New 3D lens announced


Depthcam
 

A few months ago, Canon was issued a patent for a stereo lens designed to mount on its full-frame DSLRs.  It seemed quite clear from the patent drawings that this lens would most likely be a fish-eye design for use in shooting VR180 content.

Unfortunately, so far, there has been no indication that Canon has any plans to manufacture and market that lens in the foreseeable future.  However, the concept seems to have inspired another company - well-known lens manufacturer Izugar - to design a similar lens.  Izugar is considered the leader in VR 180 lens design and their lenses are used by Zcam for its K1 and K2 VR180 professional cameras.

However Izugar's new twin-lens design will offer compatibility with regular 2D cameras.  The catch here is that they are designed primarily for professional cinematic cameras such as the Black Magic URSA mini Pro 12k (retail price: US$10,000.) or the "slightly cheaper" Zcam E2-F8 (US$6000.).

Even though such cameras are intended mostly for the cinema industry, hopefully, this new 3D lens might inspire Canon to move ahead with its own VR180 lens project.

Francois


Depthcam
 

Looking further into the company's goals for this lens, it would appear that they are aiming to make this lens compatible with far more camera models than I had originally assumed.  It seems the illustrations published were meant mainly to illustrate how these lenses could be mounted to cinematic cameras.

Even though this lens should be compatible with many more camera models, it will be limited to cameras that have full-frame sensors such as the Canon R5, the Sony Alpha 1 and the Panasonic S1H.  These are still fairly expensive cameras but a little less so than the models shown in the OP.  Of course the stereo lens itself is likely to also be quite expensive.

Francois


Michael Cosentino
 

We won't ever see it in the consumer market.
Mike C.

On Fri, Mar 26, 2021, 3:05 PM Depthcam via groups.io <depthcam=yahoo.ca@groups.io> wrote:
Looking further into the company's goals for this lens, it would appear that they are aiming to make this lens compatible with far more camera models than I had originally assumed.  It seems the illustrations published were meant mainly to illustrate how these lenses could be mounted to cinematic cameras.

Even though this lens should be compatible with many more camera models, it will be limited to cameras that have full-frame sensors such as the Canon R5, the Sony Alpha 1 and the Panasonic S1H.  These are still fairly expensive cameras but a little less so than the models shown in the OP.  Of course the stereo lens itself is likely to also be quite expensive.

Francois


Depthcam
 

> We won't ever see it in the consumer market.


Well, technically, it will be available to purchase by anyone.  It's all a matter of how much money you are willing to spend on a 3D lens (and the camera that is compatible to it).

The good news here is that this shows new 3D products are still being introduced and more affordable ones are likely coming.

Francois


Oktay
 

I am in the process of designing and building a stereo lens system, which in principle is similar to the Canon design , but much simpler.

Hopefully I will be able to use the same design for normal range 3D and for different close-up 3D ranges as well, on an APS-c body.

I hope within a week or two I will be able to send some pictures of the unit and different types of stereo photographs taken with it.

Oktay


Depthcam
 

> I am in the process of designing and building a stereo lens system


This reminds me of the Leitz Stemar or the Zeiss Stereotar C:  Twin lenses occupying the space of a single lens coupled with a prism adapter to widen the base - something that Panasonic should have done with their Lumix 3D lens.

It also is reminiscent of the several incarnations of the Loreo lens for DSLRs.  Are you working on something along the same lines ?

Francois


Oktay
 

On Thu, Apr 1, 2021 at 01:33 AM, Depthcam wrote:
>>something that Panasonic should have done with their Lumix 3D lens.<<
I am doing it with the Lumix 3D lenses.
Attached is a photo of work in progress. Had to go back to the drawing board.

Oktay


Depthcam
 

> I am doing it with the Lumix 3D lenses.


Do you mean that you are making a base expander that will fit the Lumix 3D lens without any modification of the lens or do you need to replace the entire front section of the Lumix lens in order to fit your adapter ?

