The
Pentacon Six System
by TRA
Stitching
Images to get a Wider View
Whether using the Pentacon Six or any
other camera, it has always been possible to shoot a
series of pictures and join together the prints in order
to obtain a wider view. I first did this as a
teenager with a cheap camera, joining five square images
from a cheap 6 × 6 camera, in order to produce a
panoramic result. The problem at that time was
that my black & white film was processed by a lab,
and they did not print all five images to the same
density, resulting in differences of brightness between
the shots, even though they were all shot with the same
camera settings.
It subsequently became possible for me to
avoid these problems by processing my own films and
printing my own prints with an enlarger.
That was a fixed-lens camera, and with a
camera that takes interchangeable lenses, it is
generally possible to switch to a wider-angle lens –
subject to the availability of such a lens and our
ability to pay for it.
This is, however, not a total solution,
and as wider and wider lenses become available (at a
cost!), we become more and more aware of the distortion
introduced by wide-angle lenses.
By taking and then joining together
multiple images with a “standard” lens such as the Carl
Zeiss 80mm Biometar, we can get wide-angle images
without the distortion introduced by many wide-angle
lenses. In fact, we can even get
panoramic images from a long lens, as the following
example shows.
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This image of Luzern in Switzerland
was shot from the city wall in July 2008, using a
Pentacon Six with a 250mm f/5.6 Arsat lens at f/19
with a shutter speed of 1/250 sec. Film was Fuji
NPS160. It is technically not problem-free,
but as a proof of concept, it does show what is
possible. It was scanned on a Minolta
Dimage Scan Multi PRO with Minolta software at
4800 dpi. At this scanning resolution, each
original image would be approximately 88cm high ×
88cm wide, printed at 300 dpi. The camera
was hand-held and gently panned between the two
shots, resulting in slight variation in the
vertical angle of the camera. The two images
were manually joined by me in the version of
Photoshop that I had at the time, and then
marginally trimmed top and bottom to compensate
for the change of vertical angle. The
stitched image was 399.4 Megapixels in size in
Photoshop and at 300 dpi a print would have been
117.9 cm wide (that’s over a metre wide!) × 84.88
cm high.
[C458_9&10_s.jpg]
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Stitching images on the computer enables
all signs of the joins to be avoided or
eliminated. For an extreme example of shooting
pictures hand-held for stitching on the computer, I
recommend Christopher Leggett’s video “120 Gigabyte
Image DAS” on YouTube, here: https://www.youtube.com/watch?v=jT3v4PGoO20
Shifting the
lens to produce images for stitching
The above examples do not use a shift
lens, but we have already indicated (here
and here) that by
shifting the lens it is possible to produce images with
a wider view.
The user of the Pentacon Six has many
shift lenses available. See for instance here and here.
Generally, these lenses can be used to
reduce or eliminate distortion, especially with tall
buildings. However, by shifting a lens in various
directions, we can if we wish combine far more than two
images and end up with a much larger image that still
has very high resolution.
Using Medium
Format lenses shifted on smaller-format film or
sensors
Lenses designed for
use on the Pentacon Six produce sharp images that
are at least 79mm in diameter, as this is the
diagonal dimension of 6×6 images. The image
projected by any lens covers what is sometimes
called an “image circle”, as in fact a circular
image is projected, even though we only use a
rectangle that fits within that circle. See
here.
If we use a medium format lens on
a 35mm SLR or on a digital camera that takes
interchangeable lenses, the amount of
shift available to us is enormous,
hence the value of the Hartblei shift adapters
described here.
This shift capacity can be used to
reduce or eliminate distortion, for instance, in
architectural pictures, or to take multiple
images with the lens shifted in
different directions, for subsequent stitching
together on the computer.
We can even use lenses for
the Pentacon Six shifted on Medium Format
digital cameras, such as the Fujifilm GFX
series, in which the sensor size is 43.8 × 32.9mm. And
of course, given the availability of suitable
adapters, we can use lenses from other medium
format cameras, such as those produced by Mamiya
for their RB67 and RZ67 cameras.
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[image_circle_s.jpg]
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Image
circles
I am grateful to Hartblei for the
following diagram on image circles, which I have
modified slightly.
Click on the image to see a larger
version of it.
[Shift_Summary_2_s.jpg]
The results of my initial tests of
Pentacon Six lenses on the Fujifilm GFX 50S, using the
Hartblei shift and tilt adapters, can be seen here.
“Tiles” for
Panoramic Images
The component images that are to be joined
are sometimes referred to as “tiles”. There are a
few simple rules to observe when shooting these tiles:
1. Images to be joined must
overlap. Some people suggest an overlap of one third
of the outer edges of the tile. Experience will show
what works best in any given setup.
2. Images must have the same
exposure. So do not change the aperture between
shots, and if the camera being used has an “auto” shutter
speed option, turn this off and set a manual shutter
speed.
3. If you are using a digital
camera that offers “auto
white balance”, turn this off, so that all
images have the same colour.
Beyond this, the layout of the tiles depends on the format
and size designed for the final image.
If shooting on a rectangular film or sensor format (as
opposed to the square format of the Pentacon Six),
counter-intuitively, for a horizontal panorama maximum
resolution may easily be obtained by turning the camera to
vertical and shooting an appropriate number of vertical
images, with suitable overlapping. Perhaps five
images would produce a good result.
