3D location monitors

[Dave Blackham]

The ZALMAN TRIMON ZM-M215W has been suggested as an inexpensive monitor for a location wrangler work station. I've never seen one so cant make any comment s on it, any suggestions on alternatives ?

 

[Eren Ozkural]

I've had plenty of time with the Zalman 3D monitors for the past 2 years, mainly playing games on them.

I can't comment too much about how well they work as on set monitors but in my experience they've been fraught with ghosting and bad vertical viewing angles.

Once again, I'm not too sure if this was the monitor or the Nvidia display drivers fault.

Never the less, it's better than anaglyphic solutions.

 

[David Wilson]

I agree with Eren about the Zalman. I'm writing this on one right now and use it every-day for editing 3D. It's not perfect but seems to be the only option I can find at the moment in that (under $300) price range.

The only problems I experience are:

1) the vertical viewing angle is very precise and if one is not in the sweet spot, the images fall out of stereo. An extension of this problem is that the viewing channel is pretty narrow and even when in the sweet spot the very top and bottom of the screen can fall out of stereo. Finding the right distance from the viewer to the screen can help. Narrow viewing angle is a problem but one that I can easily live with/work-around.

2) The glasses are passive (circular polarization) (not a problem really, actually a plus) but every passive system I know of (short of RealD, Dolby etc.) has some ghosting. In a shot with what might be considered normal dynamic range (not extreme) the ghosting is not very noticeable. In shots (or LUTs) that are very high contrast, the ghosting is pretty bad.

All that said, I love the monitor and it has been a life saver for us. Beats the pants off viewing everything in anaglyph to get your stereo right.

I know that Zalman is just now introducing a 21.5 inch monitor (ZM-M215W) to replace their 22 inch (ZM-220W) I have. I'm hopeful the new monitor will help, at least, the narrow viewing channel issue.

Hope this helps.

 

[Dave Blackham]

I agree with Eren about the Zalman. I'm writing this on one right now and use it every-day for editing 3D. It's not perfect but seems to be the only option I can find at the moment in that (under $300) price range.

The only problems I experience are:

1) the vertical viewing angle is very precise and if one is not in the sweet spot, the images fall out of stereo. An extension of this problem is that the viewing channel is pretty narrow and even when in the sweet spot the very top and bottom of the screen can fall out of stereo. Finding the right distance from the viewer to the screen can help. Narrow viewing angle is a problem but one that I can easily live with/work-around.

2) The glasses are passive (circular polarization) (not a problem really, actually a plus) but every passive system I know of (short of RealD, Dolby etc.) has some ghosting. In a shot with what might be considered normal dynamic range (not extreme) the ghosting is not very noticeable. In shots (or LUTs) that are very high contrast, the ghosting is pretty bad.

All that said, I love the monitor and it has been a life saver for us. Beats the pants off viewing everything in anaglyph to get your stereo right.

I know that Zalman is just now introducing a 21.5 inch monitor (ZM-M215W) to replace their 22 inch (ZM-220W) I have. I'm hopeful the new monitor will help, at least, the narrow viewing channel issue.

Hope this helps.

Thanks for the posts, its very helpful. This reflects what I've heard about the ZM-M220W model, I've heard better of the ZM-M215W but no first hand expirience of either. We don't expect miracels of it but needs something better than anaglyph and hoepe the 215 may have better viewing angles. Seems at the moment theres no obvious alternative ? Even if we chose to increase the budget for a small 3D display.

 

[David Wilson]

The next step up that I know of would be the 22 inch Hyundai W220S which now seem to go for something like $550 which is down substantially from the last time I looked. I've never used one in a real-world situation but from a cursory look and word of mouth, the image quality is quite good - better than the the 22 inch Zalzman I'm using. I'm pthink David Newman at CineForm uses one and seems to like it.

 

[Dan Hudgins]

Hood

Hood

You can't get a good idea of the stereo image separation by driect view of a monitor with glasses or Lenticular. So you cannot check the camera issues of spacing vs. focal length and you end up with too much divergence in the footage.

If you use a Stereo Hood over a normal good monitor with over/under images on the screen you can adjust the mirrors in the hood and its lenses to have the screen focus your eyes like they were in a movie theatre and you will feel the divergence issues like you were in a theatre since you eyes will be focused almost at inf by the eye lenses in the hood (that is the screen distance will be adjusted to be the same as the movie screen or IMAX screen distance, not a few feet away.) The eye lenses should be LOCKED (at the screen distance focus compensation point) and not used to compensate for the viewers eyes, you should use your eyeglasses with them just as you would in the movie theatre.

