The limited depth of field

With the Rotating Vertex adapter method, using Pentax 67 lenses by utilizing the entire images circle (7x7 cm) - you quickly realize that the depth of sharpness is rather limited. Even when you stop down to aperture ƒ16 !

So, i decided that for each of the 4 Rhinocam Vertex positions - i made 12-15 shots by shifting the focus from 1.2 to 2.2 meter at aperture ƒ 6.7.

Then i focus-stacked each of the 4 Vertex individually first in Zerene Stacker software.

The final 4 TIFF's then were stitched together in Lightroom into the final photoof 150 MP like is having used a 7x7 cm digital sensor. Despite the relatively limited aperture of ƒ6.7 - almost the entire photo is sharp in depth.

Here below an illustration of the Normal Fotodiox Rhinocam Vertex Method. There are adapters for all kinds of camera. In my case, i have one for the Canon EOS R mount = 75 MP with EOS R, as well the Fujifilm GFX mount = 150 MP

For the mina photo in this Diary entry, i used somewhere around 50-60 images in total.

It is of course a bit fiddling. But even with totally manual means possible to increase depth of sharpness, with the Rotating Vertex adapter method. Cool, that it worked :-)

Aperture ƒ3.5 • Normal vs focus stacking

Two examples below: The first are 4 Vertex images stitched together at aperture ƒ3.5 with the old, chunky Pentax 6x7 Takumar 55mm ƒ3.5 lens

The second shows where each of the four Vertex sections, got focus stacked from 12 images each - and then put together. Also taken at ƒ3.5

Clearly sharper

Is the stacked image - and it shows that the Depth of Sharpness goes though the entire image. Which normally is impossible. However, in this case, the image is a bit deceiving. The 6x7 Takumar 55mm ƒ3.5 is in its border areas not very sharp. So, when scrutinizing the photo at 100% - you see how detrimental the fine details are, especially in in the borders and corners - looking rather awful.

But hey, it is a 150 MP image - which like with film - shows at smaller enlargements, much better definition. ON top, the Takumar has an unusual "cinematic" glow which no other of the 6x7 lenses has. And this often comes to the fore with film. It is absolutely gorgeous.

Now with a digital camera, this is visible sometimes in the OVERALL photo. But in fine details, the lens is really inferior (as well when you focus in the closer ranges like 1 or 2 meters distance).

I however love the lens for its character. Even if the kitchen example is really not a show-off example of the "cinematic glow" or "cinematic feeling" that lens can render.

Quirks

• This Vertex Method + focus stacking isn't foolproof of course. I do not move the camera when i shift focus, but instead just focus with the lens at small intervalls. In bright reflections, i can sometimes get weird halo's dependent on what kind of lens i use (Likely that is how the stacking software translate those transitions, creating funny "ring outlines")

• Instead of directly being able to create a RAW DNG file with the 4 Vertex stitched images in Lightroom - i have to work with TIFF files first (focus stacking each section of the Four different Vertex images, in each of the four Vertex parts), and from those final 4 images - I can stitch them together, and create a "cargo" DNG file.

• Also, around bright light sources like the long LED lamp mounted over the kitchen sink - image focus stacking software creates strange artifacts in the outlines. They look jagged, kind of weird.

• The images are often a bit noisier when working with stacked images - but that can be addressed in post.

Well anyway - for my images here in the Diary - it is more than plenty. Again, 150 MP images equivalent to a 7x7 cm sensor - are way too much / not needed. But i do get a lot of sharpness and definition even with lesser 6x7 lenses used at wide open aperture - due to that i have to make the images much smaller compared to the original 150 MP size.

So, it is clearly a gain.

I love to be able to fully utilize the Pentax 6x7, equivalent as if using a real 7x7 cm sensor. The Vertex method works linear - without any distortion, because the lens never changes position, while taking the 4 positioned Vertex image with the Fujifilm GFX camera.

Also remember:

A 6x7 Mediumformat lens of 55mm is equivalent to a moderate (28mm-ish) wide angle lens ! 55mm ain't a normal lens like what we are used from fullframe cameras.