Image Stacking In macro

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This is reproduced with the kind permission of Stef from www.dynaxdigital.com

Stacking Images or Increasing depth of field

Most of you know that particularly in macro shooting there is the problem that even with a small aperture such as f11/ f13... you still can't get the whole subject in focus. There is a new way in Photoshop CS4 that allows you to combine various images stacked on top of each other as layers- each with a different focus point-and then to automatically erase the out of focus parts of your image. There is also a way to do that in not the newest versions of Photoshop but any other version and in fact also in Elements.

Now before we begin with the darkroom technique - to get this successfully done you need to do the following during the shooting process:

(a) camera must be on a tripod
(b) subject should not move at all during the shooting process
(c) aperture must be kept the same
(d) ideally you work with studio lights/flashes- at least make sure the lighting does not change too much
(e) now the only thing you have to change is the focus ring on your lens. This means switch to manually focussing and start with your first image to focus on a point nearest to you. Your next picture should focus on a point slightly behind the first one and so one. Try not to shoot more than about 5 images or there is a chance that your computer will get hick ups later on...

Let's assume you have done all of the above
Now here ae various ways of doing the stacking- but let's do it the way I usually do it?
(a) open all of your shots at the same time in camera raw and make sure "select all" is ticked once the RAW converter opens up
(b) set the same wb balance for all of them and correct the exposure if needed
(c) don't do too many adjustments in RAW as they can be done later on. So leave stuff like sharpening/ noise reduction and so on for now- don't do that in the RAW converter
(d) once you are done in the RAW converter do not tick open but instead just "done" -> this will close the RAW converter and the images are adjusted in Bridge or Lightroom.

Next step and this differes depending on the version of PS you have- let's go with the newest version of PS
(a) ctrl click all the images in Bridge that you want in your stack > click tools at the top of your screen > Photoshop > Load files into Photoshop layers
(b) now after opening but before you do anything else you might want to change you image mode to 8 bit files depending on how powerful your computer is! Do the following if you want to do that: Image > Mode > 8 bit. Then click the bottom layer in your layers palette- hold the shift key and click the topest layer in your palette- now all of your layer should be selected and "blue"
(c) edit > auto-align layers > click auto
(d) edit > auto-blend layers > tick "stack images" > now here it gets tricky- very much depends on the power of your computer...

If you at this time have a problem that either your program shuts down or anything else- here is a work around:

1. make sure you work with 8 bit files
2. make sure you don't take too many files at once: you can first stack the first two images of your shooting; then stack no 3/4 and 5 and lastly stack the two combined images that you should have flattened and saved by then

Now back to the last step...
(a)Let's assume your computer is still smiling and happy than you should have a bunch of files on top of each other- each with a layer maks created automatically by the program. Check at 100% image size the details of your image. There should be no problem if you did what I have written at the very top...if there is... than click and unclick one by one the eyes next to your layers and check whether this improves the quality. In worst case scenario you have to manually "repair" the mask of that layer or even just delete this one layer.

(b) once you are happy with it- flatten the layers (your file size will be huge at that time!) and save this copy (!)
(c) then and only then adjust your image as usual- preferably in LAB mode- not sure I have discussed this before- if not will come back to that at a later stage.

Now for all Elements users or former CS versions
(a) basically what you need to do is to copy and then paste the images on by one into the first one of you series. You do this by: select > all > edit > copy > click on your first image > edit > paste
(b) no add a mask to each of the layers but the background layer: layer > layer mask > reveal all
(c) now choose a soft brush and black as colour and paint on the mask to hide the blurry parts of that layer. Once done you can flatten the image and save it.

Anyhow this all sounds much more complicated than it is as long as during the shooting of the image you don't move your tripod or change the position of the subject... then it gets tricky...

Hope this helps- look here for an example:
Link to Topic
Happy photoshopping!

Stef.