Risks of
Distortion when Panning the Camera
Do bear in mind that in such cases,
the sort of distortion can occur that is often seen
with swing-lens cameras such as the Horizont/Horizon
202 or the Noblex, or with panoramic images
captured as a series of individual images obtained by
panning the camera or telephone, with the images being
stitched together on the telephone or on some cameras!
In these, the centre of the final image
is nearer to the camera (or telephone) than the sides,
so one obtains a sort of horizontal “barrel” effect in
which the portion of the subject in the centre of the
final image is larger that the portions at the sides.
The Paleis Noordeinde in The Hague, Holland
Horizon 202 camera 200 ASA film 1/125 f/11,
showing clear barrel distortion
[C354_2627.jpg]
So when using a swing-lens camera, or
swinging the camera or telephone lens manually in front
of a wide building and taking a series of images
distortion will result. By careful composition,
this can be reduced or avoided. See, for example,
this image from the swing-lens Horizon 202.
Choristers’ Close, Wells 18.7.1998 Fuji S-100 film 1/125
f/5.6
[C246_13.jpg]
Also, when an image contains
a clear horizon, whether in a landscape or a seascape,
if the horizon does not pass through the middle of the
image, the horizon will appear to be bent: up at
the ends if the horizon is below the mid point of the
image, down at the ends if it is above the mid
point. See the following two images.
Salisbury Cathedral Horizon
202 Konica 200 ASA film 28.7.2002 1/250 f/16
Sometimes images with this sort of distortion can be
corrected to some extent in programs such as PTGUI,
but it is better and much easier to start with an
original that does not display this sort of problem.
[C324_12.jpg]
On the “Red Eagle” (a Red Funnel Ferry) to
the Isle of Wight. Kodak Gold 200 film 1/250 f/11
27.7.1999
The exposure variation for which some Horizon 202
cameras were well known can be observed at both sides of
this picture,
as the exposure was controlled by the rotation speed of
the lens, which was sometimes not constant across the
whole of its travel.
[C259_22A.jpg]
The best rule is to
keep the camera horizontal, with the horizon at
the mid point between the top and the bottom of the
image. With multiple tiles to be stitched into a
large composite image, there should be space at the top
or bottom to crop the image in order to obtain the
desired composition.
Other Tiling
Layouts
When using a shift lens on a shift
adapter, a wide range of layouts is possible.
Subject to adequate coverage by the lens, the shift of
the lens and the adapter can be combined to achieve
greater shift. For instance, the 20mm shift on the
Mamiya 67 75mm shift lens plus the 12mm shift on the
Hartblei Mamiya to Fujifilm GFX adapter results in a
massive possible shift of 32mm, and as both the
lens and the Hartblei adapter can be rotated, this shift
can be in virtually any direction.
Alternatively, in a simpler layout, one
component (for instance, the lens) can be used for
sideways shift and the other (for instance, the shift
adapter) for vertical shift. If the aim is for a
final horizontal image, with this combination it could
be best to use the 20mm shift (left and
right) of the Mamiya lens for horizontal shift and the
12mm shift (up and down, or even
diagonally!) of the Hartblei adapter for vertical shift.
As an example, 3
× 3 is a possible configuration. We look at this
in more detail below.
Parallax-free
mount
When images are shot with a shift lens, the camera is
normally mounted on a tripod and the lens is shifted in
the desired direction. However, this can lead to
problems. Imagine shooting a cityscape, and there
are some newly-planted spindly trees in the
foreground. Their presence in the composition can
enhance the impression of depth in the final image.
But as one shifts the lens to the left and the right, the
position of the trees in relation to the buildings behind
them changes: they mask different parts of the
buildings. This can result in severe problems when
stitching the component images.
It is better not to shift the lens, but to
shift the camera that is behind the
lens. Then the relationship between the trees and
the buildings behind them will not change.
To do this, it is not the camera that needs
to be mounted on the tripod but the lens.
And if the lens is a shift lens, it is the part of the
lens in front of the shift mechanism that
needs to be mounted on the tripod. The lenses used
for panoramic shots are not usually long; they are
generally wide-angle, and wide angle lenses are not
supplied with a tripod mount. The
solution is to add to the lens a collar that
contains a tripod mount, and this collar needs to be
mounted near the front of the lens, forward
of the shift mechanism. Such a mount is
called a “Parallax-Free Mount” and this is what
Hartblei has made. In fact, in their latest version
of the parallax-free lens collar tripod mount for the
Mamiya RZ67 75mm Shift lens there are two tripod
mounts, at 90° to each other, so that the lens
can easily be mounted on a tripod for horizontal or for
vertical shifts of the lens.
Parallax-Free
collar on Mamiya RZ67 75mm Shift lens.
[75mmShift_paral_free_mnt_01_s.jpg]
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In this image a
second Hartblei “Arca Swiss” compatible “Quick
Release” tripod mount has been added to the side
of the lens collar, at 90° to the one at the
base.
A further “Arca Swiss” compatible “Quick Release”
plate has been temporarily added to the
Hartblei “Arca Swiss” compatible “Quick
Release” tripod mount at the base of the tripod
collar (here resting on coins in order to balance
the outfit for the purpose of taking this
photograph).