The mirrors in the hood can be adjusted to place the stereo images that are aligined at the convergence point for your eyes that is the same as the movie theatre screen as well. Done right no adjustments would then be needed in post and the footage would not need to be cropped, and overall you would get less eye strain on viewing the finished work in a movie theatre.

Small monitors viewed close with glasses do not match the angles needed for movie theatre viewing for eye strain "free" viewing.

Another option is to use two monitors and a semi-silvered mirror, put eye-lenses in glasses to get movie screen distant eye-focus, and put matching pola filters for each eye and over each screen. Then you can move you head around a bit and still get movie theatre viewing simulation without the "peepshow" effect of the viewing hood. Better for working while editing. My NLE can run on two computers in parallel in sync by SMPTE LTC so you can have the right eye on one and the left on the other and so you can view playback in stereo with a two monitor or projector setup, if all the files mirror it should be possable to copy the edit list from one eyes computer to the other to re-sync after making changes. Any other program that supports lef/right two monitor output in sync should be usable with the two monitor with beam splitter setup as well.

 

[Leonard Coster]

Hi guys,

I have a hyundai 240S. Its a lot better than the zalman but still suffers from vertical alignment issues - ie you have to get your head at the right height or it falls out of stereo. Horizontal does not seem to be a problem.

The larger monitors - hyundai 42", JVC, etc are all lot more tolerant in viewing angle - up down left right - all no problem. I'm guessing this is because the pixels are just that little bit further apart (same res, bigger screen) and its easier for them to line up the polarising grill with the pixels.

Whatever - they work HEAPS better - but 50" is a BIG location monitor...

That's nice of course if you can stand carrying the bastard around... It definitely gets you a better look at your stereo image.

Even so - trust the maths - looking at a monitor in the field and thinking "that'll be ok" is not enough!!
Use a stereo calculator and don't break divergence limits!

(commercial declaration - i do make a stereo calculator: IOD calc for iPhone, but I have nothing to do with monitor makers

Cheers,

 

[Dan Hudgins]

divergence

divergence

Use a stereo calculator and don't break divergence limits!

The best monitor to check divergence and convergence on is not a 3D monitor at all, but a 2D monitor. Anaglyph an a 2D monitor (viewed without the Anaglyph glasses) lets you see if the red or blue are too much to the left or right. On a 22" monitor the divergence is still going to be very small, only a few mm depending on the size of the movie theatre screen that will be used later.

If you view with glasses on a 3D monitor you can force you eyes into un-natural divergence for a short time until your eyes hurt. After a time your eyes may get used to the divergence so you will not feel it as much, but the movie audience will and that will put people off to the 3D conversion which would be bad for people investing in 3D production, so everyone working in 3D needs to work together to reduce eye strain and cardboarding.

So, have a switch box to switch between the 3D viewing hood and a good sharp 2D monitor so you can check both the 3D look and the stereo alingment on the 2D monitor.

When you go to see IMAX 3D take the glasses off and see how much jump and weave there is between the two images, ouch! You can't see it with the glasses on because your eyes dance around to follow the two images, so seeing a 2D superimposed view gives you better information sometimes.

 

[Hrvoje Simic]

Seems at the moment theres no obvious alternative ? Even if we chose to increase the budget for a small 3D display.

If you have active glasses support - Samsung 2233Rz and Acer GD235HZ.

I know that Zalman is just now introducing a 21.5 inch monitor (ZM-M215W) to replace their 22 inch (ZM-220W) I have. I'm hopeful the new monitor will help, at least, the narrow viewing channel issue.

Narrow viewing angle issue is normal for a passive display (at this moment).

 

[mickpacifici]

The best monitor to check divergence and convergence on is not a 3D monitor at all, but a 2D monitor. Anaglyph an a 2D monitor (viewed without the Anaglyph glasses) lets you see if the red or blue are too much to the left or right.

How are you creating the Anaglyph image on a 2d monitor?

 

[Pedro Guimaraes]

We just use transvideo monitor to view anaglyph and look at our parallax on our frame.

Nothing more is need for camera team.

3D monitors on set are for video village.....producers, friends family, clients....

 

[Dan Hudgins]

Anaglyph

Anaglyph

How are you creating the Anaglyph image on a 2d monitor?

