Date   

Re: 3D Pop-Up, 3D Pop-In, 3D Pop-Out, 3D Pop-Down, Etc

 

On Fri, Apr 23, 2021 at 03:31 PM, Antonio F.G. wrote:
I think I am starting to get the idea, the stereo print has objects with negative disparity that appear in front of the window. But the way of looking at them makes them to appear ABOVE the table, is it?
Yup. Traditional pop-ups appear above the table. Pop-downs appear below the table (or ceiling), pop-lefts appear to the left of the wall (if placed on a wall), etc...


Re: 3D Pop-Left (or Right)

 

That is how it looks in virtual reality (and in reality), so that is not the image that you rotate. This is the image you rotate 45 degrees:


Re: 3D Pop-Up, 3D Pop-In, 3D Pop-Out, 3D Pop-Down, Etc

 

On Fri, Apr 23, 2021 at 03:31 PM, Antonio F.G. wrote:
The only way I can think to do this is with an anaglyph print. Is there any other way?
Yes, with virtual reality. There is an app that converts side-by-side (crossed or parallel) pairs into 3D for virtual reality headsets:
https://store.steampowered.com/app/1068820/OVR_Toolkit/


3D Pop-Left (or Right)

 

So... a 3D pop-left (or right) is working without the neck-breaking agony of creating and viewing a 3D pop-down.
The 3D camera angle is 45 degrees (left or right), and you have to view them with that same angle.
 
Hope this helps.

Parallel view.


Re: New base extended 3D lens with single shutter use

Berezin Stereo
 

Hi,

I always added a septum.  It made it a bit sharper.  The reason that they did not do it is because it messed up the calibration in automatic print making machines.  I think the machines got more sophisticated because I did not have an issue with it.  However I only elongated the septum enough to save a bit of image, I was careful not to extend it to the point where it would make a sharp line. 

On another note has anyone tried a Loreo on a Micro 4:3 camera.  They make a special one for that but I only know a couple of people who have tried it.

https://www.berezin.com/3d/loreo_new.htm

-- 
Steve Berezin
949 215 1556
www.berezin.com
On 4/23/2021 1:45 PM, robert mcafee via groups.io wrote:

I have the old model Loreo. I was using a single camera with a slide bar and bought the Loreo to capture images when there was or may be motion. I used it on a Nikon D80. 

The images were OK. Small apertures (2 settings) so best for outdoors. Yes I had some bleed between the images- easily addressed in SPM with a slight crop (though already rather narrow images)

Is the reason there is no septum so that it does not interfere with the mirror on DSLR cameras?  If not it should be easy to add a septum maybe held with some hot melt glue or epoxy. 

Now that you reminded me I will have to take out my Loreo to shoot some images




On Friday, April 23, 2021, 4:13 PM, Laurent DOLDI (Toulouse, France) <doldi.doldi@...> wrote:

On Fri, Apr 23, 2021 at 01:29 PM, Oktay wrote:
The disadvantages of single lens adapters are already discussed here
Come on, this is the second time I have to write that this LOREO has TWO LENSES! Would you need a picture of the back of my LOREO to trust me?
So buying this LOREO 3D Lens in a Cap 9005 seems easier than building it except:
- your base seems smaller than 90 mm = better
- are your lenses better?
- the LOREO has its focus coupled to mirrors movement = better
- the LOREO is protected against dust etc.
- you can screw a pair of hoods on the LOREO

BTW I do not work for Loreo LOL
_._,_._,_


  


Re: 3D Pop-Up, 3D Pop-In, 3D Pop-Out, 3D Pop-Down, Etc

Antonio F.G.
 

So, the image should be placed horizontal, say on a table, and look at it with an angle ~45˚?
The only way I can think to do this is with an anaglyph print. Is there any other way?

I think I am starting to get the idea, the stereo print has objects with negative disparity that appear in front of the window. But the way of looking at them makes them to appear ABOVE the table, is it?

I should test this

Regards
    Antonio


On Fri, Apr 23, 2021 at 03:11 PM, Etienne Monneret (Perso) wrote:
Humm... I just think you missed something...
:)
 
There isn't any kind of keystone problem.
 
It's just a question of what should be print/displayed, and how it should be viewed.
 
