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phoenix
BRUCE ALMIGHTY
Posts: 9676
Joined: 09 May 2012, 14:40
Location: Aberdeen

Re: New to the forum

Post by phoenix » 30 Jul 2014, 16:55

One of the big advantages of aspherical lenses over normal spherical lenses is that they can produce a tighter focus with less spreading out of the different colours in visible light (aberration)
We use the term aperture to describe how much light passes through a lens and lower aperture numbers pass more light than large aperture numbers.
Mathematically, aperture is the focal length of the lens divided by it's diameter.
So, a lens with a focal length of 75mm and an aperture of f1.4 will have a diameter of approx 53mm
The light is bent (refracted) as it passes through the lens and the larger the aperture, the more bending is required to get it focussed at it's specified focal length.
For a given amount of bending, an aspheric lens produces less aberration than a spehrical lens, and so gives a sharper focus.
It can also mean that a camera lens which would normally contains several optical elements can be simplified (and manufactured at less cost) when an aspheric lens is included in the design
This probably explains it better than me
http://en.wikipedia.org/wiki/Aspheric_lens

Cheers

Bruce
LAND ROVER - THE WORLD'S WORST 4X4 BY FAR

tdea1388
Posts: 120
Joined: 16 Jul 2014, 22:25
Location: Florida

Re: New to the forum

Post by tdea1388 » 30 Jul 2014, 19:05

So it should work With the set-up? :?

phoenix
BRUCE ALMIGHTY
Posts: 9676
Joined: 09 May 2012, 14:40
Location: Aberdeen

Re: New to the forum

Post by phoenix » 30 Jul 2014, 19:27

Yep your Cosmicar lens will work just fine for a scopeless build.

Cheers

Bruce
LAND ROVER - THE WORLD'S WORST 4X4 BY FAR

tdea1388
Posts: 120
Joined: 16 Jul 2014, 22:25
Location: Florida

Re: New to the forum

Post by tdea1388 » 30 Jul 2014, 19:33

Thank you,

Guess I kinda jumped in with both feet Thinking I knew more than I did.

But I am learning a lot from you guys on this forum....

Thank you all for that.... :D

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