Difference between revisions of "TTL"

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{{glossary}}
 
{{glossary}}
The acronym '''TTL''' most commonly refers to:
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;The acronym '''TTL''' most commonly refers to,
 
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|image_source= https://www.flickr.com/photos/vox/51230035316/in/pool-camerawiki/
 
|image_source= https://www.flickr.com/photos/vox/51230035316/in/pool-camerawiki/
 
|image= https://live.staticflickr.com/65535/51230035316_ca1f0f4f9f_n.jpg
 
|image= https://live.staticflickr.com/65535/51230035316_ca1f0f4f9f_n.jpg
 
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|image_text= A diagram from [[Ricoh]] indicates two<br>approaches to TTL exposure metering
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|image_text= A diagram from [[Ricoh]] indicates two approaches<br>to TTL exposure metering
 
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|image_rights= fair use
 
|image_rights= fair use
 
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;Through The Lens: Usually referring to in-camera [[camera#TTL Metering|exposure metering]] or flash exposure control, but also used to differentiate [[viewfinder]] designs, [[autofocus]] mechanism designs, and other systems on lens-based cameras.  Measuring light or focusing through the taking lens can be more accurate than separate metering, viewfinder or focus systems, as this measures the light that will reach the film, from the exact point-of-view of the lens - and so eliminates [[parallax]] and stray light from outside the frame.
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Through The Lens: referring to in-camera [[camera#TTL Metering|exposure metering]] with photocells somewhere in the light path of the taking lens; making a distinction from older designs where a [[CdS]] or [[Selenium meter | selenium]] meter cell was attached to the body, but could not take into account light loss from filters, lens extension, etc,
  
But,
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TTL flash exposure control is another common meaning. But depending on context the term might also differentiate [[viewfinder]] designs, [[autofocus]] mechanism designs, or other camera systems.
;Transistor-Transistor Logic: TTL is a type of digital electronic circuitry which uses transistors and resistor elements (usually made of transistors) to make logic gates. It is rarely, if ever used in camera circuitry as it has fairly high power consumption.  
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;But,
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Transistor-Transistor Logic: TTL is a type of digital electronic circuitry which uses transistors and resistor elements (usually made of transistors) to make logic gates. It is rarely, if ever used in camera circuitry as it has fairly high power consumption.  
  
 
[[Category:Abbreviations]]
 
[[Category:Abbreviations]]

Revision as of 00:07, 7 June 2021

Glossary Terms
The acronym TTL most commonly refers to,

Through The Lens: referring to in-camera exposure metering with photocells somewhere in the light path of the taking lens; making a distinction from older designs where a CdS or selenium meter cell was attached to the body, but could not take into account light loss from filters, lens extension, etc,

TTL flash exposure control is another common meaning. But depending on context the term might also differentiate viewfinder designs, autofocus mechanism designs, or other camera systems.

But,

Transistor-Transistor Logic: TTL is a type of digital electronic circuitry which uses transistors and resistor elements (usually made of transistors) to make logic gates. It is rarely, if ever used in camera circuitry as it has fairly high power consumption.