On a whim I decided to email one of the best macro photographers, Don Komarechka, (www.donkom.ca) regarding his opinion on the new Olypus TG-3's marco and focus stacking capabilities. I was expecting at most a "Never tried it" and at worst no response at all. To my surprise not only did I get a response, but it was incredibly detailed and personable.
He has allowed me to post publicly his reply in case there is anyone else out there on the fence about buying the Olympus TG-3.
I must apologize for writing a response a full month after you e-mailed me. I've had a few corporate projects that dragged me away from much of my "fun" work, which includes writing e-mails (as fun as that can be!).
I'm glad you enjoy my discussions on TWiP, and I think they have me booked to record another episode later this month before I head off on some worldly travels. I'm sure you gathered from my input on the panel that my approach to photography can be rather technical at times, and the question you asked is right up my alley!
Macro photography on small-sensor cameras is an interesting concept. There are some challenges in this area of photography that are both helped and hindered by a "point & shoot" style camera, and tg-3 itself has a few unique features to consider.
One of the biggest challenges that macro photographers face is depth of field - it becomes incredibly shallow as you begin to magnify your subject, and this is the reason why focus stacking is required to get a decent amount of depth in an image. Depth of Field is controlled by a number of factors aside from the obvious aperture and the distance from the subject I previously mentioned. The other factor is focal length. Cameras with small sensors have very high "crop factors", and the actual focal length of these lenses is often in the range of 5 or 10mm. The shorter the focal length, the greater the depth of field. This is the same reason why I can shoot some of my star trail imagery with a fisheye lens at F/2.8 and still have decent sharpness across a landscape.
What does this mean for you? It means that a macro photograph taken with the tg-3 would have a greater depth of field than a similar photograph taken with a DSLR or mirrorless camera. With that advantage however, comes a compromise. Smaller sensors mean that each individual pixel on the sensor (called photosites) are incredibly small. This gets rather technical, but light passing through an aperture doesn't bend entirely the way we like - some of it diffracts away from it's target pixel. As apertures get smaller and as magnifications increase, more light end up diffracting away from the spot it *should* hit. If this stray light falls onto neighbouring pixels, the effect is a soft or slightly blurry image. The term is called "diffraction limiting", and point & shoot cameras are very susceptible to this.
With these two properties in mind, you'll likely get more in focus but less overall sharpness than you would from a larger-sensor camera. Now, let's talk about a few things specific to the tg-3.
The specs list a minimum working distance of 0.4", which is fairly close. It doesn't specify what magnification that translates to, but you can assume it'll probably be on par with most cameras in its class, or slightly better. This can always be enhanced by putting a close-up filter in front of the camera, even if such a filter doesn't mount properly. Heck, even a pair of reading glasses placed in front of the camera would increase the magnification further if you want.
The camera does have a few modes specific to macro photography, including an automated focus-stacking mode built into the camera. For the above mentioned reasons it might not be entirely necessary, and I'm skeptical of how well it would perform. Most of my handheld focus stacking requires a fair amount of post-processing corrections to get "perfect", and doing it in camera wouldn't allow the kind of precision I'd personally be looking for. The same can be said for cameras that allow HDR processing in the camera's own software, but some people are happy enough with the results. The focus bracketing mode would allow you to take the individual components and combine them yourself in Photoshop, but with a camera at this size, it's always best to use these features when secured to a tripod.
Another big challenge in macro photography is light - you never have enough of it. The tg-3 has the added bonus of being one of the only cameras of this size to have a ring light accessory. This isn't quite the same as a ring flash with xenon flash tubes, but it can help produce clean and clear shots with even lighting, depending on your subject. I don't use ring flashes for anything spherical - water droplets, spider eyes, ladybugs, etc. because the ring-shaped reflection can be quite distracting. However, I use a ring flash for my snowflakes, most insects and general macro work, and you'll probably find some success with the Olympus LG-1 if you choose to buy that as well.
What's it all boil down to? It's an interesting little camera and it seems to have a lot of features that cater to macro photography, but the underlying physics keep me skeptical. Small sensors and diffraction can cause headaches, and there is no way around it. This doesn't mean you'd fail to get great shots, but it can limit the clarity and your ability to get even closer.
For reference, I'm attaching a few pages of my book Sky Crystals that deal with diffraction - I hope the explanation helps!
Let me know if you have any follow-up questions and I'll try to answer them in a timely manner. :)
All the best,
If you happened across my stuff then please do take a moment and check out his amazing work. Not to mention the coffee table book of his snow flake photos. Stunning.