Anchor Optics Achromats?

Ryan Damm · February 20th, 2007, 02:30 PM

Ah... so you're looking to use existing telecentric lenses as a relay. That makes sense.

Modifying or supplementing them will be insanely difficult. Because the ray bundles are already parallel to the lens axis, it's tough to add convergence to any ray bundle without deflecting the outer ray bundles. As you noted, this becomes an issue at extreme angles and low f-numbers.

I'd love to hear how it goes, though - have you posted any threads that describe what you're doing in detail?

Wayne Morellini · February 21st, 2007, 12:48 PM

I am sorry I wrote that wrong, I have been quiet sick and tired, ands it has been years since I thought up the scheme. The amount of lens elements in Telecentric is staggering. There is probably some coatings that could handle the deflection, but the idea was to reduce the angel and do it in stages. I should also say, that I am planning to use an sensor with latitude extension, not that I am already. There are some excellent latitude extension sensors coming to market (as far as the latitude they can achieve, but have yet to find out if the picture is nice).

It is something, I had been planing on investigating an few years ago, but got distracted but eh Digital Cinema projects. I am learning a lot, and have some Optical reference stuff I have been planning on reading for the last few years, to brush up. I still haven't got to read that purely optical thread as well.

I now remember, I have an need for telecentric in this and other projects. I want to feed into the telecentric section directly, or to use and macro to resize down to the telecentric section. As an knowledgeable person, could I ask, does this sound practical, or are there problems in what I am thinking?

Would you know how parallel/telecentric (was that the right word) the rays coming out on an 4/3rds lens are?

It occurs to me, if the 4/3rds system is already telecentric, could an 4/3rds lens with macro feature be used as the relay section from an larger lens? I know that I could use an 4/3rds lens directly and relay down, but I like those extra stops.

Lau Ho Ming · February 21st, 2007, 06:33 PM

My post has been hijacked.

Alex Chong · February 21st, 2007, 11:04 PM

Quote:

Originally Posted by Lau Ho Ming

My post has been hijacked.

You might want to try getting a 50mm dia. plano convex lens from edmundoptics. I bought one along with a 50mm achromat. The plano only cost 30 bucks +/-. I think for personal use in your own adaptor, i think the video quality will be good enough using the commercial grade plano lens. In fact, the quality should be better than using a macro. Minimal CA and barrel distortion.

Wayne Morellini · February 22nd, 2007, 08:50 AM

Quote:

Originally Posted by Lau Ho Ming

My post has been hijacked.

Sorry about that, I have started an new thread that links back here for any further discussion on Purely Optical stuff:

http://www.dvinfo.net/conf/showthrea...954#post629954

February 20th, 2007, 02:30 PM	#16
Ryan Damm Regular Crew Join Date: Dec 2005 Posts: 46	Telecentric = difficult Ah... so you're looking to use existing telecentric lenses as a relay. That makes sense. Modifying or supplementing them will be insanely difficult. Because the ray bundles are already parallel to the lens axis, it's tough to add convergence to any ray bundle without deflecting the outer ray bundles. As you noted, this becomes an issue at extreme angles and low f-numbers. I'd love to hear how it goes, though - have you posted any threads that describe what you're doing in detail?

February 21st, 2007, 12:48 PM	#17
Wayne Morellini Inner Circle Join Date: May 2003 Location: Australia Posts: 2,762	I am sorry I wrote that wrong, I have been quiet sick and tired, ands it has been years since I thought up the scheme. The amount of lens elements in Telecentric is staggering. There is probably some coatings that could handle the deflection, but the idea was to reduce the angel and do it in stages. I should also say, that I am planning to use an sensor with latitude extension, not that I am already. There are some excellent latitude extension sensors coming to market (as far as the latitude they can achieve, but have yet to find out if the picture is nice). It is something, I had been planing on investigating an few years ago, but got distracted but eh Digital Cinema projects. I am learning a lot, and have some Optical reference stuff I have been planning on reading for the last few years, to brush up. I still haven't got to read that purely optical thread as well. I now remember, I have an need for telecentric in this and other projects. I want to feed into the telecentric section directly, or to use and macro to resize down to the telecentric section. As an knowledgeable person, could I ask, does this sound practical, or are there problems in what I am thinking? Would you know how parallel/telecentric (was that the right word) the rays coming out on an 4/3rds lens are? It occurs to me, if the 4/3rds system is already telecentric, could an 4/3rds lens with macro feature be used as the relay section from an larger lens? I know that I could use an 4/3rds lens directly and relay down, but I like those extra stops.

February 21st, 2007, 06:33 PM	#18
Lau Ho Ming Regular Crew Join Date: Nov 2006 Location: Hong Kong Posts: 81	My post has been hijacked.