Computar Lenses
User Manual: Manual
Open the PDF directly: View PDF 
.
Page Count: 4
| Download | |
| Open PDF In Browser | View PDF |
__KYVYX
lenses
. dl 2.8/30mm
_l.....
. 30...
OPTIC:AL
..... ...... .. . ru·u
~
........ AIIII .. .
12·
...... .......-- .. . llx
Color ConIc.. .
..
...,Fec:....._
11--;-(1) . .
. 44 .. . . .
4"-7'"
-,_.......
RoopF.... _
""""'.-Ig) ....... 50_
.... ,.. -(h) ...... ..
.... _
_
_ _ _ . -(0)
.. -
lUlr..
11.21_
UrIiJII·· · ..._
The 50mm focal length has long
been considered the standard
work horse for. the 35mm forma t .
In developing I,toe Compufar 50.
special emphasi s was placed on
the astigmati sm and lield curva·
ture. These are two major factor s
that contribut e to the visually
apparent ZOnal problems. These
"soU " .. reas on the. print .. re (j ue
to the negal ive being out of foc us
The Computar 50 possesses ex·
tremely good flat field charac ·
tehslics.
The most apparent difference
in thi S le n~ however. IS thai o f
relative illumination. At the edge
of the format coverage the lens
exhibits an a pertur~ efficiency
of 72 %. In terms of relative illUm·
ination thi s lepresents a marked
improvement over conventional
lenses. Combining thiS increase
in rei alive illumination with its
e xtremely
high
transmisSion
characteristics produces a gen·
eral Illumination effect that is
abSOlutely startling. Suddenly
brilliance has a new meaning.
• •C:HAMICAL
..................
_ . _M"
"'.... l ..... -Ia) ..... 71 .511•
.
.. _
- .Ib) ......... II .S_
....... -le) .... 41....
_I_"_I
.....
TlIrUII -Idl ....... .. . 31x 1.1
_"_Cal -lei 31._
FIII< ..... TlIrUII - Ii).. . 121 1.71
Cal - (kl 51.'"
eoolnlo- (I) .
Oocaslonalty. wilen developing
n_ products II Is possible to be
too succassful. as we were with
the 251nm. Wa wanted tha short·
..t foeallangth lans posslblathat
would ylald excellent parlor·
inanc:a over the total 35mm lormat
cornar to corner. and we got it.
But. since no one has had prior
dllrkrc~"~ ()Xp8 ~ i(lnce with ex·
treme wide angle enlarg i ng
l'enl1l8. we ilOon dj.seoviired a
mS,Jr problem. The lens was too
ahort. Froln a praCtical standpoint .
It beC.me extremely difficult to
pilrform nOrmal corrective opera·
tlon. auch aa dodging and burn·
Ing. AlSo. In some cases It was vir·
tu.lly Impossible to critically
loeu. a negative with a fine grali,
magnifier because it wouldn't fit
under the lens. so we opted for a
30mm focal length instead.
This type of asymmetrical
design does not lend Itself as an
all purpose lens. The Intentional
improved performance at hlgto
magnification necessitates pru·
dent use at tha lower end. I.e.
about 10X magnification . This
translates Into an 11 x 14 ' print
Irom a lull 35mm negaUve or a
5 x 7' print from the 110 formal.
Acceptable pr i nts at smallar
magnifications are obtainable but
only at the expense of raduced
apertures. A 4X print requires AI)'
proxlmatety f: 11 aperture. but
since the negative to paper
dIstance Is only 9+ 'the exposure
Um•• are relatively short.
Even though we Increa.e the
focellength 01 the lena to make It
more manageable. the Computar
30mm Is the ahorteat enlarging
lens available for the 35mm
negative. tn comparllon.. with a
conventional 50mm lens at the
same projecllo'" distance. the '
30mm wfll produc. an Image
approximately 40';' larger. AIIIO at
equivalent projection distances.
the Computar 30mm will Produce
an Image about 25% larger' than
the shortest focel length e"largIng lens available to date. As an
example. a full Irame blow·up to
an 11 x 1.. ' print requl~s a neg·
ative to paper distance of just
17·1t ' . or a 16 x 20 ' In less than
2.. •• while a huge 20 x 30' print
needing only 26V.· can be pro·
duced on most conventional
35mm enlargers.
