The Zeiss Otus 55mm APO and Focus-Stacking

[Michael Erlewine]

I understand. Diffraction is like gravity, a law of nature. I have been getting deeper into APO lenses for years, although there is no standard for correction. Some of the exotic industrial Nikkors are highly corrected, like the Printing Nikkors, which were used for scanning movies years ago on very expensive film scanners. These lenses costs something like $12,000 apiece. I have three of the four made, the 95mm, the 105mm, and the 150mm, with the 150mm being the best of the lot IMO. There is also a 75mm that I have never seen for sale. I use these on a bellows. They are very corrected, as are these two new Zeiss lenses.

So, yes, the improved lens correction carries us farther into the higher end of the apertures then uncorrected lenses do. I saw this early on with the Voigtlander 125mm f/2.5 APO-Lanthar, the Leica 100mm Elmarit-R APO, and the Coastal Optics 60 mm f/4 APO, and others. But the huge difference between those lenses and these two new Zeiss lenses amounts for my work in a giant step forward, one that might just carry me away from stacking focus for the most part. Anyway, these new lenses are an adventure.

[bjanes]

You get the idea. Glad to hear any ideas, so keep them coming. I don't know much about deconvolution, other than it is like trying to get the toothpaste back into the tube. Tell me about it.

Michael,

I am glad that you entered into discussions on this forum since you have a great depth of technical expertise and artistry. You might look into deconvolution techniques, which can impose a great deal of trouble, but no less than that involved in stacking 30 images.

To get an idea of what deconvolution can do, take a look at this thread. Bart's original post is here. Bear in mind that this is merely a demonstration of what deconvolution can do with a known PSF (point spread function), which is merely a function describing how the image was degraded. One can approximate a PSF with a gaussian function. The radius used for the deconvolution varies with the f/stop and one can estimate it with Bart's tool. One can use the results to calculate a PSF that one can use in various freeware programs or with ImagesPlus (a paid astronomical program that is also useful for processing terrestrial images).

Once the PSF is derived, you could use as a preset for processing multiple images. I have the D800e and the Zeiss 135mm f/2 Apo and will try to publish some results on the forum once the holidays are over and I get the time. Results from others are welcome.

Merry Christmas to all.

Bill

[Michael Erlewine]

I looked lightly through the deconvolution and found it, of course, convoluted enough to deter me from whatever the next step to trying it might be. Perhaps there will be some software that does this that is easy to use.

Perhaps you will do some of this and let us know how it comes out. I would like to learn more.

Meanwhile, these new Zeus lenses have opened a degree of freedom that was not apparent to me before, and I will see how far I can push that.

[Jim Kasson]

...these new Zeus lenses have opened a degree of freedom that was not apparent to me before...

Zeus? I'm setting up an altar...

Jim

[Bart_van_der_Wolf]

I looked lightly through the deconvolution and found it, of course, convoluted enough to deter me from whatever the next step to trying it might be. Perhaps there will be some software that does this that is easy to use.

Hi Michael,

There is, in the shape of a Photoshop Plugin called Focus Magic. I've heard that the price will increase next year, so check it out soon.

Another option is Topaz Labs Infocus, also a PS plugin, but it can also be called directly from e.g. Lightroom and others. They also have a plugin called Detail 3, which also has a 'Deblur' control with fewer options but in addition it offers several levels of detail enhancement that's also very useful for Macro photography.

Cheers,
Bart

[Michael Erlewine]

Thanks. I will check those programs out.

[Michael Erlewine]

I started doing close-up photography in 1956 when my dad gave me a Kodak Retina 2a, a light meter, and some close-up lenses. Over the years, but more particularly in recent years, I have been on a little Odyssey to find sharp lenses. I have written many articles about this, so I am not going to repeat that here. Those of you who might like to read some of that will find it here:

http://dharmagrooves.com/pdf/e-books/Close-Up_Macro_2012.pdf

I use Nikon cameras for the most part. I just like them, but I can see we are in a major transition phase with cameras or at least a serious segue. I just ordered a Sony A7r, and sent back a Sigma Merrill DP3. The DP3 was just too much trouble. If they would offer a large Foveon sensor in a Nikon-like body (and interface) with an A7r EVF, I would like to work with that, but until then the DP3 is just a bridge too far.

As mentioned in earlier posts, my quest for sharp lenses led me gradually through some of Nikon's finest lenses and finally beyond Nikon into Leica, Voigtlander, Zeiss, and other brands of lenses. In the end I found that sharpness was not simply what I thought sharpness was supposed to be, but rather that it depended on how well the lens was corrected for a variety of things, but particularly for color.

As we know, when color comes through a lens, each of the main colors (red, green, and blue) focus in the plane of the camera's sensor at a very slightly different depth. In other words, they don't land on the same plane (sensor), and this discrepancy causes what is called chromatic aberration and there are other anomalies too. This shows up in our photos in what is called color fringing, little red-green and blue-yellow fringing on sharp edges. Well of course we photographers hate this, but we are also kind of used to it.

Now this color fringing was not generally associated with sharpness until recently, although by definition it absolutely made the resulting photos less sharp – fringed. It is possible to create lenses that manage to bring the red, green, and blue colors to focus on the same plane, the sensor, thus removing chromatic aberration. Such corrected lenses are the APO or apochromatic lenses like the two new Zeiss offerings 135mm and 55mm APOs. But this process is very expensive and so are the resulting APO lenses.

Most manufacturers of lenses don't go to the trouble (and the resulting expense) of offering APO lenses, but some do, and I bet we start to see more of them now that Zeiss has hit a home run. But years ago I gradually realized that these APO lenses produce what I call "sharper" images, because the lenses themselves are more highly corrected, and so on. APO lenses are now coming to the fore as they never have before.

I have been using (mainly) APO lenses for many years and that is why some of my work is "sharp." Another thing I do is stack focus, which is nothing more than taking a series of photos, each in sharp focus, from the front of a still object (like a flower) to the rear, and then combine these photo layers to make a single image that is in focus from front to back. So those are the two techniques I mainly use, focus stacking and APO lenses. And I like to use very fast wide-angle APO lenses wide open so that whatever I don't stack into focus is a nice bokeh. I paint focus with the narrow depth-of-field of a fast lens.

I should be putting my new Zeiss 55mm APO through all kinds of tests, but what I find myself doing is indulging the artist in me through this great lens. I will explain.

I don't just want a photograph to be a mirror image of what I see outside in nature, but rather I want my photographs to be a mirror image of how my mind sees this natural beauty. So, by definition, I am an impressionist. I want to see for myself (and share with others) my impression of the beauty and awe I find in the natural world.

And as a naturalist since I was six-years old, I am also some percentage a scientist. I want something in a photograph to be in high focus (clarity), but not everything. I don't just want a "snapshot" of what is "out there," but rather a painting in light of what impresses my mind. So I try to get one part of a photo in clear focus and then paint with a broad "light-brush" the background as if it were a painting by one of the great French Impressionists.

At heart, my work says to me: "Look how real this dream of life we are living appears."

[Photo taken yesterday with Nikon D800E and Zeiss Otus 55mm APO (Zerene Stacker) that shows how I like to combine clarity and dreams.]