We will beat and meet any price!!!
 
BRANDS / MANUFACTURERS
ACCESSORIES
BAGS CASES
BINOCULARS-SPORT OPTICS
BOOKS
CAMERAS
CARTS
CLOSEOUTS & CLEARANCE
COLLECTIBLES
CUTTERS
DARKROOM EQUIPMENT
DIGITAL CAMERAS
DIGITAL PRODUCTS
ELECTRONICS
ENLARGING LENSES
EXPOSURE LIGHT METER
EYEWEAR SUNGLASSES
FILM
FILTERS
FLASH
FURNITURE
GAMING
GPS
GUN ACESSORIES
GUN CLEANERS
HOLSTERS
IDENTIFICATION SUPPLIES
LARGE FORMAT
LARGE FORMAT LENSES
LENSES
LINE-UP TABLES
MEDIA PLAYERS
MEDIUM FORMAT
MISCELLANEOUS
MOVIE CAMERAS
MULTIMEDIA
NETWORKING
OUTDOOR SUPPLIES
PANORAMIC CAMERAS
PRINTERS
PROJECTORS / SCREENS
RADIO
RANGEFINDER
RIFLESCOPES
SCREW MOUNT M42
SECURITY PRODUCTS
SPECIAL
TABLES
TELEPHONE
TELEPHOTO
TOOLS & KNIVES
UNUSED
USED EQUIPMENT
VIDEO CAMERAS
VIDEO CONFERENCING
VOICE RECORDERS
WINDER
REPAIRS
EMAIL US
SEARCH
TRADE INS

Schneider 28mm F2.8 PC Super-Angilon

$2119.95
Qty:



Relative density of light The brightness waste to the Bilfeldrand consists of several components. On the one hand the natural Vignettierung causes a brightness waste with the 4th power of the cosine of the angle of vision w. This effect can be changed


by distortion in the picture and by pupils coma. On the other hand curtailments of rays Ganges by lamp holder edges cause an additional brightness waste ( artificial Vignettierung). This can be reduced by fades and disappears as a rule with shading abo


ut two to three screens steps. The curves in the data sheets give(indicate) the resultierenderelative density of light (relation(connection) =Bildmitte) as a function of the angle of vision w. Distortion The distortion is an image mistake which ca


uses a distortion of the picture geometry. A rectangle is returned, e.g., according to sort of the distortion in the form of pillow or in the form of metric ton. Also a reversal of the forerunner with a certain Bidhöhe is possible. The distortion is dep


endent on the image graduation and is covered in the data sheets always to the image plane been careful for the application. Spektrale transmission By the absorption of the glasses and the rest reflections in the lenses surfaces appear bright losses


which are dependent on wavelength. The rest reflections can be decreased by suitable compensation of the lenses surfaces (Bedampfung with thin shifts). The whole transmission ( transmission degree) is represented as a function of the wavelength. Modul


ation transmission function (MTF) The ideal objective has the task to illustrate all coarse and fine structures seeming in an object realistically. This means that the brightness differences given in the object find themselves invariably in the picture


, namely for the most different structures equally. This demand is not already fulfillable for physical reasons severely. It appear in the whole area, from coarse up to the finest structures, more or less big contrast losses. Now this whole structure


area is grasped(registered) numerically by the number of line pairs per millimeter (place frequency R [1 / mm]). The MTF describes the contrast still appearing in the image plane as a function of the number of the line pairs per millimeter. The ab


breviation MTF expresses these circumstances, she comes from the English one: modulation transfer Function (modulation or contrast transmission function). This leads to a Kurvendarstellen how she is to be seen on the left. How evidently, the modulat


ion reproduction for finer structures becomes much worse and sinks for a certain number of line pairs per millimeter on zero. For the sharpness impression not this highest place frequency is authoritative, but a very high contrast reproduction about the w


hole place frequency range, up to the highest place frequency dependent on the application case. Besides, a special MTF curve is valid only for a certain point of view. In general the MTF curves differ for the different picture points, so that one wou


ld need a big number of curves to the description of the whole field of vision . Therefore, one passes over to another representation, with which the modulation for meaningfully selected place frequency about the picture height, going out from the picture


middle, is applied. This representation underlies the data sheets. In addition comes that the rays way becomes asymmetrical in the objective for picture points beyond the middle increasingly. Therefore , the MTF also still depends on the orientation


of the line pairs in the field of vision. Two are selected from the multiplicity of the possible orientations to each other vertical how in the accompanying image explains. The MTF curves valid for both orientations are sketched in the diagrams (tangen


tial) or pulled through ( sagittal) represented. Besides, the modulation transmission function depends on the opposed f-number, the applied image graduation and the weighting of the separate spektralen interests. Therefore , other MTF curves are necess


ary correspondingly to the characteristic of the image goodness. The insensitiveness to graduation changes is a quality criterion also to be considered. With extreme wide corner constructions with big angles of vision should be considered by the jud


gement of the modulation transmission that for physical reasons the modulation goes back in the field of vision for sagittale structures with the cosine, for tangential structures with the third power of the cosine of the angle of vision. The image mak


es clear on the left this at the example limited to conjugation (i.e. perfect) of objective for 20 line pairs per mm and f-number k = to 22 with a wavelength of 546 nm. The modulation is applied as a function of the angle of vision w.


   
   

Valid HTML 4.01 Transitional

Home Contact us View your shopping cart Help