Objektivi

Hello

ja se izvinjavam, ali ja bih zamolio nekog da mi pojasni sta znaci sta...

recimio

m42 je oznaka za navoj.

ali recimo kad vidim ovako nesto


Canon EF-S 18-55mm f3.5-5.6 IS
sta mu dodje f3.5-5.6 IS? [ako je to za analogni]
18-55mm je velicina objektiva, ali bih voleo da neko iznese ovde osnove u vezi sa objektivima.

hvala

nadam se da ne trazim mnogo.

Objektivi

Objektiv je osnovni optički deo svakog aparata. Mozemo ih podeliti po žižnoj daljini, konstrukciji i nameni.

Karakteristike objektiva

Žižna daljina je rastojanje između sredine objektiva i oštro ocrtane slike na filmu ili čipu. Ovaj parametar se označava sa MALIM SLOVOM "f".
Svetlosna jačina objektiva, kada objektiv ima veću svetlosnu jačinu to znači da pri najvećem otvoru blende može da primi više svetla. Ovaj parametar se obeležava sa VELIKIM SLOVOM "F". Što je broj F manji to je objektiv svetlosno jači. Ako ovaj parametar ima dve vrednosti to znači da je to zum objektiv kome se najveći otvoj razlikuje na različitim žižnim daljinama.

Podela po žižnoj daljini:
1. Širokougaoni
2. Normalni
3. Teleobjektivi

Specijalni objektivi:
1. ZOOM-objektivi
2. Makro-objektivi


Što se tiče oznaka koje stavlja proizvođač mislim da ovo može da pomogne:

Canon
EF : Lens mount designation for Canon's current camera system. Stands for Electronic Focus.
EF-S : Lens mount designation for Canon's current APS-C digital SLRs (reduced sensor size), for example the 20D, 350D, and 300D models. The S stands for "short back focus," implying that the rear element of the lens is closer to the sensor than with regular EF lenses. EF-S lenses will not mount on Canon film SLRs or Digital SLRs that do not have an EF-S mount.
TS-E : Tilt-shift lens, for control of perspective and depth of field.
MP-E : Macro Photo Electronic. These lenses do not have autofocus, the "electronic" refers to the electronic aperture control. Specialised lenses designed for macro photography.
L Lenses : L refers to Canon's professional range of lenses. Many people take the L to stand for Luxury. Purchases of such lenses can lead to 'L Fever', a condition where all future lense purchases must be L class.
IS : IS refers to Image Stabilisation, Canon's anti-shake feature. Also known as VR (Vibration Reduction - Nikon), OS (Optical Stabilisation - Sigma).
USM : USM refers to the autofocus motor. Ultrasonic Motors (USM) are piezoelectric and offer very fast and silent autofocusing. There are two types: A standard cheaper micro-USM which just replaces the regular electromagnetic AFD motor, and a Ring USM (internal focus) which is much faster and also incorporates fulltime manual focus overide without leaving AF mode (or damaging the focus mechanism).
AFD : An older type of AF motor, AFD (Arc-Form drive) is generally slower and noisier than USM.
DO : Diffractive Optics - DO lenses are found with green rings (as opposed to the red ring around the L-series lenses) to set them apart. DO considerably cuts the size and weight of a lens down while maintaining quality. Still not as sharp as a true L lens but in many cases a viable alternative when size or portability are a concern. How DO works you can read at http://diffractive-optics.org/
A note about the maximum aperture The maximum aperture in a 135mm F/2 lens is (135/2) = 67mm. This means the hole that lets the light in opens up to 67mm. This explains why lenses with larger apertures are more expensive: they require more glass inside larger barrels.

Nikon

AF-I Internal auto-focusAF-D/G with auto-focus motor built into the lens barrel itself
AF-S Silent-wave auto-focusAF-D/G with ultrasonic AF motor
ASP ASPherical lens elements A type of lenses that virtually eliminates the problem of coma and other types of lens aberration. The are particularly good at correcting distortion in wide-angle lenses as well as contributing to a lighter and smaller lens design
CRC Close Range CorrectionProvides superior image quality at close focusing distances and increases the focusing range
D (AF-D) Lens equipped with a chip which allows the body to assess the distance to the object being photographed and exposes for that object correctly
DC Defocus-image ControlA creative feature for photographers; control the degree of spherical aberration
DX Digital eXpandedLenses for DSLRs with a smaller sensor than 35mm
ED Extra-low DispersionPrevents chromatic aberration because it concentrates and directs the wavelength of the light more effectively onto the camera's sensor
G (AF-G) Same as AF-D, but without an aperture ring
IF Internal FocusTo ensure stability in focusing, this lens moves the inner lens group or groups without changing the lens' physical length
N Nano coatingNon-reflective coating for clearer images with increased detail by reducing reflection from inside the lens
RF Rear FocusThis lens is equipped with a system that moves the rear lens group for focusing SIC Super Integrated CoatingMultilayer coating of the optical elements in lenses
SWM Silent Wave MotorUltrasonic AF motor
VR Vibration ReductionA family of techniques used to reduce blurring associated with the motion of a camera. Specifically, it compensates for pan and tilt of a camera

