DIY Built-in Pop-up Flash Diffuser (soft Screen)


Introduction: DIY Built-in Pop-up Flash Diffuser (soft Screen)

Well, if you are interested enough to read this post, I assume you know what a diffuser is so no need to introduce its purpose. It's just another version.

The idea is very simple, the image speaks for itself: a cloth-hanger-wire frame with a screen cut out from vacuum bag.

Step 1: Bend the Wire, Hang the Screen

While cleaning my closet, I found the cloth hanger is pretty strong, so I bend it to fit into the flash hot shoe, basically just a few trial and error. There are many wire sizes, some are too big and some are too small. You will know which one is the right one. I had 3 sizes of wire but only one made sense to me right away.

How you want it to cover the flash is up to you. I bent it into two arms so I can hang the diffusing material in front of the flash.

Important: try to bend the wire along the side of the flash hot shoe. Because the wire's plastic coat will eventually come off, you don't want to short-circuit the pins on the hot shoe base. In my case, the inner pins are lower than the surrounding, I just had to make sure the wire is straight and not curve down to touch the inner pins when I slide it in.

Canon (D)SLR: on the Rebel XT, I found a tiny switch on the right edge of the hot shoe to detect external flash. If I slide my diffuser frame in, the built-in flash won't fire. I had to bend the frame around the switch, it's less sturdy but good enough (unfortunately, I returned the camera without taking a picture of the modified diffuser frame to show here).

My Nikon D40 doesn't have any switch around the edge of hot shoe so there is no problem.

I tried different materials, keeping in mind that I need something that diffuses the light evenly, blocks least light, and is durable. Printing paper blocks too much light, while with tissue paper, you will need to bring a whole box for replacement.

The material I'm using is from a vacuum bag. Because the air has to flow through it, its transparency is somewhat equivalent to tissue paper, but it is super durable (much better than printing paper).

I folded a flap on the screen and tape it so that it's attached to the frame and the whole thing can fold flat in my bag. You might want to tape something reflective to the frame to save some light and prevent you from being blinded by the bounced flash.

Well, it's a small idea, nothing much to talk about.

Step 2: Sample Photos for Comparison and Thoughts

As requested, I took two quick shots of a kitchen, mainly because the flash is on top of my camera so I want something that has space below it to see the shadow (the microwave oven and handlebar of the pan).

Notice that the photo taken with diffuser is darker because part of the light was blocked by the diffuser although my D40 use TTL built-in flash. But it's not a big deal, it can be easily adjusted using software. The far right photo has been adjusted from the middle one using Level tool in GIMP. Also, I love the warm tone more than the flat white.

After two weeks of carrying the diffuser in my backpack (folded flat), sometimes it came out of the backpack with the soft screen completely crumpled, and the tape I used to hold it to the frame fell off. However, the material (vacuum bag) is so durable that I just straighten it and back to good again. I had another DIY soft screen before using normal printing paper and it couldn't withstand 4 times of coming in and out of the same backpack.

Step 3: More on Material

I just had a look at different vacuum bags in my house and realize that not all vacuum bags are ideal, so I should clarify on the one I used.

On the left is the genuine bag purchased at Menard. On the right is the cheap bag at Dollar store. Looking at the vertical space in the middle of each bag, you can see that the Rubbermaid bag is almost twice as transparent as the genuine one (obviously it's thinner). So, even though the Rubbermaid bag is not good for vacuum machine, it's ideal for a soft screen.

I also tested a tissue paper I found left after dinner. I took two shots: one with Rubbermaid vacuum bag, one with the tissue paper, and I couldn't tell the difference between them. The tissue paper is pretty strong too (it's from a big roll in the kitchen), but not as strong as the vacuum bag and is thicker.



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    15 Discussions

    I have actually found that a hankerchief and elastic band is much more useful as you can add remove layers of diffusion by folding and unfilding it over the flash lens

    4 replies

    I have to disagree with you here. My definition of a good flash diffuser: lets most light through, has large surface area, and scatters light evenly on that whole surface area. The handkerchief has a pretty small surface area (I think of it as wrapping the handkerchief around the pop-up-flash and hold it by rubber band), and it blocks a lot of light, thus it can only act as a light reducer (light source is still as small as the flash itself). Think of a big reflecting umbrella in studio, it makes small light source (bulb) bigger (umbrella). I think if you look at the effect, it is different. The main purpose of my diffuser is to eliminate sharp shadow; having warm tone is just a bonus. The handkerchief method may produce the warm tone as well, but the shadow is still pretty sharp.

