Inexpensive LED lighting for photography & In-camera focus stacking of Olympus E-M1

Photography is about light and darkness, so you can get very different images from the same subject depending on how you set up the light.  I shouldn't say that lighting is the MOST important factor because finding an interesting subject and composition comes before the light.  In terms of the gear, appropriate, easy-to-control light sources can dramatically improve the images (or shorten the time required to get the images you want).  On the other hand, you might or might not get marginally better images by upgrading the camera body.  And they are usually much cheaper than a new camera body.

I have been using two to three speedlights/flashes for most of plant photography.  They are tripped by inexpensive radio remote flash triggers.  Since I don't use TTL for this kind of photography, I just use old and cheap manual flashes. I frequently use a soft box or umbrellas as the light modifiers.  These modifiers make the light more diffused.  Without the modifiers, the light becomes harsh, and the images look unnatural.  There are two common umbrellas; black umbrellas with silver inside to reflect the light and white shoot-through umbrellas.  I have both, but I use the white one more frequently.  They are cheap, so you might want to have both black and white umbrellas (link to a cheap source).  Mine is a cheap one (link), but it works ok.  A soft box is nicer, but they are quite a bit more expensive than shoot-through white umbrella.  Also, it is a bit more tedious to set it up because you have to reach into the box to get to the flash.  Mine is Westcott 2331 28-Inch Apollo.  If you prefer DIY options, there are couple ideas in this link.

More recently, I started to use in-camera focus stacking.  Basically, it takes many photos with slightly shifted focus points, and it produces an combined image (more later).  So with flash, I had to wait for the flash to recharge.   To shorten the time required for focus stacking, I decided to look into continuous light sources.  Many of the continuous light sources used for photography and videography are fairly expensive.  For my purpose, the subjects are plants, so they don't move.  This means that I don't have to have powerful light.  So I decided to see if household PAR38 type flood light can be used for photography.

With digital photography, we can correct the color in post-processing quite a bit.  But there is a limitation if the source light is far from the natural white light.  One metric of naturalness of the light is color rendition index (CRI).  Many LEDs come with CRI of 70, 80, or 90 etc.  A higher value of CRI means the light looks more natural.  With the emission spectra of white LEDs, there are two peaks, one in blue and another in yellow-red as well as a big dip in the green region.  Higher CRI LEDs have less pronounced peaks and valley.  So these are more ideal for photography.

There are high-end high CRI LED bulbs, but I wanted to see if cheaper ones are enough.  I purchased Hyperikon PAR38 dimmable LED bulbs (5000K, CRI90+, 14W, 40° beam angle, link to Amazon). About $10 per bulb.  They are attached to the clump lamp holders that you can get from Lowes or HomeDepot.  Each lamp is connected to Lutron TT-300H-WH lamp dimmer ($12 ea from Amazon).  In the photo below, I clamped them to the light stand, but if you don't have it, you can use chairs or something as the light stand.

I've been using one main light through white umbrella.  Then the other lamp without any diffusers to supplement.  In the example below, the second lamp is illuminating from the back side of the plant. You can do it to produce rim-light effect (the edge of the plant become highlighted), or if the plant part is somewhat translucent, it produces interesting effects.  I think that in the setup above, I was taking the photo of Sarracenia purpurea shown at the top of this post.  The back light created the red color in the middle of the photo.

More recently (June 2017), I decided that I liked this set-up, but I wanted to have more light.  So I got Limo Studio 4-sockets lamp holder ($19.99 from Amazon), and used 4 bulbs behind the umbrella, and 4 bulbs in the softbox (Westcott 2331 28 inch Apollo).  The light bulbs are pretty big, but I could manage to screw in 4 bulbs in the lamp holder (I had to use a bit of force).  Now I have sufficient light, and I can place the light a bit further from the subject if needed.

One advantage of continuous light sources is that you can fine tune the angle and intensity of light because you can see the effect.  With flashes, I have to do several trials to get everything adjusted.  Especially with mirror-less camera, I can see the final image in the viewfinder.  So I can use the dimmer while I'm looking through the finder to get the perfect balance.

Note that with the continuous light source, you can take nice photos with a compact camera, which can't trip remote flash.  You can try it with cell phone camera, but it may not have enough light to take photos without a tripod.

Overall, I think this is a cheap and workable light source.  The color is very nice, and I don't have to adjust the color too much in post-processing.  I used this light for the last couple photos I posted on this blog (here, here, here).  But these cheap LED bulbs only work for small subjects you need a tripod (slow shutter speed) since the total output is low.

