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relay lenses


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#1 Daniel Madsen

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Posted 10 March 2007 - 02:37 PM

What is a relay lense? That is all.
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#2 chuck colburn

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Posted 10 March 2007 - 03:29 PM

What is a relay lense? That is all.


Hi Danielle,

Most times, relay optics are used to move the image a given distance without changing the size of the original.

Chuck
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#3 Daniel Madsen

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Posted 10 March 2007 - 07:02 PM

and why would you use such a thing?
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#4 Mike Rizos

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Posted 10 March 2007 - 07:25 PM

A viewfinder extension uses them.
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#5 Phil Rhodes

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Posted 10 March 2007 - 07:34 PM

A lense is a spelling mistake.

A lens is a piece of optical equipment.

Phil
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#6 chuck colburn

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Posted 10 March 2007 - 09:43 PM

A lense is a spelling mistake.

A lens is a piece of optical equipment.

Phil


Jeeeeze Phil,

Picky picky picky LOL
And if you want to get right down to it, a lens is a component of a given piece of optical equipment.

Chuck
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#7 Rob van Gelder

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Posted 11 March 2007 - 09:13 AM

instead of picky remarks or correct but vague descriptions........

A relay lens is often used in snorkel lenses or boroscope and periscope and endoscope lenses (assemblies ;-) )

It brings the image further away from the first focal plane, normally with a 1:1 transfer ratio.
That way, you can make lenses that can fit is small holes/tubes/cavities or have wide angle macro lenses with an extension tube (relay lens) that brings the camera further away from the object, so you have less shadow and a better chance to light the subject.
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#8 chuck colburn

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Posted 11 March 2007 - 09:30 AM

What Rob said.
Oh yeah and everybodys favorite, the proctoscope! OUCH
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#9 Rob van Gelder

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Posted 12 March 2007 - 12:23 AM

i didn't go into detail about the "cavities" :D

Oh, one important thing to remember: relais lenses loose a lot of light when moving the image further.
3 to 5 stops is not unusual and so you can have a 2.8 lens on the front but still an effective opening of 8 or 11.
And then they are not even on their best in optical performance, stop down (on the relay lens, not the front lens!) to 22 to 45 for best results.

Oh, let's not forget that many of the older systems need to be completely clean or you will see every speck of dust on your final image.

nightmares.......... :blink:
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CineLab

Wooden Camera

Visual Products

Paralinx LLC

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rebotnix Technologies

New Pro Video - New and Used Equipment

Aerial Filmworks

Broadcast Solutions Inc