Please note that this is a very specialised tutorial written for a request, it’s not going to be very entertaining or light-reading but it may help with insomnia.
This is for a HD* projection which can involve using a beam splitter attached to a laptop or computer and two separate projectors with filters on the lenses. The images are compressed because the beam-splitter decompresses them. It can also be used with the DLP-ready projector in 3-D mode and active glasses. If you’re in any doubt about how your presentations or images are going to be projected please check with the projectionists before going through this marathon of a tutorial.
* HD means the images are 1920 pixels wide by 1080 pixels high.
WHAT YOU NEED
- Photoshop (even an old version like CS3 works very well but Photoshop CC is available on a monthly basis so you can only pay for a month or two) or its FREE equivalent GIMP. I am not a GIMP user but apparently it can do a lot that Photoshop does, only for free. It is also possible to use the online application freephototool.com. It works very much like Photoshop. The only drawbacks are that 1) you need an internet connection 2) there are advertisements all around your working area and 3) it is not possible to save a document under a different name (Save as …), which means you should ALWAYS work on COPIES of your document, not on the original file. Keep the latter in a separate drive so that it doesn’t get erased, change the name of the document you have just saved, make a copy of it with a slightly different name and keep all the different files in a different drive so that they don’t get written over.
- StereoPhoto Maker (created for PC but can be made to work on a Mac – see below). SPM is a FREE application developed by Masuji Suto. There seem to be issues with the latest Mac OS (Catalina) but we are working on solving them.
- A pair of anaglyph glasses (red/cyan). They are available on Amazon. They are very important to use with StereoPhoto Maker to check there is no window violation (these are all right for small images but painful when they are projected). When you put your anaglyph glasses on make sure the RED filter is on the LEFT eye !
- Keynote (Mac) or PowerPoint (Mac and PC) to play the final presentation.
USING STEREOPHOTO MAKER ON A MAC
There are many options to running Windows apps on Mac.
There is Boot Camp, which reboots the computer in Windows. It’s insanely fast (great for games) but adds an inconvenience (of restarting) if you are only using it for one thing.
There is Paralells/VMware, these run a virtual Windows on your computer. It’s easy to use, but can be quite slow and resource consuming.
Both of these also require you to have a legit copy of Windows. Either way, you have to install, configure, apply updates and run antivirus in the emulated Windows machine. It can be a hassle, especially if you really only want to run StereoPhoto Maker!
Our third option. WINE (WINE Is Not an Emulator). I’ve tried to avoid the obvious joke but wine really does solve everything.
The cons to this are that some apps have compatibility issues. The pro? StereoPhoto Maker runs (to my knowledge) flawlessly on many Mac OS – see below.
To do this, you will need:
- Stereo Photo Maker (http://stereo.jpn.org/eng/stphmkr/index.html) – WARNING – You need to download the latest PC version, not the Mac one !
- WineBottler combo (http://winebottler.kronenberg.org). Don’t worry about ‘beta’, it works for me! The download button is a little small, but you should be able to find it.
When you have downloaded them both…..
1: Unzip StereoPhoto Maker. Double clicking on the zip should be enough. Delete the zip file, you don’t need it anymore.
2: Mount the WineBottler DMG file.
3: Copy ‘Wine.app’ and ‘WineBottler.app’ to your Applications directory.
4: Unmount the WineBottler DMG, and delete it if you want. You won’t need it again.
5: Right click (or Ctrl click) on ‘stphmkre.exe’ and choose ‘Open with’. Select Wine.app, if it’s not there, browse to it in the dialog box.
6: It should open up Wine. Select the ‘Convert to simple application bundle with WineBottler’ option.
7: In the window that appears, don’t change anything, BUT check the box that says ‘Copy file (progam) and all files in the folder to the App Bundle’.
8: Press install! Name it StereoPhoto Maker or SPM for short, and save it in Applications.
9: Wait a while, and it should eventually say ‘Prefix created successfully!’.
10: Quit WineBottler.
11: Open the app you created! It may take a while to open the window to begin with, but give it a sec, it’ll open.
12: Use StereoPhoto Maker, on a Mac!
WARNING: this works for former versions of the Mac OS but there are issues with Catalina and the version before. We are trying to fix the issues.
