Best cameras for my needs? #capturing


Nima
 

Hey everyone!

I'm finally in the market to build my own dual-camera rig.  I'd love to get some recommendations from the experts on what I should get!

Here are my requirements for such a camera:

  • Global Shutter
  • Minimum camera baseline must go as low as 63.5mm
  • Must have the ability to record video(preferably 60fps, but 30fps is fine.  24fps is not)
  • Must have a simple single button synced shutter.  I'm okay with paying for a modification or hacking one, but a manufacturer method for synced shutter is preferable
  • Optional: Both cameras should be able to be charged using a cable without removing it from the rig.  This isn't a hard requirement, however, I'm willing to remove and put them back every time if it leads to superior quality
That's it!  Besides that, I obviously want the camera that fits the above needs and has the highest available quality.  Cost is not a factor.  Do any of you wonderful people have a suggestion for me?


John Rupkalvis
 

Regarding the stereo baseline, you might want to consider an adjustable system, like the attached.  This not only allows you to set the stereo baseline, but also adjust the horizontal image translation independently as well.  

John A. Rupkalvis
stereoscope3d@...

Picture


On Thu, Feb 27, 2020 at 1:06 PM Nima <contactnimaz@...> wrote:

Hey everyone!

I'm finally in the market to build my own dual-camera rig.  I'd love to get some recommendations from the experts on what I should get!

Here are my requirements for such a camera:

  • Global Shutter
  • Minimum camera baseline must go as low as 63.5mm
  • Must have the ability to record video(preferably 60fps, but 30fps is fine.  24fps is not)
  • Must have a simple single button synced shutter.  I'm okay with paying for a modification or hacking one, but a manufacturer method for synced shutter is preferable
  • Optional: Both cameras should be able to be charged using a cable without removing it from the rig.  This isn't a hard requirement, however, I'm willing to remove and put them back every time if it leads to superior quality
That's it!  Besides that, I obviously want the camera that fits the above needs and has the highest available quality.  Cost is not a factor.  Do any of you wonderful people have a suggestion for me?


George Themelis
 

Sony RX0 ii

George 

On Feb 27, 2020, at 4:53 PM, John Rupkalvis <stereoscope3d@...> wrote:


Regarding the stereo baseline, you might want to consider an adjustable system, like the attached.  This not only allows you to set the stereo baseline, but also adjust the horizontal image translation independently as well.  

John A. Rupkalvis
stereoscope3d@...

Picture


On Thu, Feb 27, 2020 at 1:06 PM Nima <contactnimaz@...> wrote:

Hey everyone!

I'm finally in the market to build my own dual-camera rig.  I'd love to get some recommendations from the experts on what I should get!

Here are my requirements for such a camera:

  • Global Shutter
  • Minimum camera baseline must go as low as 63.5mm
  • Must have the ability to record video(preferably 60fps, but 30fps is fine.  24fps is not)
  • Must have a simple single button synced shutter.  I'm okay with paying for a modification or hacking one, but a manufacturer method for synced shutter is preferable
  • Optional: Both cameras should be able to be charged using a cable without removing it from the rig.  This isn't a hard requirement, however, I'm willing to remove and put them back every time if it leads to superior quality
That's it!  Besides that, I obviously want the camera that fits the above needs and has the highest available quality.  Cost is not a factor.  Do any of you wonderful people have a suggestion for me?

<VR21a-Integral-Stereo-Camer.gif>


DaveJes1979
 

Nima, you desire a lot of things that we've all certainly had on our wish lists, ever since the advent of commercially-available digital cameras.  But all of these features do not exist with a single camera in 2020.

Global shutter cameras are just barely making it to market, and they have to compromise on dynamic range and low-light performance.  And even then we are talking about machine vision cameras or very expensive, very bulky cinema cameras (Blackmagic, Sony).  So that is in conflict with the minimum interaxial.

We might see Sony's new stacked global shutter sensor making it into cameras in the next few years: 
     https://www.digitaltrends.com/photography/sony-sensor-backlit-stacked-global-shutter/
     https://www.sony.net/SonyInfo/News/Press/201910/19-098E/

For shutter synch of video, again only cinema cameras offer genlocking to achieve shutter synch (or a proprietary synch protocol like ZCam's E2 and E2G).  If I was a video guy, I'd probably consider the E2G strongly, as this has a 1" size sensor with global shutter, with a semi-reasonable price.  But the camera is 91.2mm wide.

For still photography, you can get pretty good shutter synch results from Sony mirrorless cameras, but this isn't any sort of active synch, it is simply simultaneous shutter activation.  But this seems to yield good results, made possible, we assume, by a high polling frequency of the shutter release port in these camera models.

You are probably going to have to give up on your requirement for a minimum interaxial of 63.5mm.  The only camera that might be able to hit that parameter is the Insta360 One R (~65mm).  And that's not a bad choice since it will be shutter-synched for 3D.  But no global shutter, and you can't increase the interaxial.