The Computar 30mm perfor·
mance characteristics .re similar
enough to the 25mm to allow
using the previously published
data.
OPTICAL
_t.erriII ....... .. .. .. . II.l_
A"",,,,, . . ...... ... 11.1-11
A..... fIroIoI . .. . . .... ... .. 41'
...... .......- . .. .. . l.x
---,_--'*~
OPTICAL
. .. . . II.S-
............ 411-7 _
.. -,-111 .. ........ .. I .....
..... ..
1I111or11y-(gl............ 41....
......... ·-lh) ..... .... ...
..... _ . . . - -(i) ..
lu_
-12.'"
........... l ........ . . . '31.4_
_
_
•• CHAMIC:AL
.................
_ l..... -I·I . ...... . 41.1_
.. .......
"_-(b) ..... '...... . 11.. . .
....... _-(el · · · .. 41....
T.... -(dl .. ........ .. ·lhl.l
_
..... CaI-lel .. . 14.7_
_ _ TllrUll-Oi ..... lI4hl.71
.. ........
_"_Cal-(kl .. .
47_
c.ot -(II .. .. ........ .. 11._
g
FtcIIL. . . . . .. . . 14.I_
............. .. . IfU-12
AfIIorIIr AlII! . . . , .' 43"
-,......
......
.,...
............ .... 4x-Zlx
C.CMMIIII ........-7_
,..-.-
.
.. ....,-(f) .. .. . . .. . .
.. ...., - (g) .... , ....2_
.... v.... .....
..........
..... 1'1.-(1\) . . ... . 14....
.
........ -(1) .•. • -11.2. .
v.... v....
...... ... .. ......
..........
............
UCIIA-.cAL
47.~
..... LIiIIJI!-(a) • •
I4.3-
............ -tbl ..
l1 ....
.................
-(el .... .... ..... 4.....
...........
nr..i - (dl .. ..... 11M 1.1
CII-(.I .... . ...... ..7"
........ TInIoI
-III.... ........ ..
...............
IMIx U'
...... .. ,...CII
-(kl ........ .. ... . 1.1_
c.w-(II.; .. . .. II....
The Computar 55 represents an·
other unique approach by rethink·
Ing enlarger lens requirements.
One is providing solutions to
some of the vexing problems en·
countered in color enlarging, of
which the most serious is the dilli·
culty of color balance associated
with exte'ndetl exposure periods.
A real need exists lor a usable
high aperture projection lens. The
F/1 .9 aperture is the highest aper·
ture realistically obtainable due to
the size of the Leica mount. shal·
low depth of focus and acceptable
containment of the aberrations.
The Computar 55 is one of the very
few lenSes available that permits
using the F/2.B aperture to Obtain
professional quality prints.
1\ should be noted that lor·
merly. when making" x or 6 x
prints the F/l .9 aperture was not
usabfe because conventional tim·
ers were not fast enough to con·
sfstently obtain proper exposure.
but wfth new digital timers ac·
curate to 0.1 sec. this is now
posslbfe.
Another area of interest is that
of utilizing the ffoating element
concept to oplimlze the lens for
any magnlffcation from .. x . to
20 x . It is an optical fact that all
foxed tocal length projection lenses
will suffer image degradation when
used at any magnification other
than its design optimized value.
Some designs degrade more rapidly
than others. The floating element
optimization technique definitely
im'proves .the lens performance
the large magnification range$.
Even though the upper optimization was limited at 20 x, higher
magnifications wili stili be substantially improved'.