Click on this image to see a larger version of
it.
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For Mamiya RB/RZ67 lenses that do not have a built-in
shift, the Parallax-Free Collar is not
needed, as there is on the Hartblei adapter another
Parallax-Free Mount (!!), further back on the
adapter, but forward of the Hartblei adapter's own
shift mechanism. This is very
sophisticated.
Parallax-Free collar on Mamiya
RZ67 75mm Shift lens.
In
this image the second Hartblei “Arca Swiss”
compatible “Quick Release” tripod mount has
been removed from the side of the lens
collar. (Compare with the image above.)
The further “Arca Swiss” compatible “Quick
Release” plate remains on the Hartblei “Arca
Swiss” compatible “Quick Release” tripod mount
at the base of the tripod collar (here resting
on coins in order to balance the outfit).
[75mmShift_paral_free_mnt_02_s.jpg]
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Here with the 50mm ULD lens mounted on the
Hartblei adapter, an alternative Hartblei
Parallax-Free tripod bracket has been added to
the tab that projects below the lens mount on
the adapter, with a long forward-pointing “Arca Swiss”
compatible “Quick Release” tripod mount foot.
The clearance between the back of this “L-shaped” bracket
and the front of the base of the standard
version of the Fotga Fast Focus mount
behind it is about 1mm, enough to enable
the different components to be rotated
independently when required.
The heads of two chrome bolts can
be see on the side of the lens.
These hold in place on the lens a clever
Hartblei Depth of Field bracket that
maintains the lens aperture stopped down
at the chosen value, to avoid the need to
be holding the camera during the exposure,
as this could introduce movement, reducing
the sharpness of the image. For more
information on this see here
(about 2/3 way down
the page).
[50mmULD_paral_free_mnt_s.jpg]
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Click
on these images to see larger versions of them. |
Results that are
Possible
A 3 by 3
composition
[Stitch_components_s.jpg]
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Here is a test with
the Mamiya 67 75mm shift lens in the Hartblei
focussing and shift adapter illustrated
above. Here I have gone for a 3 by 3
composition with considerable overlaps. The
full 20mm left and right shifts of the Mamiya lens
have been used, while the Hartblei adapter was
shifted 12mm up for the top row and 12mm down for
the bottom row.
Mamiya marks shifts beyond 17mm on this lens with
red lines, so I initially thought that perhaps I
should have only shifted 17mm, which would have
reduced or perhaps eliminated the vignetting of
the images in the first column and the final
column. However, Hartblei informs me that
“the vignetting is only caused by the adapter
(starting from 20 mm shift and >f8) and not by
the lens. The vignetting always appears on the
opposite side to shift movements. Therefore, it is
totally irrelevant because it can be easily
compensated by an unshifted or less shifted
image.”
Hartblei have also explained to me that the 17mm
limitation only affects the original 6×7
image on the Mamiya RZ67 camera and only
at 45° diagonal shift, as stated in
the original Mamiya lens manual (on page 5).
In any case, as can be seen from the image circle
diagram above, even at 45° 20mm shift, the GFX
sensor is still inside of the image circle.
Indeed, as Hartblei state, the stitching software
should take the image information from the frames
that have detail, and not use the vignetted
areas. My old (2013) version of Photoshop
(bought new from Adobe at that time) did not do a
good job with this. I am told that the
current version of Photoshop does a much better
job. My old version of Photoshop also does
not recognise Fujifilm .RAF files, so I converted
them first to TIFFS for stitching in Photoshop.
I then re-stitched these nine images in Serif’s
Affinity Photo, this time using the original raw
files, which Affinity Photo does recognise.
The result was much better, although not
perfect. See below.
In a subsequent test with other images, Photoshop
did a better job and Affinity Photo generated
garbage, so it is worth testing with both programs
and/or other programs.
In Photoshop, use File, Automate,
then select Photomerge. In the dialogue box that
opens, it is suggested that Auto is chosen, at
least initially. Browse to find the
constituent images. Tick Blend Images
Together and Vignette Removal,
then click OK.
Click on this image to see it larger.
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Composite
stitched image from the above nine shots
Click on the image here to see it larger.
[Aff_Photo_from_RAW_s.jpg]
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Here is the stitched
image that Affinity Photo produced from raw.
It has on the whole done an excellent job, but I
can see two problems:
- There is a “V-shaped” dark
area in the sky (actually like an inverted
pyramid). This is the vignetting from
the top left and top right images. It
would clearly be better to edit out the
vignetted areas before stitching, and Affinity
Photo will supposedly let me do this, although
when I follow their instructions, it doesn’t
work! I have requested help on Serif’s
Affinity Photo forum, where an authoritative
response usually appears in less than an hour,
but more than a week later all I have had from
contributors to the forum is perplexed
comments and a link to the help pages that I
was already following. I can only
assume that at the time of writing none of
those who visit the forum are trying to do
this by using Affinity Photo!
- There are some stitching
errors round the window frames at the bottom
of the image. It will not be difficult
to correct these with a little cloning.
