Monday, February 4, 2013

Exploring 3D Photography with the Loreo 3D Lens in a Cap

When I hear of 3D photos or videos, my first impression is that it's gimmicky.  Interesting for one or two shots maybe and then after that it becomes dull.  But my perspective changed as it were after I tried taking 3D photos with the Loreo 3D Lens in a Cap.

In this post, I'd like to talk about shooting in 3D and why I find it interesting.  Then I'll talk about the Loreo 3D Lens in a Cap (9004).

We'll talk about this shot later.  First, a quick tutorial on viewing 3D photos.

(If you already know how to view 3D photos, just skip ahead)

There are several kinds of 3D photos.  Almost all of them present one view to one eye, and another view to the other eye, and our brain interprets the two slightly different views as a 3D view of the scene.  

A common way of presenting 3D photos is by showing the two views side by side like these:

cross-eye view
parallel view
In the cross-eye view, the right side is intended for the left eye, and vice-versa for the parallel view.  Viewing the cross-eye version is simpler but more stressful for my eyes.  You just cross your eyes and when your vision doubles, you align the right side of the left doubled image and the left side of the right doubled image.

With the parallel view, you allow your vision to diverge (like when you're drowsy or zoning out) and when your vision doubles, you align the left side of one doubled image with the right side of the other doubled image.  It sounds complicated but is easy when you get the hang of it.

In the meantime, here is an easy way to view parallel 3D images:
1.  You will need two sheets of paper.  Roll each sheet of paper into a tube, like a telescope.  
2.  Close your left eye and look through one tube with your right eye.  Aim the tube at the right image.  Position the tube and/or make it narrow enough so that the left image is not visible to the right eye.  
3.  Now with your left eye only, look through the other tube, and aim the tube at the left image only.  
4.  Now open both eyes.
It may be easier to practice with smaller images first (just don't make it too small).

Instead of looking through tubes, you can use an envelope or even your hand to do the same thing.  Just block the left image from your right eye and vice-versa.  Eventually you get used to diverging your vision so that you don't need to use devices to view side-by-side stereograms.

Other helpful techniques:
After spending a few days shooting in 3D, I've found that 3D photography has its share of techniques and challenges, and I believe it deserves appreciation on its own merits, not merely as an extension of 2D photography.

First, I find it interesting that the same shot can have a different emphasis in composition, depending on whether it is viewed in 2D or in 3D.  Here again is the shot above.  

Here is the same shot in parallel 3D format:

In the 3D version, the bird of paradise is very prominent, and the emphasis shifts from the monuments to the plants.

Similarly, certain elements that would otherwise be ignored can gain prominence in 3D.

In the 2D version, the plants in the foreground are just minor compositional elements.  In the 3D version they are prominent and help add a sense of depth to the image.

Images can have a different balance in 3D.  For example, this playground shot seems top-heavy to me.

In 3D, however, the ground and the shadows become important compositional elements, and they balance the picture.

Elements that might detract from the image in 2D can be a part of the composition in 3D.  In this image, the door at the bottom of the frame looks like it doesn't belong there.

In the 3D version, the door acts as a plane that leads the viewer to the slide.


A. Loreo's 3D Lens Lineup.
Loreo is a small Hong Kong based company that has been making photography products since 1982.  They have several 3D film cameras and 3D lenses, and a few other products.  I won't mention the 3D film cameras here but here are their 3D lenses:

  • 3D lens in a cap 9004 (the one I got). 38mm focal length.  Intended for full frame cameras. 60mm stereo base.
  • 3D lens in a cap 9004T. Similar to 9004 except it is for APS-C.  Discontinued.
  • 3D lens in a cap 9005.  Available for APS-C (9005A) or Micro 4/3 (9005B).  40mm focal length. 90mm base and has parallax control.  Accepts filters.
  • 3D macro lens 9006 for APS-C. 9 inches to 33 inches.
  • 3D lens 9008 prototype - not produced.  Had 25mm focal length and had an f/8 aperture.

B.  The Loreo 9004

Focal length: 38mm
Interaxial distance: 60mm
Apertures: f/11 or f/22
Intended for 35mm full frame use but can work on APS-C
35mm SLR film mounts: Pentax K, Canon EOS, Canon FD, Nikon F, Olympus OM, Minolta MD, Minolta AF
DSLR mounts: Pentax K, Canon EOS, Nikon F, Minolta A, Sony Alpha. No 4/3 or m4/3 mount available.

