Sp polarization

Shopping for a sewing projector may at first seem daunting with how many options are out there. Luckily, there are a few criteria that you can use to narrow your search. Three types of projectors have been found to best suit sewist's needs:

Once your device is connected, you must calibrate your projector. Calibration is the process of adjusting a projected image so that it measures a desired scale. A gridded cutting mat is ideal for the calibration process, as it gives you a clear scale to match. Without proper calibration, patterns will be warped and project at improper scale, resulting in your pattern being the wrong size.

Polarized light

For many people, cost will be a large deciding factor when choosing their projector. Mini projectors can often be found at relatively affordable prices brand new through amazon, or second hand through eBay or other resale sites. Ultra-Short Throw projectors can be pricey brand new, but there is a large selection available on eBay at prices around $100-$200 from sellers that curate projectors retired from classroom use. Short Throw projectors tend to be the most expensive and can be found brand new and second hand.

Polarization formula electric field

The plane of polarisation of a wave can be rotated using an analyser. An analyser is placed after a polarising filter at an angle. It will then rotate the polarisation of the wave by that angle. Placed between one vertical and one horizontal filter, it will allow some light to pass through where it usually would not.

"WOW. I can't recommend this enough. She really takes the mystery of how you actually *do* this. The differences in what you need for different sewing room set ups is broken down clearly. There are lots of great videos that explain things like throw, calibration, different file types and software, different   ways connect and more. I had a lot of "oh, THAT'S how that works" moments.I've spend hours in the Projectors Facebook group, but I've never seen the information laid out so clearly as in this little course."

Intensity of light

Pattern Projector is a free online site that allows you to project any digital pattern downloaded to your files. Many designers now include projector files in their digital pattern files, but A0 files are also suitable. Once you have selected your file, play around with the tools that are available through Pattern Projector. You can flip, mirror, and rotate pieces, as well as inverting the colours of the lines. Many patterns will include separate layers for each size that can been selected or hidden. You can easily switch between your pattern and the calibration screen if you want to double check your calibration. Drag your pattern piece(s) into the calibrated area and trace the lines onto your fabric or cut the fabric using the projected lines as a guide.

Intensityunits

Projector sewing is a method of pattern cutting in which sewists project their digital patterns directly onto their fabric. Over the past 5 plus years, projectors have taken sewing communities by storm. With online forums such as the Projectors for Sewing Facebook Group gaining over 75,000 members since its founding in 2019, you might ask what makes projector sewing so special?

Polarisation occurs only in transverse waves, it is the process of making a wave polarised by limiting oscillations to a single plane. Transverse waves usually have multiple planes of oscillation perpendicular to motion. Longitudinal waves cannot be polarised as the oscillations are already only in one plane.

Progressive waves transfer energy away from the source. Power is a measure of the energy transferred per unit time and intensity is the power per unit area.

Flexibility is another thing to keep in mind when choosing a projector. Do you have a dedicated space that you can mount a projector, or will you need something that is portable? Short throw and Mini projectors will need to be mounted- usually to the ceiling- to project onto a cutting surface. While it takes a bit more initial effort to install a mounted projector, having a fixed position cuts down on the time needed for calibration. Ultra-short throw projectors have a smaller throw distance, and so do not need to be mounted. This does make set up and calibration a little more time consuming, as you will need to re-calibrate when you move the projector. Not needing a permanent fixture makes UST projectors a great choice for renters. Here at Discovery Fabrics, we bought a UST because of the flexibility it allows us. We have our projector set up on a wheeled projector cart, which can be brought to any of our cutting tables.

A polarising filter is used to produce plane-polarised light, some crystalline materials only allow oscillations of light in a single plane – such as Polaroid filters.

Circular polarization

If the amplitude of the wave entering an analyser is , after it is rotated then the amplitude will be . As intensity is proportional to amplitude squared, the intensity is proportional to . This is Malus’ law:

Each person may have different reasons for choosing a style or brand of sewing projector. At Discovery Fabrics we have very high ceilings, and are often working in different areas of the workshop and store. We needed something that could be placed on a cart and be wheeled around. We chose the Epson Brightlink 575Wi model, which is an UST (ultra short throw). We purchased it used, on Ebay. We wanted to use an older ipad to connect so had to purchase a lightning-to-hdmi cable online, but once that was done it worked perfectly.

The amplitude will also change as the wave spreads out. Energy of a wave is proportional to amplitude squared, so intensity is also:

At Discovery Fabrics, we are experts on high performance fabrics...and beginners at Projector Sewing. This article was the result of us learning to use a projector for sewing samples. We invite you to ask questions about fabrics in our friendly Facebook Group.

Since writing this article, we have heard such great things about the course taught at Projector that we accepted their invitation to become an affiliate. So when you purchase the course through us, we will receive a commission.

A minimum native resolution of 720p is required for pattern projection. Within these parameters, there is still lots of room for customization to your specific needs.

An important factor when considering how to choose a sewing projector is the size of your cutting space. Mini, Short Throw, and UST projectors all have different distances needed between the projector and the cutting surface to achieve the ideal image size. This measurement is often called the throw distance. UST projectors are designed to project a large image with minimal distance required. Mini and Short Throw projectors will require an overhead mount to project a workable image size. The throw distance will vary from projector to projector. Projector Central is a great resource for calculating the throw distance of a projector. Their calculator gives you the option to input custom measurements and specs, or you can select a specific model from their list of projectors to see how it will work in your space.

Example: Plane-polarised light has an intensity of , show that the maximum intensity after passing through a polarising filter at an angle 30 to its plane of polarisation will be :

This is what Penny Schwynn, one of our experienced Facebook group admins said about the Complete Projector Confidence course...

Intensity ofunpolarizedlightformula

There are plenty of ways to calibrate your projector, but today we will focus on what we use here at Discovery, Pattern Projector. Pattern Projector is a free, web-based calibration application developed for sewists, by sewists. There is no Download or account required, just internet access on your casting device. The interface itself is fairly intuitive. The website projects a grid that you can set to custom measurements. You can then click and drag the corners and sides of the grid on your casting device so that the projected grid lines up with your cutting mat. All of the calibration work is done through your casting device, so you don’t have to fiddle around with settings on your projector. Once you are properly calibrated, you can begin projecting.

Intensity ofunpolarizedlightthrough polarizer

It is no secret that digital patterns have exploded in popularity over the past decade (see our Indie Patterns Blog for some of our favourites). While we love the versatility, size inclusivity and re-usability of digital patterns, the print at home process can be tedious. By projecting digital patterns directly onto fabric, projector sewists save the time, energy, and paper needed to print-and-tape at home or get the pattern printed at a copy shop.

The lighting of your cutting space will also be a factor to consider. Will you be able to cover windows and other light sources? UST projectors tend to be more visible in partial light than Mini or Short Throw. In our shop many of our spaces have built-in skylights and large windows that are difficult to fully cover. We decided that it was important for our projector to have a bright display that would be visible in partial daylight.

Projectors need to be connected to a casting device (Phone, laptop, ipad). Some projectors will be able to connect wirelessly, others will require a wired connection through an hdmi cable.

If you have questions about projector sewing, there are resources listed above you can go to! Or, check out the course offered below.