That said, I think it is just urban myth around here (for some) that there is something magical about the 60-70mm interaxial range.  As if it would yield a vast improvement over mild hyper-stereo in the 70-80mm range.  This just doesn't cash out in practice.  You can run a test with a single camera and a slide bar, using a static subject.

Now, having said that, I do enjoy the results of going deep into the hypo-stereo range, as I can with the Panasonic 3D1 and Red Hydrogen.  But that is a whole 'nother animal. 

In summarry, unless someone starts making a small form-factor camera with global shutter and genlock/shutter synch in the next few years, you will probably have to depend on a beamsplitter rig for normal-to-hypo interaxial distances.


Bill G
 

Dave, this was a great summary of the current status of possible cameras for 3d rigs, thx for sharing...
Like many of us, we all have Nimas wish list.... doesnt seem possible for 2020.


On Fri, Feb 28, 2020 at 10:02 AM DaveJes1979 via Groups.Io <davejes1979=yahoo.com@groups.io> wrote:
Nima, you desire a lot of things that we've all certainly had on our wish lists, ever since the advent of commercially-available digital cameras.  But all of these features do not exist with a single camera in 2020.

Global shutter cameras are just barely making it to market, and they have to compromise on dynamic range and low-light performance.  And even then we are talking about machine vision cameras or very expensive, very bulky cinema cameras (Blackmagic, Sony).  So that is in conflict with the minimum interaxial.

We might see Sony's new stacked global shutter sensor making it into cameras in the next few years: 
     https://www.digitaltrends.com/photography/sony-sensor-backlit-stacked-global-shutter/
     https://www.sony.net/SonyInfo/News/Press/201910/19-098E/

For shutter synch of video, again only cinema cameras offer genlocking to achieve shutter synch (or a proprietary synch protocol like ZCam's E2 and E2G).  If I was a video guy, I'd probably consider the E2G strongly, as this has a 1" size sensor with global shutter, with a semi-reasonable price.  But the camera is 91.2mm wide.

For still photography, you can get pretty good shutter synch results from Sony mirrorless cameras, but this isn't any sort of active synch, it is simply simultaneous shutter activation.  But this seems to yield good results, made possible, we assume, by a high polling frequency of the shutter release port in these camera models.

You are probably going to have to give up on your requirement for a minimum interaxial of 63.5mm.  The only camera that might be able to hit that parameter is the Insta360 One R (~65mm).  And that's not a bad choice since it will be shutter-synched for 3D.  But no global shutter, and you can't increase the interaxial.

That said, I think it is just urban myth around here (for some) that there is something magical about the 60-70mm interaxial range.  As if it would yield a vast improvement over mild hyper-stereo in the 70-80mm range.  This just doesn't cash out in practice.  You can run a test with a single camera and a slide bar, using a static subject.

Now, having said that, I do enjoy the results of going deep into the hypo-stereo range, as I can with the Panasonic 3D1 and Red Hydrogen.  But that is a whole 'nother animal. 

In summarry, unless someone starts making a small form-factor camera with global shutter and genlock/shutter synch in the next few years, you will probably have to depend on a beamsplitter rig for normal-to-hypo interaxial distances.


George Themelis
 

That said, I think it is just urban myth around here (for some) that there
is something magical about the 60-70mm interaxial range.
Is it a urban myth that our eyes are 65mm apart and is better to
conservative when it comes to the stereo base in 3D?

After 30+ years in stereo photography I can say that 60mm for me is the
perfect lens spacing for a general use stereo camera. 75-80mm make it
hard to shoot in close spaces with people.

Right now I am using three twin camera rigs: Sony RX0, RX10, RX100. The RX0
is perfect with 60mm lens spacing. If I want more, I double or triple it, I
don't go 80mm. The RX10 is a specialty rig that I use for close-up nature
photography and portraits. The spacing is about 125mm, which in combination
with long focal lengths and shooting from a distance, gives me the results I
want. The RX100 has a spacing of 90mm in the z-configuration. It is OK and I
can use it but I have to be careful how close I get.

Overall, the RX0 is the only rig that works for people and tight spaces and
fits my shooting style very well. I see why Nima puts the minimum stereo
base to 63.5mm and I would even say 60mm to get a nice round number.

George


Charles Kluepfel
 

I say from experience with Fuji W1's 77mm separation: unless you stand back and zoom in, portraits or full-figure shots make the subjects head seem to be projecting forward in an unnatural manner.

Charlie


-----Original Message-----
From: George Themelis <gathemelis@...>
To: main <main@Photo-3d.groups.io>
Sent: Fri, Feb 28, 2020 1:52 pm
Subject: Re: [Photo-3d] Best cameras for my needs? #capturing

> That said, I think it is just urban myth around here (for some) that there
> is something magical about the 60-70mm interaxial range.

Is it a urban myth that our eyes are 65mm apart and is better to
conservative when it comes to the stereo base in 3D?

After 30+ years in stereo photography I can say that 60mm for me is the
perfect lens spacing for a general use stereo camera. 75-80mm make it
hard to shoot in close spaces with people.