We note that Affinity Photo has in
other respects done a good job, and the person who
appeared in the middle image has
disappeared. Again, once the software works
as described, it should be easy to select areas of
different component images as desired, in order to
eliminate items that are not wished in the final
image. (Imagine a London street scene in
which one red double-decker bus reappeared in
different parts of the final image, having moved
while the photographer was shifting the lens!)
Affinity Photo also offers to fill in the gaps
round the edges of the composite image (a sort of
“content-aware fill”), and it reportedly can do a
good job with the sky but is generally less
successful with more complex components of an
image.
The height difference from left to right, visible
at the top and the bottom of the image, must be an
indication that the tripod was not totally level,
an error that is easy to correct in the future.
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The edited and
cropped image
[Aff_Photo_from_RAW_edit_s.jpg]
Click on the image to
see it larger (but nowhere near full size!!)
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Here we have
corrected the stitching errors and reduced (but
not yet totally eliminated!) the dark patch in the
sky, after which we cropped as little as possible
in order to produce a rectangular image.
It is interesting to note that the
area covered by this composite image is
equivalent to that obtained with a 40mm
medium format wide angle lens – but without
any wide-angle distortion, and with a
resolution way beyond the already extremely
high limits of this high quality digital
camera.
See
the chart below on equivalent focal lengths
achieved when taking multiple images for
stitching.
Image Resolution
and File Size
The resolution of one image taken with the
Fujifilm GFX 50S is a little over 51 megapixels,
which is massive by digital standards. If we
had used the Fujifilm GFX 100, we could have
achieved a single image with a resolution a little
over 102 megapixels.
But the TIFF version of this composite
image, before cropping, has a file size of 502.5
Megapixels, being being 15,799 pixels wide
by 11,117 pixels high.
The cropped Photoshop version of the image
(reproduced here as a jpeg) has a file size of 457.7
Megapixels, being 15,468 pixels wide by
10,342 pixels high.
So two of these images will occupy a
little over 1 Gigabyte on the hard
disk before editing and only a little under this
after cropping.
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But for those
who need the resolution, it is
amazing. In the sky in the top-right
part of the image, there is what appears
to be a little grey line, not far in from
the edge of a horizontal television
aerial, at the right-hand edge of the
picture. If we enlarge that line,
from the 500-odd Megapixel image, we can
see what it is.
It is a Wizz Air jet approaching
the airport! We must emphasise that
the airport is about 15 miles away and the
aeroplane is high enough not to be heard
from inside the house, and even hardly
noticed from the garden. (Although
anti-flight activists may disagree with
this assessment!)
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[wizz.jpg]
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Even though we are recording to
component images or tiles on a sensor that is 43.8 × 32.9mm in size, with Dual Axis
Shift shooting and stitching of the component
tiles we end up with an image that
corresponds to a 6×7 capture size!
The Mamiya brochure on the RZ67Pro-IID states
(on page 16) that the “Actual Film Image Size”
is 58×69.5mm. Pentax specified that the
“Picture size” for the Pentax 67II was
slightly smaller, at 55mm × 70mm (page 14 of
an undated Pentax 67II brochure printed in
the USA).
The largest sensor available currently
(in April 2022) in a digital stills camera seems
to be the 53 × 40mm sensor that can be found in
two cameras. The Hasselblad H6D – 100C
creates image files of “just” 100 megapixels,
with multiples of this resolution available with
some multi-shot systems. This camera is
available from various photographic retailers in
the U.K. for £31,080 in April 2022. It is
not surprising that they offer loans to
potential purchasers. The other camera
with a sensor this size is the Phase One XF
IQ4, which creates 150 megapixel
images. Dpreview describes this as “the
largest digital sensor format in large-scale
production”. See here.
(Accessed on 8.4.22.) Phase One XF and XT
IQ4 cameras have a range of prices apparently
“from £24,080.00 to £42,260.00” (plus tax),
according to London-based Teamwork
(viewed on 8.4.22.). A Google search on
8.4.22 generated this response: “Phase One, a
specialist in medium-format cameras, has
designed the XT IQ4 field system especially for
landscape photography. It costs $58,990, which
buys you the camera and the 32 mm F/4 lens, and
there's a new 90 mm F/5.6 lens available for
just under $13,000 more.” (This statement
was dated 23 Jan 2021, and it was not linked to
any website.)
Yet with the Mamiya RZ67 75mm shift
lens and this Hartblei adapter we can obtain
the equivalent of a larger sensor
size and a much higher
resolution image, and at a
fraction of the cost.
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Equivalent
focal lengths achieved when taking multiple
images for stitching
Taking multiple
images for stitching results in an angle of view
equivalent to that obtained with a lens of much
shorter focal length. As
indicated above, taking a series of images for
stitching with the Mamiya RZ67 75mm Shift lens
results in an image coverage equal to that which
would be obtained with a 40mm lens, but without
any of the distortion that wide-angle lenses can
introduce. Bear in mind that in 6×6
format a 40mm lens covers approximately the
same area as a 22mm lens on a 35mm “full
frame” camera. For more
information on focal lengths on 35mm cameras
equivalent to focal lengths on the Pentacon Six,
see here.
The following
chart from Hartblei summarises some equivalent
focal lengths for various formats, when using
the 12mm shift possibilities of the Hartblei
adapter and the shift possibilities of shift
lenses.
