Welcome back lads and ladies! I am sure you and a lot of other supportive readers have already come across one of my earliest articles Overcoming Shallow Depth of Field (DOF) In Macro Photography; it is one of the more popular articles of the site 🙂 In that particular article I have discussed one of the biggest issues in taking highly magnified shots, which is of course, the very shallow (or sometimes called thin) Depth of Field (DOF), meaning only a very small portion of your subject will be in focus.
The thinness of DOF will increase the higher magnification you go. Although various workaround techniques have been put forward in the aforementioned article, those are more suitable for taking whole-body shots or for larger subjects at “standard” magnifications (~1:1- 3:1 magnification; for more details on magnification, please click HERE). What if you are interested in shots that are even more “extreme” in terms of magnification, yet still produce good detail all around? Well then, focus stacking it is for you my friend!
Focus stacking is an image processing technique that involves the merging of photos taken at different focal lengths into one final photo with better Depth of Field. A great example would be a photo involving two mating insects or spiders etc., most of the time you will not be able to take a shot with both male and female in focus at high magnification, regardless of the angle you use (see photo below).
This is when focus stacking comes in handy: shooting from a fixed position, by taking a shot where the male is in focus, and another where the female in focus, you will be able to combine both photos in post-processing to make up a photo where both are in focus.
Of course, this is only one example where focus stacking comes in handy. in fact, focus stacking can be used in almost every case of Macro Photography when high magnification is desired or required, so it is definitely a trick worth picking up. The technique is also applicable for Microscopy in Science and Research.
The following shows a very simple example of Focus Stacking using Photoshop. There are plenty of different methods and dedicated software purposely designed for these tasks but I will leave those for more advanced articles later on, so please bear with me for now (plus its not like Photoshop is bad hehe XD).
For starters, let us begin with a Focus Stacking of two photos showing a St. Andrew’s Cross Spider eating a blowfly. This is what you are going to achieve at the end of this article:
* Make sure you take multiple photos of a subject, each from a different focal length i.e. one shot where the fly is in focus, the other the spider in focus. For more info on how to take shots like these, please read here: Macro Photography- Auto Focus or Manual Focus?
* If you are using a microscope and your sample is not entirely flat, focus stacking will work using the methods below as well. All you need to do is turn the micro focusing knob gently while capturing shots at the same time. Stop when all the features you want are photographed.
1. Open both photos in Photoshop, in my example: DSC_9286.jpg and DSC9287,jpg
2. Select the DSC_9287.jpg tab > Select All (Ctrl + A) and Copy (Ctrl + C).
3. Head back to the DSC_9286.jpg tab and Paste (Ctrl + V) the copied image (DSC_9287.jpg). Note that you have one “Layer 1” and one “Background”.
4. Select both Layer 1 and Background by Ctrl + Left-Click.
5. Under Edit > Auto- Align Layers > OK. By doing this, Photoshop will try and align your two photos together. The margin of error can be very large, so you don’t always have to take two exactly similar photos from the exact same position (i.e. using a tripod). Note that both layers have been renamed to “Layer 0” and “Layer 1”.
6. Under Edit > Auto- Blend Layers > Stack Images > Tick “Seamless Tones and Colors” > OK. By doing this, Photoshop will choose the sharpest points in the photo and merge them together into one final image.
7. Right-click on “Layer 0” and “Layer 1” and select “Flatten Image”.
8. Crop the photo (removing “missing” areas) and you are done! Feel free to apply any other post-processing techniques hehe XD Here’s the final photo:
Well, there you have it, a simple yet effective way of overcoming shallow DOF in Macro Photography. Granted, it will take a little more effort, time and processing power to get the final image, but I can assure you that it is really worth it, since you will be getting shots most are not capable of. However, there are three things that you should keep in mind:
- Focus Stacking is only good if there is minimal to no movement of your subject. Even a small movement from your subject will ruin the shot since the photos can no longer be aligned properly (unless if you are going to Photoshop everything separately).
- Your shots do not always have to be taken from exactly the same spot (i.e. using a tripod), computer software are smart and can align your shots together even if they are a little bit out-of-angle, so you don’t have to take the perfect shot.
- The higher your magnification, the more shots are required for Focus Stacking. This is especially true for those who are showing super magnified regions of a subject i.e. eyes, proboscis structure etc. For those shots, you might need up to 150 or more shots for stacking to get a detailed, final photo. Of course, for this kind of processing you will need a dedicated Image Stacking software like Zerene.
Challenge Yourself With Focus Stacking!
Now that you know the basics of Focus Stacking it is time to put your skills to the test. The biggest challenge with Focus Stacking is to see how many shots you are capable of taking before the live subject decides to move. This depends largely on
- How fast your manual focusing skills are.
- How rapid your Macro Rig’s flash system can fire without overheating/recharging.
- The subject your are shooting, and how jumpy it is.
Of course, you could take the easy way out by freezing or killing your subject prior to taking your shots, but I personally think this is a cruel and unprofessional way of getting those shots, so I wouldn’t recommend doing it, unless if you are doing it for Scientific publications. Yes, you might get more “Likes” than your usual shots, but there is really nothing to be proud of if you have to torture, or even take a life for a shot with little significance to the Scientific world. If you really want to try this method, at least have the decency to try it on pests or dead insects you find on the ground.
Okay guys, I hope you find this article useful in your quest to overcome shallow DOF in Macro Photography! To be frank, I still suck at taking multiple shots for Focus Stacking, definitely need more practising XD I will write more about this topic when I have truly mastered the necessary skills~
Until then, take care and happy macro-ing!
** All photos in this website are taken and owned by me. The use of any photos here is not allowed without my permission.
** Only one pest was harmed during the producing of this article.