Francois


Barry Aldous
 

There seems to be some confusion here.  Extending the stereo base of a cameras with two lenses will result in a very large assembly and a very limited focal length with a small FOV.  I have done experimental work, extending the the stereo base of the Panasonic 3D1 using 4 mirrors; this worked to some extent but is not very useful.  Cyclopital3D produced a base extender for the Sony TD10 camcorder; this gets as close to filling the requirements, but is still very limited.  Having built several 'Beamsplitter' rigs for single lens cameras, I find this to be the most satisfactory option, Alternatively, twinning cameras provides the ultimate solution if you master the synch issues!

Barry A


Depthcam
 

On Fri, Apr 2, 2021 at 04:12 AM, Barry Aldous wrote:
Extending the stereo base of a cameras with two lenses will result in a very large assembly

I'd like to point your attention to the Leitz Stemar and the Zeiss Stereotar C - both produced in the fifties by legendary manufacturers.  Both use a twin-lens module that mounts on a regular camera body and both feature a compact prism base extender for taking shots with a normal base.

I don't yet know exactly what Oktay has in mind.  But I know that OKtay has experience with 3D camera and 3D lens design that spans many decades. I use to correspond with him back in the eighties when he showed me several custom 3D lenses and cameras of his own creation.  So I remain curious to see what he will come up with.

Stereo converters for single lenses (unless they reorient the optical axis for head to head recording) introduce strong opposite keystone distortion; so I avoid them altogether.

The goal of using a stereo adapter is seldom to replace a stereo camera or rig.  It is primarily a matter of convenience.  For example, many people here use the Lumix 3D lens for close-ups.  If they could carry along a simple lightweight adapter, they could use the same camera and optics for the occasional normal range shot.  That may be what Oktay has in mind - or not.   I don't know yet.

Let's wait till Oktay has shown us his prototype before jumping to conclusions.

Francois


Barry Aldous
 

Perhaps I should explain a few of things.  I am aware of and possess many of the options available  including those once produced by Cyclopital3D.  I personally use a Panasonic GX-7 with versions of the Lumix 3D lens and on occasions, a  Zeiss Stereotar 842.  The Stereotar out performs all other adapters I have tried, including those produced by Franc and Pentax. 

I also use a Canon 5D MkII with a home made stereo adapter, similar to that once produced by Kula, using 4 first surface mirrors.  I would suggest to Oktay that he follows the Kula route for the adapter, using a dedicated prime lens to match the camera.  The concept of extending the stereo base of the Lumix 3D lens is a non starter in my view.

Regarding Keystone distortion, I have found that SPM corrects this very well.  The bigger problem with all these adapters is the inherent narrow field of view - no wide angle potential.  Fortunately, we do have the Fuji W3 and Panasonic 3D1 to work with, if they can be found.

I shall be glad to answer any questions relating to twinned rigs and their synchronisation.

Barry A  


Depthcam
 

> a  Zeiss Stereotar 842


Do you mean a "Steritar" single lens adapter ?


> The Stereotar out performs all other adapters I have tried, including those produced by Franc and Pentax. 


I am not clear on that last point.  Are you comparing the "Stereotar" - a twin-lens adapter - with Franka and Pentax or the Steritar single lens adapter ? And if you are using a Steritar, on which lens and digital camera are you mounting it ?  Also, please define "outperfoms".  The Franka adapter had a major flaw in that it used back silvered mirrors and was very large.  The Pentax is a smaller unit with front surface mirrors that was designed to mount on specific Pentax lenses.  In the early eighties, I also tested the Stitz adapter which only worked on lenses 55mm and longer and had a convergence button.  With shorter lenses, it would vignette. It was also very heavy and would pull down the lens.


> I would suggest to Oktay that he follows the Kula route for the adapter, using a dedicated prime lens to match the camera.


I would suggest that you wait for Oktay to show us what he has in mind.  Believe me, he knows what he is doing.  The Kula adapter already exists and perpetuates the myth that such single lens adapters are of any value.  There is no point in repeating the errors that have already been made. Such single lens mirror adapters in fact introduce such strong opposite keystone distortion that SPM can only correct it (partially) in some cases.  The reason is simply that the convergence is so pronounced that the lens is looking at different parts of the background when it is further away from a main subject at close range and nothing can correct that.

Rather than argue the point, here is a picture taken with the Kula adapter:




:There is nothing that SPM can do to correct non-matching background - not to mention internal reflections that sometimes occur with such adapters.

