Tuesday, 12 August 2014

How To Make a Digital Photogram

Oooh! A nice new blog!
And the theme is good: random.
This is my favourite theme for pretty much anything, since I have trouble keeping my interests within the bounds of any kind of helpful category.

Apropos of 'random', I have decided to write about photograms.
When I made my header image today, I tried a few different ideas before finally I settled on a faux photogram look.
In honour of the header, I will devote my first article to explaining how I made it. I will also explain how to make an image which looks more like the traditional photograms of yore.
Either way, it's kind of a fun craft project that you can do at home without any special equipment.

Digital imitation photogram of a carefully sliced
mandarin orange.
What are photograms?
A traditional photogram is made by placing objects on a sheet of high contrast photographic paper in a darkroom. This is then exposed to light for a few seconds. The resulting image will show the silhouettes of the objects in white against a black background (for those of you who are unfamiliar with photographic paper, it turns black where it is exposed to light). Semitransparent objects will usually show up in various shades of grey, since they only partially block the light from reaching the paper.

A regular photogram (which I didn't make). Attribution!
The photogram has long been regarded as one of the most simple photographic projects, yet with the invention of digital photography, traditional photographic paper has become something of an oddity, and few hobby photographers still have a darkroom.

How can a digital photographer make a photogram?
Technically, they can't.
What you can do is make an imitation photogram.
There are two ways of doing this that I can think of, and they produce slightly different results from one another, so I'll explain how to do both of them.
For both of them, you will need a digital camera (or a phone – whatever), some interestingly shaped objects, and the darkroom of the 21st century – some image processing software.
I will be using Photoshop to make my photograms, but pretty much any image processor would be just as good for this project.
Method No. 1 uses a tablet such as an iPad (or a light-box) in addition to the aforementioned items.
Method No. 2 uses a sheet of white card in place of a lighted screen.

METHOD No.1 – The Slightly Authentic Way
Step 1: Choose some objects.
Small things with interesting shapes are always good. In this method, we will be shining a light from underneath the objects, so semi-transparent things will also create an interesting effect.
Here are the things I've decided to use (shown here on white paper):

Clockwise from top: a wilted impatiens flower, a plant cutting, a scrunched tissue,
"Be@rbrick Space Dandy", and some tags from a broken Galilean thermometer.
I chose the objects above because they have varying degrees of opacity, interesting shapes and also because they happened to be lying around in my room.

Step 2: Find a blank, white screen.
If you're lucky enough to have a light-box or a light-pad, then you can use that.
I do happen to own a light-pad, but since most people aren't that nerdy, I'll use an iPad in this example.
Once I have my iPad, I need to make it show a blank white screen. There are plenty of apps which will show you a blank screen, such as drawing apps where you can hide the tools, or apps which are made especially for making blank screens, such as "Color Fill".
Alternatively, you can just look at a blank white image in your tablet's photo viewer.
Here's one you can download, if you're feeling too lazy to make your own:
Click on the image above to enlarge
it and then save it to your tablet.
(I swear it's there somewhere!)
Once you have a blank screen, turn up your tablet's brightness setting as far as it will go.

Step 3: Arrange the objects on the screen.
Lay the tablet on a flat surface (I like to put mine on the floor because it makes it easier to take the pictures later) and place your chosen objects on it.
If you've chosen something messy (like orange slices), then you will probably want to put some cling film over the screen first.

When arranging the objects, try to make it look as nice as possible. I'll admit that I didn't really put much effort into my arrangements, but this is the part where you have the opportunity to get all artistic.

Step 4: SNAP!
Grab your camera, switch off the lights and take a picture of the screen with the objects laid out on it. Try to take the picture directly from above so that the screen doesn't end up looking like a trapezium due to perspective (that's why having the tablet on the floor is a good idea), and focus the lens on a point where one of the objects is touching the screen.
... Hmmm, that last bit sounds kind of cryptic without explanation...
The thing is, on real photo paper, the image will always be "focussed" where objects touch the surface of the paper. To replicate this effect, the camera should be focussed on an object which is at the same level as the screen itself. In my example, I focussed the camera on one of the flower petals, which was lying flat on the screen.
Unfortunately, autofocus only works on sharp edges, so you can't focus on a region of the blank screen itself... and for those of you with manual focusses, this is still relevant, because... well, just try and focus your camera without looking at an edge!

Extra Tip: If you have a camera with an aperture control, you could go one step further and use a really low f-stop to get those classic photogram fuzzy edges around the more three-dimensional objects.

Here's what my photo looks like before processing:
It's a bit uneven, but I'll crop it later.
As you can see, I now have a photo of all my objects silhouetted against the iPad's bright white screen. The thermometer tags and the Be@rbrick have left interesting black shapes, while the more translucent objects have produced some interesting textures as the light shines through them.

Step 5: Process the photo.
There are a few things you will have to do to your photo before it resembles a bonafide photogram. Luckily, they are all things which any decent photo editor can accomplish in one way or another.

First up, if you've taken a wonky photo like I did, then crop and rotate the picture until it is to your liking.
Next, edit the photo so that the background is solid white and the silhouettes are black. If you have translucent objects as well, try to find a balance where the solid objects look black, but you can still see plenty of texture on translucent items.
Hmmm... it looks kind of cool already!
If you're not experienced with processing photos, then just fiddle around with the different controls until you get the right effect.