Lens
|
Shift used
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Image size
|
Direction of shift
with GFX Camera in horizontal orientation
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Image Circle
|
Focal length
Equivalent on GFX
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Focal length
Equivalent on FF
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Angle of View GFX
|
Angle of View
Panorama
|
Angle of View 6×6/6×7
|
CZ
Distagon 40 mm
|
12 mm
|
68 × 33 mm
|
Horizontal
|
90 mm
|
29.1 mm
|
22.9 mm
|
69°
|
86.7°
|
89.3°
|
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Arsat 55
mm shift
|
12 mm
|
68 × 33 mm
|
Horizontal
|
104 mm
|
40 mm
|
31.5 mm
|
53.1°
|
69°
|
71.4°
|
(equivalent
to Super-Angulon 55mm) |
24 mm1
|
92 × 33 mm
|
Horizontal
|
104 mm
|
30.9 mm
|
24.4 mm
|
53.1°
|
83.2°
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71.4°
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Mamiya
Sekor 75 mm SHIFT
|
32mm2
|
97 × 44 mm
|
Vertical
|
124 mm
|
38.7 mm
|
30.5 mm
|
40.3°
|
70.8°
|
60.4°
|
Mamiya
Sekor 75 mm SHIFT
|
32mm
|
108 × 33 mm
|
Horizontal
|
124 mm
|
36.5 mm
|
28.8 mm
|
|
73.9°
|
60.4°
|
Mamiya
Sekor 75 mm SHIFT
|
20 mm
|
84 × 57 mm3
|
Vertical
|
124 mm
|
40.6 mm
|
32 mm
|
|
68.2°
|
60.4°
|
Mamiya
Sekor 75 mm SHIFT
|
32 mm
|
65 × 44 mm
|
Vertical
|
124 mm
|
52.6 mm
|
41.4 mm
|
|
55.2°
|
60.4°
|
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Mamiya
Sekor 50 mm ULD
|
12 mm
|
68 × 33 mm
|
Horizontal
|
95 mm
|
36.4 mm
|
28.6 mm
|
57.6°
|
74.2°
|
82.3°
|
Mamiya
Sekor 50 mm ULD
|
12 mm
|
57 × 44 mm
|
Vertical
|
95 mm
|
38.2 mm
|
30.1 mm
|
57.6°
|
71.5°
|
82.3°
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Chart courtesy of
Hartblei
Notes
1 The 12mm shift of the lens + the
12mm shift of the adapter, when used in the same
direction
2 The 20mm shift of the lens + the
12mm shift of the adapter, when used in the same
direction
3 Camera vertical with lens shift
20mm to left and to right (44 + 20 + 20 = 84mm)
and with adapter shift up and down (33 + 12 + 12
= 57mm)
We note that when
we use the Mamiya RZ67 50mm ULD lens with the
shift potential of the Hartblei adapter, we
can obtain image coverage equivalent to that
obtained when using a lens with a focal length
of approximately 30mm on a 35mm (“full frame”)
camera.
When we combine the shift
potential of the Mamiya RZ 67 75mm shift lens
with the shift potential of the Hartblei
adapter, we can even obtain image
coverage equivalent to that
obtained when using a lens with a
focal length of approximately
28.8mm on a 35mm (“full frame”)
camera.
My
setup with the Hartblei Mamiya RB/RZ67 lens to
Fujifilm GFX adapter
The Hartblei adapter
is rather like a series of tubes, placed one in
front of the other. One of these tubes
contains the focussing mechanism and the camera
mount. Another one contains the shift
mechanism. The front one contains the lens
mount. Each of these tubes can be rotated
individually, making it easy to turn the camera
between horizontal and vertical without changing
the orientation of the lens, with its shift
mechanism, in the case of the 75mm Mamiya RZ67
shift lens. One can also rotate the shift
mechanism of the Hartblei adapter through 360°,
with click détentes at regular intervals.
When taking photographs, each tube is
locked in place by one or two locking
screws. Hartblei provide a large number of
locking screws with the unit, and some users
decide to use two screws for each rotation
point. I have so far found one screw for
each rotation point to be sufficient.
Rotating: My First
Tests
The first rotating movement
must be anticlockwise as viewed by the
user.
1. Align
everything with the red dots at the
top.
2.
Make sure that all locking screws are
tight. I
find that one locking screw
per adjustment ring is adequate, so I
do not use two.
3.
Loosen only the third screw counting
from the camera (with a red/orange head
on my setup). Rotate through
90° (or 180°) anticlockwise. Tighten the third screw.
4.
Loosen the second screw
counting from the camera (with a blue head
on my setup) and rotate the camera
back (clockwise) to the desired
orientation. (Note that when doing this,
vertical shift on the Hartblei unit
must be on zero, to avoid clashes with
the focussing mechanism.) Tighten second screw.
Compose, focus, set ISO, meter
light, set aperture & shutter
speed. For images to be
stitched, it is better to set a manual
shutter speed, so that all constituent
images have the same exposure.
Fire
shutter.
Repeat steps 3 & 4 as
required in order to rotate further,
adding or removing shift as
required.
See an
alternative procedure
lower down on this page.
Note
Two rasterized “clicks” = 90 degrees
Four rasterized “clicks” = 180
degrees
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The three
locking screws on my setup
Click on this image to see it larger.
