2 lenses

[anakedfish]

I think it would be cool to have a camera that had 2 lenses that combined to register on one set of CCDs with differential detection to combine them into one smooth picture. The point of this would be to allow for two exposures. One for the highlights and one for the lowlights. landscape still photographers do this and it is one of the last frontiers of digital film making. If digital can handle as great or greater ranges of light than film, we're there.

xupes@hotmail.com

tell me what you think

 

[Proteus]

2 lenses are not necessary

2 lenses are not necessary

I agree on the importance on reaching or exceeding film's dynamic range but it's not necessary at all to have 2 lenses to send the image to 2 sensors (CCD or CMOS).

You can put a pellicle beamsplitter behind the camera lens to split the image in two beams, one in the exact same direction and one 90o vertically to the first one. The second one will focus simultaneously on a second sensor and on the same focal distance. The sensor should have a ND filter in front of it to capture the highlights of the image.

The choice of a pellicle instead of a prism beamsplitter will give you the advantage of NOT introducing chromatic aberrations.

 

[acrochordon]

Canon EOS 1N RS

Canon EOS 1N RS

Good ideas. If they were bad ideas the Kodak Easyshare V610 (with two lenses) and the Canon EOS 1N RS (with a Pellicle mirror) would not exist. My examples are still cameras and not video cameras, but you get the point. The Kodak has two lenses for different focal lengths, not for exposure reasons. Sadly, I think the RED camera is too far along in development to incorporate these ideas. Maybe in RED TWO. There is no reason why it couldn't.

 

[acrochordon]

loose one f stop

loose one f stop

I think I remember that the EOS RS lost one f stop due to the Pellical mirror. Correct me if I am wrong. Would that defeat the whole purpose of splitting the image to get more detail in shadows? Would it be worth the trouble? Would it create too much noise?

Would two lenses be easy to synch? Would the weight and cost of another lens be worth it? I remember Canon was going to make a 3-D lens with two lenses in one tube, side by side. I don't know if Canon ever made it. If anyone knows please post a comment. Maybe that is the way to go, two lenses in one tube, so they would use the same mechanics to synch. I think that is beyond Cooke's lens making know how. The idea sounds do-able, maybe Canon can help both ideas become areality. But would Canon want to help RED? Does Canon see RED as a threat?

 

[Proteus]

I think I remember that the EOS RS lost one f stop due to the Pellical mirror. Correct me if I am wrong. Would that defeat the whole purpose of splitting the image to get more detail in shadows? Would it be worth the trouble? Would it create too much noise?

Splitting the image with a beamsplitter produces two images, each one with about 50% the intensity of the input image (one stop).
You can select the split ratio of the pellicle beamsplitter when you order it usually to be 50/50, 60/40, 80/20 or even 90/10, so especially in this case the loss is minimal because you want the second CCD to receive much less light anyway.
Of course it can be compensated with a bit longer exposure, so no problem at all (A beam splitter for a 3 CCD camera transmits max 33% of the input light to each CCD!).

Would two lenses be easy to synch? Would the weight and cost of another lens be worth it?

On a second thought, its' totally out of the question: Except from the sync problems, matte box problems etc, to make the two lenses "see" the same image you need ...a beamsplitter anyway, even if you place it in front : Cannot be avoided!

I remember Canon was going to make a 3-D lens with two lenses in one tube, side by side. I don't know if Canon ever made it. If anyone knows please post a comment. Maybe that is the way to go, two lenses in one tube, so they would use the same mechanics to synch

I don't think it can be made w/o seriously affecting the image quality and/or introducing serious limitations.

 

[acrochordon]

3D Canon lens

3D Canon lens

The following was coppied from
http://www.videomaker.com/scripts/news.cfm?id=492



The new 3D lens and the Canon XL1 operate similar to the human eyes and brain. Lenses of the eye project two slightly different pictures onto the retina. These images are transformed by the brain into a spatial representation. The stereoscopic observation is derived from the perception through both eyes. Unlike traditional shooting of 3D images -- two cameras synchronized to shoot the same images simultaneously -- the new Canon lens actually is two lenses in one, with stereoscopic synchronization controlled by the camcorder. Easy to use, the lens captures right and left eye images alternately on the CCD for 1/60 second using an LCD shutter panel.

The lens will be available in October 2001 at authorized Canon camera and video dealers. The suggested retail price is $8,499.

“There have been several 3D imagery booms but the most significant advancement in the technology is happening now,” said Yukiaki Hashimoto, vice president and general manager, Photographic Products Group, Canon U.S.A., Inc. “This revolutionary development in 3D imagery will create new ways to use the Canon XL1, make 3D effects easier to achieve and will bring this technology to more videographers.”

Old 3D Shooting Versus New 3D Shooting Traditionally, two cameras with separate lenses and separate imaging element units have been needed to achieve separate left and right images for 3D. The optical axes of the two images require fine adjustments to provide a perfect 3D image. Considerable time, specific knowledge and special training are required to set up and operate these cameras. The new Canon 3D lens solves these problems.

 

[acrochordon]

Canon "cyclops"

Canon "cyclops"

:thumbsup: :thumbsup: :thumbsup: :thumbsup: :thumbsup: :thumbsup: :thumbsup:

 

[Proteus]

...I was just about to post that photo too...

So I'll post another one:

The following gives much more information:

Canon 3D Concept appx $8500 limited production
Project cancelled prior to production run. This lens was a concept proposed by Canon in September 2000; however due to manufacturing impracticalities, it has been officially discontinued and is not available. Undoubtedly the few working prototypes which do exist are now in the Canon Lens Museum at corporate headquarters in Japan. Some details from the initial press release:

"The Canon 3D zoom lens... features a built-in focusing unit that uses triangulation to measure the distance to the subject and a motor that adjusts the mirrors inside the left and right lenses to set the angle of convergence automatically, enabling even novice users to create 3D videos as easily as they would any ordinary video. Equipped with a high-speed shutter, the lens enables the camcorder’s CCD to capture the left and right parallax images alternately as a field image at 1/60th second intervals. During the 1/60th of a second when a parallax image is being captured, the corresponding shutter is open while the other shutter remains closed, preventing the image from being recorded. This alternate image-capturing process is repeated each 1/60th of a second so that 30 images are taken through each of the left and right lenses per second for a combined capture-rate of 60 field images per second. During playback, the left and right parallax images are output alternately in the video signal."

(The above was copied from http://www.dvinfo.net/canon/articles/article58.php)

______________________________

So although this lens looks interesting, it didn't see the light of production. The statement "due to manufacturing impracticalities" is obviously translated to "it wasn't worth the money, it had problems, limitations, etc" because think about it: $8500 can solve ANY manufacturing impracticalities!

According to the above it is using mirrors, LCD shutters and of course a beamsplitter. It's a similar concept like the Nuview 3d adaptor although in this case there are two lenses. I can guess a few limitations: It wasn't wide enough, not very good operation of the lcd shutters (light leak on the off state), aberrations, etc. Even if everything else was perfect (which I doubt it) these tiny lenses cannot give you much confidence... and I wonder if it's triangulation system worked well...

Having said that, I'm always interested on original innovative products...

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