Normal stereos are viewed in-front while phantograms should be viewed X° (often 45°).
 


Re: New base extended 3D lens with single shutter use

Oktay
 

On Fri, Apr 23, 2021 at 03:13 PM, Laurent DOLDI (Toulouse, France) wrote:
On Fri, Apr 23, 2021 at 01:29 PM, Oktay wrote:
The disadvantages of single lens adapters are already discussed h

 On Fri, Apr 23, 2021 at 03:13 PM, Laurent DOLDI (Toulouse, France) wrote:
>>Come on, this is the second time I have to write that this LOREO has TWO LENSES! Would you need a picture of the back of my LOREO to trust me?
So buying this LOREO 3D Lens in a Cap 9005 seems easier than building it except:<<

I have acknowledged later  that this loreo has two lenses.
I have also listed my reservations about its quality, near object distance limitation due to the 90 mm base and around 150 mm focal length (35 mm equivalent based on the useable width of the sensor), The producer gives a crop factor and FL in relation to the height of the image , which is irrelevant. 

Oktay


Re: New base extended 3D lens with single shutter use

robert mcafee
 

I have the old model Loreo. I was using a single camera with a slide bar and bought the Loreo to capture images when there was or may be motion. I used it on a Nikon D80. 

The images were OK. Small apertures (2 settings) so best for outdoors. Yes I had some bleed between the images- easily addressed in SPM with a slight crop (though already rather narrow images)

Is the reason there is no septum so that it does not interfere with the mirror on DSLR cameras?  If not it should be easy to add a septum maybe held with some hot melt glue or epoxy. 

Now that you reminded me I will have to take out my Loreo to shoot some images




On Friday, April 23, 2021, 4:13 PM, Laurent DOLDI (Toulouse, France) <doldi.doldi@...> wrote:

On Fri, Apr 23, 2021 at 01:29 PM, Oktay wrote:
The disadvantages of single lens adapters are already discussed here
Come on, this is the second time I have to write that this LOREO has TWO LENSES! Would you need a picture of the back of my LOREO to trust me?
So buying this LOREO 3D Lens in a Cap 9005 seems easier than building it except:
- your base seems smaller than 90 mm = better
- are your lenses better?
- the LOREO has its focus coupled to mirrors movement = better
- the LOREO is protected against dust etc.
- you can screw a pair of hoods on the LOREO

BTW I do not work for Loreo LOL


3D Pop-Down Eye Trick

 

We can verify that this 3D pop-down eye trick works in virtual reality if we can get the correct tilt angle without getting a stiff neck. Maybe I should have tried a 3D pop-left or a 3D pop-right, first. 🧐

Parallel view.


Re: New base extended 3D lens with single shutter use

Laurent DOLDI (Toulouse, France)
 

On Fri, Apr 23, 2021 at 01:29 PM, Oktay wrote:
The disadvantages of single lens adapters are already discussed here
Come on, this is the second time I have to write that this LOREO has TWO LENSES! Would you need a picture of the back of my LOREO to trust me?
So buying this LOREO 3D Lens in a Cap 9005 seems easier than building it except:
- your base seems smaller than 90 mm = better
- are your lenses better?
- the LOREO has its focus coupled to mirrors movement = better
- the LOREO is protected against dust etc.
- you can screw a pair of hoods on the LOREO

BTW I do not work for Loreo LOL


Re: 3D Pop-Up, 3D Pop-In, 3D Pop-Out, 3D Pop-Down, Etc

Etienne Monneret (Perso)
 

Humm... I just think you missed something...
:)

There isn't any kind of keystone problem.

It's just a question of what should be print/displayed, and how it should be viewed.

Normal stereos are viewed in-front while phantograms should be viewed X° (often 45°).

You just need to imagine the geometrical projection between them.

You are an expert of this kind of transformation...
;-)


Le 23/04/2021 à 21:43, Antonio F.G. via groups.io a écrit :

[Edited Message Follows]

OK, so a phantogram is an image, stereo or not, with a strong vertical perspective deformation (vertical keystone)

Actually stereo pairs are immune to vertical perspective. It does not produce any alignment error, and can be done with any stereo pair. I did it sometimes to correct the aspect of an stereo image, only did not named phantogram.