The floating element is also a
beautiful device for filiaf "twEiak·
ing" of the image; either for bringing
it alf together or selective zone con·
trol. as the various zones can pur·
posely be defocused ..
An additional bonus. not often
considered . is the short depth of
locus of the F/l .9 apertllre provides
an excellent enlarger alignment
tool.
The net r~sutl is for the first time
a lens is available that can be tuned
by the vperator to solve his specifiC
problem whether it be utlra fast
exposure times. unusual effects.
or the capabi lity of producing beautiful mural size color prints directfy
from the original.
over
lenses
.corqJUIar- vaifacal10S.1SO
COIIIpUtar. vaifacal SO-80
4.5150 to 5.1I8Omm
from 35nwn to 6x7cm tonnat.
4.51105 to 5.1I15Omm
ftom 6x9cm to 4x5" formats
....
.
~
....
~
'4· ex
9 .
ex
8 · S
'0
7 •
36
8 • 4
S . 3
30
12 - 8
3.
26
10 - 7
28
4 • 2
2.
3 . 1
22
8· 5
18
6· 3
,.
•• 2
20
18
13
The magnification below 150mm re~
re.enu tot., 41:5" lormat coyftfaga. Th.
value below 105mm repr...nt. m-oniflcation, but nOI necnsarily the complete
format. The l05mm CO"I'II tha ".5" .t
1:1 down to tha ex9cm al infinity. With
the neglillM 10 p rint di'lt.anc. al 48 ", the
maxim um obtai nabla maQnlti catiDn of
Ihe full4ltS format is 7.5x ~ I,jling the
13Smm fo car lanoth setting,
"""CAL
Foc.' .."....
. . . . . . . ,.....
----. .. .....
........
13.2 to 71.11M1
. ... , flU..... tDl2
_
,.,...., .....
. . .............
.............
. . ....tot ......,.... j
.....·1-... .......,.. ..,,,........ ,,,....I
-
~r~
·......, ·M
CoIof~
c.e...........
,..., ,...
..II.JntM .. n.a....
v.r........... ..........
-_...
_
V. . . . .
_
17......
VtIrth .. V........... "
'ao.' ..... ,I1.3_
.. ........ I1 .....
.... 111.1 _ _ n .7 _
0NreII ....... . ,_, .••• •••. •• " '.............
~ ........ (It} •••••••• n...
"'_of
...............
u
.. ·(cJ,,)..........
....,
...... ..., ,.
:::::= .........
III) ••••.• ..., ri
......... ........ .,......
t.7'
.artt.c.I~ ."
--.... ..... · .. ........ . a ___
The v.rlfo'c .' 50·80 covers all film
fermats up te and including the 6x7cm
(2V. X 23("'). At the 50mm local length
setting ~he lens is .optimized to cover
the 35mm format, whereas at the 80mm
setting the lens covers the Sx7 nega·
tive.
These respective settings yield almest the same print magnification vs.
working distance as normal fixed focal
length lenses.
The lens is continuously usable
threughout the entire range from 50 to
80mm. Example-the complete SxScm
(2 V4 sq .) negative can be projected at
between the ·SOmm and ·the 70mm set·
ting. ·dependent upon prejected magnification. This capability is equivalent
to some .of the "wide angle" lenses introduced ever the past several years.
By selecting a short focal length . the
le·n s will permit unusually large
blewups frem the central area of large
negatives. Similarly, due te a functien
of fecal length vs. magnificatien optimization. a leng focal length will produce exceptional 4x5'" prints.trem the
35mm format
Another possibility-set the eAlarger
head at the preper height that yields an
8xl0" print from the 35mm negative
with the 80mm fecal length, then by
"zooming" up to the 50mm position
the image is enlarged te a 13" x 20" .
This increase is quite sullicient for
normal crepping and compesing requirements. As long as the negative to
paper distance .is unchanged. the exposure for any magnification is predictable once it has been established
semewhere en the fecal length scale.
Once the exposure is " zeroed in" at
...
