How to darken room

How to darken a room for your Bonfoton Camera Obscura Devices.

On this page, I have gathered some easy DIY techniques and ideas for darkening your room, that will help you to get the most of the Bonfoton Camera Obscura Devices and see the amazing effect they do!

Note that the Bonfoton Camera Obscura Room Lens and the BonfotonUP both will come with a User Manual and a Cutting Aid template so you will get a perfect size hole to any darkening material you end up using. Soft fabric curtains are not well suitable for the Bonfoton Lens attachment system.

The BonfotonUP has a strong suction cup for direct window attachment and bottom-mounted adapter for using with a tripod.


So let’s get down to business. There are many ways to darken a room. Some do-it-yourself and some off-the-shelf options, but let’s start with the one I have used myself and found out to be an easy, no hassle technique.


1. Light blackout roller blind

This is a good, cheap and widely available off-the-shelf product for darkening your room and works well with the Bonfoton Camera Obscura Room Lens. Basically, all you need is a screwdriver so you can attach the roller blind over your window. The fabric used in roller blinds is usually quite thick so it will hold the Bonfoton Room lens in place well. You can use masking tape to enhance the darkening effect.

Note, that the Bonfoton Camera Obscura Room Lens attachment system is a snap on snap off type so that it will let any blackout roller blind to be rolled back up normally after attaching the lens attachment plates on it.

Blackout roller blind


2. Tin foil / Aluminum foil (the quickes method)

The common tin foil has become my best friend and my go-to method when I'm on a BonfotonUP photoshoot and need to quickly darken a window or ten of them... 

So, what you need is only a water spray bottle and a roll of tin foil. Lightly spray the window screen with water and spread the tin foil roll over it. You can roll the tin foil over the frames of the window so no light will come through from the sides. The tin foil will stay stuck nicely for several days. But if you leave it on for too long the drying water may leave stains on the window screen that are hard to clean. This can happen even in a day or two on the sunny side of the house. Also in direct sunlight, the foil can get quite hot. So this method is recommended only for quick photoshoots.

Use the Bonfoton logo sticker or the BonfotonUP template to make a right size hole to the tin foil. Note, you should put the BonfotonUP template under the foil and then cut the correct size hole by tracing around the template with your finger nail or other "sharp" object. 

A rule of thumb for the lens positioning: The higher the Bonfoton Lens is on the window the more sky you will get on your walls and the lower the Lens is, the more ground will be seen.

The BonfotonUP has a thumbscrew operated tilt mechanism for adjusting the image vertically on the wall.


3. Black Poster Board Sheets

This material is easy to cut and quite easy to find on Craft / Art supplies stores. Cut the sheets so that they will just fit inside the window frame and attach with masking tape or Gaffers tape.  

A note about tapes. When darkening a room, for a quick Camera Obscura photoshoot. The one thing you’ll most likely need is a tape roll. Most tapes will work but the tape I would suggest is black Gaffers Tape. This is the stuff Hollywood film industry folks use, it blocks 100% of the light, it’s tough but won’t leave sticky glue on the walls after removing it like Duct tape might do, when it’s been attached for a longer time.  

You can also use painter’s tape or masking tape. I’ve used painters tape quite often, it’s cheap, you can find it anywhere and it’s gentle on the walls. Just make sure to get the wide stuff.

Gaffer Tape

Masking Tape


4. The good old cardboard / corrugated cardboard

The benefit of this material for blacking out a room is that everybody has some laying around. Of course, a bigger sheet of cardboard will be easier to use to block out the light. Something that you might have gotten from IKEA etc. bookshelf box. To install the cardboard cut it just to fit inside the window frame, or cut it larger than your window. Use tape, wide masking tape works well, to keep it in place.


5. Black trash / Garbage bags

    They don’t make for the most beautiful drapery, but they sure can darken your room effectively. You can install the trash bags only with water like with the tinfoil. So, just light spray water on to the window screen and attach the trashbag over it. 


    6. Chalkboard paint

    For a more permanent solution, you can use chalkboard paint. This will most likely to be an irreversible solution and the black paint can retain heat in the sun and this can weaken the window. So don’t use this method if in doubt.

    First, clean the glass with rubbing alcohol or glass cleaner and wipe it dry. Next, take the Bonfoton logo sticker or the BonfotonUP cutting template and use it to draw a shape to the window screen to your desired place with a permanent marker. Keep this area clean from the paint, etc.

    Next, you need to prime the surface of the window so the chalkboard paint will stick. There are at least two methods that you can use to complete this step.

    • Primer Paint Method: Use a primer paint that is designed to adhere to glass surfaces. Use the paint manufacturer’s instructions for applying the primer paint. Make sure you don’t apply primer inside the circle you draw before or over the attachment plates. Allow to fully dry.
    • Steel Wool / Sandpaper Method: Rub the window glass gently with steel wool or fine grit sand paper to give the chalkboard paint something texture to stick to. Again don’t rub inside the circle drawn before.

    Block off the areas, like window frames, you do not want to paint using painter’s tape or masking tape. Now you can apply the chalkboard paint to the primed surface. You need to test how many coatings is needed to fully block out the sun. Most likely at least two or three layers of paint is needed.

    There are two kinds of chalkboard paint to choose from. The first type comes in a spray can and the second type is applied with a paint brush. If you used the steel wool method make sure you use chalkboard paint that specifically states that it will adhere to glass. Paint applied with a paintbrush is more likely to have slightly textured surface after drying and the spray can paint will give a more smooth coating.

    Allow to fully dry. Use a carpet knife to slice along the edge of the tape and the window so you will not tear the paint off the window.

    Chalkboard Paint






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