Regards
     Antonio


On Fri, Apr 23, 2021 at 12:35 PM, Etienne Monneret (Perso) wrote:
Le 23/04/2021 à 19:12, Antonio F.G. via groups.io a écrit :
On Fri, Apr 23, 2021 at 08:18 AM, Etienne Monneret (Perso) wrote:
The illustration here is clear:

https://en.wikipedia.org/wiki/Phantogram

That illustration just describes the visual effect of a pair of stereo images.

What is really a phantogram? Is there any difference with a plain stereo pair?

All is in this sentence : "The anamorphic distortion of the source image crucial to the illusion .."

To get a phantogram you MUST inverse the perspective effect of the original anaglyph.

Have look at the exemple a gave:

 

http://abtutor.free.fr/Phanto/index.html

http://abtutor.free.fr/Phanto2/index.html

You may also search the web to find ordinary 2D anamorphisms, it the same question, without stereo.

See this video to understand the need of the perspective inversion:

https://www.youtube.com/watch?v=tBNHPk-Lnkk&ab_channel=brusspup

 



Re: New base extended 3D lens with single shutter use

Laurent DOLDI (Toulouse, France)
 

On Fri, Apr 23, 2021 at 12:00 PM, Boris Starosta wrote:
But it is unclear if the lens actually varies stereobase from 50 to 90mm
No, for me it is clear that (unfortunately) the base is 90 mm (I have this lens).
It is just the mirrors that rotate when you turn the distance ring, to avoid losing parts of the images etc.


Re: 3D Pop-Up, 3D Pop-In, 3D Pop-Out, 3D Pop-Down, Etc

Antonio F.G.
 
Edited

OK, so a phantogram is an image, stereo or not, with a strong vertical perspective deformation (vertical keystone)

Actually stereo pairs are immune to vertical perspective. It does not produce any alignment error, and can be done with any stereo pair. I did it sometimes to correct the aspect of an stereo image, only did not named phantogram.

Regards
     Antonio


On Fri, Apr 23, 2021 at 12:35 PM, Etienne Monneret (Perso) wrote:
Le 23/04/2021 à 19:12, Antonio F.G. via groups.io a écrit :
On Fri, Apr 23, 2021 at 08:18 AM, Etienne Monneret (Perso) wrote:
The illustration here is clear:

https://en.wikipedia.org/wiki/Phantogram

That illustration just describes the visual effect of a pair of stereo images.

What is really a phantogram? Is there any difference with a plain stereo pair?

All is in this sentence : "The anamorphic distortion of the source image crucial to the illusion .."

To get a phantogram you MUST inverse the perspective effect of the original anaglyph.

Have look at the exemple a gave:

 

http://abtutor.free.fr/Phanto/index.html

http://abtutor.free.fr/Phanto2/index.html

You may also search the web to find ordinary 2D anamorphisms, it the same question, without stereo.

See this video to understand the need of the perspective inversion:

https://www.youtube.com/watch?v=tBNHPk-Lnkk&ab_channel=brusspup

 


Re: New base extended 3D lens with single shutter use

Depthcam
 

> With this layout, you can view the image in stereo, on the camera’s rear viewscreen. It will be crossview.


But viewed on a small display, the glare might not be so obvious.  Also, are you going to spend time "hunting" for glare each time you wish to take a picture ?  Maybe a few times but it is is when you forget to do it that it will happen !


> Excellent work, but why not (like me) just purchasing a LOREO 3D Lens in a Cap 9005 (US$150)?


As I recall, the 9005 has a 90mm base.  They had planned a version with a normal interaxial - the 9008 - but they could not get it working right. Also, the lenses used on the Loreo 9005 are plastic.


> When the lens is focused on a subject at a given distance, the image pitch is automatically adjusted within the unit itself to suit the object distance.


And this is done by converging the mirrors - not moving the lenses laterally.  I know this because I discussed it with the inventor - Anthony Lo.  Here is the back of the 9005:




> When the subject appears in the same relative position in both the left and right image in the viewfinder, it will automatically be in focus.


But the problem here is that we don't necessarily want the focus to be on the main subject when we seek to produce an image that is sharp from near point to far point.