In-camera focus stacking:

Earlier, I mentioned focus stacking. In macro-photography, it is difficult to get everything in focus. So when you focus on the lip of the flower, the sepals which is behind the lip may be out-of-focus.  The distance between the nearest and farthest objects that look acceptably focused in an image is called depth-of-field (DOF).  You can control the DOF by adjusting the aperture.  With a smaller aperture (larger f-value), DOF becomes deeper (so more area is in-focus).  But if you close the aperture too much, the image starts to become soft due to a phenomenon called diffraction.  With my setup, I generally start to notice the problem if it is smaller than f11.  Even with the small aperture, I can't get the whole flower in focus.  The focus stacking is a technique used to widen the DOF dramatically.  Basically, you take many, many photos by shifting the focus point slightly.  Then you combines the focused areas from different photos to create a composite photo.  There are specialized softwares for this purpose.  People interested in macro-photography should check out this webpage: Extreme Macro.  You can find lots of great info, including focus stacking.

Olympus, a company that has been strong in the field of macro-photography since the film era, is the first company who incorporated the focus stacking/bracketing into a lens inter-changeable camera.  In-camera focus bracketing was first introduced in 2015 with E-M10 mark II, the lowest model of OM-D series.  The feature was brought to E-M1 and E-M5 mark II by firmware upgrades.  With Pen series, Pen-F can do this, but E-PL series (including E-PL8) can't.  In-camera focus stacking (in addition to focus bracketing) is limited to the top end, E-M1 and E-M1 mark II, at this moment (2017).  While focus bracketing works with any lens, focus stacking works with only specific lens.

I have been mostly a Nikon user since the time I got my first camera, Nikon F2 (more than 25 years ago).  But in the last couple years, I rerely bring out the big Nikon cameras.  I'm happier with the small and capable micro four-thrids (m43) system.  I admit that I'm a little bit of camera geek, so I use a couple other lens interchangeable systems for fun, and play with them.  But I goes back to Olympus when I want to get good images (without suffering).  Recently (spring 2016), I got a refurbished Olympus E-M1 as my third m43 camera.  I really like almost all aspects of this camera, but I especially love the control of this camera (easy user interface is more important for me than high ISO capacity, or number of pixels).  E-M1 has the feature of in-camera focus stacking, so I have been playing with it for a while.

Olympus E-M1 with M.Zuiko ED 60mm f2.8 Macro.  I'm using a cheap Arca-Swiss compatible quick release (from eBay) and cheap focusing stage (from eBay).  The focusing stage isn't smooth, but for the price, it will do the job.  The tripod is the old reliable Gitzo Inter Pro Studex (series 3).  It's kind of heavy to carry around, but it has been great for me in the last 20 years.  It is combined with Really Right Stuff (RRS) BH-55 ballhead.  The ballhead is expensive and overkill for this purpose, but I love it.

Basically, after you set the focusing point, the camera rapidly takes 8 photos around the focusing point after pressing the shutter.  Then it makes a focus-stacked photo without the need of post-processing on computer.  This works only with a certain lens.  The camera adjust the focus increment automatically based on the f-value (a user can somewhat control the increment).  To do this, the camera has to know the property of the lens.  This is why this feature is limited to a few lenses.  I have been using  M.Zuiko ED 60mm f2.8 Macro, which is compatible with the feature.  This is an amazingly sharp lens for a ridiculously low price.

In the following 2 photos of Sarracenia purpurea, the first photo is without focus stacking, and the second photo is with focus stacking.  It is difficult to see the differences in the small photos; you can see larger images if you click the image.  I set the focusing point around the flower.  The aperture was f9.  Without focus stacking, the pitcher behind the flower or the pitcher closer to the camera is not focused (you can check the hair inside of the pitchers).  But you can see the details of hair inside the pitchers in the stacked photos.  However, you may notice the artifacts when you see the big images.  You can look at the edge of the pitcher against the gray background.  There is a halo in the stacked photo.  Also E-M1 crops the border during the stacking.  So you have to include extra space at the edges during the composition.

With software based focus stacking, some people take hundreds of photos.  So there is a limitation from 8 photos. But I would say that it is a very nice feature, and I have been frequently using it.

without focus stacking

with in-camera focus stacking

Link to info about focus stacking:

Extreme Macro: Great resources about many macrophotography techniques.

Hugin: Open source photo-sticher, which includes focus stacking module (Enfuse).

Edu Pérez's blog post: a tutorial to use Hugin for focus stacking.

Pat David's blog post: a tutorial to use Hugin for focus stacking.

Stuart Ball's blog post: Compare Hugin against proprietary software, Zerene Stacker. 

Macro-scripts: Workflow scripts for focus stacking.  It drives several other open source packages (Hugin).

Olympus Focus stacking: Information about Olympus focus stacking/bracketing by Kazuo Unno.

gPhoto2: I haven't tried this yet, but I think this can remote control some newer cameras, so it should be able to do automated focus bracketing.  When I get time, I'll try it with my Nikon.  Nikon finally introduced in-camera focus bracketing in D850 in September 2017.  Olympus has this feature even at the low-end model such as E-M10 mark II (or later) since 2015 (except E-PL8).