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Focal Reducer - Rumour site

kainekainekaine

New member
Micro four third rumours has posted a patent application from Olympus for a focal reducer x0.5. If its decent quality it would be perfect for video users but just wondering about the still side of things. Anyone tried anything like this before? I have seen cheap chinese optical adapters to convert Pentax lenses to Nikon mount which seem to work well enough. Remember this is just rumour at the minute but looks interesting. What else can you think of that would be of interest in the adapter space for 35mm lenses? I know Tilt Shift adapters are making use of the space. This patent would be likely for OM lenses and not four thirds I assume. Maybe also other brands of 35mm lenses.
 
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Vivek

Guest
Could you give a link please. I don't know how to navigate through that site.:eek:
 

RichA

New member
Micro four third rumours has posted a patent application from Olympus for a focal reducer x0.5. If its decent quality it would be perfect for video users but just wondering about the still side of things. Anyone tried anything like this before? I have seen cheap chinese optical adapters to convert Pentax lenses to Nikon mount which seem to work well enough. Remember this is just rumour at the minute but looks interesting. What else can you think of that would be of interest in the adapter space for 35mm lenses? I know Tilt Shift adapters are making use of the space. This patent would be likely for OM lenses and not four thirds I assume. Maybe also other brands of 35mm lenses.
Focal reducers are common in astronomy, you take a 2000mm f10 SCT lens and drop it down to 1000mm f5.0. Wider field, faster, etc. But you don't see them for camera lenses. You can get a well-corrected f5-f6.3 focal reducer for telescopes for about $150.00. You can even get an f3.3 (660mm) that will support a smaller than 35mm field size.
 

Jonathon Delacour

Subscriber Member
The post from the Japanese weblog, Zuiko-FourThirds あれこれ ("This and that about Zuiko/FourThirds"), contains speculation about what might result from two Olympus patents dated February 4, 2010.

The first patent is for a "wide converter" ( ワイコン waikon) which performs the opposite function of a tele-converter (テレコン terekon) by halving the focal length of a lens, so that a legacy lens on an m4/3 camera has its original angle of view. In other words, a 24mm legacy lens performs as a 24mm wide angle rather than a 48mm-e normal lens on m4/3. Or, in the example he uses, an OM 100mm f/2.0 lens with the adapter mounted becomes a 50mm f/1.0 lens.

The writer argues that the patent illustrations suggest the waikon will only work with 35mm SLR lenses because of the depth required to accommodate the optical elements, thus excluding the use of M-mount lenses.

The speculation about the second patent is more difficult to follow but it seems to be for a (different?) adapter that uses electrical contacts together with the Olympus Supersonic Wave Drive (SWD) mechanism to somehow control the helicoid in a manual focus lens so that it can be auto-focused.

It's not clear to me whether the waikon adapter is for lenses other than those with the Olympus OM mount. He refers to 35mm SLR lenses in general but uses the specific example of an OM lens. Given that Olympus isn't manufacturing OM lenses any more, they probably have nothing to lose by producing multiple versions of the waikon for different legacy mounts. If they produce anything at all.
 

kainekainekaine

New member
Would it be possible to add autofocus ability to old Olympus manual lenses? Is that what the 2nd patent is saying? Or just to add ability to four thirds lenses which arent currently fully compatible? Or something else?
 
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Vivek

Guest
Jonathon, Thanks for the info. :)

Yes, in principle, it is possible to get AF with manual focus lenses on such a converter.

Nikon had TC-16A. This allowed manual focus lenses to be auto focused with appropriate cameras.

Rewired TC-16A can still be used this way on many current Nikon cameras as well. Pretty neat.

See: http://www.foolography.com/free-stuff/modify-tc-16a/
 

Jonathon Delacour

Subscriber Member
Would it be possible to add autofocus ability to old Olympus manual lenses? Is that what the 2nd patent is saying? Or just to add ability to four thirds lenses which arent currently fully compatible? Or something else?
No, the implication is that it would be adding auto-focus to manual lenses.
...このワイコンを付ければ装着したMFレンズが本来の画角で使えるだけでなくAFも効くようにするところだ。​
Rough translation: if this waikon is attached, the mounted MF lens would not just show the original angle of view but AF would also be effective.
 

kainekainekaine

New member
Is it just certain lenses that have this ability? I guess Olympus have the rights to add this ability to there own legacy lenses but to do this for other brands would permission be needed?
 