Right now I am using three twin camera rigs: Sony RX0, RX10, RX100. The RX0
is perfect with 60mm lens spacing. If I want more, I double or triple it, I
don't go 80mm. The RX10 is a specialty rig that I use for close-up nature
photography and portraits. The spacing is about 125mm, which in combination
with long focal lengths and shooting from a distance, gives me the results I
want. The RX100 has a spacing of 90mm in the z-configuration. It is OK and I
can use it but I have to be careful how close I get.

Overall, the RX0 is the only rig that works for people and tight spaces and
fits my shooting style very well. I see why Nima puts the minimum stereo
base to 63.5mm and I would even say 60mm to get a nice round number.

George





John Rupkalvis
 

Beamsplitters reduce the amount of light available to the sensors, and therefore the potential depth of field, as well as introduce other artifacts such as sky polarization differentials.  A better solution is often a dual full mirror one, like the Natural Vision cinema configuration.  That orientation works just fine for stills as well.   


Another possibility is to build new body shells for the cameras.  Most cameras are manufactured with bodies that are much larger than the size of the sensors, and much of the wasted space can be eliminated by rebuilding them smaller, and/or in a more favorable shape.  For example, PC boards are often mounted horizontal, while they could be vertical, or often better yet, they can be run from front to back.  Some machine vision cameras are already oriented that way.

Don't forget the possibility of using "board cameras".  These are cameras that have most or all of the components, but no existing body shells, which are great for DIY applications.  For the same features and specs, they are cheaper than complete cameras as well.   I used a pair of those for the adjustable interaxial/adjustable H.I.T. stereo camera in the picture in my previous e-mail.  

Synchronization is usually the biggest issue.  True genlocking is analog, so with digital cameras you are looking at D to A and either A to D conversion or separation of the sync pulses from the video.  Just keep in mind that for the best sync, both cameras should be "looking at the same clock", that is, the same source for the sync pulses.  For staying in the digital realm, other options exist as well, such as PixeLINK https://support.pixelink.com/support/solutions   


John A. Rupkalvis
stereoscope3d@...

Picture


On Fri, Feb 28, 2020 at 10:02 AM DaveJes1979 via Groups.Io <davejes1979=yahoo.com@groups.io> wrote:
Nima, you desire a lot of things that we've all certainly had on our wish lists, ever since the advent of commercially-available digital cameras.  But all of these features do not exist with a single camera in 2020.

Global shutter cameras are just barely making it to market, and they have to compromise on dynamic range and low-light performance.  And even then we are talking about machine vision cameras or very expensive, very bulky cinema cameras (Blackmagic, Sony).  So that is in conflict with the minimum interaxial.

We might see Sony's new stacked global shutter sensor making it into cameras in the next few years: 
     https://www.digitaltrends.com/photography/sony-sensor-backlit-stacked-global-shutter/
     https://www.sony.net/SonyInfo/News/Press/201910/19-098E/

For shutter synch of video, again only cinema cameras offer genlocking to achieve shutter synch (or a proprietary synch protocol like ZCam's E2 and E2G).  If I was a video guy, I'd probably consider the E2G strongly, as this has a 1" size sensor with global shutter, with a semi-reasonable price.  But the camera is 91.2mm wide.

For still photography, you can get pretty good shutter synch results from Sony mirrorless cameras, but this isn't any sort of active synch, it is simply simultaneous shutter activation.  But this seems to yield good results, made possible, we assume, by a high polling frequency of the shutter release port in these camera models.

You are probably going to have to give up on your requirement for a minimum interaxial of 63.5mm.  The only camera that might be able to hit that parameter is the Insta360 One R (~65mm).  And that's not a bad choice since it will be shutter-synched for 3D.  But no global shutter, and you can't increase the interaxial.

That said, I think it is just urban myth around here (for some) that there is something magical about the 60-70mm interaxial range.  As if it would yield a vast improvement over mild hyper-stereo in the 70-80mm range.  This just doesn't cash out in practice.  You can run a test with a single camera and a slide bar, using a static subject.

Now, having said that, I do enjoy the results of going deep into the hypo-stereo range, as I can with the Panasonic 3D1 and Red Hydrogen.  But that is a whole 'nother animal. 

In summarry, unless someone starts making a small form-factor camera with global shutter and genlock/shutter synch in the next few years, you will probably have to depend on a beamsplitter rig for normal-to-hypo interaxial distances.


DaveJes1979
 

I don't want to get too sidetracked from Nima's question, since this seems to be a perennial debate.  Suffice to say, I do remember the days when I had a Fuji W1 and struggled with its limitations for shooting close objects, same as everyone else here.  But remember that the W1/W3's wide end was only 35mm (equiv.) focal length, which was just too narrow for this task.  Again, one can run a slide bar test to get a feel for the differences between 60-70mm and 70-80mm interaxials, but use reasonably wide angled lenses for close-up subjects.  This pushes the 1:30 distance ratio rule of thumb down to more like 1:15.