NodIaI,.....~·I..
_ CIWIICAL
=:.~~~tbJ·::::
Varlfa 50·80
MIt_nU?
• •••
......' __ I,.· C.. ···· ·······J, .......... ,:U..'"
........ ......,·(c} .... .... lIal.O
. . . , . . , . . tIWUd -
• • ••
""'''''tty
. C.)·
,..... v....•
...........lpt.(t) ••...... ... ' ....... tD7.aNocIIII ....nt_........ .21.1_.1U_
c. '
. ..... ' ...7......
•••••• 114 ........ 22
~
. .... - r-..
.... . . . . . . . . ..JIMt
......, .(
'IO.&.Ii
OPTlCAL
foe.l..... ..
........ , ..... .... ....... ...... W .. . .
~~.... . . . . . 101 .. h
anyone focal length position, then exposure adjustment becomes predictable for the ether focal length settings.
Assuming similar negative densities,
one can new individually crop and
print complete rolls of negatives much
faster than previously possible.
+1/4 +1/2 +2/3
50
0
60
-114
70
-112 -1/4
80
-2/3 -112 -1/4
0
closely approximate an auto focusing
system .
The focus shift, itself, represents a
very desirable feature as it can be
utilized for fine focusing. Instead of trying to .obtain that critically sharp image
with enlarger focus, simply use the
lens . It has a smoother, more controllable motion. in addition te being closer
te the easel and therefere more comfortable to manipulate.
Varlfoclll05·150
+1/4 +112
A professional quality tool fer the custom and exhlbltlen printer.
+114
The 105-150 mainfains all the desirable
capabilities of the 50-80; however, the
most important and far raaching aspect
of this lens is that now - photographers
have been given "zoom" capability for
the 4)(5" format - on both the enlarger and
the view ·camera.
0
0
CHANGE IN STOPS FOR CCRRECT
EXPOSURE· ASSUMES CCNSTANT
NEGATIVE TC PRINT DISTANCE
Varllocal VI. lOOM
A high quality zoom prejectien lens,
will theoretically stay in focus as yeu
ch~nge the nlagnification. however.
they are designed to cover only one
specific format. i.e. 35 or 6x6. Unfertunately, they have a tendency te beceme
physically large, expensive. and not
nearly as versatile as a v.,lf_•••
Instead .of · just .one format, the
v.rtf_ •• has multiple format coverage capability. This type of lens does
experience a. fecus shift as the lens Is
run through the fecal range. If the enlarger is locked at a 24" prejection distance (negative te paper) the lens will
preduce a fecus shift of approximately
I " as the lens is changed frcm 50mm te
80mm. While changing the lens focal
length with one hand and refocusing
the enlarger with thli other. one ca'n
c.ra .....
The 105-150 may be meunted on a
view camera using available adapters
and the #3 shutter. With the addition .of
a special mounting bracket - the lens is
turned into a functional zoem. The
limiting factor is the capability of the
105mm fecal length te cever the full
4x5" format. Experience has shown
that, if! mest preduct photegraphy and
closeup situations. this is not a serieus
preblem . This is due to the increase in
image size as the lens approaches the
subject In terms of perspective and the
field of view. the v.rlfoc •• l05-150 e·n
a 4x5" would be equivalent to a 30-50
zoom for the 35mm SLR .
Even if the zoom motien is not a requirement . The quick composing
capability when used fer product
photoQraphv eliminates the necessity
of excessive tripod shuffling. This
saves considerable time. while insuring selection of the best cempositien.
On tile Ell.,..
It is now pessiblete produce "zeom"
prints frem straight negatives. Older
negatives can be used to produce new
images. Specialty shots that require
telephoto .or wide angle .objectives can
ultimately be presented in motion . And
the ultimate - "zoom on zoom" - once
in the camera and again in the darkroom.
For Speclel Effects
• Add and blend colers.
• Increase the zoom range and
accentuate the motion.