[Hartblei_75_setup_s.jpg]
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Camera & Lens Movements for shooting 3 ×
3 tiles with the Hartblei Module for Mamiya RB/RZ 67
lenses on the Fujifilm GFX camera
Using the
Parallax-Free mount makes
accurate stitching much
easier. With
the lens mounted onto the tripod via
the Parallax-Free lens collar mount,
to obtain the effect of shifting the
lens up one has to shift the
camera down, etc., as the
lens does not move. See the
table to the right here.
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Shift
directions
using the Hartblei movements
|
Position of Hartblei red
shift measurement index dot
|
To
shift camera down
(image moves up)
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3.00
o’clock
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To
shift camera right
(image moves left)
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12.00 o’clock
|
To
shift camera up
(image moves down)
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9.00 o’clock
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To
shift camera left
(image moves right)
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6.00 o’clock
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Shooting
Order: My First Tests
For a dual-axis shift with the
Mamiya RZ67 75mm shift lens, a good shooting
order seems to be as shown in the
chart to the right here.
It has been suggested to me that the
middle shots should be repeated, to
“encourage” Photoshop to give priority to
them and suppress the dark vignetted
corners of the peripheral images.
Photoshop can definitely cope with
multiple shots of some components.
This shooting procedure may be “overkill”:
it may be that far fewer images than this
are needed to achieve the right
result. Users should experiment with
their camera, their lenses and the
software that they use.
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|
[shoot_order.jpg]
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For
a 3 × 3 Dual Axis Shift photo, with the Mamiya
RZ67 75mm shift lens, the shifts shown in the
table below are suggested.
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Lens shift right
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Lens Zero Shift
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Lens shift left
|
Hartblei
shift camera
down
|
Image
20mm Left
12mm Up
|
Image
0 Horiz shift
12mm Up
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Image
20mm Right
12mm Up
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Hartblei
Zero
Shift
|
Image
20mm Left
0 Vert shift
|
Image
0 Horiz shift
0 Vert shift
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Image
20mm Right
0 Vert shift
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Rotate Hartblei
set rear three components through 180°
and camera back through 180°
|
Hartblei
shift camera
up
|
Image
20mm Left
12mm Down
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Image
0 Horiz shift
12mm Down
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Image
20mm Right
12mm Down
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Alternative
instructions from an experienced user
I am extremely grateful for the
support and help of an experienced user of this
system. He has proposed the following
improvements to my instructions as reproduced
above. I have not yet had time to repeat my
tests, following his instructions, but I have seen
excellent results in his photographs using this
equipment, so I reproduce his advice here.
Rotating
The first rotating movement must be
anticlockwise as viewed by the user.
1. Align everything with
the red dots at the top. Tighten all
screws.
2. Loosen the first
screw counting from the camera (with
a round, ball-like head on
my setup) and rotate the camera back
(clockwise) to the desired orientation.
Tighten this screw.
3. Loosen both second
screw counting from the camera
(with a blue
head in my setup) and the
third
screw counting from the camera (with
a red head in
my setup). Using the three long pins of
the shift module move the shift mechanism
to 12mm mark. Hold the camera in initial
position using another hand.
4. Keep moving the
shift module while holding the camera
in the initial position. Rotate
through 90° (two 45°-rasterized “clicks”)
anticlockwise. Tighten both blue head
and red head
screws.
Compose, focus, set ISO, meter light, set
aperture & shutter speed. For
images to be stitched, it is better to set
a manual shutter speed, so that all
constituent images have the same exposure.
Fire shutter.
Releasing both blue
head and red head screws
repeat step 4 as required in order to
rotate further.
For focussing on the GFX camera, maximal
red pixel peaking is recommended,
and shooting in JPEG + RAW.
My thanks to Hartblei for this advice!
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Camera
and Lens Movements
The nine images suggested
above are not required. Shoot only seven,
as indicated in the following chart.
|
Lens shift right
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Lens Zero Shift
|
Lens shift left
|
Hartblei
shift camera
down
|
Image
20mm Left
12mm Up
|
Image
0 Horiz shift
12mm Up
|
Image
20mm Right
12mm Up
|
Hartblei
Zero
Shift
|
|
Image
0 Horiz shift
0 Vert shift
|
|
Rotate Hartblei set
rear three components through
180° and camera back through
180°
|
Hartblei
shift camera
up
|
Image
20mm Left
12mm Down
|
Image
0 Horiz shift
12mm Down
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Image
20mm Right
12mm Down
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Shooting
Order
For
a dual-axis shift with the Mamiya RZ67
75mm shift lens, a good shooting order
is:
[shooting_order_rev.jpg]
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When the lens used does not include shift
When
a non-shift lens is used, movements are limited to
those offered by the Hartblei adapter. Here we
show the maximum coverage that is possible when using
the Mamiya RZ67 50mm ULD lens, data for which is
included in the above table. The lens can be
seen with the Hartblei Depth of Field Bracket here.
[50ULD_GFX50_01_pano_s.jpg]
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|
The image to the left
shows the typical maximum coverage when using a
non-shift lens. The Hartblei adapter
provides 12mm shift in any direction and it can be
rotated through 360º, with click stops every
45º. This image consists of ten images: the
unshifted (central) image, then with maximum shift
in all eight peripheral click-stop positions,
followed by a further shot of the central image,
which was not really necessary in order for
Photoshop to generate this stitched result.