Due to its wide-angle capability the RX0 camera might be an OK-ish choice for Nima.  But I don't know if anyone has actually tested the video synch performance (using Sony's proprietary synch box).  And he would have to accept the limitations of a poor-quality lens, fixed focal length, and fixed aperture (and I forget, but fixed focus distance?).

Could someone conceive of a stereo camera rig that gets you a 60mm interaxial?  That's a realistic possibility with a 1" size sensor (13.2mm wide) or micro 4/3 sized sensor (17.3mm wide).  An APS-C sized sensor (23.5mm wide) might be borderline possible, if it was custom designed for this purpose.  That's because your mirrorless camera mount is going to come in at around 46mm throat diameter.  And practical lenses tend to be in the 65-70mm dia. range, although I've seen a 62mm.

But remember the old childhood ditty?  "Nobody likes me, everybody hates me, I guess I'll go eat worms".  Sing this to yourself anytime you get the idea that someone out there is going to make us a good 3D camera or 3d-ready camera.  Nobody cares about us!  If they did, they would have already made borderline-trivial changes to their existing cameras to accommodate our needs.  Following the short-lived, post-Avatar 3D bubble, no one has given any love to the stereo photography community.  The only reason there is even a glimmer of hope right now is that VR is now a thing.  While VR video is a different animal with different requirements, it does happen to overlap in important ways that might benefit us (with some compromises and possible hacking).


Depthcam
 

> Here are my requirements for such a camera:


Wish lists are dream lists.  They have little to do with reality.  Maybe one day, sure.  But right now, nothing will match anyone's perfect 3D rig ideal.   However, for anyone looking for a normal base rig with good IQ that can shoot both stills and video...  Well there is only a single option:  Insta360 R 3D edition using a set of Leica one-inch lenses

The availability of the 3D mount has been pushed back two months due to the health crisis in China and... I am still not sure if the Leica one-inch module will fit the 3D mount.  We'll have to wait and see.  And, as I mentioned in another thread, the T-shaped form factor of the 3D edition is not to everyone's liking.  But that's about the best there is at the moment.

For stills only, I would agree with George that a pair of RX0's may be a good choice if you need a minimum 60mm base and a variable interaxial.  But video sync would require the addition of very expensive sync boxes to the back of each camera.

Francois


DaveJes1979
 

John R. said:
 
"Another possibility is to build new body shells for the cameras.  Most cameras are manufactured with bodies that are much larger than the size of the sensors, and much of the wasted space can be eliminated by rebuilding them smaller, and/or in a more favorable shape.  For example, PC boards are often mounted horizontal, while they could be vertical, or often better yet, they can be run from front to back.  Some machine vision cameras are already oriented that way."

I always thought that the Sony RX100 (1" type sensor) was a good candidate for this.  The lens/sensor assembly is quite small, so maybe something like ~50mm interaxial is possible.  Plenty of youtube clips of people disassembling these cameras.

The now-discontinued DxO One camera had a 1" type sensor (13.2mm wide) had an amazingly small form factor, only 26.25mm wide.  So we know it is possible to build a practical camera around this size.

On a related note, for Avatar 2 and 3 James Cameron had Sony modify their Venice cinema cameras to separate the sensor block from the body of the camera with an extension system.  This obviously allows him to achieve more reasonable interaxials, thus lessening his reliance on beamsplitter rigs: 
https://youtu.be/e-3yMtKXeKo
https://pro.sony/ue_US/products/camera-adaptors/cbk-3610xs

"Don't forget the possibility of using "board cameras".  These are cameras that have most or all of the components, but no existing body shells, which are great for DIY applications.  For the same features and specs, they are cheaper than complete cameras as well.   I used a pair of those for the adjustable interaxial/adjustable H.I.T. stereo camera in the picture in my previous e-mail."

A while back I looked at Raspberry Pi and Arduino-based cameras.  They were all poor-quality cameras, although maybe that has changed recently.


Nima
 

Okay, I'm sort of falling in love with the Sony Rx0ii as a sensor.

Does anyone actually have any experience with it in a stereo configuration?

I want to know how well the wireless synchronized operation works from a mobile app.  If that doesn't work, I'll have to buy the wired control boxes, and while the price isn't ideal, the bigger issue is the bulk it adds to the rig.

What I'd LOVE to do is build a rig with the following:

  • Cameras mounted on a dual rack and pinion mechanism which would allow me to easily and symmetrically move the camera baseline in and out(I may actually attempt to cannibalize an Oculus Rift and use it's IPD adjuster to make a suitable mount)
  • Nice comfortable grips and a shutter button if possible to make it feel more like a "regular" camera.  And as a cherry on top I could add a pretty wooden or 3D printed shroud/chassis all around it to protect the electronics inside from the elements and make it look prettier
  • Find the lightest USB battery I can find that has USB power in on one side and the out on the other, and use it to power both Rx0ii's and other electronics if needed.  I may need to add buttons to make it easier to turn on and off the Sony cameras. 
  • Optional: If I can somehow find a small device(Raspberry Pi 4 maybe?) that can accept dual-HDMI-in from the two Rx0ii's and marry them into a single 4K SBS video feed in real time, I can then feed it into my RED Hydrogen One over USB-C, which can act as a stereo viewfinder in realtime.  I'll probably add a nice slot to the rig to fit the phone into it.