• Spiral the image-retate the negative
or easel while zeoming.
• Multiple expesures at different
magnificatiens.
The verl'ocall05-150 cen be
• P,obie"m Solver for the pro In~ ADVERTISING-quickly and easily
obtain exact magnifications
either on negative or print.
~ PORTRAIT_asily vary print sizes from
one negative 'rom 8)(10 down to wallets.
~ COMMERCIAL-short on time-straight
shot in field "zoom" in darkroom'.
&
~ A.V.-meiling of color. produces
unusual backgrounds lor typography.
-exact sizing for multiple " drop in"
images on one frame.
The compula, v.rtfoc •• e will
add new and creative dimensions
to enhance existing photegraphic
techniques and capabilities.
© 1"9 Burtoigh B _ ()ptico, Inc.
All RIgh.. R _
lense:
computar dl 5.6/135mm
9
It
OPTICAL
Focll llngtll . .. . .. .. ... ...
'A"~u" Ringo . . ..........
Anguli' Rolli. . . . . . . . . . . . ..
Optimum Mllnlftcltion .. . ...
Cola< CorrecHon. . '" . .. . ..
Blck FoCUI DlltlnCt
"llntInlty - (f) . .. ..... ....
enlarging
lenses
135.1mm
US.&·22
&0·
fi.
400· 700nm
110.&mm
ftantI Focul Distinct
II infinity - (g). . . . . .. . . . .. 122.1m..
_Vlltlll....
_1'1. -(hI ..... . . . , .. .
, _ PoI., Se""ro1ien - (i) . .
'
t...,... .....
"'""Ung
.... l...,., -(al .... , ...
V_I " Vertel
U5m ..
+ 2.3....
45.'1 .. m
• •CHAIIICAL
Sarf""1 ..., .
•f _
- (b) . .. .. . ......
IlIlm_.f 8orre! - (el . . . . .
IlIlml'" If MounHng
Th..... - (d) ..... .. ......
IlIlml1l, If RII' Cell - (e) ...
Allor Sc..w n,,"d - 01 .... ,
IlIlmllor If FlOnl CoU - (k) ...
41.S ....
12.0....
41m ..
SO-80 for 35 to 6x7
105-1 SO for 6x9 to 4x5
3'" 1.0
37.0mm
M43. 0.75
47.0mm
DI......' Qf OI."hragm
ConI... - (II . .
. . . . .. 5Umm
'~ ,: r.e tr~: t r;F B S ~ r')t ;"a h~. tai\1 tn g
the desirabie Leica mount capa·
bility, the Computer 135 was dasigned as an 1/5.6 aperture. This
reduced effective aperture en·
abies the lens to provide excel·
lent ,elallve illumination charac·
!er!sNocs wni le still maintaining
ma,' agea llia clear apertures.
rhi s lerlO was developed to be
lhe short.est iocal length that is
practical for t he 4' x 5" format.
The lens is nominally optimized
for 6x magnification. This pro·
·,[des t he IJser the capability of
making exceptIonal print;;, from
B x. 10 or
Source Exif Data:
File Type : PDF
File Type Extension : pdf
MIME Type : application/pdf
PDF Version : 1.6
Linearized : Yes
Create Date : 2012:05:29 23:19:51-04:00
Creator : Adobe Acrobat 9.3
Modify Date : 2012:05:29 23:22:41-04:00
XMP Toolkit : Adobe XMP Core 4.2.1-c043 52.372728, 2009/01/18-15:56:37
Metadata Date : 2012:05:29 23:22:41-04:00
Creator Tool : Adobe Acrobat 9.3
Format : application/pdf
Document ID : uuid:8c5a5fd5-b779-a94d-8d28-9e558b005635
Instance ID : uuid:d1ca76e7-a70f-4943-8513-9a6064c100f5
Producer : Adobe Acrobat 9.3 Paper Capture Plug-in
Page Count : 4
EXIF Metadata provided by EXIF.tools