A fourth option, kindly given in the comments by Dave Comeau which he’s given me permission to add:
“Rather than use Wine Bottler, I do this simple way: 1) Download the latest SPM .exe for Windows. 2. Click on “StereoPhoto Maker on Mac (for Mac OS Sierra)” and get the Sierra version from Masuji’s page (http://stereo.jpn.org/eng/stphmkr/file/stphmkre523_mac.zip). 3) Mount the DMG, etc. Then right-click and Show Package Contents. 4) Navigate to C drive, Program Files and find stphmkr.exe. Delete that and drag the latest version inside.
After I write it all out it’s not much different than just bottling it yourself! Still awaiting process Catalina and for 64-bit packager, but should be easier with new SPM 64-bit version (“Pro”)”
Scan your 3-D images at the highest possible resolution (600dpi, 800dpi, or even 1200 and 2400dpi for smaller originals like Verascope glass slides). A lot of displays are now 4K (4096 by 2160 pixels) and you never know when you might have to use one. But even without a 4K display the higher the resolution, the better. PIXELS are actually more important than the dpi resolution. If you scan at 600 dpi but your image is under 2000 pixels high this is NOT high resolution.
The image itself, when cropped (that is once you have got rid of the white margin around it AND of the mount), should be at least 2500 to 3000 pixels high and never under 2000 pixels high. Remember, reducing the size of a large image does not make it worse but increasing the size of a small image will never make it sharp.
When you scan at high resolution it may take longer but you won’t have to do the scanning again and you can zoom in on some important detail.
Preferably, your pictures should be digitally cleaned, even roughly, before they are processed. Scratches and specks of dust do not match on the two halves of a stereo pair and, when projected, can be very distracting. You must never forget that looking at a stereo in a stereoscope can be very forgiving (the images are quite small after all and the scratches and specks of dust are hardly noticeable) but projecting is definitely NOT forgiving. Everything is blown up, including the faults in the pictures.
HOW TO DO IT
It all begins with a 1920×1080 pixels (HD) black template (black works best for 3-D projections as it is more immersive). This is the resolution most 3-D projectors work best with. When 4k projectors become more common you may have to use a template 4096 by 2160 pixels
And it all ends with a laterally squeezed 1920×1080 pixels image which should look like this :
Nothing to worry about though. When projected, the image will have its original proportions.
STEP BY STEP
Create a 1920×1080 black template and save it on your desktop as you will use it dozens of times. I named mine BLACKBACKGROUND.
Crop your pictures as tight as you can (get rid of the mount and everything which is NOT the image) and save the resulting image (try and keep all different versions of your images, before and after cleaning, before and after cropping). Cropping the images will give you better results when you use StereoPhoto Maker to align them.
Open StereoPhoto Maker.
In the File menu choose Open Stereo Image (if your image is a stereo pair) or Open Left/Right Images (if the two halves are two separate files). In the latter case you will have to open the Left Image first, then the Right Image.
Once your image is displayed, choose Easy Adjustment in the Adjust menu, put on your anaglyph glasses (RED filter on the LEFT eye) and check your image is in 3-D and not in inverted 3-D (pseudo). Believe me, it happens very often that 3-D pictures have been badly mounted. If your image is in inverted 3-D, click on the button showing red and blue squares with arrows. It will put things right. Check again with Easy Adjustment.
In the Adjust menu, choose Auto Alignment and wait for the computer to process the image. A window headed Auto alignment values should appear. Click on the Close button.
It is now time to CROP your halves. This is a very important step as it will greatly influence the way your picture appears when projected. Click the crop button. Vertical and Horizontal lines appear. Click the mouse where you want to start the cropping then drag it until you are satisfied everything is correctly cropped and there is nothing of the mount or of the edges of the image left. In most cases you will lose part of the original image on either side but that is the price to pay for a comfortable projection.
Auto Alignment works pretty well for modern stereos but not so well for vintage ones so it is necessary to double check that every part of your image will fit in what is called THE WINDOW.
Think of the frame of your image as an open window through which you are looking.
Everything in the image should be BEYOND the window frame, unless the picture contains elements that can come through the window at the spectator.
For instance, imagine a postman handing a letter through the open window. The letter and the postman’s arm can come through the window, but the rest of his body cannot because in real life this is impossible.