I'll readily admit it's probably a crazy idea that won't work.  But it's an attractive enough proposition that I'm more than willing to try it.


George Themelis
 

I have a lot of experience with this rig for stereo.
 
I am attaching a picture of my rig. It might look bulky but it is actually quite compact and lightweight. I take this rig with me when I go running.
 
In the side-by-side configuration with the cameras touching the spacing is 60mm. The cameras ride in platforms and the spacing can easily increase.
 
The tripod socking is aligned with the lens so the cameras could be placed bottom-to-bottom using a simple thread. Then they touch each other without a gap and the spacing now is 40mm (but the image is the portrait orientation, you can crop it to landscape, but this will decrease your field of view so you lose any wide angle benefits).
 
I use a standard Sony cord to connect the cameras (from the back). I played a little bit with wireless but I don’t think you can synchronize both cameras.
 
George
 
 

From: Nima
Sent: Tuesday, March 03, 2020 5:50 AM
Subject: Re: [Photo-3d] Best cameras for my needs? #capturing
 

Okay, I'm sort of falling in love with the Sony Rx0ii as a sensor.

Does anyone actually have any experience with it in a stereo configuration?

I want to know how well the wireless synchronized operation works from a mobile app.  If that doesn't work, I'll have to buy the wired control boxes, and while the price isn't ideal, the bigger issue is the bulk it adds to the rig.

What I'd LOVE to do is build a rig with the following:

  • Cameras mounted on a dual rack and pinion mechanism which would allow me to easily and symmetrically move the camera baseline in and out(I may actually attempt to cannibalize an Oculus Rift and use it's IPD adjuster to make a suitable mount)
  • Nice comfortable grips and a shutter button if possible to make it feel more like a "regular" camera.  And as a cherry on top I could add a pretty wooden or 3D printed shroud/chassis all around it to protect the electronics inside from the elements and make it look prettier
  • Find the lightest USB battery I can find that has USB power in on one side and the out on the other, and use it to power both Rx0ii's and other electronics if needed.  I may need to add buttons to make it easier to turn on and off the Sony cameras. 
  • Optional: If I can somehow find a small device(Raspberry Pi 4 maybe?) that can accept dual-HDMI-in from the two Rx0ii's and marry them into a single 4K SBS video feed in real time, I can then feed it into my RED Hydrogen One over USB-C, which can act as a stereo viewfinder in realtime.  I'll probably add a nice slot to the rig to fit the phone into it.

I'll readily admit it's probably a crazy idea that won't work.  But it's an attractive enough proposition that I'm more than willing to try it.


Jay Kusnetz
 

I wouldn't depend on a mechanism designed for light lenses to support my camera. Is that sort of symetrical movement nessesary, or would it be ok for just one to move, maybe on a lead screw? Or twin screws with gears at one end so they turn in opposite directions.


George Themelis
 

Sorry, I don’t understand what you’re saying / asking. 

George 

On Mar 3, 2020, at 1:17 PM, jay <jay31415@...> wrote:

I wouldn't depend on a mechanism designed for light lenses to support my camera. Is that sort of symetrical movement nessesary, or would it be ok for just one to move, maybe on a lead screw? Or twin screws with gears at one end so they turn in opposite directions.


timo@guildwood.net
 

I think they are talking about a self centring mechanism like on some laser printer paper trays. It has a gear in the middle and a rack on each paper guide so no matter what paper width you set, it is always centred.

Sounds totally unnecessary to me. Just adds weight, size, and complexity.

Timo

On Mar 3, 2020, at 1:33 PM, George Themelis <gathemelis@...> wrote:

Sorry, I don’t understand what you’re saying / asking. 

George 

On Mar 3, 2020, at 1:17 PM, jay <jay31415@...> wrote:

I wouldn't depend on a mechanism designed for light lenses to support my camera. Is that sort of symetrical movement nessesary, or would it be ok for just one to move, maybe on a lead screw? Or twin screws with gears at one end so they turn in opposite directions.


George Themelis
 

OK, well, if he is referring to my Sony RX0 rig, then:
 
1. The movement is not symmetrical, each rail can move independently.
 
2. On purpose I selected the lightest components (bar and rails) for my lightweight cameras. For a heavier cameras I would get a heavier bar and heavier/more sturdy trails.
 
3. I don’t think you need something with gears.  How heavy is your rig?
 
George
 
 
 

From: timo@...
Sent: Tuesday, March 03, 2020 2:01 PM
Subject: Re: [Photo-3d] Best cameras for my needs? #capturing
 
I think they are talking about a self centring mechanism like on some laser printer paper trays. It has a gear in the middle and a rack on each paper guide so no matter what paper width you set, it is always centred.
 
Sounds totally unnecessary to me. Just adds weight, size, and complexity.
 
Timo
 
On Mar 3, 2020, at 1:33 PM, George Themelis <gathemelis@...> wrote:
 
Sorry, I don’t understand what you’re saying / asking.
 
