T factor of a lense??????...

[peshaw 0]

Hello,

I am new in this field and have some questions from you guys.

I came accross through a term called T factor of a lense,what is it?

Thanks.

Capt.peshaw

[Cooperman 0]

Hi peshaw and welcome,

 

The "T" factor of a lens refers specifically to it's ability to transmit light through the optics.

 

Very few manufacturers use this measure (it's probably far too honest for most to cope with ), but prefer to quote the 'f' figure for the maximum aperture of the lens.

 

Whilst it is generally accepted that the smaller the 'f' number , the larger the aperture and therefore the more light should be passing through it, in practice the size of the aperture is simply an indication of expected performance, as it does not allow for the quality of the optics, lens coatings or efficiency of the optical design.

[peshaw 0]

Thank you cooperman for the reply,that really helps for the beginner.

 

 

Capt.Peshaw.