Any tips on getting 3d to work

[Frank Raia]

Hello everybody,
I have the 3d lens adaptor that is in the attached picture. I also found an odd reel of Amityville over under 3d. In the pic is the 3d glasses I found on the bay. I don't know if they are correct. I can't seem to get anything close to 3d no matter how much I fiddle with the adaptor adjustments.
I do not have 3d test film. I do not have a silver screen.
Any tips other than don't waist your time?

Thanks guys
Frank IMG_20260807_153759.jpg

[Ed Gordon]

The 3D Video Corporation went out of business in 2017

Amityville used a different 3D system

Amityville 3-D was filmed using Arrivision 3D, a system that utilized dual 35mm images on a single strip for a sharper and brighter 3D effect. This format aimed to provide a headache-free viewing experience, although it ultimately faced many projection issues in theaters.

[Frank Raia]

Well that would explain things. Thank you Ed

[Jim Cassedy]

Your 3D lens adapater-thingy looks a bit like one of the Paramount 3D lens
adapters I own. I can't tell from your picture, but does your lens adapter have
polarizing filters built in to it, or did it come with 3D filters in a frame that you
have to put in the projection port? The Paramount 3D adapters I acquired
came with a set of filters in a cardboard frame that were to be attached to
the projection port.

[Ryan Gallagher]

Yeah I was gonna say as Jim did. Were you able to overlay the over under images using that? If you were no reason it should not work really except perhaps missing polarized or color filters. What kind of glasses did you get with/for it?

[Frank Raia]

Jim, I took more pics. There are 2 little polarizing filters that slide under the outer metal (cheesy) frame. One says top the other bottom. I can get the images to overlap as far as I can tell. It did not come with any glasses. I originally needed the prime lens that was attached to the adaptor. It was cheap and thought it would be cool to have, by chance I found a 3d odd reel, again cheap. I bought what said polarized glasses from ebay. Maybe they are not the right glasses? IMG_20260807_193959.jpg IMG_20260807_193926.jpg IMG_20260807_193837.jpg IMG_20260807_193829.jpg

[Tj Hopland]

This is a polarized system similar to the current Real D. Put simply polarization has to do with the angles of light. For any 3d to work you have to get a different image into each eye and ideally only the correct image into the corrrect eye, no bleeding between them. This is where the polarization comes which was originally linear in this case. Again put simply linear filters are blocking some of the light so say the top one is the horizontal one its blocking all horizontal light so all that gets through is vertical light. Bottom one is blocking vertical so horizontal gets through. You now have one image that is horizontal light and another that is vertical headed for the screen.

This now sorted light hits the screen. If its a white screen this filtering you just did gets scattered in all directions so might as well not have even bothered trying to filter it so you are going to just see a darker version of both images through both eyes so its just gonna be a fuzzy mess not even slightly 3d. Now if its a proper silver screen its going to reflect most of this filtered light back at the viewers (well at least some of them depending on where they are seated) which are wearing filters on their glasses. Same process as the proiector one blocks horizontal so all that eye sees is vertical and the other is doing the opposite so as long as everything is set up right all square and level (including your head and glasses) and the lens is set up right so both images converge correctly and the film is framed correctly and the filters are correct in the lens and glasses each eye only more or less sees the correct image and the 3d effect works.

You can do a crude check that your projector filters are still sort of working and the glasses by overlaying them and then rotating one 90 degrees. If you then try to look through them or shine light through it should be more or less blocked. Same with the glasses, a L and and R at 90 degrees should go opaque. Same if you match the glasses up to the lens filters. If that all works then you at least have somewhat close and correct filters and glasses. There were varying qualities of filters and glasses and the projector filters would kinda get burned over time especially with larger lamps.

Read D uses circular polarization which is kinda a lot harder to wrap your brain around and isn't the vertical and horizontal so those glasses won't work for this unless you get some matching circular filters for the lens then in theory it would work. Linear works better as far as isolating each image IF everything is dialed in and level and such. Circular is more forgiving but at the expense of even if its all dialed in perfect there is going to be some bleed between the images which is called ghosting which is why there is the ghost busting software in the servers to try and somewhat compensate for this.