George

On Mar 3, 2020, at 1:17 PM, jay <jay31415@...> wrote:

I wouldn't depend on a mechanism designed for light lenses to support my camera. Is that sort of symetrical movement nessesary, or would it be ok for just one to move, maybe on a lead screw? Or twin screws with gears at one end so they turn in opposite directions.
 


Josep Barbera
 

Hi Nima

These are my considerations choosing a twinned 3D rig.

A) For years all we have been dreaming of the appearance in the market of a 3D camera with a technological level similar to the last 2D cams that were appearing in the shops... but since spring 2018, all we know (after testing many Sony models in an electronic megashop) that ALL the new Sony cameras, can be used in stereo photography, because they have a perfect synchronization through their Multi Terminal port, using two cables (female + male, plug & play, the best and natural method).

http://forum.phereo.com/viewtopic.php?f=3&t=296

https://photo-3d.groups.io/g/main/message/118953

The sync ONLY appears following the 2 steps ritual:

I.-Press the SHUTTER button halfway down to focus.
When the images are in focus, a beep sounds and the 2 focus indicators (z) lights.
II.-Press the SHUTTER button fully down to shoot the synchronized images.

The drawback is that female DSRLKIT cable, now (two years later), are very scarce and difficult to find because they are much appreciated in stereo photography

https://savemoney.es/asin/B00M6N0FQ8

https://savemoney.es/asin/B00KWXK6CC

But it is easy to obtain a cable with 2 MultiTerminal plugs (male-male) by soldering, or simply connecting the three internal cables.

In addition, now it is possible to get a cable with 2 right-angled plugs, thanks to the effort of an efficient companion in this mailing list, Laurent DOLDI:

https://www.vp-systems.eu/order_cr.html#CABLE-ZHIYUN-MULTI90

A right-angled plug (but ONLY IN THE MALE CABLE, and not the female) is available from China via Ebay (very cheap, only 3 euros):

https://www.ebay.es/itm/Removable-Shutter-Connecting-Cable-for-Sony-A7s-A7-A7R-II-NEX-3N-A6300-2-5mm-S2/361829890579?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l9372


B) A few months late, in October 12, 2018, luckely, all we know that Sony developed the perfect sync through the MultiTerminal port of its current cams using the Sony VMC-MM2 cable, not to make perfectly synchronized 3D photos, but to increase the productivity of professional event photographers using a RX0 cam paired with the different Sony Alpha models.
Both (cable and port) was not designed with the 3D world in mind, but for event photographers:

https://www.sonyalpharumors.com/jose-barbera-marti-using-the-sony-vmc-mm2-cable-for-sony-alpha-rigs


C) The Sony Multi Port sync is perfect and seems miraculous. In 2018 Dec 18, using the new and smart method developed by Barry Aldous (exposed in the Stereoscopy magazine number 115, Issue 3.2018, with good illustrations by David Kuntz), we obtained a wonderfull synchronization: less than half a millisecond:

http://phereo.com/album/5bcd974c8884287b4e000002
https://photo-3d.groups.io/g/main/message/120124

These three findings (3 dozen of usefull Sony cams, the VMC-MM2 cable, and the measurement of the prefect sync using Aldous Method) imply that today the best alternative to pair two cameras to make stereo photography is using the current Sony models (in APS-C, FullFrame and RX series, via Plug & Play) because all the latest 2D cameras marketed by Sony (more than three dozen) can be perfectly synchronized to obtain stereo photography rigs.

But only the last commercialized Sony Alpha cams are fully compatible (for still images and also for video) because we only in them we can assign in the menu, the movie recording-button to the shutter button:

https://support.d-imaging.sony.co.jp/www/cscs/accessories/compatibility.php?area=gb&lang=es&mdl=VMC-MM2&cat=3


Certainly a problem may be the price, but the gradient is huge: from 250 euros (Sony A5100) to 4500 euros (Sony A9 II), so there are adequate cameras for each budget. In addition it is possible to find the models, already discontinued, NEX 3N and A5100 (quality equivalent to the Samsung NX1000), for less than 100 euros.

https://savemoney.es/asin/B07YP4MTJD

https://savemoney.es/asin/B00MTZI1WI


Another small problem may be “the theoretically excessive stereo base”, but that “problem” is easily solvable:

A)_My wife prefers to use a very light equipment: a Sony Alpha botton to botton rig, with a fixed stereo base (68mm), close to the human interpupillary distance:

http://phereo.com/album/5c03c410e7e564831a0001aa

The photos obtained in portrait (vertical) format (no problem using the HR1 phone as a portrait screen :) can be cropped using the wonderful StereoPhotoMaker program, in order to obtain a landscape (horizontal) format, because the original resolution, 4000x6000, can easily be passed to 1920x1080.

With the Sony A7 R series (I,II,III) that's more easier, since they have a sensor with even more resolution.


B)_ I prefer to use a side by side equipment (APS-C 6x00 series, 6 models in the market) with slide variable stereo base (20 cm to the right and 26 to the left: 60 cm is the maximum) because it is easy to quickly change the settings using external buttons.