Sigma

EX : An abreviation for the "Excellence" range of lenses. These lenses are similar to Canon's L series, claimed to be superior in build and optical quality to regular lenses. Like the L series they have a distinctive exterior.
DG : A DG lens can be used with both 35mm SLR and digital SLR cameras. DG refers to additional optical coatings that are meant to minimize reflections of light off the sensor itself.
DC : A DC lens is designed so the image circle matches the smaller size of a digital SLR's image sensor compared to a 35mm frame. These are typically lighter than DG lenses but are not suitable for 35mm SLRs.
ASP: An aspherical lens, which is more compact than conventional lenses.
APO: APO or apochromatic lenses are made using a low dispersion glass to reduce chromatic aberration.
OS: Optical Stabiliser. More or less identical to Canon's IS and Nikon's VR.
HSM: "Hypersonic Motor," which in the same way as Canon's USM is used to power the autofocus mechanism and is generally quieter and faster than conventional electromagnetic motors.
RF: Rear focus lenses move the rear lens elements delivering faster, more quiet focusing.
IF: Inner focus lenses move the middle lens elements which does not change the lens' overall length when focusing. This results in better stability, which is useful for telephoto shooting.
DF: A dual focus lens. The focus ring on the lens pushes forward and backwards dis-engaging it so it does not rotate during autofocus.
Conv: These lenses are compatible with Sigma's teleconverters without and retain proper automatic exposure function.

Tamron

AD Anomalous DispersionSpecial optical glass which delivers large partial dispersion ratios relative to a specific light wavelength zone
ASL Aspherical Lens elements A type of lenses that virtually eliminates the problem of coma and other types of lens aberration. They are particularly good at correcting distortion in wide-angle lenses as well as contributing to a lighter and smaller lens design
Di Digitally integrated design Optical system designed to meet the performance characteristics of DSLR cameras as well as film cameras
Di II Digitally integrated design Lenses made exclusively for DSLR cameras with APS-C sensors
HID High Index High Dispersion glass Minimises on-axis and lateral chromatic aberrations
IF Internal FocusTo ensure stability in focusing, this lens moves the inner lens group or groups without changing the lens' physical length
LD Low DispersionLow Dispersion elements which effectively compensate for chromatic aberration that is a problem at the telephoto end and lateral aberration at the wide angle end SP Super PerformanceThe first priority in producing these lenses have been superior specifications and outstanding performance free from cost restraints
USD UltraSonic Silent DriveUltrasonic AF motor
VC Vibration Compensation - A family of techniques used to reduce blurring associated with the motion of a camera. Specifically, it compensates for pan and tilt of a camera
XR eXtra RefractiveHi Refraction index glass elements resulting in minimum aberration. Allows smaller lens diameters while maintaining aperture values for overall compactness
ZL Zoom LockPrevents undesired barrel extension


Tokina

ASA : – spherical - A type of lenses that virtually eliminates the problem of coma and other types of lens aberration. The are particularly good at correcting distortion in wide-angle lenses as well as contributing to a lighter and smaller lens design
AT-X : Advanced Technology eXtraLenses that are manufactured without compromises, using the most advanced design and fabrication technologies available
D : Digitally optimized coatings
DX : Only compatible with a cropped sensor (APS-C)
F&R : Front and Rear asphericalAspherical molded glass element in the front and in the rear FC Focus ClutchOne-touch focus clutch allows the focus to be moved quickly from the AF position back into the MF position
FE : Floating Element
HL : DHigh Refraction, Low Dispersion
IF : Internal FocusTo ensure stability in focusing, this lens moves the inner lens group or groups without changing the lens' physical length
IRF : Internal Rear FocusThis lens is equipped with a system that moves the rear lens group for focusing
PRO : Lenses that have hardened Alumite (Armalite) finish to increase durability
SD : Super Low DispersionPrevents chromatic aberration because it concentrates and directs the wavelength of the light more effectively onto the camera's sensor