Similarly the branch of a tree can come through an open window, but not the trunk of the tree since it is rooted in the ground.
A lot of vintage stereos do not take this “window” into account because it was not considered important at the time and also because the images, when seen in the stereoscope, are still quite small.
Things are different when these images are projected on a large screen and “window violations” can then be pretty painful to look at. Which is why you should always choose the Easy Adjustment option from the Adjust menu after you have automatically aligned your images. When you click on Easy Adjustment your image will appear as an anaglyph. Put on your red/cyan glasses (RED filter on the LEFT eye), make the image as big as you can and slowly move the top slider to the left or to the right until EVERYTHING that should be beyond the window is actually there. Then click OK. For a tutorial about understanding the stereo window, please see this tutorial.
Your two halves should now be ready. In the File menu choose Save Left/Right Images, give your halves a name, choose a destination and click the Save button.
Digitally clean your pictures with Gimp or Photoshop. You can clean them BEFORE opening StereoPhotoMaker but since the cropping gets rid of some parts of the image it saves time to do the cleaning AFTER the cropping as there is less surface to clean.
In the example I have chosen, the images have a round arched top which is different, after cropping, in both halves. This needs to be corrected as it will prove distracting when projected. If your image is square or rectangular you can skip the next four paragraphs.
ROUND ARCHED-TOP IMAGES
Open both halves in Photoshop. Select the left half, copy it then paste it on top of the right half.
In the Layers panel, reduce the opacity of the top layer (left image) to about 50 per cent.
Select the Elliptical Marquee tool from the tool bar. Put your cursor on the top left corner of your image and drag your mouse until you reach the other side of the image. Make sure the part above the ellipse you have just drawn will exclude the edges of the two pictures.
Hold the SHIFT key and select the Rectangular Marquee tool from the tool bar. Put your cursor where the ellipse meets the left hand side of the image and drag the mouse to the bottom right corner. Release the SHIFT key. Your selection should now look like a round arched top half stereo. In the Select menu choose Inverse. It inverts the selection. Press the Delete key of your keyboard and fill the space with black paint using the Paint Bucket tool. Do the same for the bottom layer. Save the image (the two layers together) as a Photoshop file (.psd).
CREATING THE SLIDES
Open your images (or the file containing the two photoshop layers). Resize them so that they are 1060 pixels high (or less if you want to add text at the top or at the bottom of the slide).
Open your black template and make two copies of it (in Photoshop, press the Command A keys, then the Command C keys). Choose New in the File menu and press the Command V keys. Repeat for the second copy.
Select your left picture (Command A, Command C) then paste it on one of the black templates (Command V). Flatten the image (Layers menu, Flatten Image).
In the Image menu, choose Canvas Size. You can now see a square composed of nine smaller squares with arrows in them. Click on the middle left hand side square and change the size of the canvas to 3840 by 1080 (the canvas is already 1080 pixels high so changing 1920 to 3840 should be enough).
Open the second black template, select the right half of your image and paste it on the template. Flatten the image, copy it then close it.
Paste your right image on your 3840×1080 canvas. It is a good idea to tick the Snap to Document Bounds option in the View menu so that your picture automatically aligns on the right hand side edge of your canvas when dragged towards it.
You should now have a 3840×1080 3-D slide.
The only thing to do now is to resize the image (squeeze it laterally) so that it is ready for projection. The final image should be 1920×1080 pixels
In the Image menu select the Image Size option. In the box that appears, untick Constrain Proportions (or click on the chain to dissociate width and height) then choose a width of 1920 pixels. The image is automatically squeezed horizontally to the right size and your slide is now ready ! Do not forget to tick the Constrain Proportion box again (or the chain) next time you want to resize an image or you will be surprised !
REPEAT ALL OF THE ABOVE FOR ALL YOUR SLIDES (We never said this would be easy) !!!
IF YOU CANNOT USE STEREOPHOTO MAKER
If, for some reason, you cannot use StereoPhotoMaker, it is still possible to arrive at the same result with Photoshop (or freephototool.com).
- CROP your images and create a file for the Left image and a file for the Right one.
- Paste the Left image on top of the Right one (you now have two layers).
