Firstly, thank you to all those who contributed on the night, with both questions and answers. Being able to share our combined knowledge, be it an in depth technical subject like macro focus stacking to a simple tip on how to use an ND grad and polariser filter together, it all helps to keep us interested and inspired, get the best out of our equipment, and hopefully, make us all better photographers.
Notes on Focus Stacking.
Focus stacking starts when you set up your camera and compose your photograph.
If you cannot achieve the depth of field you require in a single shot, you can take multiple shots with each focussed at a slightly different distance. Start focussed on the foreground in close, and gradually adjust the focus in as many images as it takes to get the far distance in focus. Ensure the depth of field in your first image and each successive image overlap. Your depth of field close to the camera is shallower so you'll need more overlapping images up close, than you will as you focus further away. Needless to say, the camera needs to be mounted on a tripod and remain in fixed position until all the shots are taken. Keep the same aperture and shutter speed through out each image, the exposure all need to be the same.
Once the image are loaded onto your computer we need to import them into photoshop. If you are using Lightroom CC this is a simple task. Select the all of images in your focus stack sequence from the thumbnail view in the Library Module in LR.
Right Click on one of the images selected and Select Edit in from the drop down menu, then select Edit in Adobe Photoshop CC
This will open Photoshop and open all your selected files. Photoshop will display just one open file at once.
Open the File Menu in Photoshop. Select Scripts, then from the sub menu select Load files into stack.
A pop up window opens, click on the Add Open Files, leave the check boxes un-ticked then click Ok
This will then open all the files as Layers into the one displayed image on screen. The layers panel should look like the image below. (Thank you for that tip Howard)
Select all the layers by clicking on the top layer on the stack, then move your cursor to the bottom layer of the stack, hold the shift key and simultaneously click on the bottom layer. All layers should now be selected as shown below.
Now select the Edit menu on the top line, and from there select Auto Align Layers.
This will open a pop up window.
Ensure the Auto button is selected, leave the check boxes un-ticked, select Ok.
We need to align the images as the size of the image captured by the camera varies slightly in size as we change from near focus to far focus, Auto align corrects for this.
After the images have Auto Aligned we return to the Edit Menu, and select, Auto Blend Layers
This opens up the Auto Blend Layers pop up window.
Ensure the Stacked Images button is selected and the Seamless Tones and Colours check box is ticked. Photoshop then magically uses layer masks to hide the out of focus portions of each layer and only display the in focus parts. The layers panel at the side should now look something like this.
You should have displayed on your computer screen an image which is sharp from foreground to background. You can now go into the layers menu and select flatten. This will combined all the layers and masks into one complete layer. This process is very good but not always absolutely perfect. Most issue occur at the edge of the print during the aligning phase. Check around the periphery of the image now looking to see if there are any processing artefacts, and crop in slightly to remove them.
Save your photograph and you're done.