> The 9005 is also equipped with a pair of 58mm filter threads in the front, which can be used for attaching converters, filters and hoods


Yes, the addition of lens hoods can help.


> But it is unclear if the lens actually varies stereobase from 50 to 90mm,


It does not.  The stereo base is 90mm and the adjustment to set the convergence is done by converging the mirrors. It does introduce a very slight amount of opposite keystone distortion.

Another shortcoming to keep in mind is that, due to the absence of a septum, the left and right images tend to blend into each other at the center.

Francois


Re: New base extended 3D lens with single shutter use

Oktay
 

On Fri, Apr 23, 2021 at 09:48 AM, Laurent DOLDI (Toulouse, France) wrote:
>>This Loreo has TWO LENSES otherwise I would not have talked of it.<<

Yes, this is a different system. It is attached to the camera body, not to the camera lens.

 To me the drawback is the two element 40 mm lens.
The 35 mm equivalent of 40mm at the given width is about 150 mm for APS-c , more for 4:3 

This tele equivalent lens in my opinion is not the best choice for general purpose 3D shooting, that this lens is aimed for.

Moreover with 90mm base and the given focal length of the lens you would need about 10 m! (30 ft) to place your nearest object in order to avoid excessive deviation.

Oktay


Re: 3D Pop-Up, 3D Pop-In, 3D Pop-Out, 3D Pop-Down, Etc

 

Also, for this 3D pop-down gag to work, you have to place the image above your head, as perpendicular to a flat ceiling, then view it with a +45 degree tilt angle.


Re: New base extended 3D lens with single shutter use

Oktay
 

On Fri, Apr 23, 2021 at 09:03 AM, Etienne Monneret (Perso) wrote:
>>Excellent work, but why not (like me) just purchasing a LOREO 3D Lens in a Cap 9005 (US$150)?<<
Mine is a totally different system that follows the original principles of stereoscopy.
I already have the Pentax and the Stitz attachments but never use them.
The disadvantages of single lens adapters are already discussed here.

Oktay


Re: New base extended 3D lens with single shutter use

Oktay
 

On Thu, Apr 22, 2021 at 11:23 PM, Depthcam wrote:
>>But the thing that one must always watch out for with such mirror converters is internal reflections and glare that can occur on one of the mirrors and that causes an artifact on one of the images as can be seen on the right view of the dog sample - right next to its back paw.<<
You're absolutely right. One should avoid shooting against the sun.

Not only does it cause internal reflections and glare, It also reflects the ray of the sun onto the objects surroundings if the camera faces the sun.. The photographed dog got really annoyed by those moving sun reflections and showed hostile behaviour.
A cat was chasing the reflections on the pavement.

Oktay


Re: 3D Pop-Up, 3D Pop-In, 3D Pop-Out, 3D Pop-Down, Etc

 

Before we put this spinner on a pole into motion, let's check the 3D pop-down gag. 
The 3D camera tilt angle was +45 degrees, so we have to view it at that same angle.

Parallel view.
 
"Spinnerexample" (https://skfb.ly/6YZnN) by geoffryb
"Abandoned Warehouse - Interior Scene" (https://skfb.ly/QQuJ) by Aurélien Martel


Re: 3D Pop-Up, 3D Pop-In, 3D Pop-Out, 3D Pop-Down, Etc

Etienne Monneret (Perso)
 

Le 23/04/2021 à 19:12, Antonio F.G. via groups.io a écrit :
On Fri, Apr 23, 2021 at 08:18 AM, Etienne Monneret (Perso) wrote:
The illustration here is clear:

https://en.wikipedia.org/wiki/Phantogram

That illustration just describes the visual effect of a pair of stereo images.

What is really a phantogram? Is there any difference with a plain stereo pair?

All is in this sentence : "The anamorphic distortion of the source image crucial to the illusion .."

To get a phantogram you MUST inverse the perspective effect of the original anaglyph.

Have look at the exemple a gave:

http://abtutor.free.fr/Phanto/index.html

http://abtutor.free.fr/Phanto2/index.html

You may also search the web to find ordinary 2D anamorphisms, it the same question, without stereo.

See this video to understand the need of the perspective inversion:

https://www.youtube.com/watch?v=tBNHPk-Lnkk&ab_channel=brusspup


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