These stereo base implies that the nearest object should not be closer to 2.5 meters accordin the shooting golden rule of Gerhard Herbig:

""Distance to closest subject must be greater than the result of multiplying focal length by the stereo base (all values in mm)""

I also believe that it is a magical myth that the optimal interaxial distance for twinned cameras, in s3D photo, must be between 60 and 70 mm. That is only based on what is normal telorism because hypotelorism and hypertelorism generally involve a pathology or a congenital malformation.

But those people obsessed in that range, 60-70 mm, accept without hesitation all focal distances other than 50 mm (normal in our eyes)...

A question:

Is it more "normal" to use a 200mm or even a 3000 mm zoom with continuously variable mode (as Nikon COOLPIX P1000) than a half-meter camera stereo base, or 5 meters or even more, also with continuously variable and slider mode?

In fact the perception as miniatures of the subjects in s3D hyper-stereo photos is just a psychological phenomenon (not physiological) caused because our brain does not accept that it is possible to perceive depth over great distances. Later, after training, the brain accepts that phenomenon of augmented reality (far 3D depth ) and it no longer sees miniatures where there are none.

Obviously, in everyday practice ... only in an elevator, or in a car, or in a confessional, or in a toilet it is not possible to use 10-14 cm stereobase rigs, because in all other real-life situations if the main subject is too close, it is very easy to go back a few steps before shooting.



There are 4 different ways to avoid inconveniences dues to “a theoretical excess of stereo base”:

a) By using a bottom to bottom s3D rig for decrease the stereo base until 70 mm or less
b) Walking only one step back, before shooting for increase the distance to nearest object.
c) Varying the focal length, following the 3D photo Gerhard Herbig golden rule
d) Reduce the size the image pair is shown (half the size = half the disparity, Antonio dixit :)
The excess of stereo base of my Sony A6300 rig can been compensated using these 4 mechanisms described before, and it is not possible to know, (afterwards, "a posteriori") what procedure has been used to obtain each normo stereo pic:

https://photo-3d.groups.io/g/main/topic/34931457#124315

C) The Sony RX100 series (travel cams) can be very interesing solution due its zoom, but its quality (one inch sensor) and possibilities (fixed less) are inferior:

https://www.fotocommunity.de/photo/3d-fotografie-mit-sony-ingrid-ben/42132755


D) The Sony RX0 series (I, II) is also on the market, but these cameras are focused for sports (including running :) and as secondary camera for events. The setting possibilities are very limited: fixed focal length, fixed aperture , fixed lens etc. Its lens is very inferior to other current Sony Alpha cams but its portability is a lot greater.

https://www.sony.com/electronics/support/res/manuals/4690/46902871M.pdf

It is possible also they multi inter-connection via WIFI using a smartphone:

https://support.d-imaging.sony.co.jp/app/iemobile/es/instruction/4_1_multi_rx0_connection.php


E) In addition to the the Sony Cams, other solution (also very loved by my wife for its portability) is to use a beam spliter (image spliter :). At Cardiff's convention she carry a Kula Deeper and at Suthampton a Carl Zeiss Jena f=50mm beam splitter).

https://www.kula3d.com/

https://www.bhphotovideo.com/c/product/1023756-REG/kula_kd1d77_camera_lens_attachment_for.html

Caerphilly Castle and the Stereoscopic Society Convention:

http://phereo.com/image/5935b497e7e564772600007a

http://phereo.com/image/5935b46fe7e564124a0000f2

You can hear some comments about the beam splitter can produce keystone distortion, but that problem was only true in the no digital era and now that is an urban myth because StereoPhotoMaker can automatically correct that distortion when it is making the alignments. No one can visually distinguish, afterwards, photos taken with a beam splitter (and corrected with SPM) from those made with twinned cameras.

https://www.lockhaven.edu/~dsimanek/3d/stereo/3dgallery16.htm



In fact, now there is a huge variety of Sony Alpha models with perfect synchronization on the market and every 3d photographer can choose his most suitable 3D Sony rig:

-A7 (I, II, III), A7R (I, II, III,IV), A7S (I, II) A9 (I, II) = 11 models mirrorless and Full Frame
-NEX-3N, A5000, A5100, A6000, A6100, A6300, A6400, A6500, A6600 = 9 models of mirrorlesss APS-C
-A3000, A3500
-A58, A68, A77II, A99II
-RX0 (I, II)
-RX1R II
-RX10 II , III, IV
-RX100 II , III, IV, V, VI, VII
-HX300, HX350, HX400
-HX50, HX60, HX80, HX50, HX90, WX500 (using external trigger, so not Plug&Play)


Several characteristics determines the price and therefore the cost: Sensor size/quality, range of lenses/focal lengths, apertures, flash, image stabilization, viewfinder, tilting screen, RAW support, color depth and dynamic range, pixel sensor size in microns, number of focus points, face detection focus, eyes detection focus, continuous shoting at hight resolution, maximum light sensitivity and ISO whitout noise, faster max shutter, AE bracketing range, resolution of the screen and viewfinder, environmental sealing, batery life, WIFI, GPS, Bluetooth, NFC connectivity etc


A very interesting feature of modern Sony cameras, including the RX100 series, is that you can install abundant, excellent, and cheap applications to increase creativity (but not in the latest professional models so as not to offend possibly susceptible people:-)

Here, in each application are specified the compatible cameras:
https://www.playmemoriescameraapps.com/portal

Some Sony cams apps offer amazing results:
https://www.playmemoriescameraapps.com/portal/usbdetail.php?eid=IS9104-NPIA09014_00-000006


For many people that is the game-changer, and certainly that is a new era in photo 3D.


