Tuesday, June 23, 2009

Tamron VS 3M-5CA

Tamron VS 3M-5CA

Tamron was built in Schmidt-Cassegrain designs differrence from most Russian lens which area Maksutov design

They are both in the same market share. 3M-5CA stand for latest russian Msksutov mirroe and Tamron stand for latest series of 500mm mirror too. Tamron seem to be brighter than 3M-5CA at the same speed. and got lil bit feature that can take close up at 1.70 m while 3M-5CA at 4.00 m. but The price are higher too Tamron ~ 250-300$ 3M-5CA ~ 150-200$ ( with out shipping)
weigh Tamron [0.595 kg] 3M-5CA [0.620 kg]
SIZE Tamron [87 x 91.5 mm] 3M-5CA [ 83 x 139 mm]
FILTER Tamron[ 82 mm] 3M-5CA [ 72mm]
Min focusing range : Tamron[1.70 m ] 3M-5CA [4.00m ]

for futher detail on each lens

compare size

compare photo at infinity
compare sharp ness

(Schmidt -Cassegrain) was invented by Bernhard Schmide in 1930 by using Primary mirror in Spherical type and using lens called "Corrector Plate" in aspheric element for Primary Mir ror
(Maksutov Cassegrain) was invented by Dmitri Maksutov in 1941.there aren't much different from Schmidt-Cassegrain, just a Corrector Plate was in deeply curved spherical meniscus lens which made the Maksutov limitation ,hard to make in big size. and that make msksutov limit size at 7" or perhaps hard to build bigger than this.

picture from http://www.darasart.com/telescope/catadioptric.htm

Sunday, June 21, 2009

Tamron SP 500 f8

Tamron SP (55BB) F8 / 500mm Schmidt-Cassegrain design Mirror lens

Focal length : 500 mm Macro 1:3
Maximum aperture : F 8 (fixed)
Overall dimension : 87 x 91.5 mm
FILTER : 82 mm
Weight : 0.595 kg
Min focusing range : 1.70 m

Tamron Sp was one fine mirror lens. it's pretty quite famous and well known. This version was the redesign of the 55b ( The famous sp series design by leica , have the vertical stripe on focus ring as if leica lens have) to fix some lil optic problem(close focus spherical aberration).They were first produce in 1983 and discontinue in 2005. Woking with tamron adapt to all (mine 's om mount).

picture from http://www.darasart.com/telescope/catadioptric.htm

some picture taken by tamron ( woking with olympus E3 iso 800 , A mode)

reference credit

Friday, June 19, 2009

Carsen 135 f2.8 [macro]

Carsen 135 f 2.8 macro macro 1:5
Focal length : 135 mm
Maximum aperture : F2.8-16
Overall dimension : 62 x 82 mm
FILTER : 52 mm
Weight : - kg
(having meature yet )
Min focusing range : 1.
50 m

Carsen is a Canadian medical company mostly producing mircroscope stuff .In 1949 Carsen forged a relationship with Japan's Olympus Optical Company Ltd. and become a distributer for olympus product in canada using the name of W. Carsen Co. until year 2000.
I'm not sure if which company actually build this lens some said that it's similar to sear 135 f2.8
and if it's so, It will be made by Tonika .
hear are some picture i took by this lens (with olympus E3).

ZM-5SA (3M-5CA) mirror lens

ZM-5SA (3M-5CA) russian mirror lens

ZM-5SA (3M-5CA)
Focal length : 500mm
Maximum aperture : F8 ( FIX)
Overall dimension : 83 x 139 mm
FILTER : 72mm
Weight : 0.620 kg
Min focusing range : 4 m

Describtion :
this lens was the lightest russian mirror lens , since the weight is 0.620 kg it's working pretty well with my olympus E3 . (There are some photo i took by E3 without out tripod in the bottom).
This lens was made by Muksutiove mirror optics (russian factory in Lytkarino). It's said to be buid around 1984. 3M-5CA was redesign from fomer lens 3M-5A but cutting some weight ( 3M-5A weight = 1.225 kg) buy cutting of tripod collar and also build in hood. But with same quilty built of lens some said it's have better code. Also in russian web site siad that these lens was next generation MTO.

some of the picture was pross process with lil sharpen