Experiment: Ghost Self Portraits

It all started with the latest eveready ultima advertisement. Long exposures, Animations through lighting streaks etc. etc. I also had good discussion on it, on one of my orkut community. So I was inspired to perspire (literally!) to try my hand on some long exposure photography.

While returning home from my gym, stopped by a stationary store, bought those china-made torchlight pens and a couple of black card-paper. I thought of rolling that black paper in cone like formation to further sharpen the light source. Also rolled a white paper inside black paper so the intensity doesn't reduce! Now was a time for some petty but headache giving problems. To make lighting streaks either the camera or the light source should move. Yesterday, I had created some very much acceptable lighting streaks with my CPU's green and red light, by moving my camera. (I didn't find the process worthy enough to write a blogpost!)



So flatly was not interested in again doing that. I better go to sleep than randomly moving my camera with it's shutter open every night. I will get bored soon and why to be up all night, doing boring stuff! And it is already past midnight. So the remaining option is of moving the light source.

If I move the light source, who will click?

If I use timer, how it is going to focus in all darkness?

If I prefocus it at the light source somehow, how can I move it randomly?Yeah, prefocusing at around desired distance was an option but my small little kit lens does not have a distance scale...

Hello, I know that I have written nothing yet in relation with the name of this post. But this was the process of how did I do, what did I do. (?) Here, Minimum focusing distance of 0.25m/0.8ft came to rescue me. If I have not told earlier, I have Canon 400D and EFS 18-55 F3.5-5.6 IS lens. From here a simple procedure followed. I paid some attention to details ;) but you need not if you follow my procedure!

1. Put your camera on tripod or any other firm place, where it has no chance for moving unnecessarily. (I put mine on a stool! and kept soft cotton cloth under the lens for support. )


2. Stand around 1 feet away from camera, properly posing yourself/your face. Press the shutter half way down. (My hand could easily reach there, with those torchlight pens acting as extensions!) Or better use a remote control!


3. Once you have your camera focused, switch it MF and hit the lights off.


4. I should have told this before. As I am posing in front of camera, I cant really use the bulb mode. So the standard setting used was 30 seconds exposure at F 11.


5. Now before stretching your hand to click the shutter, see if your posing just where you focused. Adjust those lights as you want. Look for some catchlight in eyes. (Special tip: You can actually see your face illuminated in the lens!)


6. Once done all this, take a deep breath, press the shutter (finally!). Breathe out, be still and switch on torchlights, as per determined before.

I have used two torchlight pens and was around a feet away in total darkness. Actual exposure around 15-20 seconds served the purpose. Then I switched off torchlights. And I think, even in total darkness, being steady in front of camera is necessary and so I did. No matter how much precautions you take, how much you try to be steady, the motion blur does get introduced in the image. May be thats why I called them ghost self portraits after I saw the first result! After four photos, total timing of that scorching torchlight into my eyes was around 1.5-2 minutes and so an eyesore. You should have seen me then; I was crying with only one eye!

Enough! I uploaded those photos on my PC. Did basic editing of some curves and contrast. And yeah to save my lazy soul from white balancing difficulties, turned them to B&W! Except the last one, which I did a bit pop art style... with too much colours and saturation not to worry about white balancing again!!

And sat down write up this blogpost immediately...

The Photogrpahic Term of Reciprocity Failure

I accidentally happened to come over a big bad and strange phrase, “Reciprocity Failure”. Before this, the jargon of photography never feared me. But now I can say that it’s not that bad how it reads! Yes, I am going to explain that. You need not be afraid though. Because I have already simplified this kind of nerdy stuff! So let’s plunge!!

So let us divide the phrase into two. ‘Reciprocity’, and ‘Failure’. Hence Understanding this phrase becomes as easy as combining both the meanings! The two most appropriate meanings of this word are, ‘Mutual action and reaction’ from Webster's Revised Unabridged Dictionary, © 1996, 1998 MICRA, Inc. & ‘a relation of mutual dependence or action or influence’ from WordNet® 3.0, © 2006 by Princeton University. This mutual thing happens between our aperture and shutter speed. When this relations or rule fails, there happens a failure!

For a photographer, it is quite a common sense that a combination of a shutter speed of 1/125th of a second with an aperture of f8, which is referred to as an exposure setting of '1/125th at f8', will give the same exposure to the film or digital sensor as 1/250th at f5.6, which is the same as 1/500th at f4 etc. This relation or phenomena between aperture and shutter speed is termed as reciprocity. So in theoretical terms, it refers to the inverse relationship between the intensity and duration of light that determines exposure of light-sensitive material. Within a normal exposure range, for example, the reciprocity law states that exposure = intensity × time. Therefore, the same exposure can result from reducing duration and increasing light intensity, and vice versa. So in practical life, what we actually do is using this law of reciprocity. This again refers to the relationship whereby the total light energy, proportional to the product of the light intensity and exposure time (controlled by aperture and shutter speed, respectively), determines the effective exposure. We use these different combinations to cater our special needs of focusing and depth of field.

Now here is a game, this law does not hold true in extreme conditions; like in long exposures or too fast exposure like 1/10000 seconds. I don’t know who is in that hurry to click this much fast. For most photographic materials, reciprocity is valid with good accuracy over a range of values of exposure duration, but becomes increasingly inaccurate as we depart from this range. Only in such conditions, certainly not in our daily life (oh, what a relief!), this reciprocity does not hold. As the light level decreases out of the reciprocity range, the increase in duration required to produce an exposure becomes higher than the formula (exposure = intensity × time) states. This breakdown in the relationship between aperture and shutter speed is known as reciprocity failure.

So you interested in getting deeper! Some physics/chemistry jargon comes into play. I have already simplified everything to my best. Still, if you stuck upon some word. Just google it! So here it goes…

Each grain must absorb a certain number of photons for the light-driven reaction to occur and the latent image to form on the film. In particular, a few dozen photons are required for the surface of the silver halide crystal to result from absorption to its developable rendering. At low light levels, i.e. few photons per unit time, photons impose upon each grain relatively infrequently; if the four required photons arrive over a long enough intervals, the partial change due to the first one or two are not stable enough to survive before enough photons arrive to make a permanent latent image center. Reciprocity failure may also affect the tonal range of a photographic scene when at the limit of exposure, resulting in burnt highlights while losing detail in the shadows.

This was all for film. But digital is neither a different story. On one hand film prints are affected by graininess, on the other hand, digital photographers may experience excessive noise, even at lower ISOs. That is all. It is not that frightening as you must have thought before is it?

I owe the information to the links that appear on the first page when I googled the term!