Not having the test film is also a big problem. For things to work those images have to he aligned as close as possible and I'm not sure how you would ever stumble on the alignment without the film. The other fun thing is figuring out which of the 2 perf frames is the pair. Thread wrong or have a wrong splice and you could have L and R images flipped with one being the previous frame and the other being the next so double wrong. The Technicolor film 3d that came out at the beginning of d cinema they tried to mitigae that issue by printing colored dots that would show on the masking you put in the port window. Green dot meant you were on the correct pair.

I think one of the fun things about all those over under film 3d systems is they were all the same but different. You could in theory align most of the lenses to work with most of the prints as long as you had the test fim for the specific flim or at least flavor of system.

The red and blue glasses are doing the same thing except instead of blocking the angles of the light they are blocking some colors which is why there really isn't color. Dolby 3d basically doing the same thing just on a much more high tech and controlled level working mostly outside the colors you can see so colors appear normal. These didn't need a silver screen because we don't care about the angles just the colors which with digital done right are carefully calibrated. The last version is 'active' glasses where the glasses are LCD panels that are literally going black alternating in time with the projector so while left is being projected the right eye is blocked then the projector and glasses swap. Same thing there angles of light don't matter so don't need a silver screen.

[Phillip Grace]

Hi Frank.
To make the polarized 3D system work you must have a silver screen. Some models of portable roll-up screens for domestic use have silver surfaces. The polarizing filters on the projector attachment and viewing glasses have to be the same type, either linear or circular polarization, and oriented so that the each eye can only see the appropriate image of the two superimposed on the screen. The earlier systems using linear polarizers used filters with the polarization "screen" oriented at 45 degrees to vertical, so a Left eye filter becomes a Right eye filter just by flipping it over. Later systems used circular polarizing filters. The filters themselves deteriorate with age and exposure to light, but new polarizing sheet can be found on the internet.
The over-under 35mm 3D systems differ in the vertical separation between the frames. Your mirror box attachment should have adjustment for converging the two images, which could probably be done with the print itself. (I wondered who bought it). The test film makes it easier to see the alignment. I think you are pretty close to having a working 3D set-up.
The was an issue of American Cinematographer magazine in the mid 1980's devoted to the 3D systems then in use. It included a table with the various frame separation dimensions for the rival systems. I think it also mentioned the names of films which employed each process.
Great fun!

[Frank Raia]

Philip, polarizing sheets that you mention, can you lead me to any?
I will also try to find a silver screen of some sort.
Thank you TJ for the info. I will do your crude check for sure!

[Frank Raia]

Here are pics of the polarization. Also the film has markings as to the frame. IMG_20260808_105413.jpg IMG_20260808_105403.jpg IMG_20260808_105507.jpg IMG_20260808_104313.jpg IMG_20260808_105515.jpg IMG_20260808_105602.jpg

[Gordon McLeod]

do you have a silver screen?
That unit ewas made by trimensional technology and will work with any overunder 3d film and I believe your title was overunder

[Frank Raia]

Gordon, at the moment I do not have a silver screen. I did order a cheap one on amazon. I hope it will be good enough

https://www.amazon.com/dp/B0D6Z5KKW5?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1

[Tj Hopland]

It kinda looks like stuff is working. Anyone else with actual tech details or better memory than me fee free to jump in and confirm or deny what the correct angles are for the crude testing. Like I said its been a very long time since I really dealt with that stuff. I do remember doing the testing just to verify what was what and that things were working but I don't remember the specific angles. Also at that time circular wasn't a thing so we were not wondering if we even had the right system.

[Phillip Grace]

Linear polarizing sheet filters are available from scientific and optical suppliers, such as Edmond Optics, and Haines Educational. Prices for different types of construction vary quite a bit. There are also a number of suppliers with cheaper products on Amazon - RENIAN Polarized Film Sheets or Yeruvce Linear Polarizer Film for example. Try searching "linear polarizing sheet filter". Some of it seems to be self adhesive for use on car windows, but I don't think that type would be any good for projection. Still, a huge variety of media turns up in that search.

[Frank Raia]

Update. Bought non adhesive linear polarize sheets, cut to match original ones on 3d lens and placed them in place of original. Matched the orientation. Bought cheap silver beaded screen.
Ran my 3d reel and still don't see any 3d effect at all. Converged the best I can.
Putting this on the shelf for now.