If you have a digital switcher (with frame buffers) you can input monitor out from each camera, then unplug the red from one and the blue/green from the other input, and set to 50/50% fade, that should give you an anaglyph display. If you can genlock the two video signals then you can just plug the red from one camera in and the blue/green from the other into the monitor. To do it right you would convert to luma first, but it depends on if your video switcher has a color control or not and how you wire it up.

What I was talking about was looking at the 2D image without the anaglyph glasses on so you can check the divergence and alignment since you cannot see those as well with the glasses on.

It does not need to be anaglyph to do that but having the right and left color coded helps you tell divergence from convergence on the face of the monitor.

The main problem with small monitors is that you are inclined to set the divergence too wide for later projection on a movie screen. You should divide the movie screen width by 62.5mm and then find that in ratio to the monitor width, and then your maximum divergence will only be maybe 3mm on the monitor, if you set it for parallel vision of 62.5mm etc. the images will be too wide to view later in a movie theatre.

If you have the time you can convert the R3D into two frame sets and then fuse those into anaglyph frames, my program can do that with BMP images to make anaglyph in various colors, interlaced for shutter glasses, and over-under for shutter glasses or a hood, as well as side by side etc. Many other programs can make 3D viewable images from BMP etc, and once you have those frames you can resize them (IRFANVIEW) and watch an uncompressed AVI in VirtualDub etc. in 3D. It all depends on your budget and how much time you have. Single frames are enough to check the 3D for some kinds of work.

If you have two video projectors you can put red and blue/green filters over them and project onto a medium size screen, hook one projector to each camera's monitor output, that way you do not need a genlock or mixer/swicther the images fuse on the screen and do not need to be in absolute sync. Also using a larger screen and projectors lets you adjust the convergence and divergence, if you put weak positive lenses over your anaglyph glasses you can simulate the movie screen distance in your eyes, in that case you do not register the projectors on the screen's edge, but offset the two images maybe 50mm to get the eyes to point to a more distant surface so it feels like a movie theatre screen when viewing, you can't do that on a monitor unless you stamp-box and offset the left and right images on the monitor screen.

 

[Vico Martin]

Wow Dan, we use a mixer for 50-50% prev for chek convergence and IO but never think about use a CC mixer for get an anaglyph in real time... for me this is post of the week.

... and a friend of mine have a Panasonic Mx-70 ;-).

Chears.

 

[Dave Blackham]

If you use a Stereo Hood over a normal good monitor with over/under images on the screen you can adjust the mirrors in the hood and its lenses to have the screen focus your eyes like they were in a movie theatre and you will feel the divergence issues like you were in a theatre since you eyes will be focused almost at inf by the eye lenses in the hood (that is the screen distance will be adjusted to be the same as the movie screen or IMAX screen distance, not a few feet away.) The eye lenses should be LOCKED (at the screen distance focus compensation point) and not used to compensate for the viewers eyes, you should use your eyeglasses with them just as you would in the movie theatre.

I dont find Stereoscopic hoods online is there a manufacturer of these easily available ?

 

[Dan Hudgins]

Stereoscopic hoods

Stereoscopic hoods

I dont find Stereoscopic hoods online is there a manufacturer of these easily available ?

They were more popular before for CRT monitors, I think it takes 6 front surface mirrors and two achromatic lenses.

Before you do the hood though you need to work out if you can use switchers to make an over-under signal to display, maybe with two switchers that have zoom and split-screen or the like.

If you want high quality and have a special size monitor you want to view over-under stereoscopic format on, it might be easer to make your own out of plywood, and probably at 1/10th the price.

The angle of view would match from where you would sit in the movie theatre and the lenses would be adjusted and locked for focus at that distance, you can set the focus by using a manual tele lens on a DSLR and set that at the screen distance, say 250 feet, then hold it up to the eye lenses on the hood and adjust them to get a sharp image through the DSLR then lock their focus.

Next put a 2D grid on the upper and lower image frames on the monitor (4:3 monitor or turned 3:4 for over-under) the grid should be zero convergence or divergence plane, then adjust the mirrors so the image is viewed at a distance of 250 feet or whatever screen distance you need, you can check that again with a DSLR on a track that lets it slide 62.5mm or whatever eye-centers your eyes are on and the eye-lenses are spaced for to match your eyes. Such tracks are sold for making 3D photos with DSLR. You can then super-impose the two images shot to see if you have the mirrors adjusted to give the right spacing, that is the grid should show slight divergence since it is at inf. and the screen is aligined to simulate 250 feet even though it is just maybe two feet away (parallel lenses shoot photos that are the same for subjects at INF., you can align your stereo cameras on the moon, it should look 2D without fringe on a 50-50% 2D monitor display.)