Jonathon Delacour

Subscriber Member
Jonathon, Thanks for the info. :)

Yes, in principle, it is possible to get AF with manual focus lenses on such a converter.

Nikon had TC-16A. This allowed manual focus lenses to be auto focused with appropriate cameras.

Rewired TC-16A can still be used this way on many current Nikon cameras as well. Pretty neat.

See: http://www.foolography.com/free-stuff/modify-tc-16a/
Vivek, thank you! I couldn't help thinking that the whole concept (MF -> AF) sounded rather far-fetched but your example indicates it's clearly possible.

Is it just certain lenses that have this ability? I guess Olympus have the rights to add this ability to there own legacy lenses but to do this for other brands would permission be needed?
Given the plethora of m4/3 adapters, I wouldn't think permission would be needed or, if it was, that permission would be difficult to obtain.
 

pellicle

New member
and it uses the SWD technology (which is like the Canon USM ring motor)

very interesting. To me this indicates that Olympus and Panasonic are doing different things with their AF motors ... might swing me towards Oly if that is the case
 
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raymondluo

Guest
So by that count even an om 35-70mm f/4 would become a 35-70mm f/2? Or are zooms more complicated. If so that's just incredible.
 

pellicle

New member
Hi

firstly, thanks for bring this up ... very interesting development

The speculation about the second patent is more difficult to follow but it seems to be for a (different?) adapter that uses electrical contacts together with the Olympus Supersonic Wave Drive (SWD) mechanism to somehow control the helicoid in a manual focus lens so that it can be auto-focused.
I suspect it would not touch the manual lens focus at all (hard to do from behind even if it had the power), but would indeed work like say the 20 f1.8 behind a telescope (as in digiscoping)

very interesting
 

pellicle

New member
So by that count even an om 35-70mm f/4 would become a 35-70mm f/2? Or are zooms more complicated. If so that's just incredible.
as I understand it, the light gathering will be equivalent, but probably the DoF will still remain as it is.

interesting stuff however.

I was recently told that a potential is that (for example with the Nikon adaptor) the lens could be restricted to a specific aperture, such as f4 prior to being placed on the adaptor.

I have no experience in this area, and I'm reporting what I was told.
 

PeterB666

Member
If Olympus produce the 0.5x converter with a SWD focusing helicoil it will indeed be interesting but based on the price of thier 1.4x and 2.0x teleconverters and their SWD lenses, it isn't going to come cheap.

I had been thinking of getting rid of my 50mm f/1.4 OM lens, but may just hold onto that for a while. I also have a very nice 28mm f/2.8.

I wonder how long from patent to production?
 
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Vivek

Guest
Usually, the product is ready at hand when a patent is filed (for cameras and such).

If Oly succeed in getting such a gizmo into the market, it be will be fantastic! :thumbs:
 

Bernard

Member
Angénieux and Zeiss used to offer a similar adapter for using 35mm motion picture lenses on 2/3" video cameras, called the 'CLA 35 HD.' It essentially refocused the image out of the original lens onto a smaller sensor.

I don't think they are available anymore, but that's mainly because the market isn't there anymore. There are a lot more good HD lenses around, and newer video cine cameras can take cine lenses directly (because they have sensors that are the same size as film cameras).

I would love to see this type of adapter, but not in OM mount. Maybe Olympus can make the adapter with an intermediate mount, and then offer additional adapters for Leica R, Contax, Rollei, Nikon, etc.

As for autofocus on such an adapter, I think Yashica offered an AF teleconverter in the late 1980s.
 
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Vivek

Guest
Bernard, Nikon still offers such converters. They are special order stuff and are mighty expensive. Century Optics also have made (custom orders) such adapters.
 
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