Anyhow, I think we are moving quite far from the original topic. Although I fully agree that such adapters when used for "normal 3D" provide a limited FOV, it's a quite a different story when twin 180 fisheye lenses record their image on a 12K full frame sensor since the FOV remains at 180 degrees. Even though the Izugar solution is for pro cinematic use only, the Canon version discussed a few months ago may be more accessible to those interested in exploring VR180.

Francois




Oktay
 

I am not using the Lumix 3D lens as it is because of the following reasons:

-The width of the Panasonic camera sensor is narrower compared to APS-c sensor.
(We are dividing the sensor into two, minus septum; so the more width the better.)

-It's base is only 10mm , almost impossible to use extending mirrors or prisms.

-The Lumix lens is focused to 60cm and a little beyond whereas I want to use the base extended lens from 2.00m to infinity.

I want to use the same lenses for close-up 3D as well.



So, I have dismantled the Lumix 3D lens.

I have re-installed them on a 30mm threaded filter ring that can be screwed out of the adapter 
(More about the reason of this later.)

The new stereo base is 12.5mm.(  The centres of two halves of the 23.6mm sensor + septum width.)

It is attached on a Fujifilm X-E2 APS-c Camera.(Attached photo)

Four front coated mirrors taken from old Polaroid cameras will extend the base to about 70mm.

I am trying to extract about 10mm width for each side's image on the 23.6mm sensor.

With the Lumix lenses' 12.5mm focal length this will yield a FOV of 44 degrees which is not narrow at all.
The 35mm equivalent focal length will be 45mm which can be considered slightly wider than normal.

Stemar lenses when used on 35mm film (36mm width) create indeed narrow images because their focal length is 33mm.

The 35mm equivalent of the 12.5mm Lumix lens is only 19mm.(compared to 33mm of the Stemar)
This property of the Lumix lenses is actually the reason why I am using them.
(This wide angle of course brings up some challenges in modelling the extender.)

I own already the Pentax and Stitz adapters for single lenses ,but I very rarely use them because of their many limitations.


Now about the installation of the lens pair on a filter ring with thin threads.

When the base extending mirrors unit will be removed, only the two lenses will remain on the camera.

Every time the lens pair will be turned 180 degrees (half turn) the lens pair will extend outside for a fraction of a mm.
This means that the focusing  will be adjusted to a closer object.

I can half turn the ring six times before it gets loose out of the adapter, at each turn the lenses extending more from the sensor.
This also means that I can shoot close-up 3D at five different magnification ratios.
A fraction of a mm is a considerable amount in the extension of a 12.5mm lens.

Because I use only simple hand tools , lenses and mirrors have to be mounted to very precise standards.
When it is finished, hopefully I will be able to use the same camera and lenses for both normal and close-up ranges with the advantage of having a single shutter only, that excludes al synchronization issues.

The image size of each side will be about 2000 px X 2000 px on the X-E2.

Oktay


George Themelis
 

Wow, impressive work Oktay!

 

Thank you for explaining this very well and for the pictures showing your setup.

 

I am looking forward to more impressions/results when this is up and running.

 

George

 

 

From: Oktay via groups.io
Sent: Saturday, April 3, 2021 6:07 PM
To: main@photo-3d.groups.io
Subject: Re: [Photo-3d] New 3D lens announced

 

I am not using the Lumix 3D lens as it is because of the following reasons:

-The width of the Panasonic camera sensor is narrower compared to APS-c sensor.
(We are dividing the sensor into two, minus septum; so the more width the better.)

-It's base is only 10mm , almost impossible to use extending mirrors or prisms.

-The Lumix lens is focused to 60cm and a little beyond whereas I want to use the base extended lens from 2.00m to infinity.

I want to use the same lenses for close-up 3D as well.



So, I have dismantled the Lumix 3D lens.

I have re-installed them on a 30mm threaded filter ring that can be screwed out of the adapter 
(More about the reason of this later.)

The new stereo base is 12.5mm.(  The centres of two halves of the 23.6mm sensor + septum width.)