The body is smaller than I expected.  The front element is not much larger than a credit card.
The build quality is not as good as I expected.  It is made of plastic, like I figured, but it's a lightweight kind, like a plastic toy.  I guess it's similar to the radio triggers I've bought from eBay.

The Loreo lens is completely manual.  Nonetheless, metering works in manual exposure mode.  I control the shutter speed and ISO on the camera.  I control aperture by using a switch on the lens to choose either f/11 or f/22.  The chosen aperture isn't reflected on the camera unless I manually enter it into the D600's manual lens database and I actively select that lens.  I created two profiles - one for f/11 and one for f/22.  Using one profile or another has no effect on the metering but the EXIF helps me keep track of whether I used f/11 or f/22.

If I want the camera to adjust the exposure automatically, I can use either aperture priority or turn on Auto ISO in manual exposure mode.  In the latter case, I choose the aperture (through the lever on the lens) and the shutter speed, then the camera chooses the ISO, and I can adjust the exposure upward or downward with exposure compensation.  TTL flash works as well.

As for focusing, it's really simple.  There's a lever on the side of the lens where I select to focus at any of 3 preselected distances: short (1 meter), medium (3 meters), or infinity.

Composition has a few challenges: First, the aperture is tiny, therefore the display is dark in low light.  Under normal indoor artificial light, I can barely see anything.  Second, the image that I see through the viewfinder is of course the side-by-side image, which I can see only through one eye and therefore I can't see it in 3D.  I either have to resort to Live View or chimp the composition with the LCD.  Third, the composition is always vertical (you can't rotate the camera into portrait orientation) and you need to keep the camera more or less level when you shoot.

While we're talking about shooting with the Loreo 9004 I should mention that I've tried it on an APS-C camera and it can work.
full frame


Images taken with the Loreo 3D lens are side-by-side stereo pairs in parallel view (not cross-eye view).  The images can be viewed in 3D using the methods described above.  The lens also comes with a 3D Lite viewer -- a foldable cardboard viewer with two prisms that help one view parallel stereograms as a 3D image.  When using the viewer, I find it easier to view the image very close.

The images can also be viewed through the freeware StereoPhotoMaker.  StereoPhotoMaker has several functions for viewing and creating 3D images.  It can open a side-by-side stereogram from the Loreo (as a JPEG) and present the 3D image in several ways such as a cross-eye side-by-side view, an anaglyph (viewable with red/green glasses), or even an interlaced 3D image for 3D TVs.  The JPEG can be re-saved as an MPO file (a file format that stores a pair of images, and is used by several 3D software).

The 3D effect of images from the Loreo 9004 is most noticeable within 10 feet (the closer, the more noticeable).  Beyond about 50 feet everything looks flat.  By comparison, the 9005 lens has a wider 90mm base (much wider than the human average of 64mm), therefore the 3D effect is very noticeable (hyperstereo).

The 3D effect is most noticeable with closer objects.
The image quality of the Loreo 9004 is not good but it's serviceable.  In terms of sharpness, the lens is visibly soft at f/11, losing smaller details.  I would guess that an iPhone 4 is sharper.  The lens does improve noticeably at f/22, so I usually keep it there if I can manage it.

In practical terms, however, the softness doesn't really hurt the lens' functionality, because 3D images like these are intended to be viewed at no more than 1 foot wide -- any more than that makes it difficult to view the images in 3D (unless you have eyes like a goldfish).  At the intended maximum viewing size, the difference in sharpness between f/11 and f/22 is less noticeable.

f/11.  Resolution, flare and vignetting.  click for 1200 pix version.
f/22.  Resolution, flare and vignetting.  click for 1200 pix version.

Another thing that is not so noticeable at that size is the noise at 24mp.  I don't use noise reduction because the image looks better without it.  I also sharpen the image to crazy levels without the sharpening artifacts (or the noise) becoming visible.

A bigger concern I have is flare.  The lens is very susceptible to it.  In many of the sample shots above, you can clearly see a rectangular-shaped reflection on the left edge or sometimes the middle of the shot.

Another issue is vignetting.  There is some improvement when stopped down to f/22 but there's still plenty of it either way.

There are several alternatives for shooting in 3D.

The most basic one is to take two separate shots a few inches apart.  The problem with that method is that you won't be able to capture moving subjects.  Another alternative is to shoot with two cameras (or two phone cameras) at the same time.  If the cameras are positioned at an appropriate distance and are aligned properly, it could work, though I think it would be unwieldy.

