Wednesday, February 10, 2010

Alexander 4, V5.

Another day, after experimenting again with my censer and the flash. Well, I learned it the hard way, that putting my flash on "manual external metering" does not allow for auto-bracketing of the exposure in the camera itself. I think what we need here is, a coherent light source, like a spot light. In fact, we might need two. One on left and the other on right and both pointing at the censer in a dark room.
You might ask, why I'm taking all that pain just take a picture in the darkness while I have a beautiful green big room with many lights in its ceiling. Well, mainly, there are 2 reasons:
1. I want to work more with my flash and get used to it.
2. I want to emphasize the contrast between the flames inside the censer and the surrounding atmosphere. Taking the picture in a bright room will make the candle flame not so unique and not "flamboyant" if I should say. There must be some contrast... and if possible, a strong one.

However, the experiments didn't go all with no results at all. Despite the darkness of the images taken (even with a flash), I combined some of the images (3 of them) by Photomatix which allowed me to change a bit in the EV values of the images, and hence, in the HDR historgram I got a wide range of EVs (but it's fake since I entered the values myself!). After all, the tone-mapping was not so bad I guess. I saved the file as an EXR and worked on tone-mapping in Photoshop and Photomatix.

Censer (manual tone-mapping in Photoshop)

Photoshop manual tone-mapping

Censer (tone-mapped with photomatix)

Photomatix tone-mapping

I do prefer the second one though for the high contrast, but this façade is only in a small thumbnail. In the real sized image, the situation is completely different with the noise level (mainly because of the long exposures times).
Moreover, I combined another 3 images, but this time they are not different in exposure value, but in ISO value. Two of them were taken in ISO100 (but they were different in EV) and one of them was in ISO200. The result was somehow OK when the HDR histogram is examined, but yet, the noise was so hard to clear off (after the tone-mapping of course).

Censer (Manual tone-mapping)

ISO100 and ISO200 combined with manual tone-mapping

In a conclusion, I think that we can try other ways to make out a HDR image. Yes, the best method is, I would say, either by auto-bracketing or by using different shutter speeds, but I guess the main idea is to get different light levels of the same object and make the computer do its own algorithms and logical comparisons to build up a unique "data sheet" with values corresponding to the light level of the object.
Today, I think I'm going to experiment again, and this time I'm going to use my flash again with my filters, and change them gradually.

Away from HDR and its fuss, I was doing some experiment the day before with my flash in "stroboscopic mode." That is, the continuous pulses of lights. These are useful to catch up a moving object.One experiment I still remember from high school time, when we used a stroboscopic source against the fan up in the ceiling to determine its frequency (that is, how many times does it turn around in one second), and as you may know already, frequencies are measured in Hertz (Hz). When the target object looks like if it was still in its place, then you can say that you got the right frequency value. Why? Think of it: a light source gives a pulse in the same amount of time in which the fan does one complete circle, hence, whenever there is light available, the fan is always in the same position ready for a new cycle and so on. Thus, with time, you will see as if the fan is still and not moving.
Anyway, taking a photograph of a still object is not so funny, is it? What's the problem with that? I can turn off the fan and snap a picture of it and post it and say "hey, this IS rotating fan, but got paralyzed by my flash." Well, no. Our lives must have a problem; and yes, I'm a pessimist.
The thing about snapping such an image is to produce some pattern; a beautiful one. Hence, we have to use the stroboscopic source, either in a frequency lesser than the one of the fan, or more. Lesser frequencies are not fun, I tell you. All what your camera would get is a plain white disk. Thus, we must use higher frequencies. Notice that we are using these high frequencies in connection with a long exposure (relative long exposure, I don't mean here the 30 seconds and above). Well, maximum of 5 seconds I'd say it's enough. One more thing to note is that it is better to have a dark space as well. Otherwise, what's the use of the stroboscopic flash?
Anyway, here you go with some results, which unfortunately, I've forgot the frequencies for each!

Vent fan 1

Vent fan 3

Vent fan 2

However, the "faster" the fan looks, the higher the frequency is. Why? Well, to think about it, if you use a high frequency (more than that of the fan), you will be able to catch the fan in moments before completing a full circle. Thus, the higher the frequency, the closer the fan's wings will appear because they just moved a little before the last pulse of light, and building up those several shots, you will have a faster looking fan. On the other hand, if you happen to use a high frequency for the light, but "just" high above the fan's, then the wings of the fan will move a bit further until the occurence of the next pulse, and so on. Building up the snaps together, you will have a slow-looking rotating fan.
The electricity in Kuwait runs at 240V-50Hz, thus it is natural to guess that the fan frequency is at 50Hz, and I tried it and it worked and the fan was like stable in its place. I changed the frequencies many times when I snapped the previous images, but I would say the best results (to me) were those taken at 70Hz to 80Hz (or 90Hz).

I think I will continue my trials with the censer as usual for today, and this time, I will try to fix the flash to some amount (maybe full power), and then I will fix the the shutter speed and the aperture, and after all, change only the filters. I think by that you should have different exposures already, but the problem is with the flash being close and will give a reflection off from the body of the censer as usual. I do need a remote trigger!

I wrote another poem today, and I called it "Zvinkle and Danim" (or Daneem). Don't ask me about the meaning of the title because I don't know, but if you are interested in the meaning of the whole thing, then you might have to read it yourself and judge what I'm talking about. In fact, I think it was more like a nonsense in the first place but anyway my thoughts played the trick here while my fingers obeyed the orders. Again, it is for you to judge what is going on here...

97. the men gathered around Alexander
98. and he ordered the pikemen to advance
99. and then raise the pikes like thorns
100. while the archers pointed to te sky and shot
101. and the swordsmen prepared for intruders
102. and the circles of fighters twirled
103. and Alexander in the middle slaughtering
104. his sword was the Charnagút of the three points
105. amid the mutants he was clearing them with no shield
106. while the beasts ate the bodies of soldiers
107. and few villagers remained in their place
108. and the shouts of agony started in the camp
109. and the loyals before left Alexander in his trouble
110. while Alexander was thickened with injuries
111. and thus with the anger in his heart
112. for all the trickery he faced in his camp
113. Alexander made a scream of wrath
114. when men faces turned yellow and red
115. and the beasts of Zimúrá ran away
116. just then the camp started marching behind them
117. picking them and slaughering them like insects
118. and Alexander was swimming in his blood
119. coping to stand up amid his victorious men
120. and looking at the massacre and the red trees

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