Obviously, with the four diagonal shift
positions the outer edges of the resultant images
are not so far from the upright or top/bottom
edges of the cental image, resulting in the
typical “cross-like” shape of the stitched image.
Image-processing software may on some
occasions generate an acceptable fill
(“content-aware fill” or equivalent) in sky areas,
but is unlikely to produce satisfactory results in
areas of image detail.
The resolution of the Mamiya RZ67 50mm ULD
lens is phenomenal, with also a virtually total
lack of chromatic aberrations.
With the Fujifilm GFX 50S camera, the total
file size of the stitched image is also
substantial. For this image, I converted the
raw “RAF” files of the component images to
16-bit Tiffs, which Photoship then stitched.
The resultant file was too big for the standard
Photoshop PSD format, which has a maximum size of
2 Gigabytes. I therefore saved it in
Photoshop’s PSB format. After making minor
adjustments to the raw colour and the brightness
range, I reduced the file to 8 bits, which made it
possible to save the image in PSD format.
Naturally, images have to be massively reduced for
hosting on this website. Nevertheless,
potential coverage and some idea of image detail
is discernable.
Click on this image in order to see it larger.
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For more information on using
non-shift lenses with a Hartblei shift adapter,
see here.
File Sizes
Here I give
some data on typical file sizes with the
ten consituent images of the above
picture. It would have worked
adequately with nine images, so if one
takes off approximately 10% of the file
size numbers (but not of the total image
dimensions, which would not change with
nine constituent images), one might obtain
an approximate idea of the file sizes
involved.
To the right I reproduce the pixel
dimensions and the physical document size
numbers from the above stitched
file. We see that the Pixel
Dimensions are over 765 megapixels.
These numbers do not change depending on
the format, but the file size obviously
does.
Here
are the file size details derived
from images taken with the GFX50S
camera:
The Photoshop image size
table reproduced on the right is
taken from the 16-bit Tiff file.
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Pixel Dimensions
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Total file size
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16-bit Tiff file
with all ten layers
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765.8M
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4.72G
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8-bit Tiff file
including all ten layers
plus three correction
layers (Levels, Color
Balance, Curves)
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382.9M
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2.25G
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8-bit JPEG,
uncompressed
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382.9M
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376.3M
|
|
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[50ULD_50S_pixdat.jpg]
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Here
are the file size details derived
from equivalent images taken with
the GFX100 camera:
The Photoshop image size
table reproduced on the right is
taken from the 16-bit Tiff file.
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|
|
Pixel Dimensions
|
Total file size
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16-bit Tiff file
with all ten layers
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1.51G
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8.85G
|
8-bit Tiff file
including all ten layers
plus three correction
layers (Levels, Color
Balance, Curves)
|
772.4M
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3.94G
|
8-bit JPEG,
uncompressed
|
772.4M
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772.7M
|
|
Large
file sizes do of course impact on the
time taken by the computer to process
images, especially for opening,
stitching and saving, as well as on
computer storage requirements (hard disk
space needed). |
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[50ULD_GFX100_pixdat.jpg]
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Alternative solutions for rectangular images
The
above “cross-shaped” image format is impressive, but
is unlikely to meet all requirements. What other
way is it possible to get larger rectangular
images with the GFX camera? If enlarging the
image in one dimension only is satisfactory, using a
Pentacon Six shift lens on the GFX via the “basic”
Pentacon Six-GFX adapter (see here) is an easy
solution. For more information on shift lenses,
see here.
Most Pentacon Six shift lenses provide 12mm of shift,
and as this can be in any direction (with most of the
lenses), it is easy to see that images could be
produced that were 24mm (2× 12mm) wider or higher
than the basic camera format. Remembering that
the best result may sometimes be obtained with the
camera vertical, there is a considerable range of
possibilities.
Another way to achieve the same result is to
use a Pentacon Six non-shift lens on the Hartblei
Pentacon Six to GFX shift adapter (illustrated here).
Remembering that the
size of the Fujifilm GFX sensor is 43.8 × 32.9mm, if we use
the 12mm shift possibility of a Pentacon
Six shift lens in two directions (for
instance, up and down with the camera horizontal),
or the 12mm shift possibility of the
Hartblei shift adapter in two directions
(also up and down with the camera horizontal),
effectively to widen the narrower dimension
of the GFX sensor, we create an effective
sensor size equivalent to 43.8mm × 56.9mm, which
is rounded in the above chart to 57 × 44mm, larger
than the Phase One sensor size of 53 × 40mm (see above), for
less than a tenth of the cost, when we add the cost
of a Pentacon Six shift lens or a Hartblei
shift adapter to our existing GFX camera and
Pentacon Six non-shift lenses. With
these shift movements to widen the effective
narrower dimension of the GFX sensor, the
camera can of course be held in horizontal or
vertical orientation.
This result is clearly not achieved
with a single shot, and stitching is not
suitable for action images, but for many other
subjects the result will be indistinguishable
from that achievable with a Phase One camera
and back. Obviously, this effectively
larger equivant sensor size will result in a
correspondingly higher resolution of the
resultant stitched image, with the
highest-possible resolution being achieved
with a GFX100 or GFX100S camera.