Using a DSLR with tele lens lets you get true readings, you cannot align the hood with you eyes alone since they will compensate for lack of alignment.

Since the hood MUST be adjusted for the exact image size, it would be hard to find a stock hood that would give as high quality results as are needed maybe for any odd monitor that works with your other equipment.

If you look in older published works on 3D viewing you can see various kinds of hoods in photos.

Do not use the wedge prism method, it will reduce image resolution and introduce anamorphic distortion into each image.

This place makes a two monitor display,

http://www.planar3d.com/landing/stereomirror/

I don't see a left right adjustment for the whole top monitor so you cannot get INF 62.5mm offset alignment without maybe stamp-boxing the L/R images. It would be nice if they would have a screw to shift the monitors so you can use the full screen width. Then you just put 1000mm or so fl achromats on your eyes and you can see and focus INF in the right zero divergence (of your eyes) way.

Used photogrammetry equipment dealers might have some older hoods that could be updated?

==

If you don't need to have just one monitor (one monitor is easer for editing and playback) you can use two lenses and two front surface mirrors and put one monitor on each side 90 degrees to your angle of view, fewer mirrors can give better results and be easer to get aligined.

For smaller 16:9 monitors you can do side-by-side and use two lenses and four mirrors as well with some letter-boxing as needed to fit the two images side-by-side.

As I mentioned, the lenses on the hood are fixed at the right focus point for the mirror alignment of INF and the movie screen, and you use your eyeglasses all the time to be able to see in focus.

 

[Johnny Johnson]

Is it likely the new Panasonic BT-3DL2550will become the standard monitor for both clients and stereographers?

bloody expensive though!

 

[noel paul]

3D monitors on set are for video village.....producers, friends family, clients....

On my short I rolled without a 3D monitor, instead using a calculation system (like the ones now available in iphone apps) to determine my interaxial by the numbers. It worked great. Next time I shoot 3D I plan to mirror flip one Red LCD (I hear this is possible in the new build) and freeview. But everything will still be done by the numbers as then you know its scaled to the screen size you're actually shooting for.

I worked on a 3D spot for a big car company last month and we had a computer running DepthQ software and a Samsung 3D monitor on set. One of my jobs was to align, grade, and output clips as fast as possible to show the clients. This was a really high end job, and I thought it was interesting that the only on-set 3D was really just for show & tell.

 

[Rudi Herbert]

Don't knock anaglyphic down just yet...

The truth is, for on set monitoring, anaglyphic is not that bad, it actually has many advantages. You can play on any monitor, including large size DLP, LCD or plasma televisions, so the option of which monitor becomes irrelevant. Viewing angle is not a problem, regardless of where you look at it from, you'll stay in stereo, which under the rushed conditions of a set, it is a big asset not having to position yourself at a certain angle in front of your monitor. Lastly, glasses are cheap, and you can even check convergence without glasses like someone already said. Truth is, the Zalman and other monitors are a must for color correction and serious post work, but for anything else that does not require grading or careful corrections, like on set monitoring, anaglyphic is the simplest, easiest, cheapest, most reliable solution.

Just my two pences...

 

[icester]

How are you creating the Anaglyph image on a 2d monitor?

Just feed Red video output from left camera to Red input on the RGB 2D monitor and feed Blue and Green from right camera
into Blue and Green of the 2D monitor RGB input lines.
All that assumes that your cameras are gen-locked.

Mathew Orman

For state of the art stereoscopic vision systems with: eyestrain free, distortion free and realistic immersion stereoscopic experience contact me
at:
http://www.tyrell-innovations-usa.com/

 

[Samuel Martin]

3D monitors

3D monitors

We have Hyundai monitors for circular polarised viewing and standard HD panasonic monitors for Anaglyph or 50/50 monitoring (using special boxes!). Our stereographers seem to be ok with the pana ones with anaglyph signal as they are only interested in convergence and separation mainly. For the director and production we have the circular polarized hyundai ones or if part of a 3D video village we use the lovely JVC 46" ones. Fantastic monitors but not for fast moving crews!!