I found a 60mm achromat with +7.35 diopter in Anchor Optics for about $29. And now I want to modify my own adapter into a HD ready one so that it can be used on Sony HVR-V1P. I would like to know if the quality of these achromat is acceptable. Since I really can't afford redrock's one. Anyone have tried Anchor Optics stuff?

achromat, or macro? for 29 bucks i cant imagine the quality would be that good. Is it a twopiece achromat?

The achromat might be stock left over from an OEM production run and sold at a discounted price, so you may come up lucky.

If you can put it in front of your camera before buying, try to do so.

Even better, try to shoot an image of a barcode which should be near enough to the right size although it is a little bit larger than the motion picture frame and about the same size as the still-camera frame.

This should suggest how sharp it is, what the contrast if like and if the camcorder/achromatic dioptre combination creates distortion in the image.

It is achromat. Just that this is a division of Edmund Optics which sells experimental grade optics.
http://www.anchoroptics.com/catalog/product.cfm?id=257

Hi,
I've ordered achromats from here before about a year ago. They are very low quality, some were green glass, some are filled with bubbles. Just a warning...

Ah, experimental grade. Those are for high school science projects, not HD imaging. Steer clear.

Oh Fxxk. I just ordered them. I thought they are at least better than those achromat in those $20 cheap binocular. But I ordered those so-called "Grade 1" one. They said they are free of oxidation and scratches. I wish that I will have some luck man.

I've ordered some optics at Anchor - the Grade 1 optics seemed to be okay. Don't bother with any other grade, though. Of course, I wasn't using them in a critical imaging application....

But for $29, who cares? At worst it's a (cheap) lesson. At best, you got a great deal for what would normally be a quite expensive piece of glass.

It's worth noting, by the way, that if it was originally designed for OEM it may have different performance characteristics (if it were truly custom ground, etc, it may not perform that well beyond the conjugates it was meant for). Just a warning, for anytime you try to repurpose optics.

I have macro out of Binocular lens, would they be of suitable quality? If so, that could be an cheap option.

I used binocular optics for standard definition video. It works really great for me. But the problem is that you won't find a single piece powerful achromat. You will probably need to combine two of the achromat. And I still have not try them on HD yet.

Wayne's achromat for £99 looks like the best bet out there for my money!

It was free actually. An engineer at an optical shop gave it to me. It is an dual lens. I thought it might be an interesting source, old Binoculars, and enough to do 3D adaptor ;). Actually an friend of mine gave me a bunch of lens from an film processing unit. I guess some may have telecentric properties.

There maybe achromatic in a number of lens, but an problem might be chromatic aberrations. An lens system is balanced, and individual parts might not work because they are only shaped to fit the system they are in.

4/3rd lens systems are designed to be telecentric for Digital sensors. I wonder if they would make an good optical only adaptor?

Hey Wayne,

Just out of curiosity, why the interest in telecentric systems? Are you looking to replace the stock lens on a 3-chip camera? And you may want to read this thread before thinking too hard about optical-only systems (I presume that means no scattering plate).

http://www.dvinfo.net/conf/showthread.php?t=83854

The thread gets more technical as it proceeds. Near the end, I conclude that an optical-only system would have to be unreasonably fast to get the best DOF benefits (particularly if you're trying to go from 35mm to 1/3" chip size).


Cheers,


Ryan

Thanks for that, it is time I looked at it, I have been talking about this for around 4 years.

Yes, I know this problem, I would solve it with variable density filter ;). If I am using an sensor with range extension (I have been in the Digital Cinema camera projects) then I have upto 27 stops of latitude at the moment.

My interests in telecentric systems is simple. The faster the system the more extreme the angle the rays come in. In an 3 chip camera, we found that the 3 chip prism did not like apertures faster than f1.6 I think, and with microlens, the lens did not like apertures of more than f1.3, which produces chroma aberration, or washout I forget. If I can figure out how to project the lens image onto an system that straightens it, I can get the extra stops of light while delivering the image at an low aperture, which eliminates the chromatic aberrations. I also have interests for it in other areas.

I forgot to mention, an telecentric lens (the 4/3rds lens) should give an better image, and potentially easier to relay down to target size. I wonder if this sensor/lens format would give an suitable image, and DOF, for digital cinema.

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?

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.

My post has been hijacked.

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.

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/showthread.php?p=629954#post629954