video tuttorial of how to manually align and then merge two already processed images in Photoshop?

I have an HOO image and corresponding RGB star image which need to be manually brought together - unfortunately the FOV of the two data sets don't naturally match but are otherwise they are the same i.e same OTA and camera.  I realise there's software such as Registar and APP which I believe can do this but for the moment I'd rather not go down that track (cost).

Thanks    

Edited September 29, 2020 by groberts

[michael8554]

IGNORE - didn't initially spot the images were different FOV.

 

Edited September 29, 2020 by michael8554

[wornish]

When you say different FOV do you mean they have the same image scale but one is positioned slightly different to the other.

I assume you have tried using the EDIT - Auto Align Layers function and that is failing to find a match.

To do the alignment manually:-

If the image scale is identical then its a simple case of load the two images into two separate layers in a PS document.

Then select the top layer and reduce the opacity slider until you can see the second layer starting to show through.

Then with the top layer still selected  from the top menu press 

Select - ALL 

Increase the zoom so the stars are bigger.

Select the Move tool

and simply use the UP/Down - Left/Right keyboard keys to move the top layer until the stars are aligned

When happy with the alignment return the Opacity of the top layer to 100%.

To then combine the two layers you need to decide what blend mode to use for the top layer.

Using the EDIT - Auto Merge  option for the two layers might work but that usually selects on focus/contrast and might not give you what you want

Alternatively You can select the blend mode drop down in the layer tool and see what works best. It will show as Normal  by default.

When you are happy with the blending you can then Flatten the image and save the result.

Hope this makes sense and helps a bit.

As you say APP does this as by default.

 

 

Edited September 30, 2020 by wornish

[groberts]

Thanks Dave, yes I messed up the framing after a Meridian flip! I'll give your ideas a try and next time be more careful.

Graham 

[johneta]

Similar to 'wornish' manual alignment procedure.

You can also try File, Scripts, Load Files into Stack. Then browse to the 2 images and load them. Then check "Attemt to Automatically align source images" and hit OK.

It will load both images as 2 layers and most times they will be aligned very well.  Do the 50% opacity technique as above to see if they are.