It is attached on a Fujifilm X-E2 APS-c Camera.(Attached photo)

Four front coated mirrors taken from old Polaroid cameras will extend the base to about 70mm.

I am trying to extract about 10mm width for each side's image on the 23.6mm sensor.

With the Lumix lenses' 12.5mm focal length this will yield a FOV of 44 degrees which is not narrow at all.
The 35mm equivalent focal length will be 45mm which can be considered slightly wider than normal.

Stemar lenses when used on 35mm film (36mm width) create indeed narrow images because their focal length is 33mm.

The 35mm equivalent of the 12.5mm Lumix lens is only 19mm.(compared to 33mm of the Stemar)
This property of the Lumix lenses is actually the reason why I am using them.
(This wide angle of course brings up some challenges in modelling the extender.)

I own already the Pentax and Stitz adapters for single lenses ,but I very rarely use them because of their many limitations.


Now about the installation of the lens pair on a filter ring with thin threads.

When the base extending mirrors unit will be removed, only the two lenses will remain on the camera.

Every time the lens pair will be turned 180 degrees (half turn) the lens pair will extend outside for a fraction of a mm.
This means that the focusing  will be adjusted to a closer object.

I can half turn the ring six times before it gets loose out of the adapter, at each turn the lenses extending more from the sensor.
This also means that I can shoot close-up 3D at five different magnification ratios.
A fraction of a mm is a considerable amount in the extension of a 12.5mm lens.

Because I use only simple hand tools , lenses and mirrors have to be mounted to very precise standards.
When it is finished, hopefully I will be able to use the same camera and lenses for both normal and close-up ranges with the advantage of having a single shutter only, that excludes al synchronization issues.

The image size of each side will be about 2000 px X 2000 px on the X-E2.

Oktay

Attachments:

 


dinoDDD
 

Congratulations on the design of this impressive lens. Which Polaroid camera do you get your mirrors from and how do you cut them?


Barry Aldous
 

Thanks to Oktay for clarifying his project.  The details provided make a lot of sense, I'm sure we all wish him well with his endeavour, and look forward to seeing his results.  I am now encouraged to look further into a much needed base extender for the Panasonic 3D1.  Is it worth cutting open the Kula for that purpose!

Barry A 


Oktay
 

On Sat, Apr 3, 2021 at 07:56 PM, dinoDDD wrote:
>>Which Polaroid camera do you get your mirrors from and how do you cut them?<<
Any old Polaroid camera, except the ones with bellows will do. Even Kodak cameras of the same type will be useful.
I use a glass cutter, apply a little amount of diesel oil onto the surface of the mirror.
After cutting I rub the cut edge to a sandpaper not harder than grade 120.

Oktay


Laurent DOLDI (Toulouse, France)
 

On Sun, Apr 4, 2021 at 03:24 AM, Barry Aldous wrote:
a much needed base extender for the Panasonic 3D1
Simpler solution : a W3 (joke - actually the image quality of the 3D1 is better)
I use a W3, a 3D1, a pair of Sony RX100-VI or my Pentax KP (cha-cha) depending on the subject (or a Huawei P30 pro if I do not have any camera with me).


robert mcafee
 

Quality front surface mirrors of various dimensions are readily available online (cheap ones from China). 




On Sunday, April 4, 2021, 10:50 AM, Laurent DOLDI (Toulouse, France) <doldi.doldi@...> wrote:

On Sun, Apr 4, 2021 at 03:24 AM, Barry Aldous wrote:
a much needed base extender for the Panasonic 3D1
Simpler solution : a W3 (joke - actually the image quality of the 3D1 is better)
I use a W3, a 3D1, a pair of Sony RX100-VI or my Pentax KP (cha-cha) depending on the subject (or a Huawei P30 pro if I do not have any camera with me).


Barry Aldous
 

Me too!  The attached image was taken with a Panasonic GX7 and a Steritar 812 single lens mirror adapter mounted onto a Lumix 12 to 32mm Lumix lens.  I use the zoom to set the horizontal alignment; usually around 25mm mark (MFT).  The Steritar 812 is intend for 50mm lens and has a focal range of 2.5m < infinity;
Francois has pointed out the failings of other adapters.

Check out the metadata of the attached image.

Barry A