There are also several lower-cost dedicated digital 3D cameras.
  • Fuji W1 and its successor, the W3.  These are probably the best dedicated 3d cameras.  When they came out they were priced at around $600, but since then the price has gone down to very reasonable levels ($240 at Amazon last time I checked).  75mm base.
  • Sony Bloggie. 20mm base means that the 3D effect is not very noticeable.
  • Toshiba Camileo 3D camcorder.  30mm base.
  • Aiptek 3D HD camcorder. 40mm base.
  • Nintendo 3DS - the 3D camera works and you don't even need glasses to see it.  However, the image quality is poor (webcam quality). Offers parallax control.
  • Panasonic Lumix 3D lens for m4/3.  Lenses are too close (20mm base).  Most common criticism is that the 3D effect is not very noticeable.
  • Vivitar, DXG, etc. 

Loreo vs. Dedicated digital 3d cameras:
  • Cost: the Loreo used to have cost as an advantage but with many low-cost alternatives now available, its advantage has been reduced.
  • Compared to 3D camcorders with still-photo capability (e.g. Aiptek), the Loreo enables us to have control over the exposure.  Not so much the aperture but the shutter speed.
  • Notwithstanding the Loreo lens' optical weakness, it may have better image quality than some of the low-cost alternatives.
  • The biggest advantage the Loreo has is probably the option to use external flash.  None of the other alternatives have a hotshoe.

After shooting in 3D for a few days, I now have a greater appreciation for 3D photography.  It's not simply like shooting in 2D.  3D photography poses unique challenges and opportunities.  Many people will still dismiss it as a gimmick and that's not likely to change anytime soon, but I don't care -- I find it fun and interesting, and will probably shoot in 3D regularly.

The Loreo 9004 seems like a good way to get started in 3D photography, as long as you don't mind its optical flaws.  However, with the price reduction on the Fuji W3, it might be better to spend the extra to get the features of the W3 (wider aperture, zoomable, can see 3D on the LCD without a viewer, etc.).  Because I've enjoyed shooting in 3D, I've ordered the W3 and will be posting a review of that in a couple of weeks to see if it's indeed better than the Loreo.

More samples at the end of this post.  Meanwhile here are some links:
How to See 3D
Loreo Guide to Taking Stereo Photographs
Low-Cost 3D Camcorders
Here's another method to view a 3D photo:
1. Open a parallel view 3D picture on your smartphone. I recommend a person, let's say this one:

Set the smartphone aside.

2. Look at a picture or text on your computer monitor, let's say about 2 feet away.

3. While keeping your focus on the picture on the monitor, slowly raise your smartphone with the 3D picture in front of your face, let's say about 6 inches away from your eyes. Raise it so it is just below the level you are looking at the monitor.

4. Still looking at the picture on the monitor, use your peripheral vision to just notice the picture on the smartphone. You're not trying to look at the picture on the smartphone yet. Just notice and observe it.

- The picture on the smartphone is out of focus. That's ok.

- The picture on the smartphone looks doubled. For example, if it's a side-by-side picture of a person (two heads) you will see four heads. The two heads in the middle will be close together.

5. While keeping the smartphone distance to your eyes constant, try moving your head back and forth, farther and nearer to the monitor. Notice with your peripheral vision that the smartphone doubled image is coming together or farther apart. As you get closer to the monitor, the dobuled images look like they are getting closer.

6. Move your head and smartphone closer to the monitor until the two heads in the middle are so close together that they look like only one head.

- If you are viewing the 3d image on an iphone sideways, and the iphone is about 6 inches from your eyes, the monitor will be about 10 or 11 inches away from your eyes.

7. Use your peripheral vision to observe the combined head and note that even though it is out of focus, it appears 3D.

8. Keeping your focus on the monitor, slowly raise the smartphone until it is now covering whatever you were looking at. Hopefully you will see the 3D image in focus!

Optional step:
After step 7, you can try looking alternately at the monitor and directly at the smartphone. Try to remember what it feels like to move from looking directly at the smartphone to directly at the monitor. If you can consciously do that even with an image in front of your eye (and no other image behind it to look at) then you have gained the eye muscle control needed to cause your vision to diverge, which will allow you to view parallel view 3D images! From here on, it's just a matter of controlling the degree of divergence of your vision (really divergent or not so divergent).