CREATIVE FILTERS courtesy of DeForestRanger for "A Treasure Hunt"

This assignment is a "hands-on" project which you should enjoy doing. However, you'll need some special equipment (cheap if you don't have it around the house). Have handy
1) a sheet of glass from a picture frame
2) some petroleum jelly or other oil
3) several small pieces of sheer fabric of various types and
4) (optional) a small embroidery hoop to hold the fabric taut.

Today, we think of filters in terms of something you screw onto the camera lens or something which can be applied with photo processing software. In the Good Old Days before these ready-made tools were available commonly, photographers resorted to their own creativity, inventing filters of their own to achieve certain effects. Although in those days photographers relied on manual focus, we're going to be using the built-in focus of our cameras to accomplish the same thing.

Let's begin with fabric. If you have an embroidery hoop, stretch a piece of voile or other similar sheer in the hoop to hold it tight. If you don't have a hoop, you may want an assistant. Place your camera on a tripod or flat surface so you can have both hands free. Focus on your subject, and if you have Focus Lock, lock it at this point. If you do not have Focus Lock, depress the shutter button HALFWAY. Hold the button in the halfway position with one hand and with the other, position the stretched fabric in front of the lens (if you don't have a hoop, this is your assistant's job). Now fully depress the button (or if you were using Focus Lock, take the picture). The focus remains on the distant subject and blurs out the fabric via Depth of Field. Experiment with different f-stops, zoom factors and the distance between the lens and the fabric.

Plain voile:
Iris Voile - www.ipernity.com/doc/298501/22411481

A very unusual piece of fabric was used to create this shot:
Spring Nest - www.ipernity.com/doc/298501/22411817

Would you have expected this?
Spring Nest Filter - www.ipernity.com/doc/298501/22411813

My all-time favorite creative filter is vaselined glass, i.e., a sheet of clear picture-frame glass (not the "no glare" type) smeared with a VERY THIN layer of petroleum jelly. By wiping the oil in different directions (straight lines, swirls, etc.), different effects can be achieved. Have a lot of paper towels or tissues handy because it only takes a little bit of oil! In the Good Old Days, this technique was used to soften "romantic" portraits and wedding photos.

The principle is the same as that given for a fabric filter:
1) Focus your camera on the subject
2) Hold the focus with the button half-depressed or lock the focus with Focus Lock
3) Place the filter against the lens (oiled side out!)
4) Finish the capture by fully depressing the shutter button.

If you are not using Focus Lock, the important words here are "Hold the focus with the button half-depressed." If you release the button and then try to refocus after applying the filter, the camera will try to focus on the filter instead of the subject.

These images were created using Vaselined glass:
Feather Dream - www.ipernity.com/doc/298501/22411471
Ginger Mist - www.ipernity.com/doc/298501/22411477

Another possibility you might want to consider is one which was popular in the jewelry trade to give "glitter" to their wares using a piece of ordinary plastic window screen as a filter. This technique creates small asteriations (flares) from the glints of light on the glitter very similar to the effect given by a manufactured "star filter." A net fabric such as tulle gives a somewhat larger-scale effect.

Window screen:
Class Star - www.ipernity.com/doc/298501/22411463

Black tulle:
Jewels And Gems - www.ipernity.com/doc/298501/22411801
Vintage Bling - www.ipernity.com/doc/298501/22411823

The possibilities for creative filters are myriad. Have fun using this old-fashioned technique to create unique images!