instance_of canon tlb
The T - mount is a ___MASK92___ ___MASK80___ for cameras and other optical assemblies . The usual T - mount is a screw mount using a male 42 × 0 . 75 ( 42 mm ___MASK78___ , 0 . 75 mm thread pitch ) metric thread on the lens with a flange focal distance of 55 mm and a mating female 42mm thread on a ___MASK13___ adapter or other optical component . This thread form is referred to as T - thread . ( This should not be confused with the M42 ___MASK80___ which is also 42 mm ___MASK78___ , but has a ___MASK27___ mm thread pitch .) A ___MASK80___ is an ___MASK23___  mechanical and often also electrical  between a photographic ___MASK13___ body and a lens . It is confined to cameras where the body allows interchangeable lenses , most usually the rangefinder ___MASK13___ , ___MASK51___ lens reflex type or any movie ___MASK13___ of 16 mm or higher gauge . Lens mounts are also used to connect optical components in instrumentation that ___MASK34___ not involve a ___MASK13___ , such as the modular components used in optical laboratory prototyping which join via C - mount or T - mount elements . In a ___MASK13___ , flash synchronization is defined as synchronizing the firing of a photographic flash with the opening of the shutter admitting light to photographic film or electronic image sensor . It is often shortened to flash sync or flash synch . A rangefinder ___MASK13___ is a ___MASK13___ fitted with a rangefinder , typically a split - image rangefinder : a ___MASK83___ - finding focusing mechanism allowing the photographer to measure the subject distance and take photographs that are in sharp focus . Most varieties of rangefinder ___MASK6___ two images of the same subject , one of which moves when a calibrated wheel is turned ; when the two images coincide and fuse into one , the distance can be read off the wheel . Older , non - coupled rangefinder cameras display the focusing distance and require the photographer to transfer the value to the lens focus ring ; cameras without built - in rangefinders could have an external rangefinder fitted into the accessory shoe . Earlier cameras of this type had separate viewfinder and rangefinder windows ; later the rangefinder was incorporated into the viewfinder . More modern designs have rangefinders coupled to the focusing mechanism , so that the lens is focused correctly when the rangefinder images fuse ; compare with the focusing screen in non - autofocus SLRs . A hot ___MASK32___ is a mounting point on the top of a ___MASK13___ to attach a flash unit and other compatible accessories . It takes the form of an angled metal bracket surrounding a metal contact point which shorts an electrical connection between ___MASK13___ and accessory for standard , ___MASK52___ - independent flash synchronization . The ___MASK49___ TLb is a 35 mm ___MASK51___ - lens reflex camera introduced by ___MASK49___ in September 1974 . It features a ___MASK49___ FD lens mount , and is also compatible with ___MASK49___ ' s earlier FL - mount lenses in stop - down metering mode . The TLb was a cheaper version of the ___MASK49___ FTb for the export market , as was the slightly later TX . Compared to the TX , the hot shoe was omitted , although the camera included a PC terminal for flash sync . The TLb was later ( April 1976 ) sold in Japan . The movie ___MASK13___ , film ___MASK13___ or cine - ___MASK13___ is a type of photographic ___MASK13___ which takes a rapid sequence of photographs on an image sensor or on a film . In contrast to a ___MASK30___ , which captures a ___MASK51___ snapshot at a time , the movie ___MASK13___ takes a series of images ; each image constitutes a " frame ". This is accomplished through an intermittent mechanism . The frames are later played back in a movie projector at a specific speed , called the frame rate ( number of frames per second ). While viewing at a particular frame rate , a person ' s eyes and brain merge the separate pictures together to create the illusion of ___MASK39___ . Japan (" Nippon " or " Nihon " ; formally "" or " Nihon - koku ", means " ___MASK94___ of Japan ") is a sovereign island nation in Eastern Asia . Located in the Pacific ___MASK95___ , It is lying off the eastern coast of the Asia Mainland ( east of China , Korea , Russia ) and stretching from the ___MASK99___ of Okhotsk in the north to the East China ___MASK99___ and near Taiwan in the southwest . The ___MASK49___ FT QL is a 35mm ___MASK51___ - lens reflex camera introduced by ___MASK49___ of Japan in March 1966 . It has a ___MASK49___ FL lens mount compatible with the large range of FL series lenses . The FT can also operate the later ___MASK49___ FD series lenses in stop - down mode , but the earlier R series has a different lens aperture mechanism and cannot be used , although the ___MASK55___ fitting is similar . The standard kit lenses were ___MASK49___ ' s 50mm f / 1 . 8 ; 50mm f / 1 . 4 and 58mm f / 1 . 2 , the body - only option was offered later . The ___MASK49___ FTb is a 35 mm ___MASK51___ - lens reflex camera manufactured by ___MASK49___ of Japan from March 1971 replacing the ___MASK49___ FT QL . It features a ___MASK49___ FD lens mount , and is also compatible with ___MASK49___ ' s earlier FL - mount lenses in stop - down metering mode . Launched alongside the top - of - the - line F - 1 , the FTb was the ___MASK60___ - market camera in the range .