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For the result of widening the longer
dimension of the GFX sensor format by 2×12mm, see the horizontal black rectangle
(marked 68mm) on the Image Circles chart above.
For the result of increasing the height (in
horizontal orientation of the camera) of the shorter
dimension of the GFX sensor format by 2×12mm, see the
vertical black rectangle (marked 57mm) on the Image
Circles chart above.
But
the greatest flexibility is achieved by combining
a Pentacon Six shift lens with the Hartblei
Pentacon Six to GFX shift adapter.
If the shift of both components is in the same
direction (subject to the results of tests to check
the coverage of the lens!), massive amounts of shift
can be obtained, up to a possible 24mm shift in
two opposite directions, a total of 48mm
of additional equivalent sensor dimension
on the chosen axis. This can potentially produce
some really wide panoramic images. Here is an
example, courtesy of
Hartblei, using the Arsat
55mm shift lens (see here):
[55mm_-24mm_s.jpg]
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[55mm_-12mm_s.jpg]
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[55mm_Mitte_s.jpg]
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[55mm+12mm_s.jpg]
|
[55mm+24mm_s.jpg]
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For these images taken on a Fujifilm
GFX50S, the Arsat shift lens was mounted via the
Hartblei shift adapter (see here).
Both the lens and the Hartblei adapter offer 12mm
of shift in any direction. For the first
image on the left here, both the lens and the
adapter were shifted 12mm left, giving 24mm of
total shift. For the next image, there was
only 12mm of shift to the left, for the middle
image, zero shift on both the lens and the
adapter, and so on.
Click on the images to see them larger. As
always, the resolution that we can host on the
internet is much lower than the original, but
it does give an idea of the potential.
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Stitching these images together, we achieve the
following result:
As with all images on this page, it
has been necessary to reduce the resolution of the
original image.
[Arsat55_pano01_s.jpg]
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Rotating this
image 0.5º anti-clockwise and performing a
minimal crop results in the following image:
[Arsat55_pano01_c_s.jpg]
Click on
this image to see it larger. With most
browsers, clicking again on the enlarged
image will enlarge it further.
Our thanks to Hartblei for these images
and for permission to reproduce them here.
This is
incredibly impressive. The
reduced-size version of the image that I am
working with here has a width of 35.81 cm
and pixel dimensions of 18.3
Megapixels. The original will have
been much larger than this.
We also note that even the 24mm shift is
completely free of adapter vignetting.
This is due to the large inner diameter of
the shift modules in both the lens and the
adapter.
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“Dual-Axis Shift”
Christopher Leggett has described images for which the
camera or the lens is shifted both up-and-down and
from-left-to-right as “Dual-Axis Shift”, or
“DAS”. He describes this in his videos on
YouTube. See, for instance, the following video,
which is one of several by him: https://www.youtube.com/watch?v=SiLxjWpG9c8&t=452s
or this one: https://www.youtube.com/watch?v=t25L-vGgVAk&t=297s.
Indeed, with shift lenses perhaps the most
useful is to have the built-in lens shift moving
in one direction (for instance, to the
left and to the right) and the adapter shift
moving in the other direction, at 90º to it
(for instance, up and down). This can produce
results comparable to those obtained with the above
Mamiya 67 75mm shift lens used on the Hartblei
adapter, with the combination capable of producing the
3 × 3 component images layout illustrated above.
Stitching Software
Most image processing software now seems to offer
stitching of images as an option. For instance, both Adobe
Photoshop and Serif’s Affinity Photo offer this
possibility, and so, apparently, do many other
programs. It is reasonable to expect that some
programs will do a better job of stitching than others, so
testing is advised, perhaps with a free trial version of
the program before purchasing it.
A note on the “Arca Swiss” mount
The mount developed by Arca Swiss is described here. It has over
recent years become a popular mounting system, adopted by
a wide range of manufacturers, including Novoflex, Benro
and others.
Unfortunately, the implementation of this mount has not
been totally standardised world-wide, so many
manufacturers offer “Arca Swiss-compatible” mounts that
may have been made without any access to the original Arca
Swiss technical engineering specification. This has
principally resulted in some variation of the thickness
of mounts that will be securely held by so-called “Arca
Swiss-compatible” mounts. For mounts from Novoflex
and some other manufacturers, it appears that a
slightly thinner plate is required than for
others (including the original Arca Swiss!).
To maximise compatibility with equipment from a wide range
of manufacturers, Hartblei took the decision to work to
the Novoflex standard for its “Arca Swiss-compatible”
mounts. They are held tightly in place with Novoflex
equipment with which they have been tested.
However, they may not be held tightly with mounts
from some other manufacturers, no matter how much the
mount is tightened. This is clearly
dangerous, as in the event that the mount is tilted to
quite an angle, the Hartblei equipment might slide
out! Hartblei suggest that with such
mounts, the best solution is to add some teflon
tape to the base of the Hartblei mount, to increase
the total thickness of the mount by approximately 0,5
mm. The Hartblei “Arca Swiss-compatible”
“Quick Release” feet can thus be safely used with the
widest-possible range of equipment.
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