For my photo, I increased the brightness, decreased the contrast, and changed the levels.
In some image processors (like Picasa), there are no brightness or contrast controls. In most of these, there will be adjustors for "shadows" and "highlights". Fiddling those will produce the right effect.

Remember that in a traditional photogram, the solid objects would have blocked all the light from reaching the photographic paper so their silhouettes would be completely black. That's what I tried to achieve with my processing.
If you don't care so much about being authentic-looking, then this doesn't really matter.

Next up, invert the colours on your photo so that black is white and white is black. All the other colours will change too. (Any photo editing software worth its salt will have a function called something like "invert" or "nega" which will do this for you.)
You'll get something that looks a bit like this:
This looks cool too!

Now might be a good time to mention that there is, of course, no obligation to keep going until you've made an imitation photogram.
Both of the last two images look perfectly good as they are, and are a testament to the versatility of digital photography.
Where a ye olde photogram is limited to black and white, its digital cousin can be displayed in loads of different ways! There are lots of fun things you can do to your photogram at this point.

However, for the sake of completeness, I will go on to the next and final step of the processing you'll need to make a reasonably authentic-looking photogram.

This is, of course, to convert the photo to black and white! (The editing program can do this too.)
And here it is – the finished faux photogram:
I thought the black was a bit too black, so I used Photoshop's selective colour tool to change
it to a very dark grey, but that's completely up to personal taste.
And there you have it.
Method No. 1 for making a reasonably authentic-looking digital imitation photogram!

EDIT: Just out of interest, I tried doing the same processing on Picasa (which is FREE!) and I got results which were at least as good:

... actually, in some ways I like the Picasa one better.

METHOD No. 2 – The Completely Phoney Way

This is the method I used to create my header image, and it kind of gives the impression of being a photogram at first glance, but in most other ways, it's just a funky over-processed picture.
It has an advantage over the more traditional photograms, however, in that you can see patterns on the surfaces of objects when you're done.
Here's how to make one:

Step 1: Lay out a sheet of white card.
Take a piece of white card or paper and, as in METHOD No. 1, lay it flat on the floor.

Step 2: Choose objects and arrange them on the card.

Yep, to make a proper comparison, I'm using all the same stuff as last time. In fact, I'm going to process this exact photo into a faux photogram.

This time, there will be no light shining through translucent objects, so the tissue, the plant and the flower are going to look different. In addition, patterns and colours on opaque objects will be visible in the final image.
You will also be able to see some of the shadows cast by the objects onto the paper, which can make some cool effects (not that I have bothered to put enough thought into this particular image to get said cool effects...).
It's worth thinking about this when you choose and place your objects.

Step 3: Photograph your objects.
This is exactly the same as for METHOD No. 1, with one exception – The light is overhead.
Beware; during processing, the photo will be brightened so that the background card appears bright white. Because of this, you have to be careful when taking the picture that any shiny objects (such as the metal tags in my photo) don't come out brighter than the background paper.
Anything as bright or brighter than the background will ultimately become invisible during processing. (The white tissue could also pose a problem.)

Step 4: Process!
Again, this is similar to METHOD No. 1.

Crop and straighten the photo to your liking.
Next, edit the picture so that you get that oh-so-white background:
Note how the white tissue blends into the background.

With this method, you don't need to worry about making the objects into silhouettes.
In my case, the colouring on the toy is quite interesting, so I want to keep it.

Note: After I loaded the photo onto the computer and cropped it, I decided that the flower was in slightly the wrong place, so I moved it using Photoshop's lasso tool, which was much quicker than taking a whole new photo. That's the great thing about photographing stuff against a white backdrop – you can move things around easily without leaving any noticeable blank spaces where they were.
In fact, my header image is not just one photo, but a collage of several photos which were taken separately. I combined the photos using photoshop, but since they all had white backgrounds, the only thing that gives it away as a collage is the fact that the items are not shown to scale...

Okay, next up, invert the colours, like before:
Now the tissue is almost invisible, except for its shadow.

If you like, you could apply a gradient map to the image rather than inverting the colours at this point.
That's what I did when I made my header image, because I wanted it to be green and white, rather than black and white.

If your image processor doesn't have a gradient map function, you can still make a coloured image, but you will need to use a tint effect after inverting the colours and converting to black and white.

Now back to the example photo. Of course, all that's left to do is convert it to black and white.
And we're done:
Be@rbrick Space Dandy looks like he's gone nuclear, and the flower is really bizarre!
The effect produced by this method is quite a lot more striking than METHOD No. 1 and both the colours on the toy and the texture of the metal tags provide a lot of the interest.
On the other hand, the photogram is less authentic-looking, and you don't get the cool effect of the light shining through the tissue or the flower.

I suppose it is the way of life that there will always be positives and negatives to everything.

... well, except digital photography. That doesn't have any negatives!



Want to try METHOD No. 1, but don't have an iPad or light-box?
Luckily, you can still make perfectly nice, classic-looking photograms by using a piece of white paper and a brightly lit window in place of a screen.
The image below was made by sticking tissues, string and an action figure to a piece of paper using clear sticky tape. The paper was then taped to a window and photographed.
I processed it just the same as any other METHOD No. 1 photogram. This one was done using Picasa.

Well, well,  it looks like both methods have been explained, and so it is that my first article draws to a close.
Thanks so much for reading, and if you have any questions, feel free to drop me a message via the contact form on the righthand side of this page, under my profile.

Happy photogram-ing!
All the best,