    I see your point we were using this method for macro ranges really on a scale of 10-20cm in reality but it can be used to create a nice pictures by softening the light and leaving shadows, ( i had to get it out and try it again to see what differences there were and you can get a really interesting photo with my method but overall yours wins out for a studio effect but maybe a redesign in the intstructable for adding this to a creative compact most of which have no hot shoe I found your design with an elastic band run through the hooped part of the hanger and down below the lense worked for the fuji S5600 and the canon 10D (older model) requires a bit of fiddling into place

    Maybe I should add my original design that involved no hot shoe. It's very similar to other people design: a small carton box, with bottom cut to have hole to slide into the pop-up flash; the inside is covered with tin foil and the screen is changeable. I switched to this design because the box would fall off every time I tilt the camera to take vertical shot, and the it got crushed in my backpack. I was thinking about modifying your handkerchief method a little bit: using rubber band to tight two arms to the pop-up flash so that you can have the diffuser/handkerchief further and larger from the flash. However, it's not flexible as the pop-up flash cannot be closed/open freely. Also, I'm not sure the spring in the flash can hold the additional weight well. Eventually, some ideas will arrive for the no-hot-shoe problem. See a need, fill a need. Thanks for sharing!

    I made the basic idea for the hot shoe one minus the piece shaped for the hot shoe but used an elastic band around the back of the pop up flash and under the fixed lens (this only works for lenses with no adjustments near the bottom of the lens though)

    While this isn't a great Instructable, it is clear what you did. What I am interested in is your choice of material (which must be important0 Could you expand upon 'vacuum bag', what else might be good, and exactly what type of bag did you use? (the bags I have wouldn't let much light through) L

    4 replies

    I added the picture of the bags I used. I was lucky to get that bag since normally nobody would buy that bag for vacuum machine. The tissue paper is pretty strong too.

    will have to try that sometimes, I always thought cotton doesn't diffuse light much because the holes between fibers are a little large. But now that you mention it, probably putting 4-8 small light sources together could also eliminate harsh shadow. So, the cotton might create dozen of "big" light sources (comparing to paper/tissue) and it should work.

    I bought the vacuum bag in a dollar store (3 pack for $1), but it couldn't fit on my vacuum machine so it was sitting in the corner for a while. Maybe because it's cheap, it's thinner than other bags. When I compare the pictures with those taken by tissue paper, there's almost no difference. what I usually do is keeping a good reference (e.g. tissue paper), and every time I found an interesting material, I hold them both in front of a light source and compare them. If I couldn't tell clearly which one is better, I would setup my camera on a tripod, take pictures with those two materials and compare them on computer. Perhaps when I have more time, I could shoot a series of different materials and post them all for people to compare, or any of you could do it. The only problem is to how to setup the test. What are the criteria to a good diffuser? Personally, I think a good diffuser should let most of the light goes through while diffusing the light evenly on its surface. What do you think?

    Nice idea:) What am I missing are final pictures, or more speciffically, one w/out the diffuser and second w/ it. Could you post something like that? :)

    2 replies

    I uploaded 1502x1000 photos for easy comparison but they were resized, should I post the zoomed in of the shadow or are they good enough? Comparing to my previous diffuser made from a carton box, this one is much more stable and portable. Everytime I tilt the camera, the box would fall off, and there was no way for me to put it in my backpack. You know how strong an external flash attached to the hotshoe, this one is no difference, and best of all, it folded flat.

    Good job :) This size is absolutely OK. What would be totally perfect is a single picture composed of three stripes of those newly uploaded pictures, so that one doesn't have to click and wait to see the difference:) But, never mind, this way is OK too. I like the results, it really works :)

    im sorry...but, what does this do?....the picture does not show that part of it...thanks

    1 reply

    The purpose of these things is to diffuse the harsh light of the built in flash so it doesn't wash out the colors in such a harsh way...