In the world, there are things that seem too good to believe.
Medium format focal reducer is the ‘magic tube’ which makes medium format lens work as
medium format ANGLE OF VIEW and DEPTH OF FIELD to full frame body. Sounds exciting.
Actually too much exiting….
The shiny chrome lens above is ‘Carl Zeiss Planar 80mm f2.8’, the standard lens of the Hasselblad 500C.
Chrome version Planar is pre-T* coating lens except small number in between chrome to black barrel transition.
There is no red T * mark behind the name Planar. This lens, however, is what makes Hasselblad camera a legend
and makes it a synonym of medium format cameras (and bluntly kick Rolleiflex out of medium format market…)
Personally, I like the chrome version Hasselblad Planar most as the beauty from Sweden…. : -)
Hasselblad lens adapters have been around for a while, but what’s a focal reducer?
Adapters that attach the Hasselblad lens to the Canon or Sony have been around since earlier days.
It makes a medium format 80mm f2.8 lens working as 80mm f2.8 to a full frame body. The adapter is just a tube
to connect the different lens – mounts combination.
The focal reducer literally reduces the focal length. The Kipon reducer has 0.7X factor, so if attach an 80mm lens,
will get a 56mm (= 80×0.7) focal length lens. At the same time, the brightness of the lens goes up +1 stop which
makes the lens of f2.8 to f2.0. The principle is reducing the focal distance increases brightness by collecting light
in a smaller area.
Here is 3 lenses conversion when using 0.7X focal reducer
1) 80mm f2.8 Planar -> 56mm f2.0
2) 150mm f4.0 Sonnar -> 85mm f2.8
3) 50mm f4.0 Distagon -> 35mm f2.8
The idea of a focal reducer is great, but I wonder if anyone needs to convert a Hassy lens to a mediocre stuff
in full frame where exotic lenses such as 35mm f1.4, 50mm f1.2, 85mm f1.2 … are readily available.
The first area where the Focal Reducer came out is the APS-C body. When the full-frame mirrorless body
was not available in the market, the idea ignited to convert full frame lens as the same angle of view and
depth of field with APS-C body. But when it became a real product from a fancy idea, Sony launched full frame
camera A7 suddenly and put the fire off to ash. Attention shifted to full frame body swiftly from
full-frame-look-a-like focal reducer.
Now, upgraded to bigger frame, focal reducer that uses a medium format lens for a full-frame body is created.
However, converted lens spec is not impressive at all. I think it is hard to attract attention again in the market.
Does full-frame 55mm f2.0 make the same picture as medium-format 80mm f2.8?
I used to use Rolleiflex 3.5E, SL66 and Hasselblad 500C in film, so I always look after the medium format
photo quality & feeling. That’s why I’m not satisfied entirely with full-frame and pursuing digital bags.
However, from an empirical point of view, it is really hard to recognize a 55mm f2.0 as the same lens
(angle of view / depth of field) as 80mm f2.8 in medium format.
The full-frame 24mm x 36mm is not just different in size from the Rolleiflex & Hasselblad’s 55mm x 55mm frame.
The shape is also completely different. Of course medium format photo cropped to fit into magazine, poster
or book but also often used as a square as it is. Most of all, taking picture is square format anyway…
On the other hand, film photographs have distinctive grains which differs much medium format from full-frame,
but in digital photographs, grain is not shown or different unless artificially added.
Square format Hasselblad 500C
24 X 24
If want to make a photo feeling like a medium-format in angle of view / depth of field, it would be better starting
from 24mm x 24mm. Some cameras support square-framed photos in the body but Sony A7 does not,
therefore need to crop in Photoshop or Lightroom.
To display the same angle and DoF on a 24X24 frame as a 55mm f2.0 lens in full frame 24X36, the focal length
should be reduced to 40mm and the lens brightness increased to f1.4. This means if I shoot a 40mm lens
with a max opening at f1.4 and cut it into a square, it will look like 80mm f2.8 lens in 6×6 format.
I think this makes sense according to my experience (I use 35mm f1.4 in wide often almost always)
Screen area 55 x 55 / 80mm f2.8 Lens = Screen area 24 x 24 / 40mm f1.4 Lens
There are other factors. The use of medium format cameras and full-frame cameras are not the same due to
a big difference in operation & handling. And there are non-metric factors such as sharpness, clarity and
transparency at the final result. But at least, I can say it is very similar ….
Even though I miss the feeling and quality of medium format photo, I know it is not a good idea to attach a
medium format lens to the full frame body with an adapter. Simply it’s not working like that.
Even the focal reducer is not close to the goal. The calculation shows that using the Focal Reducer can achieve
the same angle of view and depth of field as a medium camera, 24 X 36 is never resembled to medium format
photo at all.
Using the wide-angle lens like 35mm f1.4 or 40mm f1.4 in open aperture and crop to 24X24 produces the best results
so far. Of course, the best of best way to do this is to shoot a film with a medium format camera. : -)