- Select those two layers (Click on one then hold the SHIFT key and click on the other)
- In the Edit Menu choose the Auto-Align Layers option. A new box appears. Click the Reposition button then click OK. [It is also possible to click the Auto button but it sometimes distorts the images – Reposition is usually safer]
- Go to the top layer and in the layer box decrease the opacity to about 50% so that you can see both layers.
- Using the Rectangular Marquee tool select what belongs to the TWO images and click Crop.
- Your pictures should now be aligned and cropped but you still need to find out whether everything is in the window.
- Set the opacity of the top layer back to 100%
- Remember the top layer should be your LEFT image and the bottom one your RIGHT image.
- In the layer box click on the top layer (LEFT image) then double click on the thumbnail image. A new window appears. Uncheck the Green and Blue Channels and click OK.
- In the layer box click on the bottom layer (RIGHT image) then double click on the thumbnail image. A new window appears. Uncheck the Red Channel and click OK.
- If you put your anaglyph glasses on you should see your photo in 3-D. If you think the background seems to be coming out while the foreground seems to be receding to the back it means you are dealing with a pseudoscopic picture. They happen quite often. In that case the bottom layer is the left image and the top one is the right half, so you need to swap them and the colour channels.
- To make sure everything is in the window, select the top channel. If things come out of the window which shouldn’t, click the Select tool and, using the left arrow key of your keyboard, move the top layer to the left until everything is inside the window.
- You should see a black strip on the right of your picture. You need to crop both images again so that this part of the picture disappears and they are both the same size.
- All you need to do now is to go back to the top layer, double click on the thumbnail image and make sure all three channels are ticked. Do the same with the bottom layer.
- Copy your top layer and create a new file. That will be your LEFT IMAGE. Save it with –L (for LEFT) at the end of its name.
- Copy the bottom layer and create a new file. That will be your RIGHT IMAGE. Save it with –R (for RIGHT) at the end of its name.
You have your two halves and you can now resize them and paste them onto your black template to create the two parts of your slide.
If you have several photos with the same format (45×107 mm slides for instance) it may be easier and faster to use a template.
Say you want all your pictures to be the same size.
- Open a new Photoshop document. Make it 1090 pixels wide by 1060 pixels high (this is just an example, you can make it wider if necessary but remember we are using slides which are 1920×1080 pixels).
- Paint it white.
- Paste it on your 1920×1080 pixels black background.
- Flatten the image.
- Select it and Copy it.
- Go to Canvas Size, click on the middle left-hand side square in the Anchor box (the one with 9 squares bearing arrows) and choose a width of 3840 pixels or a value of 200%.
- Copy your selection and align it so that its right edge touches the right edge of you 3840×1080 black and white rectangle.
- Flatten the image again.
- Select the whole image and copy it on top of the other one (or use the option Duplicate Layer). Select the bottom layer, select it all and press the delete key. You should now have a white background.
- Now go to the top layer and with the Magic Wand Tool select the left white rectangle and press the delete key.
- Do the same for the right-hand side white rectangle.
- Select the bottom layer again (that’s important) and SAVE your template as a PSD file.
When you want to create a slide open your two halves, resize them to 1080 pixels high and paste them between the bottom and top layer (if the bottom layer is selected it will do it automatically. Slide the left image so that it appears in the window you have created. Repeat with the right image.
The advantage of using templates is that you don’t have to crop your two halves as much and you can control that everything is in the window. Make the document small enough and use an Owl or Lite Owl viewer or, if you would prefer checking with a bigger image use a mirror viewer for computer screens, like the ones mentioned in my previous blog post https://stereoscopy.blog/2019/08/04/how-to-view-stereoscopic-3-d-images-basic-tutorial/.
If some elements of the pictures come out too much when they should not either slide the left picture to the left OR the right picture to the right. To make something come out a bit more, slide the left picture to the right OR the right half to the left.
You can give your templates any shape you want: rectangular, square, circle, with arched tops, with two or four round corners. Give them numbers or names.
Remember when you use templates to flatten the final image and to save it UNDER A DIFFERENT NAME, otherwise you will lose the template and you will have to make one again. Believe me, it can happen very easily.
The original tutorial was written by Denis Pellerin and myself to help staff and students in Lisbon University prepare slides for presentations at conferences. Many thanks to Denis for letting me use this and for the staff and students for their feedback to help make this completed tutorial.
If you’re still awake and you have any questions, please get in touch.
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