MINOX -- DEPTH OF FIELD , HYPERFOCAL DISTANCE, HYPERFOCAL SERIES

The following are depth of field tables for:

MINOX A/B/C/LX/TLX Minox EC AT 4 X 6 INCH enlargement,
Minox A/B/C/LX/TLX at 6 x 8 inch enlargment.
Minox A/B/C/LX/TLX at 8 x 10 inch enlargment.
(Zeiss Planar 50mm lens -- for comparision purpose.)

A. DOF OF MINOX AT 4 X 6 INCH ENLARGEMENT
VIEWING AT A DISTANCE OF 8 INCHES.

MINOX MINOX PLANAR 50mm
EC A/B/LX

focal length ( mm) 15 15 50
f number 5.6 3.5 11

infinity infinity infinity
Hyperfocal distance(FEET) H 7.4 11.7 12.6
H/2 3.7 6.0 6.3
H/3 2.5 4.0 4.2
H/4 1.8 2.9 3.2
H/5 1.5 2.3 2.5
H/6 1.2 2.0 2.1
H/7 1.1 1.7 1.8
H/8 0.9 1.5 1.6
H/9 0.8 1.3 1.4

For Minox A/B/C/LX/TLX

At 4 x 6 inches enlargement, hyperfocal distance is
12 feet, when set focus at 12 feet, objects from 6 feet to infinity
will be sharp.
The number corresponding to H/1 H/2 H/3 ETC are the
hyperfocal series: any consecutive three numbers forms a hyperfocal
triplets, for instance,

Hyperfocal set focus at far limit near limit
6, 4, 3 feet 4 ' 6' 3'

B. DOF OF MINOX A/B/C/LX/TLX AT 6 X 8 INCH ENLARGEMENT
VIEWING AT A DISTANCE OF 8 INCHES.

MINOX PLANAR 50mm
A/B/C
LX/TLX

focal length ( mm ) 15 50
f number 3.5 11

Infinity infinity
Hyperfocal distance ( FEET) H 15.5 16.8
H/2 7.8 8.4
H/3 5.2 5.6
H/4 3.9 4.2
H/5 3.1 3.4
H/6 2.6 2.8
H/7 2.2 2.4
H/8 1.9 2.1
H/9 1.7 1.9

C. DOF OF MINOX A/B/C/LX/TLX AT 8 X 10 INCH ENLARGEMENT
VIEWING AT A DISTANCE OF 8 INCHES.

MINOX PLANAR 50mm
A/B/C
LX/TLX

focal length ( mm ) 15 50
f number 3.5 11

infinity infinity
Hyperfocal distance ( FEET) H 19.4 20.9
H/2 9.7 10.5
H/3 6.5 7.0
H/4 4.8 5.2
H/5 3.9 4.2
H/6 3.2 3.5
H/7 2.8 3.0
H/8 2.4 2.6
H/9 2.2 2.3

D. DEPTH OF FIELD COMPARISON, MINOX VS 35MM

Minox 15mm Complan lens has trememdous depth of field, its depth of
field at wide open f3.5 is equivalent to F11 of a 50mm 35mm camera
lens for same size enlargements.

The dof scale on Minox mini cameras is calibrated for
postcard size enlargment only.

For 6 x 8 inch enlargement, a different set of table is needed
Sometimes I use the DOF scale on Zeiss Planar 50/1.4 read at F11,
in lieu of the depth of field of the on Minox B and IIIs.
( The DOF scale engraved on Zeiss 50mm Planar lens for Contax
SLR corresponds to 6 x 8 size enlargement viewing at 8 inch
distance.)

A 6 X 8 inch enlargement from Minox negative means an enlargement
factor of 18.2
A 8 x 10 inch enlargement from Minox negative means an enlargement
factor of 22.7
The following table listed films which can be enlarged to
the required factor without visible grains. Only a few of the films
films listed are available in 8 x 11 film format. To be able to access
wider variety of films, film slitter comes in handy.

MINOX
Enlargement Enlargment Film without
size factor visible grain

6 x 8 18.2 AGFAPAN 25,
TECHPAN,
ORWO PAN 25
ILFORD PAN F PLUS 50
ILFORD DELTA 100

KODAK GOLD 100
AFGACOLOR 160 PRO
FUJI REALA 100/200/400
EKTAR 25/25 PRO

8 x 10 22.7 AGFAPAN 25,
ILFORD PAN F PLUS 50
TECHPAN

FUJI REALA 100
EKTAR 25/25 PRO

For BW, AGFAPAN 25 is suitable for up to 8 x 10 enlargement
Minox- AGFAPAN 100/400 is too grainly -- unless artistically
grain is deliberately required.

Ilford Pan F plus seems to be an ideal BW film for Minox
it has ASA 50/18 speed same grainularity as AGFAPAN 25 and slightly
higher resolution.
Ilford Pan F 35mm is available in bulk, and not available in
Minox format-- a good reason to seek or build a film slitter.

E) HYPERFOCAL SERIES.

H denotes hyperfocal distance.

H/0 (= infinity), H/1, H/2, H/3 H/4 .... forms "Hyperfocal Series".

It has the unique charaterisc that any consecutive three numbers
in the series forms a triplet of far limit, point of exact focus
and near limit.

F) DEPTH OF FIELD FOR CLOSE UP MINOX PHOTO

At closeup distance, the scale on Minox is not fine
enough. One need a depth of field table, or alternatively
use the following simpler method.

If a Minox is close focus at D= H/n where n is a number

then the depth of field is D/n, in other words

the far limit would be D + D/n
near limit D- D/n

For instance a Minox A/B/C/LX/TLX with target enlargement
of 6 x 8 inch, has a Hyperfocal distance of about 5 meters
at closest focusing distance of 20 cm, then n =25
and the depth of field is about 0.8 cm infront and 0.8 cm behind
the object. 20cm/25 = 0.8 cm

Once remember the hyperfocal distance of Minox, depth of table
become unnecessary. Here Minox user has one advantage over
35mm--- its hyperfocal distance is independent of aperture setting--
it is always fixed, so there is only one Hyperfocal distance for
Minox, unlike 35mm, there is one for each F number.

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| Minox -- 5 |
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This is my Minox depth of field table !

Focus at 5 meters, anything from half of 5 meters (= 2.5 meter)
to infinity will be sharp ( correspond to H/0, H/1 H/2 )

Focus at infinity, then everything from 5 feet to infinity
will be sharp

Focus at H/2 which is 2.5 meter, than every thing fomr

H to H/3 ( that is 5 meter to 1.7 M ) will be sharp

Etc.