Pentax

K : Is the first generation K mount lens, Manual Focus, Manual Exposure. (Listed as Pentax smc)
M : Second generation of K mount lens, smaller then their K counterparts, manual focus manual exposure
A : First Auto exposure lenses from Pentax, manual focus.
F : First generation Auto Focus, Auto exposure lens
FA : Second generation Auto Focus, Auto Exposure lens, On board chip contains lens MTF data for Hyper Program compatible bodies
FA-J : Similar to FA lenses but don’t have an aperture ring.
DA : Digital Lenses, no aperture ring, some have reduced images circle some don’t, Digital coatings and optimised construction.
D-FA : Digital Lenses, aperture ring, covers a 35mm frame. Digital coatings and optimised construction.
* (star) lens : Pentax’s equivalent to Canon’s L, lenses of exception quality. (A, F, FA)
DA* : Pentax’s High spec Digital lenses, Exceptional quality, weather sealed, SDM (Super Sonic Direct drive Motors)
Limited : A prime lens of unparalleled image quality and construction, hand made to the highest quality.
AL : A lens that uses one or more aspherical elements to help improve wide angle performance and sharpness.
ED : A lens that uses extra-low dispersion glass elements reduces chromatic aberrations.
IF : A lens that uses an internal focusing mechanism.
SDM : Super Sonic in lens lens AF motors, silent and accurate Autofocus.
Fixed Rear Element Extension (FREE) : A lens whose last element group remains fixed during focusing.
SMC : Pentax’s lens coating technology.
Quick Shift : Allows manual adjustment of AF after AF lock has been achieved.
PZ : Power Zoom, and Electronic zoom function on KAF-2 mount FA lenses, only functional on Z series FSLRs and K10D digital body.

Žižna daljina se označava u milimetrima, a otvor blende malim slovom f, tačnije f/... Primer:

http://www.photozone.de/

Otvori bilo koji test, svuda su iste oznake.

M42 je oznaka za Praktica navoj koji je korišćen kao univerzalni na starijim nemačkim, ruskim i japanskim aparatima.

Moja greska, f je blenda, a F zizna daljina. Milimetri su jedinica kojom se meri.

IvanStanimirovic ::

Evo male ilustracije

pooolako :/ malo mi je tesko ovako da skontam, ali verovatno je u praksi sve lakse

znaci 18-55mm je raspon zuma i to razumem a malo f je blenda... a blenda je otvor na objektivu [mislim u trenutku fotkanja]? ili sta nemojte da mi se smejete molim Vas

p.s. evo gledam svoj objektiv za Zenit em
pise
helios - 44m 2/58 i ima neki crtez [cetvorougao sa gornjom kracom stranom i neke dve linije]

kada na objektivu vidis oznaku ili bilo sta drugo napisano u formi razlomka

2/50 ili formi dvotacke 2:50 ili F: 2 a f: 50mm onda je prica sledeca.
jednocifreni broj je maksimalni otvor blednde na tom objektivu a dvocifreni broj je zizna daljina tog objektiva u milimetrima.
helios 44m i crtez cetvorougla i ostalog su oznake samog proizvodjaca npr. model, logo i slicno.
na svakom objektivu ces naci gore pomenute brojke, jednocifrene (ili decimalne npr 1, za otvor blende i dvocifrene u milimetrima za ziznu daljinu a ako je u pitanju zoom onda se zizna daljina izrazava u rasponu (18-55 i slicno).
na vrlo vrlo starim 'predratnim' objektivima i nekim proizvedenim do 60ih godina proslog veka ces naci i oznake zizne daljine izrazene u centimetrima 50mm=5,0cm, 35mm=3,5cm.

tvoje konkretno pitanje, da li je 18-55mm za analogni aparat.

odgovor ne. govoreci cisto o optickim karakteristikama, zapamti sledece:
analagni objektivi mog na digitalna tela ali digitalni objektivi ne mogu na analogna tela.
postoje jos neke mehanicke i elektronske zackoljice ali sto se optickih svojstava tice, ovo je prava istina.

nasao sam jeftin MIP 1B - 2.8/37 [mislim da je MIR , ali kopiram kako je napisano]

i prodavac ne zna da li ima navoj m42 koji bi odgovarao mom zenitu. Pa pitam Vas da li mozda znate da li ovaj ruski objektiv ima navoj koji mi odgovara?


p.s. kako da znam koj aparat ima koj navoj/bajonet?

Leverquin ::

kako da znam koj aparat ima koj navoj/bajonet?

Postoji nešto što se zove google

P.S. MIP 1B - 2.8/37 ima M42 navoj.

Taj MIR je najverovatnije M42 ako ima navoj. Ako ima prikljucak u 6 segmenata naizmenicno po obodu prikljucka aonda je bajonet.
Ruski objektivi za Zenit su svi M42.

coolenough ::

Ruski objektivi za Zenit su svi M42.

Starije verzije su pravljene u M39 navoju, a poslednji modeli, pocev od Automat verzije, ako se ne varam, u Pentax mount-u, iako velika vecina jeste M42, ipak treba proveriti pre kupovine.

zanimljivo, nisam znao za tu foru sa Pentax K mountom..bice da sam se okrenuo od rusa pre toga. 39ku nisam spominjao jer mislim da je vrlo malo kamera sa tim navojem stiglo u YU, mahom je to 42ka.

Znam razliku kod nikona izmedju DX i FX,ono sto ne znam je kako su oznaceni objektivi za full frame tijela,NPR ako uzmam objektiv 50 mm 1.8 dx znam da je to objektiv za crop tijelo (to mi kaze ono dx)ali kako da znam koji je objektiv FX,mislim kakvu oznaku nose.

Vrlo prosto. Sve gde ne piše DX može na oba formata (za Sigma objektive DC).

Hvala Ljubo.