That is a new world... :-)


Best regards

Josep Barbera

http://phereo.com/josebarbera
https://stereopix.net/jose_barbera
https://holopix.page.link/S7K9







El 2020-02-27 22:06, Nima escribió:
Hey everyone!
I'm finally in the market to build my own dual-camera rig. I'd love
to get some recommendations from the experts on what I should get!
Here are my requirements for such a camera:
* Global Shutter
* Minimum camera baseline _must_ go as low as 63.5mm
* Must have the ability to record video(preferably 60fps, but 30fps
is fine. 24fps is not)
* Must have a simple single button synced shutter. I'm okay with
paying for a modification or hacking one, but a manufacturer method
for synced shutter is preferable
* Optional: Both cameras should be able to be charged using a cable
without removing it from the rig. This isn't a hard requirement,
however, I'm willing to remove and put them back every time if it
leads to superior quality
That's it! Besides that, I obviously want the camera that fits the
above needs and has the highest available quality. Cost is not a
factor. Do any of you wonderful people have a suggestion for me?
Links:
------
[1] https://Photo-3d.groups.io/g/main/message/124157
[2] https://groups.io/mt/71595794/2020442
[3] https://Photo-3d.groups.io/g/main/post
[4] https://groups.io/mk?hashtag=capturing&subid=4331125
[5] https://Photo-3d.groups.io/g/main/editsub/2020442
[6] https://Photo-3d.groups.io/g/main/leave/defanged


George Themelis
 

Hi Jose,

Your enthusiasm is admirable but you should avoid using worlds like:
perfect, miraculous, wonderful, amazing.

The Sony multiport synchronization is very good, maybe excellent, depending on a person’s needs & subjects photographed, but it is not perfect.

George

perfect synchronization through their Multi Terminal port,
luckely, all we know that Sony developed the perfect sync
The Sony Multi Port sync is perfect and seems miraculous.
we obtained a wonderfull synchronization
can be perfectly synchronized to obtain stereo photography rigs.
there is a huge variety of Sony Alpha models with perfect synchronization
Some Sony cams apps offer amazing results <<


George Themelis
 

Greetings,

I find it funny that the common wisdom that a good range of stereo base for
a general purpose camera is 60-70mm, is now questioned.

If Sony twin camera rigs could easily get this lens distance, there would be
no discussion. But because they can't, some people are defending the
usefulness of these rigs *as general purpose stereo rigs* by trying to
convince us that the 60-70mm lens spacing is a "magical myth" propagated by
"obsessed people."

There is no question that great stereo pictures can be taken using shorter
and longer stereo bases. For a while the Panasonic 3D1 camera (30mm) had
become my main stereo camera. While on vacation, I used the Sony RX100 rig
with 90mm lens spacing, and took great pictures that look normal/fine. These
"out of normal range" stereo bases work with some care and at the exclusion of a lot of general, everyday, normal stereo pictures (especially the longer end).

Josep asks:

"Is it more "normal" to use a 200mm or even a 3000 mm zoom with
continuously variable mode (as Nikon COOLPIX P1000) than a half-meter
camera stereo base, or 5 meters or even more?"

I routinely use my pair of RX10 cameras at the end of the focal length
(600mm) to photograph close-ups from distances as short as 2m and a stereo
base of around 125mm. With some cropping, the equivalent focal length is
over 1000mm. The close-ups look fine because the background is blocked.
Pictures of birds, flowers, frogs, insects, portraits, all look fine. But
this is a specialty rig for distant close-ups, not a general purpose stereo
camera.

"Obviously, in everyday practice ... only in an elevator, or in a car, or
in a confessional, or in a toilet it is not possible to use 10-14 cm
stereobase rigs, because in all other real-life situations if the main
subject is too close, it is very easy to go back a few steps before
shooting."

Ha! Seriously? These are the only situations where you cannot use the 10-14
cm rig? For these situations, I think a 30mm stereo base is more
appropriate. The 10-14 cm stereo base rig is severely limited when it comes
to taking pictures in interior spaces, inside houses, with people, etc.
That's a lot of photography excluded, not just the elevator. The 10-14 cm
stereo base is useful for some pictures but it is not a general purpose
stereo rig. Just image if the Stereo Realist had a lens spacing of 140mm,
what kind of family 3D memories from the 1950s we would have today?

George, Stereoscopist